### Install and Setup Dependencies

Source: https://github.com/antonputra/tutorials/blob/main/lessons/222/elixir-app/README.md

Run this command to install project dependencies and perform initial setup.

```bash
mix setup
```

--------------------------------

### Set up Python Virtual Environment and Install Dependencies

Source: https://github.com/antonputra/tutorials/blob/main/lessons/199/README.md

Initializes a Python virtual environment, activates it, installs Flask, and saves the dependencies to requirements.txt. This is a standard setup for Python web applications.

```bash
python3 -m venv .venv
```

```bash
source .venv/bin/activate
```

```bash
pip install Flask
```

```bash
pip freeze > requirements.txt
```

--------------------------------

### Install and Configure Valkey

Source: https://github.com/antonputra/tutorials/blob/main/lessons/258/README.md

Installs Valkey from source, configures system settings for performance, and sets up a systemd service. Ensure Valkey is not already installed before running.

```bash
export VALKEY_VER="8.1.1"

wget https://github.com/valkey-io/valkey/archive/refs/tags/${VALKEY_VER}.tar.gz
tar -xzf ${VALKEY_VER}.tar.gz
sudo mv valkey-${VALKEY_VER}/ /opt/valkey
cd /opt/valkey/
make
sudo make install

cat <<EOF | sudo tee -a /etc/sysctl.conf
vm.overcommit_memory = 1
EOF

sudo sysctl vm.overcommit_memory=1

sudo tee /etc/valkey.conf <<EOF
maxclients 10000
protected-mode no
appendonly no
save ""
EOF

sudo useradd --system --no-create-home --shell /bin/false valkey

sudo chown valkey:valkey /etc/valkey.conf

sudo tee /etc/systemd/system/valkey.service <<EOF
[Unit]
Description=Valkey
Wants=network-online.target
After=network-online.target

StartLimitIntervalSec=500
StartLimitBurst=5

[Service]
LimitNOFILE=100000
User=valkey
Group=valkey
Type=simple
Restart=on-failure
RestartSec=5s
ExecStart=/usr/local/bin/valkey-server /etc/valkey.conf --port 6379

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl enable valkey
sudo systemctl start valkey
sudo systemctl status valkey
```

--------------------------------

### Start Minikube

Source: https://github.com/antonputra/tutorials/blob/main/lessons/173/README.md

Starts a Minikube cluster using the Docker driver. Ensure Docker is installed and running.

```bash
minikube start --driver=docker
```

--------------------------------

### Install Valkey Server on Ubuntu

Source: https://github.com/antonputra/tutorials/blob/main/lessons/281/README.md

Installs Valkey from source, configures system settings for memory overcommit, creates a dedicated user, and sets up a systemd service for Valkey. Ensure build tools are installed.

```bash
sudo apt -y install build-essential pkg-config

export VALKEY_VER="9.0.2"

wget https://github.com/valkey-io/valkey/archive/refs/tags/${VALKEY_VER}.tar.gz
tar -xzf ${VALKEY_VER}.tar.gz
sudo mv valkey-${VALKEY_VER}/ /opt/valkey
cd /opt/valkey/
make
sudo make install

cat <<EOF | sudo tee -a /etc/sysctl.conf
vm.overcommit_memory = 1
EOF

sudo sysctl vm.overcommit_memory=1

sudo useradd --system --no-create-home --shell /bin/false valkey

sudo tee /etc/systemd/system/valkey.service <<EOF
[Unit]
Description=Valkey
Wants=network-online.target
After=network-online.target

StartLimitIntervalSec=60
StartLimitBurst=3

[Service]
LimitNOFILE=100000
User=valkey
Group=valkey
Type=simple
Restart=on-failure
RestartSec=30s
ExecStart=/usr/local/bin/valkey-server --io-threads 9 --io-threads-do-reads yes --save --protected-mode no

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl enable valkey
sudo systemctl start valkey
sudo systemctl status valkey
```

--------------------------------

### Start Minikube Cluster

Source: https://github.com/antonputra/tutorials/blob/main/lessons/182/2-pod/README.md

Initiates a local Kubernetes cluster using Minikube. Ensure Minikube is installed before running.

```bash
minikube start
```

--------------------------------

### Run Setup Task

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Execute the rake app:setup task to perform initial setup operations for the gate-sso application.

```bash
rake app:setup
```

--------------------------------

### Start React App Locally

Source: https://github.com/antonputra/tutorials/blob/main/lessons/100/README.md

Navigate to the project directory and start the development server.

```bash
cd react-pages-demo
npm start
```

--------------------------------

### Start Minikube with Multiple Nodes

Source: https://github.com/antonputra/tutorials/blob/main/lessons/170/README.md

Use this command to start a local Kubernetes cluster with a specified number of nodes. Ensure Docker is installed and configured as the driver.

```bash
minikube start --nodes 3 --driver=docker
```

--------------------------------

### Install and Configure Redis

Source: https://github.com/antonputra/tutorials/blob/main/lessons/258/README.md

Installs Redis from source, configures system settings for performance, and sets up a systemd service. Ensure Redis is not already installed before running.

```bash
export REDIS_VER="8.0-rc1"

wget https://github.com/redis/redis/archive/refs/tags/${REDIS_VER}.tar.gz
tar -xzf ${REDIS_VER}.tar.gz
sudo mv redis-${REDIS_VER}/ /opt/redis
cd /opt/redis/
make
sudo make install

cat <<EOF | sudo tee -a /etc/sysctl.conf
vm.overcommit_memory = 1
EOF

sudo sysctl vm.overcommit_memory=1

sudo tee /etc/redis.conf <<EOF
maxclients 10000
protected-mode no
appendonly no
save ""
EOF

sudo useradd --system --no-create-home --shell /bin/false redis

sudo chown redis:redis /etc/redis.conf

sudo tee /etc/systemd/system/redis.service <<EOF
[Unit]
Description=Redis
Wants=network-online.target
After=network-online.target

StartLimitIntervalSec=500
StartLimitBurst=5

[Service]
LimitNOFILE=100000
User=redis
Group=redis
Type=simple
Restart=on-failure
RestartSec=5s
ExecStart=/usr/local/bin/redis-server /etc/redis.conf --port 6379

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl enable redis
sudo systemctl start redis
sudo systemctl status redis
```

--------------------------------

### Enable and Start acme-dns Service

Source: https://github.com/antonputra/tutorials/blob/main/lessons/081/README.md

Configure the acme-dns service to start on boot and then start it immediately.

```bash
sudo systemctl enable acme-dns.service
sudo systemctl start acme-dns.service
```

--------------------------------

### GET /api/devices Response Example

Source: https://github.com/antonputra/tutorials/blob/main/lessons/222/ruby-app-node-equivalent/README.md

Example JSON response for the GET /api/devices endpoint, listing sample devices with their details.

```json
[
  {
    "id": 1,
    "uuid": "9add349c-c35c-4d32-ab0f-53da1ba40a2a",
    "mac": "5F-33-CC-1F-43-82",
    "firmware": "2.1.6",
    "created_at": "2024-05-28T15:21:51.137Z",
    "updated_at": "2024-05-28T15:21:51.137Z"
  },
  ...
]
```

--------------------------------

### ArgoCD Setup and Deployment Commands

Source: https://github.com/antonputra/tutorials/blob/main/lessons/179/README.md

A sequence of bash commands to start Minikube, initialize and apply Terraform configurations, inspect ArgoCD pods and services, retrieve the initial admin password, set up port forwarding for the ArgoCD server, and manage Git repositories for deployment updates.

```bash
minikube start
cd terraform
terraform init
terraform apply
kubectl get pods -n argocd
kubectl get svc -n argocd
kubectl -n argocd get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d
kubectl port-forward svc/argocd-server 8080:80 -n argocd
git add .
git commit -m 'deploy nginx to staging'
git push origin main
kubectl apply -f k8s/
git add .
git commit -m 'fix the bug'
git push origin main
kubectl get application nginx -o yaml -n argocd
git add .
git commit -m 'update spec for nginx deployment'
git push origin main
```

--------------------------------

### Run Sample Express App Locally

Source: https://github.com/antonputra/tutorials/blob/main/lessons/073/README.md

Starts a local Express.js server that exposes a Fibonacci calculation endpoint and a /metrics endpoint for Prometheus. Ensure Node.js is installed.

```bash
node 0-express/server.js
```

```bash
curl localhost:8081/fibonacci \
    -H "Content-Type: application/json" \
    -d '{"number": 10}'
```

```bash
curl localhost:8081/fibonacci \
    -H "Content-Type: application/json" \
    -d '{"number": 20}'
```

```bash
curl localhost:8081/metrics
```

--------------------------------

### Install Redis Server on Ubuntu

Source: https://github.com/antonputra/tutorials/blob/main/lessons/281/README.md

Installs Redis from source, configures system settings for memory overcommit, creates a dedicated user, and sets up a systemd service for Redis. Ensure build tools are installed.

```bash
sudo apt -y install build-essential pkg-config

export REDIS_VER="8.6.0"

wget https://github.com/redis/redis/archive/refs/tags/${REDIS_VER}.tar.gz
tar -xzf ${REDIS_VER}.tar.gz
sudo mv redis-${REDIS_VER}/ /opt/redis
cd /opt/redis/
make
sudo make install

cat <<EOF | sudo tee -a /etc/sysctl.conf
vm.overcommit_memory = 1
EOF

sudo sysctl vm.overcommit_memory=1

sudo useradd --system --no-create-home --shell /bin/false redis

sudo tee /etc/systemd/system/redis.service <<EOF
[Unit]
Description=Redis
Wants=network-online.target
After=network-online.target

StartLimitIntervalSec=60
StartLimitBurst=3

[Service]
LimitNOFILE=100000
User=redis
Group=redis
Type=simple
Restart=on-failure
RestartSec=30s
ExecStart=/usr/local/bin/redis-server --io-threads 9 --io-threads-do-reads yes --save --protected-mode no

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl enable redis
sudo systemctl start redis
sudo systemctl status redis
```

--------------------------------

### Initialize Project and Install Dependencies

Source: https://github.com/antonputra/tutorials/blob/main/lessons/088/README.md

Initialize a new Node.js project and install necessary GitHub Actions toolkit packages.

```bash
cd increment-git-tag
npm init -y
npm i @actions/core
npm i @actions/exec
```

--------------------------------

### Install Ruby Dependencies

Source: https://github.com/antonputra/tutorials/blob/main/lessons/222/ruby-app-node-equivalent/README.md

Installs all the necessary Ruby gems specified in the Gemfile. Run this command after cloning the repository or before starting the application locally.

```bash
bundle install
```

--------------------------------

### Install Redis

Source: https://github.com/antonputra/tutorials/blob/main/lessons/228/README.md

Installs Redis from source. This includes setting up build tools, downloading, compiling, and installing Redis. It also configures system settings for Redis and sets up a systemd service for it.

```bash
sudo apt -y install build-essential pkg-config

export REDIS_VER="7.4.1"

wget https://github.com/redis/redis/archive/refs/tags/${REDIS_VER}.tar.gz
tar -xzf ${REDIS_VER}.tar.gz
sudo mv redis-${REDIS_VER}/ /opt/redis
cd /opt/redis/
make
sudo make install

cat <<EOF | sudo tee -a /etc/sysctl.conf
vm.overcommit_memory = 1
EOF

sudo sysctl vm.overcommit_memory=1

sudo tee /etc/redis.conf <<EOF
maxclients 10000
protected-mode no
appendonly no
save ""
EOF

sudo useradd --system --no-create-home --shell /bin/false redis

sudo chown redis:redis /etc/redis.conf

sudo tee /etc/systemd/system/redis.service <<EOF
[Unit]
Description=Redis
Wants=network-online.target
After=network-online.target

StartLimitIntervalSec=500
StartLimitBurst=5

[Service]
User=redis
Group=redis
Type=simple
Restart=on-failure
RestartSec=5s
ExecStart=/usr/local/bin/redis-server /etc/redis.conf

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl enable redis
sudo systemctl start redis
sudo systemctl status redis
```

--------------------------------

### Install Core Snap and Refresh

Source: https://github.com/antonputra/tutorials/blob/main/lessons/078/README.md

Ensure the core snap is installed and refresh it to the latest version.

```bash
sudo snap install core; sudo snap refresh core
```

--------------------------------

### GET /healthz Response Example

Source: https://github.com/antonputra/tutorials/blob/main/lessons/222/ruby-app-node-equivalent/README.md

Example response for the GET /healthz endpoint. Returns 'OK' if the server is running correctly.

```text
OK
```

--------------------------------

### Navigate to Project Directory

Source: https://github.com/antonputra/tutorials/blob/main/lessons/182/1-container/README.md

Change your current directory to the '1-container' folder within the tutorials. This is the starting point for building the image.

```bash
cd tutorials/lessons/182/1-container
```

--------------------------------

### Install Wireshark

Source: https://github.com/antonputra/tutorials/blob/main/lessons/083/README.md

Install the Wireshark network protocol analyzer using Homebrew.

```bash
brew install wireshark
```

--------------------------------

### Setup Database for Ruby Application

Source: https://github.com/antonputra/tutorials/blob/main/lessons/220/ruby-app/README.md

Run these commands to create and migrate the database for the Ruby application.

```bash
bin/rake db:create
bin/rake db:migrate
```

--------------------------------

### Start Redis and Valkey Servers with IO Threads

Source: https://github.com/antonputra/tutorials/blob/main/lessons/281/README.md

Use these commands to start Redis and Valkey servers with specified IO threads for performance tuning. Ensure the paths to the executables are correct.

```bash
# ec2: c8g.4xlarge -> 16/32
/usr/local/bin/redis-server --io-threads 9 --io-threads-do-reads yes --save --protected-mode no
/usr/local/bin/valkey-server --io-threads 9 --io-threads-do-reads yes --save --protected-mode no
```

--------------------------------

### Create Directory and Change to It

Source: https://github.com/antonputra/tutorials/blob/main/lessons/081/README.md

Prepare the environment for installing acme-dns by creating a directory and navigating into it.

```bash
sudo mkdir /opt/acme-dns
cd !$
```

--------------------------------

### Preview VPA Installation YAMLs

Source: https://github.com/antonputra/tutorials/blob/main/lessons/074/README.md

Use the `vpa-process-yamls.sh` script to preview the YAML manifests that will be applied for VPA installation without actually applying them.

```bash
./hack/vpa-process-yamls.sh print
```

--------------------------------

### Start Nginx Service

Source: https://github.com/antonputra/tutorials/blob/main/lessons/078/README.md

Start the Nginx web server process.

```bash
sudo systemctl start nginx
```

--------------------------------

### Monitor Pods During Installation

Source: https://github.com/antonputra/tutorials/blob/main/lessons/089/README.md

Use 'watch' to continuously monitor the pods across all namespaces during the installation process, helping to identify any issues.

```bash
watch kubectl get pods -A
```

--------------------------------

### Install Helm Chart

Source: https://github.com/antonputra/tutorials/blob/main/lessons/021/README.md

Installs the 'hello-wolrd' Helm chart into the 'dev' namespace. It uses a specified values file for configuration.

```bash
kubectl create namespace dev
```

```bash
helm install -f hello-wolrd/values.yaml -n dev hello-wolrd ./hello-wolrd
```

--------------------------------

### Install gate-sso Dependencies

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Navigate into the gate-sso directory and install its Ruby dependencies using Bundler.

```bash
cd gate
bundle install
```

--------------------------------

### Install Dependencies with Bun

Source: https://github.com/antonputra/tutorials/blob/main/lessons/213/bun-app/README.md

Use this command to install all project dependencies managed by Bun.

```bash
bun install
```

--------------------------------

### Install Certbot via Snap

Source: https://github.com/antonputra/tutorials/blob/main/lessons/078/README.md

Install the Certbot client using the snap package manager.

```bash
sudo snap install --classic certbot
```

--------------------------------

### Install MySQL Client on Ubuntu

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install the MySQL client package, which is needed to connect to and manage MySQL databases.

```bash
sudo apt install mysql-client
```

--------------------------------

### Install Node.js

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install Node.js, which is often required for front-end asset compilation or other build processes.

```bash
sudo apt install nodejs
```

--------------------------------

### Enable Nginx Service

Source: https://github.com/antonputra/tutorials/blob/main/lessons/078/README.md

Configure Nginx to start automatically on system boot.

```bash
sudo systemctl enable nginx
```

--------------------------------

### Install MySQL Client Development Library

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install the MySQL client development library, which may be a dependency for certain gems.

```bash
sudo apt-get install libmysqlclient-dev
```

--------------------------------

### Install PostgreSQL Helm Chart

Source: https://github.com/antonputra/tutorials/blob/main/lessons/072/README.md

Installs the Bitnami PostgreSQL Helm chart with specified values, version, and namespace. Creates the namespace if it doesn't exist.

```bash
helm install postgres \
bitnami/postgresql \
--values postgres-values.yaml \
--version 10.5.0 \
--namespace db \
--create-namespace
```

--------------------------------

### Start Elixir Server with IEx

Source: https://github.com/antonputra/tutorials/blob/main/lessons/222/elixir-app/README.md

Use this command to start the Elixir interactive shell and run the application server.

```bash
iex -S mix
```

--------------------------------

### Install Project Dependencies

Source: https://github.com/antonputra/tutorials/blob/main/lessons/050/drage/README.md

Run this command in your project's root directory to install all necessary npm packages.

```bash
npm install
```

--------------------------------

### Enable OpenVPN Server Service on Boot

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Configure the OpenVPN server service to start automatically when the system boots up.

```bash
sudo systemctl enable openvpn-server@server
```

--------------------------------

### Start Rails Server

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Start the Rails server in the background, binding to all interfaces on port 80.

```bash
rvmsudo rails server \
  --port 80 \
  --binding 0.0.0.0 \
  --daemon
```

--------------------------------

### Install Rust and Build Release Project

Source: https://github.com/antonputra/tutorials/blob/main/lessons/245/README.md

Installs Rust using rustup and then builds a Rust project in release mode, ensuring the environment is set up for performance testing.

```bash
curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf | sh -s -- -y
cd /tmp/rust-app
source $HOME/.cargo/env && cargo build --release
```

--------------------------------

### Install RVM (Ruby Version Manager)

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Download and install RVM using the provided script. RVM allows managing multiple Ruby environments.

```bash
curl -L https://get.rvm.io | bash -s stable
```

--------------------------------

### Install Prometheus Stack Helm Chart

Source: https://github.com/antonputra/tutorials/blob/main/lessons/072/README.md

Installs the kube-prometheus-stack Helm chart with specified values, version, and namespace. Creates the namespace if it doesn't exist.

```bash
helm install monitoring \
prometheus-community/kube-prometheus-stack \
--values prometheus-values.yaml \
--version 16.10.0 \
--namespace monitoring \
--create-namespace
```

--------------------------------

### Install Vercel NCC for Bundling

Source: https://github.com/antonputra/tutorials/blob/main/lessons/088/README.md

Install vercel/ncc globally to bundle your JavaScript action into a single file.

```bash
npm i -g @vercel/ncc
```

--------------------------------

### Install Dependencies

Source: https://github.com/antonputra/tutorials/blob/main/lessons/076/README.md

Install necessary npm packages for AWS SDK, UUID generation, and HTTP requests.

```bash
npm i aws-sdk uuid axios
```

--------------------------------

### Install Metrics Server using Helm

Source: https://github.com/antonputra/tutorials/blob/main/lessons/074/README.md

Install the `metrics-server` Helm chart into the `kube-system` namespace. Specify the chart version and a custom `values.yaml` file.

```bash
helm install metrics bitnami/metrics-server \
--namespace kube-system \
--version 5.8.13 \
--values values.yaml
```

--------------------------------

### Application Setup and Port Forwarding

Source: https://github.com/antonputra/tutorials/blob/main/lessons/178/README.md

Navigate to the application directory, tidy dependencies, and set up port forwarding for Grafana and the application.

```bash
cd ..
cd myapp
go mod tidy
kubectl get pods -n monitoring
kubectl port-forward svc/tempo 4318 -n monitoring
export OTLP_ENDPOINT=localhost:4318
curl http://0.0.0.0:8080/devices
kubectl port-forward svc/grafana 3000:80 -n monitoring
# Datasource URL: http://tempo.monitoring:3100
```

--------------------------------

### Install Docker Engine on Ubuntu

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Update the package list and install Docker CE, the command-line interface, and containerd.io.

```bash
sudo apt update
sudo apt install \
  docker-ce docker-ce-cli containerd.io
```

--------------------------------

### Install LibreSSL using Homebrew

Source: https://github.com/antonputra/tutorials/blob/main/lessons/074/README.md

Install or upgrade LibreSSL using the Homebrew package manager on macOS.

```bash
brew install libressl
```

--------------------------------

### Navigate to Application Directory

Source: https://github.com/antonputra/tutorials/blob/main/lessons/182/0-app/README.md

Change your current directory to the '0-app' folder within the tutorials lesson.

```bash
cd tutorials/lessons/182/0-app
```

--------------------------------

### Clone and Navigate Tutorial Repository

Source: https://github.com/antonputra/tutorials/blob/main/lessons/178/README.md

Clone the tutorial repository and navigate to the specific lesson directory.

```bash
git clone git@github.com:antonputra/tutorials.git
cd tutorials/lessons/178
```

--------------------------------

### Install Istio Ingress Controller

Source: https://github.com/antonputra/tutorials/blob/main/lessons/280/README.md

Installs or upgrades the Istio ingress controller (istiod) using Helm, creating the necessary namespace if it doesn't exist.

```bash
helm upgrade --install istiod istio/istiod --namespace istio-system --create-namespace
```

--------------------------------

### Install Psycopg for Python

Source: https://github.com/antonputra/tutorials/blob/main/lessons/199/README.md

Installs the psycopg library for Python, including binary and pooling support, to enable database connections.

```bash
pip install "psycopg[binary,pool]"
```

--------------------------------

### POST /api/devices Request Body Example

Source: https://github.com/antonputra/tutorials/blob/main/lessons/222/ruby-app-node-equivalent/README.md

Example JSON request body for creating a new device via the POST /api/devices endpoint. Requires MAC address and firmware version.

```json
{
  "mac": "AA-BB-CC-DD-EE-FF",
  "firmware": "1.0.0"
}
```

--------------------------------

### Start OpenVPN Server Service

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Start the OpenVPN server service. The '@server' part typically refers to the configuration file name (e.g., server.conf).

```bash
sudo systemctl start openvpn-server@server
```

--------------------------------

### Get OpenSSL Version on Mac/OS X

Source: https://github.com/antonputra/tutorials/blob/main/lessons/074/README.md

Check the currently installed version of OpenSSL on your macOS system.

```bash
openssl version
```

--------------------------------

### Install Certbot via Snap

Source: https://github.com/antonputra/tutorials/blob/main/lessons/081/README.md

Install Certbot using snap, ensuring core components are up-to-date and creating a symbolic link for easier access.

```bash
cd
sudo snap install core; sudo snap refresh core
sudo snap install --classic certbot
sudo ln -s /snap/bin/certbot /usr/bin/certbot
```

--------------------------------

### Install Vertical Pod Autoscaler

Source: https://github.com/antonputra/tutorials/blob/main/lessons/074/README.md

Execute the `vpa-up.sh` script to install the Vertical Pod Autoscaler components into the Kubernetes cluster.

```bash
./hack/vpa-up.sh
```

--------------------------------

### Install OpenVPN and Easy-RSA

Source: https://github.com/antonputra/tutorials/blob/main/lessons/270/README.md

Installs OpenVPN and its certificate management tool, Easy-RSA, on a Debian-based system. Ensures repositories are updated and keys are managed securely.

```bash
sudo apt-get update && sudo apt-get -y upgrade
curl -fsSL https://swupdate.openvpn.net/repos/repo-public.gpg | sudo gpg --dearmor -o /etc/apt/keyrings/openvpn.gpg
echo "deb [signed-by=/etc/apt/keyrings/openvpn.gpg] http://build.openvpn.net/debian/openvpn/stable $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/openvpn.list
sudo apt-get update
sudo apt-get install -y openvpn
wget https://github.com/OpenVPN/easy-rsa/releases/download/v3.2.4/EasyRSA-3.2.4.tgz
tar -zxf EasyRSA-3.2.4.tgz
sudo mv EasyRSA-3.2.4/ /etc/openvpn/easy-rsa
sudo ln -s /etc/openvpn/easy-rsa/easyrsa /usr/local/bin/
```

--------------------------------

### Install and Connect to vcluster

Source: https://github.com/antonputra/tutorials/blob/main/lessons/092/README.md

Use these commands to create a new vcluster, connect to it, and then create and manage resources within a specific namespace.

```bash
vcluster create vcluster-1 -n host-namespace-1
vcluster connect vcluster-1 --namespace host-namespace-1
kubectl get namespace
kubectl create namespace demo-nginx
kubectl create deployment nginx-deployment -n demo-nginx --image=nginx
kubectl get pods -n demo-nginx
kubectl get deployment -n host-namespace-1
kubectl get pods -n host-namespace-1
```

--------------------------------

### Get Pod Metrics

Source: https://github.com/antonputra/tutorials/blob/main/lessons/074/README.md

Use `kubectl top pods` to view resource (CPU/memory) usage for pods in the `kube-system` namespace. Requires the metrics server to be installed.

```bash
kubectl top pods -n kube-system
```

--------------------------------

### Install Specific OpenVPN Version

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install a specific version of OpenVPN from the configured repository. Ensure the version number matches availability.

```bash
sudo apt install openvpn=2.5.3-focal0
```

--------------------------------

### Get Application URL with ClusterIP Service

Source: https://github.com/antonputra/tutorials/blob/main/lessons/022/3/app/templates/NOTES.txt

This snippet sets up port-forwarding for a ClusterIP service to access the application locally. It retrieves the pod name and container port, then echoes a local URL and starts the port-forwarding.

```bash
{{- else if contains "ClusterIP" .Values.service.type }}
  export POD_NAME=$(kubectl get pods --namespace {{ .Release.Namespace }} -l "app.kubernetes.io/name={{ include "app.name" . }},app.kubernetes.io/instance={{ .Release.Name }}" -o jsonpath="{.items[0].metadata.name}")
  export CONTAINER_PORT=$(kubectl get pod --namespace {{ .Release.Namespace }} $POD_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
  echo "Visit http://127.0.0.1:8080 to use your application"
  kubectl --namespace {{ .Release.Namespace }} port-forward $POD_NAME 8080:$CONTAINER_PORT
{{- end }}
```

--------------------------------

### Setup and Use Overlay Network for Swarm

Source: https://github.com/antonputra/tutorials/blob/main/lessons/188/README.md

Demonstrates setting up an overlay network for Docker Swarm. Includes initializing a swarm, creating an attachable overlay network, and running containers on different hosts within the overlay network.

```bash
(host 1) ip addr
(host 1) sudo ethtool -K ens33 tx-checksum-ip-generic off
(host 2) ip addr
(host 2) sudo ethtool -K ens33 tx-checksum-ip-generic off
(host 1) docker swarm init
(host 2) docker swarm join ...
(host 1) docker network create -d overlay --attachable my-overlay-net
(host 1) docker network ls
```

```bash
(host 1) docker run -d --name myapp --network my-overlay-net aputra/myapp-188:v3
(host 2) docker network ls
(host 2) docker run -dit --name myapp-v2 --network my-overlay-net aputra/myapp-188:v3
(host 2) docker network ls
(host 2) docker exec -it myapp-v2 sh
curl myapp:8080/api/info
```

--------------------------------

### Terraform Initialization and Application

Source: https://github.com/antonputra/tutorials/blob/main/lessons/178/README.md

Initialize Terraform and apply the configurations for setting up the environment.

```bash
cd terraform
terraform init
terraform apply
```

--------------------------------

### Install/Update Snapd

Source: https://github.com/antonputra/tutorials/blob/main/lessons/078/README.md

Install snapd if not present, or update it to the latest version.

```bash
sudo apt install snapd
```

--------------------------------

### POST /api/devices Success Response Example

Source: https://github.com/antonputra/tutorials/blob/main/lessons/222/ruby-app-node-equivalent/README.md

Example JSON response for a successful device creation (201 Created) via POST /api/devices. Includes the generated ID and UUID.

```json
{
  "id": 4,
  "uuid": "generated-uuid",
  "mac": "AA-BB-CC-DD-EE-FF",
  "firmware": "1.0.0",
  "created_at": "2024-11-08T12:34:56.789Z",
  "updated_at": "2024-11-08T12:34:56.789Z"
}
```

--------------------------------

### Update Helm Dependencies and Install Chart

Source: https://github.com/antonputra/tutorials/blob/main/lessons/022/README.md

After defining dependencies, run `helm dependency update` to fetch them and then `helm install` to deploy your chart.

```bash
$ helm dependency update
$ helm install -f values.yaml web .
```

--------------------------------

### Install AWS SAM CLI on macOS

Source: https://github.com/antonputra/tutorials/blob/main/lessons/075/README.md

Installs the AWS SAM CLI using Homebrew on macOS. Ensure Homebrew is installed first.

```bash
brew tap aws/tap
```

```bash
brew install aws-sam-cli
```

```bash
sam --version
```

--------------------------------

### Initialize PKI Directory

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Prepare the directory structure for the Public Key Infrastructure (PKI) using easy-rsa.

```bash
easyrsa init-pki
```

--------------------------------

### Install Cert-Manager Helm Chart

Source: https://github.com/antonputra/tutorials/blob/main/lessons/089/README.md

Install the cert-manager Helm chart into the 'cert-manager' namespace. This command installs version v1.6.0 and disables Prometheus metrics.

```bash
helm install \
  cert-manager jetstack/cert-manager \
  --namespace cert-manager \
  --create-namespace \
  --version v1.6.0 \
  --set prometheus.enabled=false \
  --set installCRDs=true
```

--------------------------------

### Install Nginx Ingress Controller

Source: https://github.com/antonputra/tutorials/blob/main/lessons/083/README.md

Installs the Nginx Ingress Controller using Helm. This command specifies the chart version, namespace, and a custom values file.

```bash
helm install ing-083 ingress-nginx/ingress-nginx \
  --namespace ingress \
  --version 4.0.1 \
  --values nginx-ingress-values.yaml \
  --create-namespace
```

--------------------------------

### Install PyTorch Pip Package (macOS)

Source: https://github.com/antonputra/tutorials/blob/main/lessons/067/README.md

Install the PyTorch and Torchvision packages using pip on macOS. This command installs the default versions available.

```bash
pip install torch torchvision
```

--------------------------------

### Fetch and Configure Protobuf

Source: https://github.com/antonputra/tutorials/blob/main/lessons/274/app/CMakeLists.txt

Downloads the Protobuf library from GitHub and configures it to disable tests and examples, speeding up the build process.

```cmake
include(FetchContent)
FetchContent_Declare(
        protobuf
        GIT_REPOSITORY https://github.com/protocolbuffers/protobuf
        GIT_TAG v33.2
)

# Disable tests and examples to speed up the build
set(protobuf_BUILD_TESTS OFF CACHE BOOL "" FORCE)
set(protobuf_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)

FetchContent_MakeAvailable(protobuf)
```

--------------------------------

### Run Ruby Application Server

Source: https://github.com/antonputra/tutorials/blob/main/lessons/220/ruby-app/README.md

Start the Ruby application server using Iodine on port 8080.

```bash
bin/iodine -p 8080
```

--------------------------------

### Run Development Server

Source: https://github.com/antonputra/tutorials/blob/main/lessons/219/my-website/README.md

Use one of these commands to start the Next.js development server. Open http://localhost:3000 in your browser to view the application.

```bash
npm run dev
# or
yarn dev
# or
pnpm dev
# or
bun dev
```

--------------------------------

### Install Ruby Version with RVM

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install a specific Ruby version (e.g., 2.4.3) using RVM. This command fetches, compiles, and installs the Ruby interpreter.

```bash
rvm install 2.4.3
```

--------------------------------

### Run NestJS Application

Source: https://github.com/antonputra/tutorials/blob/main/lessons/050/drage/README.md

Commands to start the NestJS application in different modes. Use 'start:dev' for development with watch mode, and 'start:prod' for production builds.

```bash
npm run start
```

```bash
npm run start:dev
```

```bash
npm run start:prod
```

--------------------------------

### Install Dragonfly

Source: https://github.com/antonputra/tutorials/blob/main/lessons/228/README.md

Installs Dragonfly using a .deb package. Ensure the version variable is set correctly. This process involves downloading, installing, configuring, and enabling the Dragonfly service.

```bash
export VERSION="1.25.4"

wget https://github.com/dragonflydb/dragonfly/releases/download/v${VERSION}/dragonfly_amd64.deb
sudo dpkg -i dragonfly_amd64.deb

sudo tee /etc/dragonfly/dragonfly.conf <<EOF
--pidfile=/var/run/dragonfly/dragonfly.pid
--log_dir=/var/log/dragonfly
--dir=/var/lib/dragonfly
--max_log_size=20
--cache_mode=true
--df_snapshot_format=false
EOF

sudo chown dfly:dfly /etc/dragonfly/dragonfly.conf

sudo systemctl enable dragonfly
sudo systemctl restart dragonfly
sudo systemctl status dragonfly
```

--------------------------------

### Install Calico on Amazon EKS

Source: https://github.com/antonputra/tutorials/blob/main/lessons/066/README.md

Apply the Calico operator and custom resource manifests to install Calico on your Amazon EKS cluster. Monitor the calico-node DaemonSet in the calico-system namespace to verify installation.

```bash
kubectl apply -f https://raw.githubusercontent.com/aws/amazon-vpc-cni-k8s/master/config/master/calico-operator.yaml
```

```bash
kubectl apply -f https://raw.githubusercontent.com/aws/amazon-vpc-cni-k8s/master/config/master/calico-crs.yaml
```

```bash
kubectl get daemonset calico-node -n calico-system
```

--------------------------------

### Create Website Directory

Source: https://github.com/antonputra/tutorials/blob/main/lessons/078/README.md

Create a directory to host the website's files.

```bash
sudo mkdir -p /var/www/devopsbyexample.io/html
```

--------------------------------

### Install Specific Nginx Version

Source: https://github.com/antonputra/tutorials/blob/main/lessons/078/README.md

Install a specific version of Nginx from the added repository.

```bash
sudo apt install nginx=1.20.1-1~focal
```

--------------------------------

### Generate Client Certificate and Keys

Source: https://github.com/antonputra/tutorials/blob/main/lessons/270/README.md

Generates a certificate and private key for a client named 'example-1' and signs it with the CA. This allows the client to connect to the OpenVPN server.

```bash
easyrsa gen-req example-1 nopass
easyrsa sign-req client example-1
```

--------------------------------

### Run the Application

Source: https://github.com/antonputra/tutorials/blob/main/lessons/182/0-app/README.md

Execute the Go application using the 'go run .' command.

```bash
go run .
```

--------------------------------

### Initialize Firebase Hosting

Source: https://github.com/antonputra/tutorials/blob/main/lessons/085/README.md

Configure Firebase Hosting for your project. This command sets up the necessary configuration files and prompts for project settings.

```bash
firebase init hosting
```

--------------------------------

### Install Bundler Gem

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install the Bundler gem, which manages application dependencies for Ruby projects.

```bash
gem install bundler
```

--------------------------------

### Create and Insert Data into PostgreSQL Tables

Source: https://github.com/antonputra/tutorials/blob/main/lessons/169/README.md

Defines and populates several tables ('customer', 'event', 'action', 'event_v2', 'teacher', 'student') with sample data. This script is used to set up a database for testing queries.

```sql
CREATE TABLE customer (
  customer_id integer PRIMARY KEY,
  name varchar(256),
  address varchar(256)
);

INSERT INTO customer
VALUES
  (1, 'Casey', '2295 Spring Avenue'),
  (2, 'Peter', '924 Emma Street'),
  (3, 'Erika', '397 Terry Lane');

CREATE TABLE event (
  event_id integer PRIMARY KEY,
  customer_id integer REFERENCES customer(customer_id),
  action varchar(256)
);

INSERT INTO event
VALUES
  (101, '3', 'LOGIN'),
  (102, '3', 'VIEW PAGE'),
  (103, '1', 'LOGIN'),
  (104, '1', 'SEARCH');

CREATE TABLE action (
  action_id integer PRIMARY KEY,
  name varchar(256)
);

INSERT INTO action
VALUES
  (201, 'LOGIN'),
  (202, 'VIEW PAGE'),
  (203, 'SEARCH'),
  (204, 'LOGOUT');

CREATE TABLE event_v2 (
  event_id integer PRIMARY KEY,
  customer_id integer REFERENCES customer(customer_id),
  action_id integer REFERENCES action(action_id)
);

INSERT INTO event_v2
VALUES
  (101, 2, 201),
  (102, 2, 204);

CREATE TABLE teacher (
  teacher_id integer PRIMARY KEY,
  name varchar(256),
  age integer
);

INSERT INTO teacher
VALUES
  (1, 'Tiffany', 28),
  (2, 'Mathew', 35);


CREATE TABLE student (
  student_id integer PRIMARY KEY,
  name varchar(256),
  age integer
);

INSERT INTO student
VALUES
  (1, 'Ben', 28),
  (2, 'Jenny', 21);
```

--------------------------------

### Install gh-pages

Source: https://github.com/antonputra/tutorials/blob/main/lessons/100/README.md

Install the `gh-pages` npm module to facilitate publishing to a GitHub Pages branch.

```bash
npm install gh-pages
```

--------------------------------

### Build and Run Ruby Application with Docker

Source: https://github.com/antonputra/tutorials/blob/main/lessons/220/ruby-app/README.md

Build the Docker image for the Ruby application and run it, then benchmark using wrk.

```bash
docker build -t ruby-app .
docker run --rm -p 8080:8080 --name ruby-app ruby-app
wrk -c 10 -t 2 -d 10 --latency http://localhost:8080/api/devices
```

--------------------------------

### Install Tunnelblick on macOS

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Tunnelblick is a popular OpenVPN client for macOS. Use Homebrew Cask to install it.

```bash
brew install --cask tunnelblick
```

--------------------------------

### Set Up Docker Stable Repository

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Configure the Docker stable repository for your Ubuntu system. This command adds the repository details, signed by the GPG key previously added.

```bash
echo \
  "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
```

--------------------------------

### Create OpenVPN Server Configuration File

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Create the main configuration file for the OpenVPN server. This step involves using a text editor like vim.

```bash
sudo vim /etc/openvpn/server/server.conf
```

--------------------------------

### Install Docker Compose on Ubuntu

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install the Docker Compose plugin, which allows you to manage multi-container Docker applications.

```bash
sudo apt install docker-compose
```

--------------------------------

### Install Crossplane on Kubernetes

Source: https://github.com/antonputra/tutorials/blob/main/lessons/176/README.md

Installs Crossplane using Helm on a Minikube cluster. Ensure Docker is available for Minikube.

```bash
minikube start --driver=docker
helm repo add crossplane-stable https://charts.crossplane.io/stable
helm repo update
helm search repo crossplane
helm install crossplane \
    --namespace crossplane-system \
    --create-namespace \
    --version 1.13.2 \
    crossplane-stable/crossplane

kubectl get pods -n crossplane-system
kubectl get crds | grep crossplane.io
```

--------------------------------

### Apply AWS Provider Installer

Source: https://github.com/antonputra/tutorials/blob/main/lessons/079/README.md

Apply the Kubernetes manifests for the AWS Secrets & Configuration Provider (ASCP) installer.

```bash
kubectl apply -f aws-provider-installer
```

--------------------------------

### Navigate to VPA Directory (Continued)

Source: https://github.com/antonputra/tutorials/blob/main/lessons/074/README.md

Change directory to the VPA installation path, assuming it's located within a `Developer` directory.

```bash
cd Developer/autoscaler/vertical-pod-autoscaler
```

--------------------------------

### Create React App

Source: https://github.com/antonputra/tutorials/blob/main/lessons/100/README.md

Use this command to create a new React application.

```bash
npx create-react-app react-pages-demo
```

--------------------------------

### Add OpenVPN APT Repository

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Configure your system to use the official OpenVPN APT repository for stable releases.

```bash
echo "deb http://build.openvpn.net/debian/openvpn/stable focal main" > /etc/apt/sources.list.d/openvpn-aptrepo.list
```

--------------------------------

### Start Redis and Valkey Servers with IO Threads

Source: https://github.com/antonputra/tutorials/blob/main/lessons/272/README.md

Launches Redis and Valkey servers on an EC2 c8g.4xlarge instance, configuring them to use 9 IO threads and disabling protected mode. This is useful for performance testing and comparison.

```bash
# ec2: c8g.4xlarg
/usr/local/bin/redis-server --io-threads 9 --save --protected-mode no
/usr/local/bin/valkey-server --io-threads 9 --save --protected-mode no
```

--------------------------------

### Install Firebase CLI Globally

Source: https://github.com/antonputra/tutorials/blob/main/lessons/085/README.md

Install the Firebase Command Line Interface globally. This tool is required for interacting with Firebase services.

```bash
npm install -g firebase-tools
```

--------------------------------

### Set Vcpkg Installation Directory

Source: https://github.com/antonputra/tutorials/blob/main/lessons/248/app/CMakeLists.txt

Defines the VCPKG_ROOT_DIR variable, which points to the Vcpkg installed libraries directory based on the determined target triplet.

```cmake
set(VCPKG_ROOT_DIR ${CMAKE_BINARY_DIR}/vcpkg_installed/${VCPKG_TARGET_TRIPLET})
```

--------------------------------

### Install IP Tables Persistent

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install the iptables-persistent package to ensure that IP Tables rules are saved and reloaded automatically after a system reboot.

```bash
sudo apt-get install iptables-persistent
```

--------------------------------

### Manage OpenVPN Server Service

Source: https://github.com/antonputra/tutorials/blob/main/lessons/270/README.md

Starts, checks the status of, and enables the OpenVPN server service to run on boot. Also shows how to follow the server logs in real-time.

```bash
sudo systemctl start openvpn-server@server
sudo systemctl status openvpn-server@server
sudo systemctl enable openvpn-server@server
journalctl --no-pager --full -u openvpn-server@server -f
```

--------------------------------

### Install Cert-Manager with Helm

Source: https://github.com/antonputra/tutorials/blob/main/lessons/083/README.md

Installs Cert Manager into the specified Kubernetes namespace using Helm. Ensure you have a 'cert-manager-values.yaml' file if overriding defaults.

```bash
helm install cert-083 jetstack/cert-manager \
  --namespace cert-manager \
  --version v1.5.3 \
  --values cert-manager-values.yaml
```

--------------------------------

### List PKI Directories

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Inspect the contents of the PKI directory after initialization.

```bash
ls
ls pki
```

--------------------------------

### Install Nginx Ingress Controller with Helm

Source: https://github.com/antonputra/tutorials/blob/main/lessons/280/README.md

Installs or upgrades the Nginx Ingress controller using Helm, applying custom configurations from a values file.

```bash
helm upgrade --install ingress ingress-nginx/ingress-nginx --values values/nginx-ingress.yaml --namespace ingress --create-namespace
```

--------------------------------

### Initialize Terraform

Source: https://github.com/antonputra/tutorials/blob/main/lessons/020/README.md

Run this command in your Terraform project directory to initialize the backend and download provider plugins.

```bash
$ terraform init
```

--------------------------------

### Set Up Default Google Cloud Credentials

Source: https://github.com/antonputra/tutorials/blob/main/lessons/069/README.md

Run this command to authenticate and set up default credentials for Google Cloud. This is necessary before using gcloud or other tools that interact with Google Cloud.

```bash
gcloud auth application-default login
```

--------------------------------

### Terraform and Git Commands for EKS Setup

Source: https://github.com/antonputra/tutorials/blob/main/lessons/268/README.md

Execute these commands to initialize Terraform, apply configurations for S3, IAM, ECR, VPC, and EKS, and then push changes to trigger the CI/CD pipeline.

```bash
cd envs/global/s3
terraform init
terraform apply -var-file=../global.tfvars
```

```bash
terraform init -migrate-state -backend-config=../state.config
cd ../iam
terraform init -backend-config=../state.config
terraform apply -var-file=../global.tfvars
```

```bash
cd ../ecr
terraform init -backend-config=../state.config
terraform apply -var-file=../global.tfvars
```

```bash
git commit --allow-empty -m "trigger ci/cd"
git push origin main
```

```bash
cd ../../dev/vpc/
terraform init -backend-config=../state.config
terraform apply -var-file=../dev.tfvars -var-file=vpc.tfvars
```

```bash
cd ../eks
terraform init -backend-config=../state.config
terraform apply -var-file=../dev.tfvars -var-file=eks.tfvars
```

--------------------------------

### Verify Terraform and Ansible Installation

Source: https://github.com/antonputra/tutorials/blob/main/lessons/101/README.md

Checks if Terraform and Ansible are installed and accessible in the system's PATH. This is a prerequisite for running Terraform and Ansible commands.

```bash
command -v terraform
command -v ansible-playbook
```

--------------------------------

### Build Zig and Rust Projects for Release

Source: https://github.com/antonputra/tutorials/blob/main/lessons/278/README.md

Use these commands to compile your Zig and Rust projects with optimizations enabled for performance benchmarking. Ensure you are in the project's root directory.

```shell
zig build -Doptimize=ReleaseFast
```

```shell
cargo build --release
```

--------------------------------

### Initialize Application

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Run the rake task to initialize the gate-sso application.

```bash
rake app:init
```

--------------------------------

### Run React App Locally

Source: https://github.com/antonputra/tutorials/blob/main/lessons/085/README.md

Start the development server to run the React application locally. This allows for real-time preview during development.

```bash
npm start
```

--------------------------------

### Kubernetes Deployment and Service Management

Source: https://github.com/antonputra/tutorials/blob/main/lessons/178/README.md

Apply Kubernetes configurations, check pods and services, and port-forward the application service.

```bash
kubectl apply -f k8s
kubectl get pods -n default
kubectl get svc -n default
kubectl port-forward svc/myapp 8080:8080 -n default
```

--------------------------------

### Install Secrets Store CSI Driver using Helm

Source: https://github.com/antonputra/tutorials/blob/main/lessons/079/README.md

Install the Secrets Store CSI Driver using its Helm chart into the kube-system namespace.

```bash
helm -n kube-system install csi-secrets-store secrets-store-csi-driver/secrets-store-csi-driver
```

--------------------------------

### Assemble OpenVPN Client Profile (.ovpn)

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Concatenate the CA certificate, client certificate, client private key, and TLS auth key to create the client's .ovpn profile file. Ensure all paths are correct.

```bash
cat /etc/openvpn/easy-rsa/pki/ca.crt
cat \
  /etc/openvpn/easy-rsa/pki/issued/example-1.crt
cat \
  /etc/openvpn/easy-rsa/pki/private/example-1.key
cat /etc/openvpn/ta.key
```

--------------------------------

### Install Gateway API CRDs

Source: https://github.com/antonputra/tutorials/blob/main/lessons/280/README.md

Applies the standard installation of Gateway API Custom Resource Definitions (CRDs) to the Kubernetes cluster using server-side apply.

```bash
kubectl apply --server-side -f https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.4.1/standard-install.yaml
```

--------------------------------

### Run Flask Application Locally

Source: https://github.com/antonputra/tutorials/blob/main/lessons/199/README.md

Starts the Flask development server. Ensure the Flask app is correctly configured with the --app flag.

```bash
flask --app app run
```

--------------------------------

### Create Redis Cluster

Source: https://github.com/antonputra/tutorials/blob/main/lessons/228/README.md

Sets up a Redis cluster. This involves installing Redis, configuring it for cluster mode, and then using redis-cli to create the cluster with specified nodes and replica count.

```bash
export REDIS_VER="7.4.1"

wget https://github.com/redis/redis/archive/refs/tags/${REDIS_VER}.tar.gz
tar -xzf ${REDIS_VER}.tar.gz
sudo mv redis-${REDIS_VER}/ /opt/redis
cd /opt/redis/
make
sudo make install

cat <<EOF | sudo tee -a /etc/sysctl.conf
vm.overcommit_memory = 1
EOF

sudo sysctl vm.overcommit_memory=1

sudo tee /etc/redis.conf <<EOF
cluster-enabled yes
cluster-config-file /etc/redis/nodes.conf
cluster-node-timeout 5000

dir /etc/redis/
maxclients 10000
protected-mode no
appendonly no
save ""
EOF

sudo useradd --system --no-create-home --shell /bin/false redis

sudo mkdir /etc/redis
sudo chown -R redis:redis /etc/redis
sudo chown redis:redis /etc/redis.conf

sudo tee /etc/systemd/system/redis.service <<EOF
[Unit]
Description=Redis
Wants=network-online.target
After=network-online.target

StartLimitIntervalSec=500
StartLimitBurst=5

[Service]
User=redis
Group=redis
Type=simple
Restart=on-failure
RestartSec=5s
ExecStart=/usr/local/bin/redis-server /etc/redis.conf

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl enable redis
sudo systemctl start redis
sudo systemctl status redis

redis-cli --cluster create redis-0.antonputra.pvt:6379 redis-1.antonputra.pvt:6379 redis-2.antonputra.pvt:6379 redis-3.antonputra.pvt:6379 --cluster-replicas 0
```

--------------------------------

### Install Docker Repository Prerequisites on Ubuntu

Source: https://github.com/antonputra/tutorials/blob/main/lessons/084/README.md

Install necessary packages for adding Docker's official repository. These include tools for managing repositories and secure transport.

```bash
sudo apt install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg \
    lsb-release
```

--------------------------------

### Apply Demo Application Deployment

Source: https://github.com/antonputra/tutorials/blob/main/lessons/074/README.md

Apply the Kubernetes manifests for the demo application and its VPA configuration. Ensure the `1-demo` directory contains the necessary YAML files.

```bash
kubectl apply -f 1-demo
```

--------------------------------

### Initialize Node.js Project

Source: https://github.com/antonputra/tutorials/blob/main/lessons/075/README.md

Initializes a new Node.js project in the current directory. This creates a package.json file for managing dependencies.

```bash
npm init
```

--------------------------------

### Install Actions Runner Controller Helm Chart

Source: https://github.com/antonputra/tutorials/blob/main/lessons/089/README.md

Install the actions-runner-controller Helm chart version 0.14.0 into the 'actions' namespace. This configures the controller with a sync period of 1 minute.

```bash
helm install actions \
    actions-runner-controller/actions-runner-controller \
    --namespace actions \
    --version 0.14.0 \
    --set syncPeriod=1m
```

--------------------------------

### Format and Run Go Application

Source: https://github.com/antonputra/tutorials/blob/main/lessons/086/README.md

Tidy Go module dependencies, format the code using goimports, and run the application. Ensure goimports is installed.

```bash
# go install golang.org/x/tools/cmd/goimports@latest
go mod tidy
goimports -w .
go run main.go
```