### Install QEMU on Fedora

Source: https://angie.software/adc/docs/install/cloud-init/install-qcow2-0.5.2

Installs QEMU and related virtualization utilities on Fedora systems.

```bash
$ sudo dnf install qemu libvirt libguestfs-tools libguestfs virt-viewer virt-install
```

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

### Install QEMU on Ubuntu/Debian

Source: https://angie.software/adc/docs/install/cloud-init/install-qcow2-0.5.2

Installs QEMU and related virtualization utilities on Ubuntu and Debian systems.

```bash
$ sudo apt update
$ sudo apt install -y \
  qemu-kvm qemu-system-x86 qemu-utils \
  libvirt-daemon-system libvirt-clients virtinst virt-manager \
  ovmf cpu-checker
```

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

### cert-config match command examples

Source: https://angie.software/adc/docs-0.8.2/management/cli-commands

Provides examples of using the 'cert-config match' command to verify if a certificate and its corresponding private key are a valid pair.

```none
(cert-config)$$ match site1.crt site1.key
Certificate and key match
(cert-config)$$ match site1.crt site2.key
Certificate and key DO NOT match
(cert-config)$$
```

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

### Angie ADC Configuration Mode Example

Source: https://angie.software/adc/docs/management/cli-commands

This example demonstrates entering configuration mode, setting a system interface type to DHCP, showing the configuration differences, and committing the changes.

```none
$$ configuration
## set system interface enp0s2 type dhcp
## show
-> Current configuration
set system interface enp0s2 type static
set system interface enp0s2 ip address 10.21.20.31/22
set system interface enp0s2 ip gateway 10.21.20.1
set system interface enp0s2 ip dns 8.8.8.8
set system interface enp0s2 ip dns 1.1.1.1

-> Candidate configuration
set system interface enp0s2 type dhcp
## commit
```

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

### GlobalConfiguration Example

Source: https://angie.software/anic/docs/configuration/globalconfiguration-resource

Example of a GlobalConfiguration resource defining UDP and TCP listeners for DNS traffic.

```yaml
apiVersion: k8s.angie.software/v1alpha1
kind: GlobalConfiguration
metadata:
  name: angie-configuration
  namespace: angie-ingress
spec:
  listeners:
  - name: dns-udp
    port: 5353
    protocol: UDP
  - name: dns-tcp
    port: 5353
    protocol: TCP
```

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

### Comprehensive Angie Configuration with Metrics

Source: https://angie.software/angie/docs/configuration/modules/http/http_api?ra=yes

An example of a complete Angie HTTP server configuration that includes various modules like resolver, upstream, caching, connection limits, request limits, and access to HTTP API metrics. This configuration demonstrates how to integrate metrics access within a typical server setup.

```nginx
http {

    resolver 127.0.0.53 status_zone=resolver_zone;
    proxy_cache_path /var/cache/angie/cache keys_zone=cache_zone:2m;
    limit_conn_zone $binary_remote_addr zone=limit_conn_zone:10m;
    limit_req_zone $binary_remote_addr zone=limit_req_zone:10m rate=1r/s;

    upstream upstream {
        zone upstream 256k;
        server backend.example.com service=_example._tcp resolve max_conns=5;
       keepalive 4;
    }

    server {
        server_name www.example.com;
        listen 443 ssl;

        status_zone http_server_zone;
        proxy_cache cache_zone;
        proxy_cache_valid 200 10m;

        access_log /var/log/access.log main;

        location / {
            root /usr/share/angie/html;
            status_zone location_zone;
            limit_conn limit_conn_zone 1;
            limit_req zone=limit_req_zone burst=5;
        }
        location /status/ {
            api /status/;

            allow 127.0.0.1;
            deny all;
        }

    }
}

```

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

### Configure Stream Server Zones and Connection Limits

Source: https://angie.software/adc/docs/monitoring-and-statistics/console-light

Example Nginx configuration demonstrating the setup of `limit_conn_zone`, `limit_conn`, and `status_zone` directives within a stream context. Requires specific directives to be set in server or stream contexts.

```nginx
stream {

    # ...
    limit_conn_zone $connection zone=limit-conn-stream:10m;

    server {

        # ...
        limit_conn limit-conn-stream 1;
        status_zone foo;
    }
}
```

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

### Install Angie Console Light Package

Source: https://angie.software/news/articles/multifaceted-monitoring

Install the Console Light package using apt-get. This is the first step to enable the monitoring interface.

```bash
sudo apt-get install angie-console-light
```

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

### Listener Configuration Example

Source: https://angie.software/anic/docs/configuration/globalconfiguration-resource

Example of a listener configuration specifying the name, port, and protocol for incoming traffic.

```yaml
name: dns-tcp
port: 5353
protocol: TCP
```

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

### Postgres Configuration Example

Source: https://angie.software/angie/docs/installation/external-modules/postgres

Example Nginx configuration demonstrating how to use the Postgres module for database operations. Includes setting up an upstream, defining output format, and creating locations for SQL queries.

```nginx
http {
    upstream database {
        postgres_server 127.0.0.1 dbname=ang_test
                         user=ang_test password=ang_test;
    }

    server {
        listen 80;
        postgres_output text;

        location /create {
            postgres_pass database;
            postgres_query "CREATE TABLE cats (id integer, name text)";
        }

        location /insert {
            postgres_pass database;
            postgres_query "INSERT INTO cats (id, name) VALUES ($arg_id, '$arg_name')";
        }

        location /select {
            postgres_pass database;
            postgres_query "SELECT name FROM cats WHERE id=$arg_id";
        }
    }
}
```

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

### MP4 Pseudo-Streaming Request Example

Source: https://angie.software/angie/docs/configuration/modules/http/http_mp4

Example of an HTTP request to an MP4 file with a specified start time for pseudo-streaming.

```none
http://example.com/elephants_dream.mp4?start=238.88
```

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

### Load Echo Module for Configuration Example

Source: https://angie.software/angie/docs/installation/external-modules/geoip2

Load the echo module, which is used in the provided configuration example for displaying information.

```nginx
load_module modules/ngx_http_echo_module.so;
```

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

### Stream Module Configuration Example

Source: https://angie.software/angie/docs/configuration/modules/stream

This example demonstrates a basic configuration for the Stream module, including defining upstream servers, setting up server blocks for TCP and UDP listeners, and configuring proxying behavior.

```nginx
worker_processes auto;

error_log /var/log/angie/error.log info;

events {
    worker_connections  1024;
}

stream {
    upstream backend {
        hash $remote_addr consistent;

        server backend1.example.com:12345 weight=5;
        server 127.0.0.1:12345            max_fails=3 fail_timeout=30s;
        server unix:/tmp/backend3;
    }

    upstream dns {
       server 192.168.0.1:53535;
       server dns.example.com:53;
    }

    server {
        listen 12345;
        proxy_connect_timeout 1s;
        proxy_timeout 3s;
        proxy_pass backend;
    }

    server {
        listen 127.0.0.1:53 udp reuseport;
        proxy_timeout 20s;
        proxy_pass dns;
    }

    server {
        listen [::1]:12345;
        proxy_pass unix:/tmp/stream.socket;
    }
}
```

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

### Install Angie Package

Source: https://angie.software/news/articles/acme-angie-avtomaticheskii-https

Installs the Angie web server package on the Debian system.

```bash
sudo apt-get install -y angie
```

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

### Example Usage and Verification

Source: https://angie.software/news/articles/wasm-angie

Demonstrates how to make a request to the configured Angie server and verifies the WASM module file.

```bash
$ curl "http://127.0.0.1:8080?id=1&id2=5"
sql(1..5)=foo2,foo3,foo4

$ ls -lh "conf/ngx_http_vars.wasm"
-rwxr-xr-x 1 demo demo 1.3M Nov  2 11:34 conf/ngx_http_vars.wasm
```

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

### Install Yandex.Cloud CLI

Source: https://angie.software/anic/docs/installation/installation-in-YC

Installs the Yandex.Cloud CLI tool for managing cloud resources. Follow the interactive prompts for authentication.

```bash
curl -sSL https://storage.yandexcloud.net/yandexcloud-yc/install.sh | bash
yc init
```

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

### Zstandard Module Configuration Example

Source: https://angie.software/angie/docs/installation/external-modules/zstd

Configure Zstandard compression for dynamic responses and static files. Set compression level, minimum response length, and specify content types to compress. This example also shows how to handle pre-compressed .zst files.

```nginx
server {
    listen 80 default_server;

    zstd_types text/plain text/css;
    zstd_min_length 256;         # Минимальная длина ответа для сжатия
    zstd_comp_level 3;           # Уровень сжатия (от 1 до 22)

    # Динамическое сжатие файлов
    location / {
        zstd on;
        root /usr/share/angie/html;
    }

    # Динамическое сжатие ответов от бэкенда
    location /bk/ {
        zstd on;
        proxy_pass http://127.0.0.1:8081/;
    }

    # Использование заранее сжатых файлов .zst
    location /static/ {
        zstd_static on;
        root /usr/share/angie;
    }
}

server {
    listen 8081;
    location / {
        root /usr/share/angie/html;
        index index.html;
    }
}
```

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

### Install OctoDNS and Cloudflare Provider

Source: https://angie.software/news/articles/acme-angie-avtomaticheskii-https

Install the necessary OctoDNS package and the Cloudflare provider using pip.

```console
$ pip install octodns octodns_cloudflare
```

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

### Basic Memcached Configuration Example

Source: https://angie.software/adc/docs/configuration_lb/reference/http/http_memcached

This example shows a basic server block configuration for using Memcached with Angie. It sets the memcached key and specifies the memcached server address. A fallback location is defined for error handling.

```nginx
server {
    location / {
        set            $memcached_key "$uri?$args";
        memcached_pass host:11211;
        error_page     404 502 504 = @fallback;
    }

    location @fallback {
        proxy_pass     http://backend;
    }
}
```

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

### Cloud-Init Meta-data Example

Source: https://angie.software/adc/docs-0.6.0/install/cloud-init/install-qcow2-0.5.2

Define essential information for the virtual machine, such as its unique identifier and hostname.

```yaml
instance-id: my-adc1
local-hostname: my-server
```

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

### Stream Upstream Probe Configuration Example

Source: https://angie.software/adc/docs/configuration_lb/reference/stream/stream_upstream_probe

Example of configuring an upstream probe for a backend server. This includes setting timeouts, intervals, test conditions, and send/receive modes.

```nginx
server {
    listen ...;

    # ...
    proxy_pass backend;
    upstream_probe_timeout 1s;

    upstream_probe backend_probe
        port=12345
        interval=5s
        test=$good
        essential
        fails=3
        passes=3
        max_response=512k
        mode=onfail
        "send=data:GET / HTTP/1.0\r\n\r\n";
}
```

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

### Cache Shard Configuration Example

Source: https://angie.software/adc/docs-0.6.0/configuration_lb/reference/http/http_api

Example JSON structure representing cache shards and their properties like size and cold status.

```json
{
  "name_zone": {
    "shards": {
        "/path/to/shard1": {
            "size": 0,
            "cold": false
        },

        "/path/to/shard2": {
            "size": 0,
            "cold": false
        }
    }
}
}
```

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

### HTTP Access Control Configuration Example

Source: https://angie.software/adc/docs-0.8.2/configuration_lb/reference/http/http_access

This example demonstrates how to configure access control within a location block. It denies access to a specific IP, allows broader access to an IPv4 subnet and a different IPv4 network, allows access to an IPv6 network, and finally denies all other access. Rules are processed sequentially.

```nginx
location / {

    deny 192.168.1.1;
    allow 192.168.1.0/24;
    allow 10.1.1.0/16;
    allow 2001:0db8::/32;
    deny all;
}
```

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

### Proxy Protocol TLV Examples

Source: https://angie.software/adc/docs-0.6.0/configuration_lb/reference/stream/stream

These examples demonstrate how to access TLV (Type-Length-Value) data from the PROXY protocol header. The PROXY protocol must be enabled using the proxy_protocol parameter in the listen directive. Specific TLV types can be accessed by name or numerical value.

```none
$proxy_protocol_tlv_alpn
$proxy_protocol_tlv_0x01
```

```none
$proxy_protocol_tlv_ssl_version
$proxy_protocol_tlv_ssl_0x21
```

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

### Basic Angie Server Configuration Example

Source: https://angie.software/adc/docs/configuration_lb/reference/core

A foundational Nginx configuration block setting up user, worker processes, error logging, and event handling with kqueue and connection limits.

```nginx
user www www;
worker_processes 2;

error_log /var/log/error.log info;

events {

    use kqueue; worker_connections 2048;
}

```

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

### MP4 Pseudo-Streaming with Start and End Times

Source: https://angie.software/angie/docs/configuration/modules/http/http_mp4

Example of an HTTP request to an MP4 file specifying both start and end times for pseudo-streaming.

```none
http://example.com/elephants_dream.mp4?start=238.88&end=555.55
```

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

### HLS Configuration with Encryption

Source: https://angie.software/angie/docs/installation/external-modules/vod

Example Nginx configuration for serving HLS streams with sample-AES-Cenc encryption and DRM enabled. This setup is suitable for adaptive bitrate streaming.

```nginx
location ~ ^/cenchls/p/\d+/(sp/\d+/)?serveFlavor/entryId/([^/]+)/(.*) {
    vod hls;
    vod_hls_encryption_method sample-aes-cenc;
    vod_hls_encryption_key_format "urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed";
    vod_hls_encryption_key_format_versions "1";

    vod_drm_enabled on;
    vod_drm_request_uri "/udrm/system/ovp/$vod_suburi";

    vod_last_modified_types *;
    add_header Access-Control-Allow-Headers '*';
    add_header Access-Control-Expose-Headers 'Server,range,Content-Length,Content-Range';
    add_header Access-Control-Allow-Methods 'GET, HEAD, OPTIONS';
    add_header Access-Control-Allow-Origin '*';
    expires 100d;
}
```

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

### Configure ip6tables for IPv6 Access Control

Source: https://angie.software/adc/docs/common-tasks-and-examples/ipv6

This example demonstrates an ip6tables configuration for managing IPv6 traffic. It mirrors the iptables setup but includes IPv6-specific rules like 'ipv6-icmp' and adjusts the UDP port for '521'.

```bash
[root@angie-va angie-va]# ip6tables -S
-P INPUT DROP
-P FORWARD DROP
-P OUTPUT ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 8080 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 443 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 53 -j ACCEPT
-A INPUT -p udp -m state --state NEW -m udp --dport 53 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 2022 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 179 -j ACCEPT
-A INPUT -p ipv6-icmp -j ACCEPT
-A INPUT -p ospf -j ACCEPT
-A INPUT -p udp -m state --state NEW -m udp --dport 521 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp6-adm-prohibited
```

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

### cert-config list command example

Source: https://angie.software/adc/docs-0.8.2/management/cli-commands

Demonstrates how to list all traffic certificates and keys managed by Angie ADC, indicating their validity status.

```none
(cert-config)$$ list
cp.crt   : invalid
cp.key   : invalid
site1.crt: certificate
site1.key: key
```

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

### Launch Virtual Machine with virt-install

Source: https://angie.software/adc/docs-0.6.0/install/cloud-init/install-qcow2-0.5.2

This command deploys the Angie ADC qcow2 image on a KVM (QEMU) virtual machine. Ensure the seed.iso is attached as a CD-ROM.

```bash
virt-install \
  --virt-type kvm \
  --name adc \
  --ram 2048 \
  --vcpus 2 \
  --disk angie-adc-0.5.2-x86_64.cloud-init.qcow2,format=qcow2 \
  --disk seed.iso,device=cdrom \
  --network=bridge:virbr0 \
  --graphics vnc,listen=0.0.0.0 \
  --os-variant=centos8 \
  --import
```

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

### Install Helm Chart Skipping CRDs

Source: https://angie.software/anic/docs/installation/installation-with-helm

If Custom Resource Definitions (CRDs) are not needed or already installed, you can skip their installation using the `--skip-crds` flag with the `helm install` command.

```console
$ helm install <имя_релиза> <путь_до_чарта> --skip-crds
```

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

### Install ANIC Helm Chart

Source: https://angie.software/anic/docs/installation/installation-with-helm

Install the Helm chart by specifying a release name and the path to the chart. Helm will generate Kubernetes manifests and install them.

```console
$ helm install <имя_релиза> <путь_до_чарта>
```

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

### Enter BFD Configuration Mode

Source: https://angie.software/adc/docs/routing/bfd

Navigate to the BFD configuration mode to begin setting up a peer. This is the initial step before defining peer addresses.

```console
angie-va# conf t
angie-va(config)# bfd
angie-va(config-bfd)# peer
```

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

### Create Working Directory and Virtual Environment

Source: https://angie.software/news/articles/acme-angie-avtomaticheskii-https

Set up a dedicated directory and a Python virtual environment for OctoDNS. Activate the environment before proceeding.

```console
$ sudo mkdir /dns
$ cd /dns
$ python -m venv env
$ source env/bin/activate
```

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

### cert-config info command example

Source: https://angie.software/adc/docs-0.8.2/management/cli-commands

Shows how to display information about a traffic certificate using the 'cert-config info' command with a specified filename.

```none
(cert-config)$$ info traffic name site1.crt
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 1 (0x1)
        Signature Algorithm: sha1WithRSAEncryption
        Issuer: C = RU, ST = Moscow, O = Angie, OU = EVO, CN = Root CA
        Validity
            Not Before: Feb 18 12:23:08 2025 GMT
            Not After : Feb 18 12:23:08 2027 GMT
        Subject: CN = Demo Certificate, ST = Moscow, C = RU, O = Angie, OU = EVO
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (4096 bit)
                Modulus:
... 
(cert-config)$$
```

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

### Install Auxiliary Packages for Angie Repository

Source: https://angie.software/news/articles/acme-angie-avtomaticheskii-https

Installs necessary packages for connecting to the Angie repository on Debian systems.

```bash
sudo apt-get update
sudo apt-get install -y ca-certificates curl
```

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

### Using Include Directive for Configuration Management

Source: https://angie.software/adc/docs-0.7.3/configuration_lb/reference/configfile

Demonstrates how to use the 'include' directive in the main 'angie.conf' file to reference external configuration files for HTTP and stream traffic, promoting modularity.

```nginx
include /etc/angie/http.d/*.conf;
include /etc/angie/stream.d/*.conf;
```

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

### Install ACME Module and yq

Source: https://angie.software/news/articles/acme-angie-avtomaticheskii-https

Installs the necessary angie-module-cgi and yq packages for managing DNS records and YAML files.

```bash
$ sudo apt-get install -y angie-module-cgi yq
```

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

### Nginx Configuration for Backup Server Groups

Source: https://angie.software/adc/docs/configuration_lb/backup-server-groups

This example demonstrates how to configure primary and backup server groups using directives like 'backup', 'backup=n', and 'backup_switch permanent'. It shows different levels of backup servers and a permanent switchover with a time limit.

```nginx
upstream my_backend {
    server primary1.example.com;
    server primary2.example.com;

    server backend.example.com service=http resolve backup=prio;

     server backup1a.example.com backup;
     server backup1b.example.com backup;

     server backup2a.example.com backup=2;
     server backup2b.example.com backup=2;

     backup_switch permanent=2m;
}
```

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

### Deploy Angie ADC qcow2 Image

Source: https://angie.software/adc/docs/install/install-qcow2

Moves the Angie ADC qcow2 image to the libvirt images directory and then uses virt-install to create and start a new virtual machine from the image.

```bash
$ sudo mv angie-adc-1.0-rc2-x86_64.cloud-init.qcow2 /var/lib/libvirt/images/
$ sudo virt-install  --name angie-adc-1.0-rc2 --ram 2048 --disk /var/lib/libvirt/images/angie-adc-1.0-rc2-x86_64.cloud-init.qcow2 --os-variant generic --import
```

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

### Create Configuration Directory

Source: https://angie.software/news/articles/acme-angie-avtomaticheskii-https

Create a directory to store OctoDNS configuration files.

```console
$ sudo mkdir /dns-conf
```

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

### Example upstream configuration with resolve and SRV record

Source: https://angie.software/configuration/modules/http/http_api

An example of an upstream block with a server defined using a service name for SRV record resolution.

```nginx
upstream backend {
    server backend.example.com:8080 service=_example._tcp resolve;
    server 127.0.0.1:12345;
    zone backend 1m;
}
```

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

### Example upstream configuration with random load balancing

Source: https://angie.software/configuration/modules/http/http_api

An example of an upstream block configured with the 'random' load balancing method and a server with 'max_conns' parameter.

```nginx
upstream backend {
    zone backend 256k;
    server backend.example.com resolve max_conns=5;
    random;
}
```

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

### RealIP Configuration Example

Source: https://angie.software/adc/docs-0.6.0/configuration_lb/reference/http/http_realip

This snippet demonstrates a typical configuration for the RealIP module, including trusted IP sources, the header to use, and recursive resolution settings.

```nginx
set_real_ip_from  192.168.1.0/24;
set_real_ip_from  192.168.2.1;
set_real_ip_from  2001:0db8::/32;
real_ip_header    X-Forwarded-For;
real_ip_recursive on;
```

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

### Example upstream configuration with resolve and SRV record

Source: https://angie.software/configuration/modules/http/http_api

An example of an upstream block with a server defined using a service name for SRV record resolution, including the 'resolve' directive.

```nginx
upstream backend {
    server backend.example.com service=_http._tcp resolve;
    server 127.0.0.1;
    zone backend 1m;
}
```

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

### Example uWSGI Temporary File Path

Source: https://angie.software/angie/docs/configuration/modules/http/http_uwsgi

Illustrates the resulting temporary file path structure based on the `uwsgi_temp_path` configuration.

```nginx
/spool/angie/uwsgi_temp/7/45/00000123457
```

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

### DNS Challenge Handler Example (FastCGI)

Source: https://angie.software/adc/docs-0.8.2/configuration_lb/reference/acme

Example of configuring a `fastcgi_pass` handler within an `acme_hook` location for DNS-based ACME challenges. ACME variables are passed using `fastcgi_param`.

```nginx
location @acme_hook {
    acme_hook example;
    fastcgi_pass unix:/var/run/acme-dns.sock;
    fastcgi_param SCRIPT_FILENAME $document_root;

    # Pass ACME variables
    fastcgi_param ACME_HOOK $acme_hook_name;
    fastcgi_param ACME_CHALLENGE $acme_hook_challenge;
    fastcgi_param ACME_DOMAIN $acme_hook_domain;
    fastcgi_param ACME_TOKEN $acme_hook_token;
    fastcgi_param ACME_KEYAUTH $acme_hook_keyauth;
}
```

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

### Custom Output: PID, PPID, Command, Start Time

Source: https://angie.software/adc/docs-0.6.0/management/cli-commands

Shows the Process ID (PID), Parent Process ID (PPID), command name, and the start time of the process.

```bash
ps -o pid,ppid,cmd,start_time
```

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

### HTTP Challenge Handler Example (Proxy Pass)

Source: https://angie.software/adc/docs-0.8.2/configuration_lb/reference/acme

Example of configuring a `proxy_pass` handler within an `acme_hook` location for HTTP-based ACME challenges. ACME variables are passed using `proxy_set_header`.

```nginx
location @acme_hook {
    acme_hook example;
    proxy_pass http://127.0.0.1:8080;

    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    # Pass ACME variables
    proxy_set_header ACME_HOOK $acme_hook_name;
    proxy_set_header ACME_CHALLENGE $acme_hook_challenge;
    proxy_set_header ACME_DOMAIN $acme_hook_domain;
    proxy_set_header ACME_TOKEN $acme_hook_token;
    proxy_set_header ACME_KEYAUTH $acme_hook_keyauth;
}
```

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

### Angie Logging Example

Source: https://angie.software/angie/docs/developer_guide

Demonstrates setting the log action and using ngx_log_error and ngx_log_debug macros for logging information and debug messages in Angie.

```c
/* specify what is currently done */
log->action = "sending mp4 to client";

/* error and debug log */
ngx_log_error(NGX_LOG_INFO, c->log, 0, "client prematurely
              closed connection");

ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
               "mp4 start:%ui, length:%ui", mp4->start, mp4->length);
```

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

### Configure Angie for NTLS

Source: https://angie.software/adc/docs-0.6.0/configuration_lb/reference/stream/stream_proxy

Example command to configure Angie compilation with NTLS support, specifying the TongSuo SSL library and its NTLS option.

```bash
./configure --with-openssl=../Tongsuo-8.3.0 \
            --with-openssl-opt=enable-ntls  \
            --with-ntls
```

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

### Retrieve HTTP Configuration

Source: https://angie.software/adc/docs/configuration_lb/reference/http/http_api

Use the GET method to retrieve configuration entities from the /config path. You can query specific parameters or the entire configuration. Use 'defaults=on' to get default values.

```bash
$ curl http://127.0.0.1/config/http/upstreams/backend/servers/backend.example.com/max_conns
$ curl http://127.0.0.1/config/http/upstreams/backend/servers/backend.example.com
$ curl http://127.0.0.1/config/http/upstreams/backend/servers
$ # ...
$ curl http://127.0.0.1/config
```

```bash
$ curl http://127.0.0.1/config/http/upstreams/backend/servers?defaults=on
```

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

### Angie Configuration Example for VTS

Source: https://angie.software/angie/docs/installation/external-modules/vts

This Nginx configuration snippet demonstrates how to enable the VTS module, serve the status HTML page, and define a location to display traffic status in JSON format.

```nginx
http {
    # ...
    vhost_traffic_status_zone;

    server {
        listen 80;
        server_name localhost;

        root  /usr/share/angie/html;
        index index.html index.htm;

        location = /status.html {
            root  /usr/share/angie-module-vts;
        }

        location /status {
            vhost_traffic_status_display;
            vhost_traffic_status_display_format html;
        }
    }
}
```

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

### Basic Limit Conn Configuration

Source: https://angie.software/adc/docs/configuration_lb/reference/http/http_limit_conn

This example shows how to limit connections from a single IP address to one per download location. Ensure the `limit_conn_zone` is defined in the http block and the `limit_conn` directive is applied to the desired location.

```nginx
http {
    limit_conn_zone $binary_remote_addr zone=addr:10m;

    ...

    server {

        ...

        location /download/ {
            limit_conn addr 1;
        }
    }
}
```

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

### Disable Symlinks Example

Source: https://angie.software/adc/docs-0.7.3/configuration_lb/reference/http/http

This example demonstrates how to disable symbolic links in a specific path, using the `on` and `from=` parameters. It ensures that if any component of the path is a symbolic link, access is denied, unless it's within the specified `$document_root`.

```nginx
disable_symlinks on from=$document_root;
```

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

### Entering TLS Upload Mode

Source: https://angie.software/adc/docs-0.7.3/common-tasks-and-examples/tls

Connect to the CLI and enter the certificate configuration and TLS upload modes to prepare for uploading certificate files.

```console
cert-config
tls-upload
```

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

### Setting SSL Buffer Size

Source: https://angie.software/adc/docs-0.7.3/configuration_lb/reference/http/http_ssl

This example demonstrates how to configure the buffer size for SSL data transmission. A smaller buffer size can help reduce the Time To First Byte for large responses.

```nginx
ssl_buffer_size 4k;
```

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

### Demonstrate Unbrotli Decompression

Source: https://angie.software/angie/docs/installation/external-modules/unbrotli

This example shows how to test the unbrotli module's decompression. When a client does not support Brotli, the module decompresses the file on the server before sending it.

```bash
$ curl -s -o tmp/war-and-peace.txt localhost/storage/war-and-peace.txt

$ ls -l tmp/
total 3284
-rw-r--r-- 1 asv asv 3359405 Feb 27 16:39 war-and-peace.txt
```

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

### Angie GeoIP2 Configuration Example

Source: https://angie.software/angie/docs/installation/external-modules/geoip2

Configure the GeoIP2 module to use a GeoLite2-Country database, set auto-reloading, and define variables for country code and name based on the X-Forwarded-For header. This example also includes a map for access control and a custom log format.

```nginx
http {
    geoip2 /var/lib/GeoIP/GeoLite2-Country.mmdb {
        auto_reload 1h;
        $geoip2_country_code default=RU source=$http_x_forwarded_for country iso_code;
        $geoip2_country_name source=$http_x_forwarded_for country names ru;
    }

    log_format with_geoip '$server_port $remote_addr - $remote_user [$time_local] "$request" ' 
                           '$status $body_bytes_sent "$http_referer" ' 
                           '"$http_user_agent" "$http_x_forwarded_for" "$http_host" ' 
                           'country="$geoip2_country_code"';

    map $geoip2_country_code $denied {
        PL "1";
        QA "1";
    }

    server {
        listen 80;
        root /usr/share/angie/html;
        index index.html index.htm;
        access_log /var/log/angie/geoip_access.log with_geoip;

        if ($denied) {
            return 403;
        }

        location / {
            echo "ip = $http_x_forwarded_for";
            echo "code = $geoip2_country_code";
            echo "name = $geoip2_country_name";
        }
    }
}
```

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

### CLI Command Syntax

Source: https://angie.software/adc/docs-0.8.2/management/cli-commands

Illustrates the general syntax for CLI commands, including mandatory and optional parameters, and user input.

```none
command option0 {option1|option2|...|option N} [option3] [{option4|option5|...|option M}] [option6 <user-input1>] [<user-input2>] <user-input3>
```