Kroki

https://github.com/yuzutech/kroki
Admin
Kroki provides a unified HTTP API to convert plain text diagram definitions into images across...
Tokens:16,553
Snippets:233
Trust Score:7.4
License:MIT
Update:1 month ago
Show doc for...
Tokens:
Raw
### Install Kroki via Helm

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Add the repository and install the Kroki chart.

```cli
helm repo add cowboysysop https://cowboysysop.github.io/charts/
helm install my-kroki cowboysysop/kroki
```

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

### Start a Kroki instance

Source: https://github.com/yuzutech/kroki/blob/main/DOCKERHUB.md

Run a basic Kroki container instance.

```bash
$ docker run --name some-kroki -d yuzutech/kroki
```

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

### Start Kroki Gateway Server

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-docker-or-podman.adoc

Commands to launch the Kroki gateway container in the foreground.

```docker-cli
docker run yuzutech/kroki
```

```podman-cli
podman run yuzutech/kroki
```

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

### Verify Kroki CLI installation

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/kroki-cli.adoc

Check the installed version of the Kroki CLI.

```cli
/path/to/kroki version
```

```cli
kroki version
```

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

### Docker Compose Configuration

Source: https://github.com/yuzutech/kroki/blob/main/README.adoc

Example configuration for running Kroki core and companion containers.

```yml
services:
  core:
    image: yuzutech/kroki
    environment:
      - KROKI_MERMAID_HOST=mermaid
      - KROKI_BPMN_HOST=bpmn
      - KROKI_EXCALIDRAW_HOST=excalidraw
      # experimental!
      - KROKI_DIAGRAMSNET_HOST=diagramsnet
    ports:
      - "8000:8000"
  mermaid:
    image: yuzutech/kroki-mermaid
    expose:
      - "8002"
  bpmn:
    image: yuzutech/kroki-bpmn
    expose:
      - "8003"
  excalidraw:
    image: yuzutech/kroki-excalidraw
    expose:
      - "8004"
  # experimental!
  diagramsnet:
    image: yuzutech/kroki-diagramsnet
    expose:
      - "8005"
```

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

### Start Kroki Container with SSL

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Run the Kroki container with SSL enabled using an environment file.

```bash
docker run -p8000:8000 -e KROKI_SSL=true --env-file=.env yuzutech/kroki
```

```bash
podman run -p8000:8000 -e KROKI_SSL=true --env-file=.env yuzutech/kroki
```

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

### Run Kroki Server

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/manual-install.adoc

Starts the Kroki web server on the default port 8000.

```java-cli
java -jar kroki-server.jar
```

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

### Convert diagrams using the CLI

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/kroki-cli.adoc

Examples of converting diagram files with various options and input/output methods.

```cli
kroki convert diagram.puml
```

```cli
kroki convert diagram.puml --type plantuml --format svg --out-file diagram.svg
```

```cli
kroki convert simple.er --out-file out.png
```

```cli
cat hello.dot | kroki convert - -t dot
```

```cli
cat hello.dot | kroki convert - -t dot -o out.png
```

```cli
kroki convert simple.er --out-file -
```

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

### Download and extract Kroki definition files

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Commands to download the example bundle and extract the Kubernetes definition files.

```cli
wget http://docs.kroki.io/kroki/setup/_attachments/kroki-k8s-multipod.zip -O kroki-k8s-multipod.zip
```

```cli
unzip kroki-k8s-multipod.zip -d kroki-k8s
```

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

### Start a Kroki instance with port mapping

Source: https://github.com/yuzutech/kroki/blob/main/DOCKERHUB.md

Run a Kroki container while mapping the internal port 8000 to the host machine.

```bash
$ docker run -p8000:8000 --name some-kroki -d yuzutech/kroki
```

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

### Verify Helm installation

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Check the status and resources of the deployed Helm release.

```cli
helm status my-kroki --show-resources --show-desc
```

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

### Run Kroki with Custom GraphViz Path

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/manual-install.adoc

Starts the Kroki server while specifying the path to the GraphViz binary using a system property.

```java-cli
java -DKROKI_DOT_BIN_PATH=/path/to/dot -jar kroki-server.jar
```

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

### Pass options via query parameters

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Add configuration options to a GET request URL.

```http
GET /graphviz/svg/eNpLyUwvSizIUHBXqPZIzcnJ17ULzy_KSanlAgB1EAjQ?key=value
```

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

### Run Multiple Containers with Podman Compose

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-docker-or-podman.adoc

Command to start multiple Kroki containers using podman-compose.

```podman-cli
podman-compose up -d
```

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

### Encode diagram with Python

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Use a CLI one-liner to prepare a diagram for a GET request.

```cli
cat hello.dot | python -c "import sys; import base64; import zlib; print(base64.urlsafe_b64encode(zlib.compress(sys.stdin.read().encode('utf-8'), 9)).decode('ascii'))"
```

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

### Validate Kroki installation

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Commands to verify pod status and establish a local port-forwarding connection to the Kroki service.

```cli
kubectl get pod
```

```cli
kubectl port-forward service/kroki 8000:8000
```

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

### Send a GET request with encoded diagram

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/http-clients.adoc

Sends a GET request to the Kroki API with a pre-encoded diagram string.

```cli
curl https://kroki.io/graphviz/svg/eNpLyUwvSizIUHBXqPZIzcnJ17ULzy_KSanlAgB1EAjQ
```

```cli
http https://kroki.io/graphviz/svg/eNpLyUwvSizIUHBXqPZIzcnJ17ULzy_KSanlAgB1EAjQ
```

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

### Run Multiple Containers with Docker Compose

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-docker-or-podman.adoc

Command to start multiple Kroki containers defined in a docker-compose.yml file.

```docker-cli
docker-compose up -d
```

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

### Define an Entity Relationship Diagram

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/http-clients.adoc

Example content for an ERD file named project.erd.

```erd
[Person]
*name
height
weight
+birth_location_id

[Location]
*id
city
state
country

Person *--1 Location
```

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

### Validate Kroki installation

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Verify the Kroki service is running by sending a request to the local endpoint.

```cli
curl http://localhost:8000/seqdiag/svg/eNorTi1MyUxMV6jmUlBIKsovL04tUtC1UyhPTQKyyoCc6JzEpNQcBVsFJXfXEAX9zLyU1Aq9jJLcHKVYayQ9Nrq6CE3WhA0L8A8GmpaUk5-un5yfm5uaVwIxD6EWqDElsSQxKbE4FUmfp1-wa1CIAg49IFfANOFxXS0A68hQUg==
```

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

### Start Kroki in Detached Mode

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-docker-or-podman.adoc

Commands to run the container in the background using the -d flag.

```docker-cli
docker run -p8000:8000 -d yuzutech/kroki
```

```podman-cli
podman run -p8000:8000 -d yuzutech/kroki
```

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

### Subclassing mxGraph

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/assets/mxgraph/src/index.txt

Basic setup for creating a subclass of mxGraph using the prototype chain.

```javascript
MyGraph.prototype = new mxGraph();
MyGraph.prototype.constructor = MyGraph;
```

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

### Request diagram via GET

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Retrieve an SVG image using an encoded diagram string in the URL.

```http
GET /graphviz/svg/eNpLyUwvSizIUHBXqPZIzcnJ17ULzy_KSanlAgB1EAjQ
```

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

### GET /<diagram_type>/<output_format>/<encoded_diagram>

Source: https://github.com/yuzutech/kroki/blob/main/README.adoc

Generate a diagram by providing the diagram type, output format, and a deflate+base64 encoded diagram source in the URL path.

```APIDOC
## GET /<diagram_type>/<output_format>/<encoded_diagram>

### Description
Generate a diagram using a URL-encoded source string.

### Method
GET

### Endpoint
/<diagram_type>/<output_format>/<encoded_diagram>

### Parameters
#### Path Parameters
- **diagram_type** (string) - Required - The type of diagram (e.g., plantuml)
- **output_format** (string) - Required - The desired output format (e.g., svg)
- **encoded_diagram** (string) - Required - The diagram source encoded using deflate + base64
```

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

### Build and Run Commands

Source: https://github.com/yuzutech/kroki/blob/main/README.adoc

Commands for building the project and running containers.

```bash
$ task mavenBuild
```

```bash
$ sudo task dockerBuildImages
```

```bash
$ docker run -d -p 8000:8000 yuzutech/kroki
```

```bash
$ docker-compose up -d
```

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

### Use custom configuration file

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/kroki-cli.adoc

Specify an alternate configuration file for the conversion process.

```cli
kroki convert hello.dot --config config.yml
```

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

### Deploying mxClient

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/assets/mxgraph/src/index.txt

Include the mxClient.js library in the head section of your HTML document to initialize the framework.

```html
<script type="text/javascript" src="js/mxClient.js"></script>
```

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

### Display help information

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/kroki-cli.adoc

Access usage instructions for the CLI or specific commands.

```cli
kroki --help
```

```cli
kroki convert -h
```

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

### Configure SSL Private Key via File Path

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Point to the location of the private key PEM file.

```bash
KROKI_SSL_KEY_PATH="/etc/ssl/certs/mydomain/privatekey.pem"
```

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

### Sync diagrams.net assets using import.sh

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/README.md

Execute the import script to synchronize assets from a local drawio repository checkout.

```bash
$ ./import.sh /path/to/drawio/checkout assets/
```

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

### Download and extract single-pod bundle

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Commands to fetch and unpack the single-pod deployment bundle.

```cli
wget http://docs.kroki.io/kroki/setup/_attachments/kroki-k8s-singlepod.zip -O kroki-k8s-singlepod.zip
```

```cli
unzip kroki-k8s-singlepod.zip -d kroki-k8s
```

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

### Configure Server Listening Host and Port

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Set the host and port for the Kroki server using environment variables or Java system properties.

```java-cli
KROKI_LISTEN=127.0.0.1:1234 java -jar kroki-server.jar
```

```java-cli
java -DKROKI_LISTEN=127.0.0.1:1234 -jar kroki-server.jar
```

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

### Configure SSL Private Key via Environment Variable

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Set the private key directly as a PEM-formatted string.

```bash
KROKI_SSL_KEY="-----BEGIN RSA PRIVATE KEY-----<PRIVATE_KEY>-----END RSA PRIVATE KEY-----"
```

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

### Pass options via HTTP headers

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Use custom headers prefixed with Kroki-Diagram-Options to pass configuration.

```request
POST /graphviz
Accept: image/svg+xml
Content-Type: text/plain
Kroki-Diagram-Options-Key: value

digraph G {
  Hello->World
}
```

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

### Apply Kubernetes objects individually

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Commands to deploy specific Kroki services and ingress configurations individually from remote URLs.

```cli
kubectl apply -f {uri-k8s-kroki-examples}/mermaid-deployment.yaml
kubectl apply -f {uri-k8s-kroki-examples}/mermaid-service.yaml
```

```cli
kubectl apply -f {uri-k8s-kroki-examples}/bpmn-deployment.yaml
kubectl apply -f {uri-k8s-kroki-examples}/bpmn-service.yaml
```

```cli
kubectl apply -f {uri-k8s-kroki-examples}/excalidraw-deployment.yaml
kubectl apply -f {uri-k8s-kroki-examples}/excalidraw-service.yaml
```

```cli
kubectl apply -f {uri-k8s-kroki-examples}/kroki-deployment.yaml
kubectl apply -f {uri-k8s-kroki-examples}/kroki-service.yaml
```

```cli
kubectl apply -f {uri-k8s-kroki-examples}/kroki-ingress.yaml
```

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

### Instantiating the Subclass

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/assets/mxgraph/src/index.txt

Creating a new instance of the subclass, requiring a DOM container node.

```javascript
var graph = new MyGraph(container);
```

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

### Export SSL Certificates to Environment File

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Format certificate and key files for use in an environment file.

```bash
cat cert.pem | tr -d '\n' | sed 's/^/KROKI_SSL_CERT=/' >> .env
echo >> .env
cat key.pem | tr -d '\n' | sed 's/^/KROKI_SSL_KEY=/' >> .env
```

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

### Request diagram via POST with format in URL

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Specify output format in the URL path while sending plain text.

```http
POST /graphviz/svg
```

```request
Content-Type: text/plain

digraph G {
  Hello->World
}
```

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

### Apply Kubernetes objects in batch

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Use kubectl to apply all YAML definition files from a directory at once.

```cli
kubectl apply -f _/path/to/kroki-k8s_
```

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

### Request diagram via POST with JSON

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Send diagram source and configuration as a JSON object.

```http
POST /
```

```json
{
  "diagram_source": "digraph G {Hello->World}",
  "diagram_type": "graphviz",
  "output_format": "svg"
}
```

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

### Configure Kroki via Environment Variables

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/kroki-cli.adoc

Override default settings by passing environment variables directly to the CLI command.

```cli
KROKI_ENDPOINT=https://localhost:8000 KROKI_TIMEOUT=1m kroki convert hello.dot
```

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

### Configure Kroki via YAML

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/kroki-cli.adoc

Define the endpoint and timeout settings in a kroki.yml configuration file.

```yml
endpoint: 'https://localhost:8000'
timeout: '30s'
```

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

### Run the linter for Mermaid

Source: https://github.com/yuzutech/kroki/blob/main/CLAUDE.md

Execute the biome linter for changes made within the mermaid directory.

```bash
npm run lint
```

```bash
biome check src
```

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

### POST /

Source: https://github.com/yuzutech/kroki/blob/main/README.adoc

Generate a diagram by sending a JSON payload containing the diagram source, type, and output format.

```APIDOC
## POST /

### Description
Generate a diagram by sending a JSON object.

### Method
POST

### Endpoint
/

### Request Body
- **diagram_source** (string) - Required - The diagram source code
- **diagram_type** (string) - Required - The type of diagram (e.g., plantuml)
- **output_format** (string) - Required - The desired output format (e.g., svg)

### Request Example
{
  "diagram_source": "Bob -> Alice : hello",
  "diagram_type": "plantuml",
  "output_format": "svg"
}
```

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

### Connect companion containers with Docker Compose

Source: https://github.com/yuzutech/kroki/blob/main/DOCKERHUB.md

Configure the core Kroki service to communicate with companion containers for Mermaid, BPMN, and Excalidraw support.

```yaml
services:
  core:
    image: yuzutech/kroki
    environment:
      - KROKI_MERMAID_HOST=mermaid
      - KROKI_BPMN_HOST=bpmn
      - KROKI_EXCALIDRAW_HOST=excalidraw
    ports:
      - "8000:8000"
  mermaid:
    image: yuzutech/kroki-mermaid
    ports:
      - "8002:8002"
  bpmn:
    image: yuzutech/kroki-bpmn
    ports:
      - "8003:8003"
  excalidraw:
    image: yuzutech/kroki-excalidraw
    ports:
      - "8004:8004"
```

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

### Kroki CLI command structure

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/kroki-cli.adoc

General syntax for executing commands with the Kroki CLI.

```cli
kroki <command> [options] <arguments>
```

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

### Register Mermaid Layouts and Icon Packs

Source: https://github.com/yuzutech/kroki/blob/main/mermaid/assets/index.html

Initializes Mermaid with ELK and Tidy Tree layouts and registers a custom icon pack from a JSON file.

```javascript
import mermaid from './mermaid/mermaid.esm.min.mjs' import elkLayouts from './mermaid/mermaid-layout-elk.esm.min.mjs' import tidyTreeLayouts from './mermaid/mermaid-layout-tidy-tree.esm.min.mjs' mermaid.registerLayoutLoaders([...elkLayouts, ...tidyTreeLayouts]) mermaid.registerIconPacks([ { name: 'logos', loader: () => fetch('./icons.json').then((res) => res.json()), }, ]) // export as global window.mermaid = mermaid
```

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

### Request diagram via POST with JSON source

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Send diagram source as a JSON object with format in the URL.

```http
POST /graphviz/svg
```

```json
{
  "diagram_source": "digraph G {Hello->World}"
}
```

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

### POST /<diagram_type>/<output_format>

Source: https://github.com/yuzutech/kroki/blob/main/README.adoc

Generate a diagram by sending the source as plain text in the request body, with the type and format specified in the URL.

```APIDOC
## POST /<diagram_type>/<output_format>

### Description
Generate a diagram by sending the source as plain text.

### Method
POST

### Endpoint
/<diagram_type>/<output_format>

### Request Body
- **body** (text/plain) - Required - The diagram source code

### Request Example
Content-Type: text/plain

Bob -> Alice : hello
```

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

### Upload a file to the Kroki API

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/http-clients.adoc

Sends a local file to the Kroki API using cURL or HTTPie.

```cli
curl https://kroki.io/erd/svg --data-binary '@project.erd'
```

```cli
cat project.erd | http https://kroki.io/erd/svg Content-Type:text/plain
```

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

### Define a GraphViz diagram

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

A basic GraphViz diagram source file.

```graphviz
digraph G {
  Hello->World
}
```

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

### Prefetching Images

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/assets/mxgraph/src/index.txt

Use this pattern to load images into the browser cache during application runtime to improve rendering performance.

```javascript
var image = new Image();
image.src = url_to_image;
```

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

### Configure Delegate Timeout

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Sets the maximum time in milliseconds the main server waits for a companion container response.

```bash
KROKI_DELEGATE_TIMEOUT_MS=30000 # default, 30 seconds
```

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

### Generate Self-Signed SSL Certificate

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Use OpenSSL to create a self-signed certificate and private key.

```bash
openssl req -nodes -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365
```

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

### Configure Convert Timeout

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Set the KROKI_CONVERT_TIMEOUT environment variable to adjust the wait time for Java library diagram conversions.

```bash
KROKI_CONVERT_TIMEOUT=10s # <1>
KROKI_CONVERT_TIMEOUT=1m # <2>
KROKI_CONVERT_TIMEOUT=4000ms # <3>
```

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

### Set Kroki Safe Mode

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Configure the security level for the Kroki server to restrict filesystem or network access.

```java-cli
java -DKROKI_SAFE_MODE=unsafe -jar kroki-server.jar
```

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

### POST /

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Converts a diagram provided in a JSON request body.

```APIDOC
## POST /

### Description
Converts a diagram source provided within a JSON object.

### Method
POST

### Endpoint
/

### Request Body
- **diagram_source** (string) - Required - The plain text diagram source.
- **diagram_type** (string) - Required - The type of diagram.
- **output_format** (string) - Required - The desired output format.
- **diagram_options** (object) - Optional - Additional options for the diagram library.

### Request Example
{
  "diagram_source": "digraph G {Hello->World}",
  "diagram_type": "graphviz",
  "output_format": "svg",
  "diagram_options": {
    "key": "value"
  }
}
```

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

### Send a POST request with cURL

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/http-clients.adoc

Sends a Graphviz diagram source to the Kroki API using a POST request.

```cli
curl https://kroki.io/graphviz/svg --data-raw 'digraph G {Hello->World}'
```

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

### Registering a Codec

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/assets/mxgraph/src/index.txt

Ensures the same codec is used for both the base class and the subclass during serialization.

```javascript
var codec = mxCodecRegistry.getCodec(mxGraph);
codec.template = new MyGraph();
mxCodecRegistry.register(codec);
```

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

### Encode Diagrams in Tcl

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/encode-diagram.adoc

Uses built-in zlib and binary encoding commands to prepare the diagram string.

```tcl
# assuming the diagram code is stored in the variable named `diagramSource`:
puts [string map {+ - / _} [binary encode base64 [zlib compress $diagramSource]]]
```

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

### Configure Delegate Connection Pool Size

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Sets the maximum number of HTTP connections kept open per companion container.

```bash
KROKI_DELEGATE_MAX_POOL_SIZE=10 # default
```

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

### Pass options via POST JSON body

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/usage.adoc

Include diagram options within the JSON payload.

```http
POST /
```

```json
{
  "diagram_source": "digraph G {Hello->World}",
  "diagram_type": "graphviz",
  "output_format": "svg",
  "diagram_options": {
    "key": "value"
  }
}
```

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

### Send Diagram as Plain Text

Source: https://github.com/yuzutech/kroki/blob/main/README.adoc

Send diagram source as plain text in the request body with appropriate headers.

```http
Accept: image/svg+xml
Content-Type: text/plain

Bob -> Alice : hello
```

```http
Content-Type: text/plain

Bob -> Alice : hello
```

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

### Compress and Encode Diagrams in Node.js

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/encode-diagram.adoc

Uses the pako library to deflate and base64-encode diagram strings for URL safety.

```javascript
const pako = require('pako')

const diagramSource = `digraph G {
  Hello->World
}`

const data = Buffer.from(diagramSource, 'utf8') // <1>
const compressed = pako.deflate(data, { level: 9 }) // <2>
const result = Buffer.from(compressed)
  .toString('base64') // <3>
  .replace(/\+/g, '-').replace(/\//g, '_') // <4>

console.log(result)
```

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

### Send Diagram via POST JSON

Source: https://github.com/yuzutech/kroki/blob/main/README.adoc

Send diagram source as a JSON object to the Kroki API.

```json
{
  "diagram_source": "Bob -> Alice : hello",
  "diagram_type": "plantuml",
  "output_format": "svg"
}
```

```json
{
  "diagram_source": "Bob -> Alice : hello"
}
```

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

### Configure CORS Allowed Headers

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Set the KROKI_CORS_ALLOWED_HEADERS environment variable to permit additional custom headers.

```bash
KROKI_CORS_ALLOWED_HEADERS="x-requested-with,x-app-version"
```

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

### Configure Command Timeout

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Set the KROKI_COMMAND_TIMEOUT environment variable to adjust the wait time for external diagram binaries.

```bash
KROKI_COMMAND_TIMEOUT=10s # <1>
KROKI_COMMAND_TIMEOUT=1m # <2>
KROKI_COMMAND_TIMEOUT=4000ms # <3>
```

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

### Configure Mermaid Convert Timeout

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Sets the maximum time in milliseconds the Mermaid container allows for a single render operation.

```bash
KROKI_MERMAID_CONVERT_TIMEOUT=10000 # default, 10 seconds
```

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

### Send a POST request with HTTPie

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/http-clients.adoc

Sends a JSON request to the Kroki API using HTTPie.

```cli
http https://kroki.io/ diagram_type='graphviz' output_format='svg' diagram_source='digraph G {Hello->World}'
```

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

### Defining a Subclass Constructor

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/assets/mxgraph/src/index.txt

When subclassing, call the superclass constructor using the call function to ensure proper initialization of the instance.

```javascript
function MyGraph(container)
{
  mxGraph.call(this, container);
}
```

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

### Uninstall Kroki via Helm

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Remove the Helm release from the cluster.

```cli
helm uninstall my-kroki
```

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

### Configure Mermaid Concurrency Limit

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/configuration.adoc

Sets the maximum number of simultaneous rendering processes allowed in the Mermaid container.

```bash
KROKI_MERMAID_MAX_CONCURRENCY=6 # default
```

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

### Configuring Apache Compression

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/assets/mxgraph/src/index.txt

Add this directive to your .htaccess file to enable mod_deflate for faster loading of JavaScript source files.

```apache
SetOutputFilter DEFLATE
```

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

### Uninstall Kroki via YAML

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/use-kubernetes.adoc

Remove Kubernetes objects using the original YAML manifest files.

```cli
kubectl delete -f _/path/to/kroki-k8s_
```

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

### Adding New Methods

Source: https://github.com/yuzutech/kroki/blob/main/diagrams.net/assets/mxgraph/src/index.txt

Adding custom methods to the subclass prototype.

```javascript
MyGraph.prototype.getXml = function()
{
  var enc = new mxCodec();
  return enc.encode(this.getModel());
}
```

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

### Kroki API Endpoints

Source: https://github.com/yuzutech/kroki/blob/main/docs/modules/setup/pages/install.adoc

List of available diagram endpoints provided by the yuzutech/kroki container.

```text
/actdiag
/blockdiag
/bytefield
/c4plantuml
/d2
/ditaa
/erd
/goat
/graphviz
/dot
/nomnoml
/nwdiag
/packetdiag
/pikchr
/plantuml
/rackdiag
/seqdiag
/structurizr
/svgbob
/symbolator
/umlet
/vega
/vegalite
/wavedrom
/wireviz
```
Tokens:
Raw