Commands

Commands

Customize command names and parameters for maximum flexibility.

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Default Commands

Function	Query Parameter	HTTP Header	Description
Custom Body	echo_body	x-echo-body	Set custom response body
Environment Body	echo_env_body	x-echo-env-body	Use environment variable as body
Status Code	echo_code	x-echo-code	Set HTTP status code
Custom Headers	echo_header	x-echo-header	Add custom response headers
Response Delay	echo_time	x-echo-time	Add response delay (milliseconds)
File Operations	echo_file	x-echo-file	Read file or list directory

Usage Examples

# Custom body
curl http://localhost:80/?echo_body=hello

# Custom status code
curl -I http://localhost:80/?echo_code=404

# Custom header
curl -I http://localhost:80/?echo_header=Custom:Value

# Response delay (2 seconds)
curl http://localhost:80/?echo_time=2000

# File operations
curl http://localhost:80/?echo_file=/tmp

# Environment variable as body
curl http://localhost:80/?echo_env_body=HOSTNAME

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Customization

All command names can be customized using environment variables.

Custom Body

export COMMANDS__HTTPBODY__QUERY=custom_body
export COMMANDS__HTTPBODY__HEADER=x-custom-body

# Usage
curl http://localhost:80/?custom_body=hello
curl -H "X-Custom-Body: world" http://localhost:80

Status Code

export COMMANDS__HTTPCODE__QUERY=status
export COMMANDS__HTTPCODE__HEADER=x-status

# Usage
curl -I http://localhost:80/?status=404
curl -I -H "X-Status: 500" http://localhost:80

Custom Headers

export COMMANDS__HTTPHEADERS__QUERY=headers
export COMMANDS__HTTPHEADERS__HEADER=x-headers

# Usage
curl -I http://localhost:80/?headers=Custom:Value

Response Delay

export COMMANDS__TIME__QUERY=delay
export COMMANDS__TIME__HEADER=x-delay

# Usage
curl http://localhost:80/?delay=2000

File Operations

export COMMANDS__FILE__QUERY=file
export COMMANDS__FILE__HEADER=x-file

# Usage
curl http://localhost:80/?file=/tmp

Environment Body

export COMMANDS__HTTPENVBODY__QUERY=env_response
export COMMANDS__HTTPENVBODY__HEADER=x-env-response

# Usage
curl http://localhost:80/?env_response=HOSTNAME

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Examples

API-Style Naming

export COMMANDS__HTTPBODY__QUERY=response_body
export COMMANDS__HTTPBODY__HEADER=x-api-response-body
export COMMANDS__HTTPCODE__QUERY=response_code
export COMMANDS__HTTPCODE__HEADER=x-api-response-code
export COMMANDS__TIME__QUERY=response_delay
export COMMANDS__TIME__HEADER=x-api-response-delay

# Usage
curl http://localhost:80/?response_body=hello&response_code=201
curl -H "X-Api-Response-Body: success" http://localhost:80

Docker

docker run -p 80:80 \
  -e COMMANDS__HTTPBODY__QUERY=response \
  -e COMMANDS__HTTPCODE__QUERY=code \
  echoserver:latest

Docker-Compose

services:
  echoserver:
    image: echoserver:latest
    environment:
      - COMMANDS__HTTPBODY__QUERY=body
      - COMMANDS__HTTPCODE__QUERY=status
      - COMMANDS__TIME__QUERY=delay

Kubernetes

apiVersion: v1
kind: ConfigMap
metadata:
  name: echoserver-commands
data:
  COMMANDS__HTTPBODY__QUERY: "response_body"
  COMMANDS__HTTPCODE__QUERY: "response_code"
  COMMANDS__TIME__QUERY: "response_delay"

Update at runtime:

kubectl patch configmap echoserver-commands \
  -p '{"data":{"COMMANDS__HTTPBODY__QUERY":"new_body"}}'

kubectl rollout restart deployment/echoserver

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Related: Configuration →