bash-rest

Light-weight web framework for Bash

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Introduction

bash-rest provides a similar (albeit simplistic) experience to spring-web for Java.

The script starts a basic webserver that serves http requests over locahost, where functions annotated with request mapping annotations are invoked when their respective endpoints are called.

At present, only path variables are parsed (e.g. request body and request parameters are not captured, and the presence of characters like '?' in a path variable interfere with parsing due to reliance on regex and lookarounds).

Default port is 3000.

Usage

Arguments passed to annotated functions are path variables in order of appearance in endpoint.

1. Define functions and map them to unique endpoints:

#!/usr/bin/env bash

# controller.bash

source "./request_mapping.bash"

@get_mapping "/api/v1/{userId}/dashboard/{profileId}"
get_dashboard() {
    local user_id="${1}" 
    local profile_id="${2}"

# Configure valid http and json response
    cat <<EOF
HTTP/1.1 200
Content-Type: application/json

{
    "userId": "${user_id}",
    "profileId": "${profile_id}"
}
EOF
}

2. Start the webserver bash bash-rest.bash controller.bash. Arguments are paths to sh or bash files with request mapping annotated functions.

3. Send request to the endpoint defined above:

curl -X GET "http://localhost:3000/api/v1/5499/dashboard/1" 

# { "userId": "5499", "profileId": "1" }

Overriding default behaviour

bash-rest defines bash_rest_404_not_found() as a default function to handle instances when a requested endpoint cannot be found.

This can be overridden by simply defining your own implementation of bash_rest_404_not_found() in a file sourced by bash-rest.bash.

Template for custom implementation is:

bash_rest_404_not_found() {
	cat <<EOF
HTTP/1.1 404 NotFound
Content-Type: # e.g. text/html

# Desired 404 response here
EOF
}

Credits

Request parsing and netcat implementation with named pipes is taken from https://dev.to/leandronsp/building-a-web-server-in-bash-part-i-sockets-2n8b