Debugger functions for OpenFaaS

This repo contains several functions that can be helpful to testing or debugging an OpenFaaS installation.

Functions

1. echo - a very simple echo function that returns in the input as output

   Usage:

   $ faas-cli deploy \
       --image=ghcr.io/lucasroesler/echo:latest \
       --name=echo
   $ faas-cli invoke echo <<< "payload data here"
   payload data here

2. status-echo - a slightly more complicated echo function that returns a JSON payload that contains the original request data: path, headers, payload

   You can request a specific response status code by adding /<desired code> to the function path.

   Usage:

   $ faas-cli deploy \
       --image=ghcr.io/lucasroesler/status-echo:latest \
       --name=status-echo
   $ faas-cli invoke status-echo <<< "payload data here" | jq
   {
       "status": 200,
       "method": "POST",
       "path": "/",
       "message": "payload data here",
       "headers": {
           "Accept": [
               "*/*"
           ],
           "Accept-Encoding": [
               "gzip"
           ],
           "Content-Type": [
               "application/x-www-form-urlencoded"
           ],
           "User-Agent": [
               "curl/7.68.0"
           ]
       }
   }
   $ curl -vs localhost:8080/function/status-echo/code/400 | jq
   *   Trying 127.0.0.1:8080...
   * TCP_NODELAY set
   * Connected to localhost (127.0.0.1) port 8080 (#0)
   > GET /function/status-echo/code/400 HTTP/1.1
   > Host: localhost:8080
   > User-Agent: curl/7.68.0
   > Accept: */*
   >
   * Mark bundle as not supporting multiuse
   < HTTP/1.1 400 Bad Request
   < Content-Length: 310
   < Content-Type: application/json
   < Date: Sat, 20 Feb 2021 14:28:37 GMT
   < X-Call-Id: a2b4f5a3-f5ac-40b5-8c59-de902cb0bb08
   < X-Duration-Seconds: 0.000311
   < X-Start-Time: 1613831317854614082
   <
   { [310 bytes data]
   * Connection #0 to host localhost left intact
   {
   "status": 400,
   "method": "GET",
   "path": "/code",
   "message": "",
   "headers": {
       "Accept": [
       "*/*"
       ],
       "Accept-Encoding": [
       "gzip"
       ],
       "User-Agent": [
       "curl/7.68.0"
       ],
       "X-Call-Id": [
       "a2b4f5a3-f5ac-40b5-8c59-de902cb0bb08"
       ],
       "X-Forwarded-For": [
       "127.0.0.1:47968"
       ],
       "X-Forwarded-Host": [
       "localhost:8080"
       ],
       "X-Start-Time": [
       "1613831317854614082"
       ]
   }
   }

3. nats-publisher - is a test function to use with the nats-connector. It can be configured to send messages to a specified NATS topic. The default topic is nats-test

   $ faas-cli deploy \
       --name publish-message \
       --image ghcr.io/lucasroesler/nats-publisher:latest \
       --fprocess='./handler' \
       --env nats_url=nats://nats.openfaas:4222
   $ faas-cli invoke publish-message <<< "test message"
   $ faas-cli invoke publish-message -H "nats-subject=alerts" <<< "test message"

4. nats-reciever - is a test function to use with the nats-connector. It can be configured at deploy time via the annotations to receive messages from a NATS topic. The received messages are then echoed to the logs for debugging

   $ faas-cli deploy \
       --name receive-message \
       --image ghcr.io/lucasroesler/nats-receiver:latest \
       --fprocess='./handler' \
       --annotation topic="nats-test"
   $ faas-cli logs receive-message --tail

   Note: a) this requires nats-connector to be installed and configured correct, see the README instructions