hapttic
What is this good for?
- You want to run some code in response to a webhook, like a github push.
- You have some code on your Raspberry Pi that you want to run from work (great in combination with ngrok).
- That's pretty much it.
How does it work?
Hapttic listens for incoming HTTP connections. When it receives a connection, it dumps all relevant data (headers, path, parameters, the body and other stuff) into a JSON object and calls a bash script with this object as its parameters.
Isn't this just a reinvention of CGI?
The basic idea is pretty similar. The main advantage of hapttic is ease of setup with a simple Docker image that lets you quickly connect a shell script to a http endpoint.
Show me an example
First, create a request handler at ~/hapttic_request_handler.sh
:
echo $1
Then run the following command to spin up the docker container that runs hapttic:
docker run --rm -p 8080:8080 -v ~/hapttic_request_handler.sh:/hapttic_request_handler.sh --name hapttic jsoendermann/hapttic -file "/hapttic_request_handler.sh"
Finally, run open http://localhost:8080
to see the output of your script.
Show me a more realistic example
REQUEST=$1
SECRET_TOKEN=$(jq -r '.Header."X-My-Secret"[0]' <(echo $REQUEST))
if [[ "$SECRET_TOKEN" != "SECRET" ]]; then
echo "Incorrect secret token"
exit -1
fi
curl https://www.example.com/api/call/in/response/to/webhook
This request handling script can be run with curl -H "X-My-Secret: SECRET" http://localhost:8080
The jsoendermann/hapttic
Dockerfile includes jq
and curl
, if you need any other command in your request handling script, you should create your own image.
The Request JSON object
The JSON object your request handling script gets called with is a subset of Go's http.Request
. It's defined in hapttic.go as marshallableRequest
. For documentation on http.Request, see the official net/http page.
SSL Support
You can add encryption by putting an nginx proxy in front of it with a docker-compose file like so:
version: '3'
volumes:
vhost:
html:
services:
nginx-proxy:
restart: always
image: jwilder/nginx-proxy
ports:
- 80:80
- 443:443
volumes:
- /var/run/docker.sock:/tmp/docker.sock:ro
- /var/certs:/etc/nginx/certs:ro
- vhost:/etc/nginx/vhost.d
- html:/usr/share/nginx/html
labels:
- "com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy=true"
letsencrypt-nginx-proxy-companion:
restart: always
image: jrcs/letsencrypt-nginx-proxy-companion
volumes:
- /var/run/docker.sock:/var/run/docker.sock:ro
- /var/certs:/etc/nginx/certs:rw
- vhost:/etc/nginx/vhost.d
- html:/usr/share/nginx/html
hapttic:
restart: always
image: jsoendermann/hapttic
environment:
- VIRTUAL_HOST=hapttic.your.domain.com # Replace this
- LETSENCRYPT_HOST=hapttic.your.domain.com # Replace this
- LETSENCRYPT_EMAIL=your@email.address # Replace this
volumes:
- /my-request-handler.sh:/hapttic_request_handler.sh # Replace this
command: ["-file", "/hapttic_request_handler.sh"]
depends_on:
- nginx-proxy
- letsencrypt-nginx-proxy-companion