Return the output from exec as HTTP response

sinky · February 5, 2024, 11:39am

1. The problem I’m having:

I’m using a custom build with the http.handlers.exec module
My goal is to return the output from a command as HTTP Response
I don’t know how to do this or iif it’s possible at all with caddy

This is my current Config

:2015

route /update {
    exec powershell -command (get-date).toString() {
				log file caddy.log
    }
}

The Command output is logged to the logfile but the http response is {"status": "success"}

How to output the that is currently logged as http response?

2. Error messages and/or full log output:

caddy run --config Caddyfile
2024/02/05 11:33:57.291 INFO    using provided configuration    {"config_file": "Caddyfile", "config_adapter": ""}
2024/02/05 11:33:57.292 WARN    Caddyfile input is not formatted; run 'caddy fmt --overwrite' to fix inconsistencies    {"adapter": "caddyfile", "file": "Caddyfile", "line": 4}
2024/02/05 11:33:57.295 INFO    admin   admin endpoint started  {"address": "localhost:2019", "enforce_origin": false, "origins": ["//127.0.0.1:2019", "//localhost:2019", "//[::1]:2019"]}
2024/02/05 11:33:57.295 INFO    tls.cache.maintenance   started background certificate maintenance      {"cache": "0xc0003f9a00"}
2024/02/05 11:33:57.295 INFO    http.log        server running  {"name": "srv0", "protocols": ["h1", "h2", "h3"]}
2024/02/05 11:33:57.296 INFO    autosaved config (load with --resume flag)      {"file": "C:\\Users\\....\\AppData\\Roaming\\Caddy\\autosave.json"}
2024/02/05 11:33:57.296 INFO    serving initial configuration
2024/02/05 11:33:57.298 WARN    tls     storage cleaning happened too recently; skipping for now        {"storage": "FileStorage:C:\\Users\\kragem\\AppData\\Roaming\\Caddy", "instance": "167e29d2-cc58-47ad-897b-1e8f482260d2", "try_again": "2024/02/06 11:33:57.298", "try_again_in": 86400}
2024/02/05 11:33:57.298 INFO    tls     finished cleaning storage units
2024/02/05 11:34:00.096 INFO    http.handlers.exec.exit         {"command": ["powershell", "-command", "(get-date).toString()"], "duration": 0.1574295}

3. Caddy version:

v2.7.6 h1:w0NymbG2m9PcvKWsrXO6EEkY9Ru4FJK8uQbYcev1p3A=

4. How I installed and ran Caddy:

b. Command:

caddy run --config Caddyfile

5. Links to relevant resources:

matt · February 5, 2024, 5:32pm

You likely want a CGI plugin like this one: GitHub - aksdb/caddy-cgi: Common Gateway Interface plugin for the Caddy HTTP server

But perhaps @abiosoft can answer your question better.

abiosoft · February 5, 2024, 8:39pm

Currently, returning the output as part of the HTTP response is not supported.

IIRC, the main reason it was not implemented is to have a common approach for both background and foreground commands.

If this is indeed a common usecase for people, the feature can be added.

francislavoie · February 6, 2024, 1:26am

Relevant open issue:

github.com/abiosoft/caddy-exec

Input query/post data and return script stdout in response?

opened 09:40PM - 16 Dec 20 UTC

patxipierce

Hello, and thanks so much for this great module. <3 I have looked for caddy-e…xec related issues and in the caddy documentation to see if I am missing something. But now I come to you, my last hope. :-) ## My setup: I'm building a caddy image with caddy-exec and [caddy-hmac](https://github.com/abiosoft/caddy-hmac) like so: `$PWD\docker-compose.yml` ```yaml version: "3.7" services: caddy: build: context: . dockerfile: $PWD/config/caddy/caddy.Dockerfile container_name: caddy restart: unless-stopped ports: - "80:80" - "443:443" env_file: - $PWD/config/secrets/local.env volumes: - $PWD/config/caddy/Caddyfile:/etc/caddy/Caddyfile - $PWD/site:/site - $PWD/api:/api - caddy_data:/data - caddy_config:/config volumes: caddy_data: caddy_config: ``` My `$PWD/config/secrets/local.env` file: ```env # Use localhost for local or an IP or Domain SITE_ADDRESS=localhost # API key API_KEY=abcde123456 ``` `$PWD/config/caddy/caddy.Dockerfile` ```Dockerfile FROM caddy:2.2.1-builder-alpine AS builder RUN xcaddy build v2.2.1 \ --with github.com/abiosoft/caddy-exec \ --with github.com/abiosoft/caddy-hmac FROM caddy:2.2.1-alpine COPY --from=builder /usr/bin/caddy /usr/bin/caddy # Install python3 ENV PYTHONUNBUFFERED=1 RUN apk add --update --no-cache \ python3 && ln -sf /bin/python3 /usr/bin/python ``` And my `$PWD/config/caddy/Caddyfile`: ```Caddyfile {$SITE_ADDRESS} { root / /site/index.html header Content-type application/json file_server # API Routes route /api/example/python { exec { command /usr/bin/python3 args \ /api/example/python/python-example.py \ {$API_KEY} \ {query} directory /api/example/python timeout 5s foreground } } } ``` ## My issue(s): 1.- So far I can pass my env vars to the scripts (not only python, but bash and other unforeseen languages), but the {query} shows up in the logs as {http.request.uri.query}, and not the intended string. 2.- Then I only see a JSON response giving a `success` status, or `error` status, but I do not see how to pass my scripts output to the response. Any insight about something that I'm obviously missing is appreciated. And thank you again for the support, documentation and development you have provided so far.

sinky · February 7, 2024, 10:05am

Ah nice now i’m trying aksdb/caddy-cgi
That seems the right one.

But i’m running on an error while runnning on windows.
It does not matter in which format I enter the exe/script.

C:\Windows\system32\hostname.exe does exist

caddy run --config Caddyfile
2024/02/07 09:59:31.872 INFO    using provided configuration    {"config_file": "Caddyfile", "config_adapter": ""}
2024/02/07 09:59:31.876 INFO    admin   admin endpoint started  {"address": "localhost:2019", "enforce_origin": false, "origins": ["//localhost:2019", "//[::1]:2019", "//127.0.0.1:2019"]}
2024/02/07 09:59:31.876 INFO    tls.cache.maintenance   started background certificate maintenance      {"cache": "0xc000130d00"}
2024/02/07 09:59:31.876 INFO    http.log        server running  {"name": "srv0", "protocols": ["h1", "h2", "h3"]}
2024/02/07 09:59:31.876 INFO    autosaved config (load with --resume flag)      {"file": "C:\\Users\\...\\AppData\\Roaming\\Caddy\\autosave.json"}
2024/02/07 09:59:31.877 INFO    serving initial configuration
2024/02/07 09:59:31.879 WARN    tls     storage cleaning happened too recently; skipping for now        {"storage": "FileStorage:C:\\Users\\...\\AppData\\Roaming\\Caddy", "instance": "0689bf7e-c42b-4533-9c97-07daf87cc2c0", "try_again": "2024/02/08 09:59:31.879", "try_again_in": 86400}
2024/02/07 09:59:31.879 INFO    tls     finished cleaning storage units
2024/02/07 09:59:33.781 INFO    CGI error: fork/exec .\hostname.exeC:\Windows\system32\hostname.exe: Die Syntax für den Dateinamen, Verzeichnisnamen oder die Datenträgerbezeichnung ist falsch.

Caddyfile

{
	order cgi before respond
}

:2015

cgi /update hostname.exe {
	#script_name /script.cgi
}

francislavoie · February 7, 2024, 11:39am

You should open an issue on that plugin’s repo.

system · March 8, 2024, 11:40am

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