mqttpc
v1.0.1
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Advanced process control via MQTT
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mqttpc
Advanced process control via MQTT :satellite:
Documentation
Installation
Needs Node.js and npm.
npm install -g mqttpc
Command line options
Usage: index.js [options]
Options:
-v, --verbosity possible values: "error", "warn", "info", "debug"
[default: "info"]
-n, --name instance name. used as mqtt client id and as prefix for
connected topic [default: "pc"]
-u, --url mqtt broker url. See
https://github.com/mqttjs/MQTT.js#connect-using-a-url
[default: "mqtt://127.0.0.1"]
-f, --config config file [default: "./procs.json"]
-h, --help Show help
--version Show version number
Config file
The config file contains a JSON definition of all processes you want to control via MQTT:
{
"<process_name>": {
"path": "/usr/bin/example",
"args": ["-x", "-y"],
...
},
...
}
Availabe attributes
The only mandatory attribute for each process is "path", all others are optional.
- path - (string) path to the process
- args - (array[string]) arguments
- cwd - (string) the working directory (default: the cwd of mqttpc)
- env - (object) key-value paired environment (default: the env of mqttpc)
- uid - (number) user id
- gid - (number) group id
- shell - (boolean|string) run command in a shell (default: false). See https://nodejs.org/api/child_process.html#child_process_child_process_spawn_command_args_options
- disableStdin - (boolean) Disable the possibility to send data through MQTT to the process stdin (default: false).
- disableStdout - (boolean) Disable MQTT publish of the process stdout (default: false).
- disableStderr - (boolean) Disable MQTT publish of the process stderr (default: false).
Usage example
Let's say we got a backup script located in /usr/local/bin/my-backup.sh
that we want to control via MQTT.
Create a config entry like this:
{
"my-backup": {
"path": "/usr/local/bin/my-backup.sh"
}
}
...and (Re)start mqttpc. Now you can start your Backup Script by publish on pc/set/my-backup/spawn
(Payload is irrelevant).
If you want to stop your script via MQTT you could publish SIGKILL
on the topic pc/set/my-backup/signal
.
Topics mqttpc publishes
pc/status/<process_name>/pid
After process start the pid is published retained. When process ends an empty payload will be published (removing the retained message).
pc/status/<process_name>/exit
After process exit the exit code (or the killing signal) will be published retained.
pc/status/<process_name>/error
Errors on process spawn will be published retained on this topic. On next successful process start an empty payload will be published (removing the retained message).
pc/status/<process_name>/stdout
The processes stdout will be published on this topic (not retained).
pc/status/<process_name>/stderr
The processes stderr will be published on this topic (not retained).
Topics mqttpc subscribes
pc/set/<process_name>/spawn
Start the process
pc/set/<process_name>/pipe
Pipe payload into stdin of the process
pc/set/<process_name>/signal
Send a signal to the process (Payload should be a string containing the signal name, e.g. "SIGHUP")
License
MIT (c) Sebastian Raff