README
¶
cronmon
A lightweight service manager that monitors itself using crond. Designed to be used where a service manager is not available.
Differences vs. Other Monitors
- Cron-based.
- Simple service file syntax (there's none).
- Easily statically compiled (
CGO_ENABLED=0 go build).
For a detailed explanation of how cronmon works exactly, see its documentation.
Compatibility
Cronmon uses two features that makes it only work on Linux:
(syscall.SysProcAttr).Pdeathsig and PR_SET_CHILD_SUBREAPER. The usage of
these two features are documented in the above documentation.
Installation
- Install cronmon:
go install git.unix.lgbt/diamondburned/cronmon. - Edit crontab:
crontab -e. - Add cronmon into the cron file.
Cron File
A cron file can be generated by running cronmon cron. Below is a simple
example:
# Start cronmon immediately on startup.
@reboot /tmp/cronmon
# Monitor cronmon's status every minute.
* * * * * /tmp/cronmon
This cron file will launch cronmon with the journal file pointing to
~/.config/cronmon/journal.json and the scripts (service) directory pointing to
~/.config/cronmon/scripts/.
Service File Example
$ # Shell script example.
$ cat <<'EOF' > ~/.cronmon/scripts/sysmetd.sh
#!/bin/sh
exec sysmet -flag "$shell_env" -listen unix:///tmp/a.sock
EOF
$ chmod +x ~/.cronmon/scripts/sysmetd.sh
$
$ # Executable example.
$ wget -O ~/.cronmon/scripts/example https://dodgy.site/executable
$ chmod +x ~/.cronmon/scripts/example
New service files will automatically be executed, and old service files that are
updated will automatically restart the process. Removing a service file will
stop the process. Removing the executable bit from a file (chmod -x) makes
cronmon stop the process as well. Adding back the bit (chmod +x) makes it
start the process again.
Documentation
¶
There is no documentation for this package.
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
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Package cronmon is the core of the cronmon application, providing individual components that work independently, while communicating with eachother concurrently over channels.
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Package cronmon is the core of the cronmon application, providing individual components that work independently, while communicating with eachother concurrently over channels. |
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exec
Package exec provides an abstraction around package os' Process implementation for easier testing.
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Package exec provides an abstraction around package os' Process implementation for easier testing. |
|
journal
Package journal provides an implementation of cromon's Journaler interface to write to a file.
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Package journal provides an implementation of cromon's Journaler interface to write to a file. |