shell command filter

[ssube]

Summary

Some filters are too complex for rules (they may require outside data sources, be written in other languages, etc). The simplest way to support a broad variety of other tools is a shell command hook. While a shell controller is probably necessary in the long-run, a shell filter should handle most of the requirements for #556, #557, and even #313 and #316 to some extent.

Scope

• shell command filter
• serialize filter value as JSON and write to stdin
• behavior:
  • allow value when command succeeds, log stdout
  • drop value when command writes to stderr
  • drop value when command exits non-0

Use Case

Using curl/jq to check commit status.

Questions

Any benefits to using a shell-exec library over child_process.exec?

[ssube]

exec had issues with sending input in headless envs (child would hang), spawn appears to work as expected and allows the bot to buffer/ignore output.