how to use --stdin-from-command with resticprofile

[nathanejohnson]

Just curious how you would use the --stdin-from-command option with resticprofile? I see that it passes this along to the restic command if it's in the profile, but I see no way to have it pass along the command for restic to execute. The main thing I'm trying to accomplish is being able to do a pg_dump and have dump failures signal a failed backup, similar to what is discussed here:

https://restic.readthedocs.io/en/latest/040_backup.html#reading-data-from-a-command

Thanks in advance!

[creativeprojects]

resticprofile already had this feature implemented (with the option stdin-command) before it was introduced in restic 0.17 (we actually never used the --stdin-from-command flag #350)

Basically it's starting both commands in parallel and wire up the output of one to the input of the other. By starting the command separately and doing the pipe ourselves, we know when any of the command fail.

You don't need to worry about it, it would return an error if your pg_dump fails.

One thing to keep in mind though, is howpg_dump locks your database (per db, table, row, etc.). Typically, the lock(s) will stay in place for the whole duration of the backup, as the output of the pg_dump will be limited by the speed of restic reading from the pipe.
Your database could be locked for a long time if your backup is running on a slow network (well, maybe it's only me who has dialup connections in rural Scotland these day...)

[nathanejohnson]

Thanks for the reply. The --stdin-from-command flag is actually recognized in a profile, it's non-flag arguments (-- command -flag -flag etc) doesn't seem to be implemented. But if the resticprofile version of stdin is safe, that's good enough for me.

Re locking, that's always a tradeoff. In this case this is a backup of a smallish database over a local gigabit link, so a full backup took 2 minutes just now. I can live with that.