Allow custom shell scripts to be defined by derivative images and have Canasta run them at both compile time and runtime

[yaronkoren]

This is already possible for runtime, no? Just add them to the maintenance-scripts/ directory?

[jeffw16]

Well, yes, except I think today you closed the PR without merging it that would've actually fixed this issue. Right now, the scripts are being called manually.

Also, there needs to be a way to run the runtime scripts on startup only, not over and over again on a cron like maintenance-scripts does.

[yaronkoren]

Ooh - what was the PR? I didn't think there was anything useful among the stuff I closed.

[jeffw16]

269

[yaronkoren]

Oh, okay. But please check the relevant code in run-apache.sh (a script that will hopefully be renamed soon, but that's another story) - I think you may have the wrong impression about what it currently does:

https://github.com/CanastaWiki/Canasta/blob/master/_sources/scripts/run-apache.sh#L103

[jeffw16]

I still think my comment is relevant. What if a derivative image needed to add their own maintenance script? They should be able to do so, and they should be able to control the order in which the scripts run.

[yaronkoren]

Well, we can talk about setting the order - but what does that have to do with this issue? It doesn't say anything about order of operation.

[jeffw16]

I think it's an implied nonnegotiable prerequisite that the scripts should be run in a well-ordered manner. We don't want nondeterministic script runs!

[yaronkoren]

Well, they're run in alphabetical order, so it's not nondeterministic... is that good enough? I hope so, because that's how things are done right now. :)

[jeffw16]

They are? But I thought the PR to do that was closed without being merged, much to my dismay :(

[yaronkoren]

Okay - run-all.sh (until recently known as run-apache.sh) uses the "find" command to traverse through all the sripts in maintenance-scripts/ - I thought that "find" always returned files in alphabetical order, but as I just found out, apparently it only usually does that - there's no guarantee of the order unless you then run "sort" or something. Anyway, if you think the current approach to sorting should change, you should either create a different issue for it, or rename this issue - it's very confusing to have a discussion here about functionality that's not discussed in either the issue title or description.

[jeffw16]

Closing this -

• Compile-time scripts can be run by the derivative image themselves at any time with the RUN command.
• Runtime scripts can be added to maintenance-scripts/ to run.

[jeffw16]

I should add that we still need to alphabetize the order in which the maintenance-scripts/ files are run.