CD unnecessarily deploys files that haven't changed

[lindenwells]

Somehow do some clever GitHub Actions magic to only re-deploy files that have changed on the new commit.

[lindenwells]

This article will be handy
https://dev.to/scienta/get-changed-files-in-github-actions-1p36

[lindenwells]

Say you have the following two files which describe where each file needs to be deployed to:

$ cat nectar_files
nectarfile_1.R
nectarfile_2.RData

$ cat workstation_files
getIt.bom.R
runHindcast.R
foo.txt

And you have a means of getting the files that have changed in this commit (GitHub Actions have a "current commit"). It probably won't be an environment variable but let's pretend it is for now.

$ echo $CHANGED_FILES
nectarfile_2.RData runHindcast.R foo.txt

This ought to filter them:

$ echo $CHANGED_FILES | grep -o -f nectar_files - | xargs
nectarfile_2.RData

$ echo $CHANGED_FILES | grep -o -f workstation_files - | xargs
runHindcast.R foo.txt

• -o is to print only the matches.
• -f is to take PATTERNs from files.
• - means read from stdin

Pipe those into scp with appropriate keys and config for each destination.