chore: add directories to dockerignore (used to speed up local dev)

[blakepettersson]

Add a bunch of directories to .dockerignore which are not required when doing the initial build of the Argo images. The background is that when developing locally, I use Skaffold to incrementally rebuild the image on any changes (see #11980). When doing any changes to directories which do not strictly require a rebuild of the Docker image, Skaffold proceeds to rebuild the image. This PR just adds the directories which should not force a rebuild of the image.

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Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR states what changed and the related issues number (used for the release note).
• I have signed off all my commits as required by DCO
• My build is green (troubleshooting builds).

[codecov]

Codecov Report

Base: 47.78% // Head: 47.78% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (c6f32e5) compared to base (743b09f).
Patch has no changes to coverable lines.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #12620   +/-   ##
=======================================
  Coverage   47.78%   47.78%           
=======================================
  Files         246      246           
  Lines       41921    41944   +23     
=======================================
+ Hits        20031    20045   +14     
- Misses      19891    19898    +7     
- Partials     1999     2001    +2     

Impacted Files	Coverage Δ
controller/health.go	78.00% <0.00%> (-10.38%)	⬇️
applicationset/generators/merge.go	53.24% <0.00%> (-4.37%)	⬇️
pkg/apis/application/v1alpha1/types.go	58.54% <0.00%> (-0.49%)	⬇️
applicationset/generators/cluster.go	80.27% <0.00%> (ø)
controller/appcontroller.go	53.04% <0.00%> (+0.41%)	⬆️
applicationset/generators/matrix.go	77.50% <0.00%> (+7.75%)	⬆️

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[34fathombelow]

I do not see any of these directories in our final images or any COPY or ADD instructions in the Dockerfile. I'm I missing something?

[blakepettersson]

@34fathombelow sorry that was sloppy phrasing from my side. What I meant to say was that when building the image locally, changes to any files that are within the directories that are now in .dockerignore forces a rebuild of the Docker image. Since those files shouldn't force a rebuild, I added those to .dockerignore.

To be clear this is an issue only for local development (see description for more context) 😄

[34fathombelow]

lgtm

[WitoDelnat]

Hi! I was trying to run Argo CD locally for development and I think this PR has impacted the build on master.

I'm unfamiliar with the build setup but running make start fails. It tries to build an image from the Dockerfile in test/container/dockerfile which relies on files that are missing because test/ was added to the dockerignore in this PR.

Let me know if I can help.

test/container/dockerfile:64
COPY ./test/fixture/testrepos/id_rsa.pub /root/.ssh/authorized_keys
etc

[blakepettersson]

@WitoDelnat sorry about that! If you add !test/fixture to .dockerignore does that solve your issue?

[blakepettersson]

If so #12640 will fix it for everyone else that might be affected

[WitoDelnat]

No worries! It was easy to work around. You missed a file to exclude (see PR) but after that it should be good to go!