fix: Remove kubectl binary from argo image(#5005)

[iam-veeramalla]

Signed-off-by: iam-veeramalla abhishek.veeramalla@gmail.com

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[codecov-io]

Codecov Report

Merging #5101 (ed4ad4b) into master (e26ad30) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #5101      +/-   ##
==========================================
- Coverage   40.90%   40.88%   -0.02%     
==========================================
  Files         136      136              
  Lines       18419    18426       +7     
==========================================
  Hits         7534     7534              
- Misses       9810     9816       +6     
- Partials     1075     1076       +1     

Impacted Files	Coverage Δ
server/project/project.go	55.46% <0.00%> (-0.92%)	⬇️
cmd/util/app.go	33.43% <0.00%> (-0.32%)	⬇️

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[iam-veeramalla]

@jannfis @jessesuen This is as part of our discussion at #5005

[alexmt]

Please also remove hack/installers/install-kubectl-linux.sh

[jessesuen]

This change is incomplete, because the last place where we still use kubectl is at the version endpoint:

See: https://github.com/argoproj/argo-cd/blob/master/server/version/version.go#L32-L51

Can you also update version.go to somehow report the version that we import in go modules?

[iam-veeramalla]

This change is incomplete, because the last place where we still use kubectl is at the version endpoint:

See: https://github.com/argoproj/argo-cd/blob/master/server/version/version.go#L32-L51

Can you also update version.go to somehow report the version that we import in go modules?

If we decide to remove kubectl from the image, why should we import or print the version ? @jessesuen

[alexmt]

If we decide to remove kubectl from the image, why should we import or print the version ? @jessesuen

Was trying to find a related discussion but looks like it is gone in slack history. Argo CD still uses kubectl as a library. So user still need to know which version it is e.g. to determine if the target k8s cluster compatible or not.

[jessesuen]

We still care about the version of library because it's intended to be equivalent in behavior to the corresponding kubectl binary (including its bugs and fixes)

[jannfis]

Since we use a version pin on the Kubernetes libraries in go.mod (in the replace) section, I think the version could be figured out as follows (Kubernetes libraries use a weird versioning scheme, but effectively v0.20.1 is v1.20.1, v0.18.6 is v1.18.6 etc):

awk '/k8s.io\/client-go => k8s.io\/client-go/ { print $4 }' go.mod | sed -e 's/v0\.\(.*\)/v1\.\1/'

I.e. on current master code this will yield:

$ awk '/k8s.io\/client-go => k8s.io\/client-go/ { print $4 }' go.mod | sed -e 's/v0\.\(.*\)/v1\.\1/'
v1.20.1

We can pass this in Makefile via linker flags to the build process of the binaries, like we already do with the Argo CD version and Git commit SHA, as seen here:

argo-cd/Makefile

Line 118 in 64e1c38

override LDFLAGS += \

Then use this version identifier in the version endpoint, and get rid of kubectl for good.

Btw, there is a version discrepancy in client libs used and kubectl installed in the image currently, so the version information is quite misleading currently.

[jannfis]

Due to GNU make's own variable expansion, print $4 should be print $$4 here so that the identifier will be processed correctly by awk

[iam-veeramalla]

Please also remove hack/installers/install-kubectl-linux.sh

Please review

[iam-veeramalla]

This change is incomplete, because the last place where we still use kubectl is at the version endpoint:

See: https://github.com/argoproj/argo-cd/blob/master/server/version/version.go#L32-L51

Can you also update version.go to somehow report the version that we import in go modules?

Please check

[jannfis]

LGTM!

[alexmt]

LGTM. Awesome! Minus 42 MB from the image.

requested change was implemented