KEYCLOAK-13634 Support for multiple architectures

[slaskawi]

JIRA ID

KEYCLOAK-13634

Additional Information

This Pull Request allows to compile Keycloak Operator against multiple architectures.

Verification Steps

Checklist:

• Verified by team member
• Comments where necessary
• Automated Tests
• Documentation changes if necessary

Additional Notes

[slaskawi]

I will turn it to a proper Pull Request once I get a chance to test it on other platforms.

[coveralls]

Coverage remained the same at 41.127% when pulling aac72b0 on slaskawi:KEYCLOAK-13634-multi-platform-support into 3bb62aa on keycloak:master.

[slaskawi]

Verified on s390 - the binary is produced properly for this specific architecture. The binary starts up without any problems.

However, the image generation part ca not be tested because of https://bugzilla.redhat.com/show_bug.cgi?id=1825848. Once the issue is solved, I will be possible to test image generation process.

[slaskawi]

The Bugzilla is solved and I've successfully tested this out on a Z-series machine. The output is exactly as expected:

$ docker build .
...
e9f0572efc5a8b8fe36cfe5c6aaf1af54da506ff50858c8e2bba25be6c35ba84
$ docker run e9f0572efc5a8b8fe36cfe5c6aaf1af54da506ff50858c8e2bba25be6c35ba84
{"level":"info","ts":1587388735.1324008,"logger":"cmd","msg":"Go Version: go1.12.12"}
{"level":"info","ts":1587388735.1324267,"logger":"cmd","msg":"Go OS/Arch: linux/s390x"}
{"level":"info","ts":1587388735.1324306,"logger":"cmd","msg":"Version of operator-sdk: v0.15.1"}
{"level":"info","ts":1587388735.1324341,"logger":"cmd","msg":"Operator version: 9.0.2"}
{"level":"error","ts":1587388735.1324384,"logger":"cmd","msg":"Failed to get watch namespace","error":"WATCH_NAMESPACE must be set","stacktrace":"github.com/go-logr/zapr.(*zapLogger).Error\n\t/src/vendor/github.com/go-logr/zapr/zapr.go:128\nmain.main\n\t/src/cmd/manager/main.go:81\nruntime.main\n\t/usr/lib/golang/src/runtime/proc.go:200"}

Note, the architecture - it's s390x, as we expected.

[mhajas]

Thanks @slaskawi