chore: update go up to 1.14.2

[lobkovilya]

Summary

A primary goal was to update Go up to 1.14, but there is an issue that doesn't allow us to do it. By default Go 1.14 check if vendor folder exists and runs build in vendoring mode. But our vendor folder is used for prometheus and isn't synced and the build fails. To avoid it we can pass flag -mod=mod to any Go command (test, build, fmt ...) and force to use modules (not vendor). But go tool cover ... doesn't have such -mod flag and under the hood calls go list that starts working in vendor mode and fails. As a workaround, we can run GO111MODULE=off go tool cover but in that case, we should always checkout code on CI under GOPATH.

It is not possible to run go test being outside of the module since go 1.13. That's why I had to slightly modify make test targets. Instead of one go test ./... ./api/... ./pkg/plugins/resources/k8s/native/... now we call go test 3 times for each go module. That leads to the creation of 3 separate coverage files. There is a special third party tool that allows us to merge them, but I don't know how urgent is it and are coverage files even used now.

upd: thanks to @jakubdyszkiewicz and GOFLAGS managed to update Go to 1.14.2

[nickolaev]

I am not a big fan of splitting the test targets as proposed. Can we have a "parametrised" target instead?

[nickolaev]

Hmm can we have a common target that gets arguments for PKG and COVERAGE to test and input the results to?

[lobkovilya]

Are you talking about something like this:

test/api: MODULE=./api COVERAGE_PROFILE=../$(BUILD_COVERAGE_DIR)/coverage-api.out
test/api: test/module

test/k8s: MODULE=./pkg/plugins/resources/k8s/native COVERAGE_PROFILE=../../../../../$(BUILD_COVERAGE_DIR)/coverage-k8s.out
test/k8s: test/module

test/module:
	GO_TEST='${GO_TEST}' GO_TEST_OPTS='${GO_TEST_OPTS}' COVERAGE_PROFILE='${COVERAGE_PROFILE}' make test -C ${MODULE}

[nickolaev]

Yes! At least we get a more structured testing pattern to follow. @jakubdyszkiewicz what do you think?

[jakubdyszkiewicz]

Sure, as long as we've got a single make test target that tests everything (which I see we do) I'm ok with it

[nickolaev]

Why removing the -u?

[lobkovilya]

At first, we install make dev/install/protoc-gen-go with the provided version (make target right above).
Then we run make dev/install/protoc-gen-validate with -u and it updates protoc-gen-go to the latest version, which is incompatible for us.

Maybe all dependencies should be installed without -u flag

[nickolaev]

I see. Well removing -u everywhere makes sense to me. Let's stick with the specific versions we know are working.

[jakubdyszkiewicz]

+1 to removing -u

[nickolaev]

Actually according to https://golang.org/doc/go1.14 :

When the main module contains a top-level vendor directory and its go.mod file specifies go 1.14 or higher, the go command now defaults to -mod=vendor for operations that accept that flag.

Note that the condition is that the toplevel go.mod shall be pointing to 1.14. If you keep it at 1.13 the problem with -mod=mod does not exist. @lobkovilya maybe we can put this in one fo the next PRs.