[25.0 backport] scripts/build/plugins: don't override CGO_ENABLED set by .variables

[thaJeztah]

• backport scripts/build/plugins: don't override CGO_ENABLED set by .variables #5393

The .variables sets CGO_ENABLED=1 on arm;

cli/scripts/build/.variables

Lines 57 to 68 in b0c41b7

	if [ -z"$CGO_ENABLED" ];then
	case"$(go env GOOS)"in
	linux)
	case"$(go env GOARCH)"in
	amd64|arm64|arm|s390x|riscv64)
	CGO_ENABLED=1
	;;
	*)
	CGO_ENABLED=0
	;;
	esac
	;;

And if enabled, it sets -buildmode=pie;

cli/scripts/build/.variables

Lines 79 to 88 in b0c41b7

	if [ "$CGO_ENABLED"="1" ] && [ "$(go env GOOS)"!="windows" ];then
	case"$(go env GOARCH)"in
	mips*|ppc64)
	# pie build mode is not supported on mips architectures
	;;
	*)
	GO_BUILDMODE="-buildmode=pie"
	;;
	esac
	fi

But that looks to be conflicting with the hardcoded CGO_ENABLED=0 in this script, which causes the build to fail on go1.22;

> [build-plugins 1/1] RUN --mount=ro --mount=type=cache,target=/root/.cache xx-go --wrap && TARGET=/out ./scripts/build/plugins e2e/cli-plugins/plugins/*:
0.127 Building static docker-helloworld
0.127 + CGO_ENABLED=0
0.127 + GO111MODULE=auto
0.127 + go build -o /out/plugins-linux-arm/docker-helloworld -tags ' osusergo' -ldflags ' -X "github.com/docker/cli/cli/version.GitCommit=5c123b1" -X "github.com/docker/cli/cli/version.BuildTime=2024-09-02T13:52:17Z" -X "github.com/docker/cli/cli/version.Version=pr-5387" -extldflags -static' -buildmode=pie github.com/docker/cli/cli-plugins/examples/helloworld
0.135 -buildmode=pie requires external (cgo) linking, but cgo is not enabled

This patch sets the CGO_ENABLED variable before sourcing .variables, so that other variables which are conditionally set are handled correctly.

Before this PR:

#18 [build-plugins 1/1] RUN --mount=ro --mount=type=cache,target=/root/.cache xx-go --wrap && TARGET=/out ./scripts/build/plugins e2e/cli-plugins/plugins/*
#18 0.123 Building static docker-helloworld
#18 0.124 + CGO_ENABLED=0
#18 0.124 + GO111MODULE=auto
#18 0.124 + go build -o /out/plugins-linux-arm/docker-helloworld -tags ' osusergo' -ldflags ' -X "github.com/docker/cli/cli/version.GitCommit=c8c402e" -X "github.com/docker/cli/cli/version.BuildTime=2024-09-03T08:28:25Z" -X "github.com/docker/cli/cli/version.Version=pr-5381" -extldflags -static' -buildmode=pie github.com/docker/cli/cli-plugins/examples/helloworld
....

With this PR:

#18 [build-plugins 1/1] RUN --mount=ro --mount=type=cache,target=/root/.cache xx-go --wrap && TARGET=/out ./scripts/build/plugins e2e/cli-plugins/plugins/*
#18 0.110 Building static docker-helloworld
#18 0.110 + GO111MODULE=auto
#18 0.110 + go build -o /out/plugins-linux-arm/docker-helloworld -tags '' -ldflags ' -X "github.com/docker/cli/cli/version.GitCommit=050d9d6" -X "github.com/docker/cli/cli/version.BuildTime=2024-09-03T09:19:05Z" -X "github.com/docker/cli/cli/version.Version=pr-5387"' github.com/docker/cli/cli-plugins/examples/helloworld
....

(cherry picked from commit 9e29967)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 61.36%. Comparing base (a73610d) to head (06e1305).
Report is 5 commits behind head on 25.0.

Additional details and impacted files

@@ Coverage Diff @@## 25.0 #5397 +/- ##
=======================================
Coverage 61.36% 61.36% =======================================
Files 290 290 Lines 20098 20098 =======================================
Hits 12334 12334 Misses 6871 6871 Partials 893 893 

[thaJeztah]

@laurazard ptal 🤗

[laurazard]

LGTM

[laurazard]

Sorry, missed this one 😅 thanks!

[thaJeztah]

No worries; I saw #5406 was blocked on this one 😅