WIP: use static linking with cgo

[jpeeler]

This is really to just serve as discussion. As far as I can tell, statically linking to glibc is at best fragile and not supported well.

With the recent change to turn on cgo, binaries started being linked dynamically instead of statically as before. This might not be a problem when using a glibc based container, but obviously increases compatibility concerns. However, in our alpine local test images, the binaries no longer run since it is musl based.

This PR enables static linking and works in alpine, but I don't think it's a good solution. Here's the build output with warnings:

CGO_ENABLED=1  go build -mod=vendor -ldflags "-linkmode external -extldflags '-Wl,-Bstatic -lpthread -lc -static' -X github.com/operator-framework/operator-lifecycle-manager/pkg/version.GitCommit=04b659c6850eb87eab461213e77a94079ea42114 -X github.com/operator-framework/operator-lifecycle-manager/pkg/version.OLMVersion=`cat OLM_VERSION`" -o bin/catalog github.com/operator-framework/operator-lifecycle-manager/cmd/catalog
# github.com/operator-framework/operator-lifecycle-manager/cmd/catalog
/usr/bin/ld: /tmp/go-link-274462539/000019.o: in function `mygetgrouplist':
/workdir/go/src/os/user/getgrouplist_unix.go:16: warning: Using 'getgrouplist' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-274462539/000018.o: in function `mygetgrgid_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:38: warning: Using 'getgrgid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-274462539/000018.o: in function `mygetgrnam_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:43: warning: Using 'getgrnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-274462539/000018.o: in function `mygetpwnam_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:33: warning: Using 'getpwnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-274462539/000018.o: in function `mygetpwuid_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:28: warning: Using 'getpwuid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-274462539/000004.o: in function `_cgo_26061493d47f_C2func_getaddrinfo':
/tmp/go-build/cgo-gcc-prolog:58: warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
CGO_ENABLED=1  go build -mod=vendor -ldflags "-linkmode external -extldflags '-Wl,-Bstatic -lpthread -lc -static' -X github.com/operator-framework/operator-lifecycle-manager/pkg/version.GitCommit=04b659c6850eb87eab461213e77a94079ea42114 -X github.com/operator-framework/operator-lifecycle-manager/pkg/version.OLMVersion=`cat OLM_VERSION`" -o bin/olm github.com/operator-framework/operator-lifecycle-manager/cmd/olm
# github.com/operator-framework/operator-lifecycle-manager/cmd/olm
/usr/bin/ld: /tmp/go-link-425091651/000007.o: in function `mygetgrouplist':
/workdir/go/src/os/user/getgrouplist_unix.go:16: warning: Using 'getgrouplist' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-425091651/000006.o: in function `mygetgrgid_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:38: warning: Using 'getgrgid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-425091651/000006.o: in function `mygetgrnam_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:43: warning: Using 'getgrnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-425091651/000006.o: in function `mygetpwnam_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:33: warning: Using 'getpwnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-425091651/000006.o: in function `mygetpwuid_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:28: warning: Using 'getpwuid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-425091651/000004.o: in function `_cgo_26061493d47f_C2func_getaddrinfo':
/tmp/go-build/cgo-gcc-prolog:58: warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
CGO_ENABLED=1  go build -mod=vendor -ldflags "-linkmode external -extldflags '-Wl,-Bstatic -lpthread -lc -static' -X github.com/operator-framework/operator-lifecycle-manager/pkg/version.GitCommit=04b659c6850eb87eab461213e77a94079ea42114 -X github.com/operator-framework/operator-lifecycle-manager/pkg/version.OLMVersion=`cat OLM_VERSION`" -o bin/package-server github.com/operator-framework/operator-lifecycle-manager/cmd/package-server
# github.com/operator-framework/operator-lifecycle-manager/cmd/package-server
/usr/bin/ld: /tmp/go-link-877205879/000007.o: in function `mygetgrouplist':
/workdir/go/src/os/user/getgrouplist_unix.go:16: warning: Using 'getgrouplist' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-877205879/000006.o: in function `mygetgrgid_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:38: warning: Using 'getgrgid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-877205879/000006.o: in function `mygetgrnam_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:43: warning: Using 'getgrnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-877205879/000006.o: in function `mygetpwnam_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:33: warning: Using 'getpwnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-877205879/000006.o: in function `mygetpwuid_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:28: warning: Using 'getpwuid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-877205879/000004.o: in function `_cgo_26061493d47f_C2func_getaddrinfo':
/tmp/go-build/cgo-gcc-prolog:58: warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking

[openshift-ci-robot]

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[jpeeler]

All of these flags are related to using gcc as the linker (which I bet nobody wants as a build dependency)

[jpeeler]

This was done only because I don't have 32 bit libraries on my system to link to (I think). In theory could be made to work though.

[openshift-ci-robot]

@jpeeler: The following tests failed, say /retest to rerun all failed tests:

Test name	Commit	Details	Rerun command
ci/prow/e2e-aws-olm	1d84ff9	link	/test e2e-aws-olm
ci/prow/e2e-gcp	1d84ff9	link	/test e2e-gcp

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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[jpeeler]

#1219 is a better way forward.