cmd/k8s-operator: add .gitignore for generated chart CRDs (#17406)

Add a .gitignore for the chart version of the CRDs that we never commit,
because the static manifest CRD files are the canonical version. This
makes it easier to deploy the CRDs via the helm chart in a way that
reflects the production workflow without making the git checkout
"dirty".

Given that the chart CRDs are ignored, we can also now safely generate
them for the kube-generate-all Makefile target without being a nuisance
to the state of the git checkout. Added a slightly more robust repo root
detection to the generation logic to make sure the command works from
the context of both the Makefile and the image builder command we run
for releases in corp.

Updates tailscale/corp#32085

Change-Id: Id44a4707c183bfaf95a160911ec7a42ffb1a1287

Signed-off-by: Tom Proctor <tomhjp@users.noreply.github.com>

cmd/k8s-operator/deploy/chart/templates/.gitignore

@@ -0,0 +1,10 @@
+# Don't add helm chart CRDs to git. Canonical CRD files live in
+# cmd/k8s-operator/deploy/crds.
+#
+# Generate for local usage with:
+# go run tailscale.com/cmd/k8s-operator/generate helmcrd
+/connector.yaml
+/dnsconfig.yaml
+/proxyclass.yaml
+/proxygroup.yaml
+/recorder.yaml

cmd/k8s-operator/generate/main.go

@@ -41,11 +41,16 @@ func main() {
 	if len(os.Args) < 2 {
 		log.Fatalf("usage ./generate [staticmanifests|helmcrd]")
 	}
-	repoRoot := "../../"
+	gitOut, err := exec.Command("git", "rev-parse", "--show-toplevel").CombinedOutput()
+	if err != nil {
+		log.Fatalf("error determining git root: %v: %s", err, gitOut)
+	}
+
+	repoRoot := strings.TrimSpace(string(gitOut))
 	switch os.Args[1] {
 	case "helmcrd": // insert CRDs to Helm templates behind a installCRDs=true conditional check
 		log.Print("Adding CRDs to Helm templates")
-		if err := generate("./"); err != nil {
+		if err := generate(repoRoot); err != nil {
 			log.Fatalf("error adding CRDs to Helm templates: %v", err)
 		}
 		return

cmd/k8s-operator/operator.go

@@ -67,6 +67,9 @@ import (
 // Generate static manifests for deploying Tailscale operator on Kubernetes from the operator's Helm chart.
 //go:generate go run tailscale.com/cmd/k8s-operator/generate staticmanifests
 
+// Generate the helm chart's CRDs (which are ignored from git).
+//go:generate go run tailscale.com/cmd/k8s-operator/generate helmcrd
+
 // Generate CRD API docs.
 //go:generate go run github.com/elastic/crd-ref-docs --renderer=markdown --source-path=../../k8s-operator/apis/ --config=../../k8s-operator/api-docs-config.yaml --output-path=../../k8s-operator/api.md