[7.0.x] Add Helm 3 binary (#2345)

* [7.0.x] Backport 'Add Helm 3 binary' (#2303)

* Create symlink on host for Helm 3

* Fix variable

* Set helm 3 binary path on host

* Bump planet tag

* Change planet tag and branch for testing

* Change planet branch to default

Makefile

@@ -46,7 +46,7 @@ RELEASE_OUT ?=
 TELEPORT_TAG = 3.2.16
 # TELEPORT_REPOTAG adapts TELEPORT_TAG to the teleport tagging scheme
 TELEPORT_REPOTAG := v$(TELEPORT_TAG)
-PLANET_TAG := 7.0.53-$(K8S_VER_SUFFIX)
+PLANET_TAG := 7.0.54-$(K8S_VER_SUFFIX)
 PLANET_BRANCH := $(PLANET_TAG)
 K8S_APP_TAG := $(GRAVITY_TAG)
 TELEKUBE_APP_TAG := $(GRAVITY_TAG)

lib/defaults/defaults.go

@@ -350,6 +350,17 @@ const (
 	// systems where /usr/bin is not writable
 	HelmBinAlternate = "/writable/bin/helm"
 
+	// Helm3Bin is the location of helm 3 binary inside planet
+	Helm3Bin = "/usr/bin/helm3"
+
+	// Helm3Script is the location of the helm 3 script, which the host's helm
+	// is symlinked to, inside the planet
+	Helm3Script = "/usr/local/bin/helm3"
+
+	// Helm3BinAlternate is the alternative location of helm 3 symlink on
+	// systems where /usr/bin is not writable
+	Helm3BinAlternate = "/writable/bin/helm3"
+
 	// PlanetBin is the default location of planet binary
 	PlanetBin = "/usr/bin/planet"
 

lib/update/system/system.go

@@ -713,6 +713,18 @@ func updateSymlinks(planetPath string, logger log.Logger) (err error) {
 			"Failed to update helm symlink.")
 	}
 
+	// update helm3 symlink
+	helmPath = filepath.Join(planetPath, constants.PlanetRootfs, defaults.Helm3Script)
+	for _, path := range []string{defaults.Helm3Bin, defaults.Helm3BinAlternate} {
+		out, err = exec.Command("ln", "-sfT", helmPath, path).CombinedOutput()
+		if err == nil {
+			logger.Infof("Updated helm 3 symlink: %v -> %v.", path, helmPath)
+			break
+		}
+		logger.WithError(err).WithField("output", string(out)).Warn(
+			"Failed to update helm 3 symlink.")
+	}
+
 	// update kube config environment variable
 	kubeConfigPath := filepath.Join(planetPath, constants.PlanetRootfs, defaults.PlanetKubeConfigPath)
 	environment, err := utils.ReadEnv(defaults.EnvironmentPath)