feat(comp): Add descriptions for helm env vars

When completing the helm env command, extra information will be shown
for shells that support completions (fish, zsh).  For example:

$ helm env HELM_RE<TAB>
HELM_REGISTRY_CONFIG    -- /me/Library/Preferences/helm/registry.json (Path to the registry configuration file)
HELM_REPOSITORY_CACHE   -- /me/Library/Caches/helm/repository (Path to the file containing cached repository indexes)
HELM_REPOSITORY_CONFIG  -- /me/Library/Preferences/helm/repositories.yaml (Path to the file containing repository names and URLs)

Signed-off-by: Marc Khouzam <marc.khouzam@montreal.ca>

cmd/helm/env.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io"
 	"sort"
+	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -38,8 +39,17 @@ func newEnvCmd(out io.Writer) *cobra.Command {
 		Args:  require.MaximumNArgs(1),
 		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
 			if len(args) == 0 {
-				keys := getSortedEnvVarKeys()
-				return keys, cobra.ShellCompDirectiveNoFileComp
+				var vars []string
+				for _, v := range settings.EnvVarsWithDesc() {
+					if strings.HasPrefix(v.Name, toComplete) {
+						val := strings.TrimSpace(v.Value)
+						if val == "" {
+							val = `""`
+						}
+						vars = append(vars, fmt.Sprintf("%s\t%s (%s)", v.Name, val, v.Desc))
+					}
+				}
+				return vars, cobra.ShellCompDirectiveNoFileComp
 			}
 
 			return nil, cobra.ShellCompDirectiveNoFileComp

cmd/helm/env_test.go

@@ -22,9 +22,15 @@ import (
 
 func TestEnv(t *testing.T) {
 	tests := []cmdTestCase{{
-		name:   "completion for env",
-		cmd:    "__complete env ''",
+		name: "completion for env",
+		// We disable descriptions by using __completeNoDesc because they would contain
+		// OS-specific paths which will change depending on where the tests are run
+		cmd:    "__completeNoDesc env ''",
 		golden: "output/env-comp.txt",
+	}, {
+		name: "completion for env",
+		cmd: "__complete env HELM_K	",
+		golden: "output/env-desc-comp.txt",
 	}}
 	runTestCmd(t, tests)
 }

cmd/helm/testdata/output/env-comp.txt

@@ -3,17 +3,17 @@ HELM_CACHE_HOME
 HELM_CONFIG_HOME
 HELM_DATA_HOME
 HELM_DEBUG
-HELM_KUBEAPISERVER
-HELM_KUBEASGROUPS
-HELM_KUBEASUSER
-HELM_KUBECAFILE
-HELM_KUBECONTEXT
-HELM_KUBETOKEN
-HELM_MAX_HISTORY
-HELM_NAMESPACE
 HELM_PLUGINS
 HELM_REGISTRY_CONFIG
 HELM_REPOSITORY_CACHE
 HELM_REPOSITORY_CONFIG
+HELM_NAMESPACE
+HELM_MAX_HISTORY
+HELM_KUBECONTEXT
+HELM_KUBETOKEN
+HELM_KUBEASUSER
+HELM_KUBEASGROUPS
+HELM_KUBEAPISERVER
+HELM_KUBECAFILE
 :4
 Completion ended with directive: ShellCompDirectiveNoFileComp

cmd/helm/testdata/output/env-desc-comp.txt

@@ -0,0 +1,8 @@
+HELM_KUBECONTEXT	"" (Kubernetes context to which this helm command applies)
+HELM_KUBETOKEN	"" (Path to the token file helm should use to contact the Kubernetes API server)
+HELM_KUBEASUSER	"" (Username to impersonate for the operation)
+HELM_KUBEASGROUPS	"" (Comma-separated list of groups to impersonate for the operation)
+HELM_KUBEAPISERVER	"" (<IP>:<port> helm should use to reach the Kubernetes API server)
+HELM_KUBECAFILE	"" (Path to the certificate authority file helm should use to contact the Kubernetes API server)
+:4
+Completion ended with directive: ShellCompDirectiveNoFileComp

pkg/cli/environment.go

@@ -144,28 +144,46 @@ func envCSV(name string) (ls []string) {
 	return
 }
 
-func (s *EnvSettings) EnvVars() map[string]string {
-	envvars := map[string]string{
-		"HELM_BIN":               os.Args[0],
-		"HELM_CACHE_HOME":        helmpath.CachePath(""),
-		"HELM_CONFIG_HOME":       helmpath.ConfigPath(""),
-		"HELM_DATA_HOME":         helmpath.DataPath(""),
-		"HELM_DEBUG":             fmt.Sprint(s.Debug),
-		"HELM_PLUGINS":           s.PluginsDirectory,
-		"HELM_REGISTRY_CONFIG":   s.RegistryConfig,
-		"HELM_REPOSITORY_CACHE":  s.RepositoryCache,
-		"HELM_REPOSITORY_CONFIG": s.RepositoryConfig,
-		"HELM_NAMESPACE":         s.Namespace(),
-		"HELM_MAX_HISTORY":       strconv.Itoa(s.MaxHistory),
+// EnvironmentVariable represents information about helm env vars
+type EnvironmentVariable struct {
+	Name  string
+	Value string
+	Desc  string
+}
+
+// EnvVarsWithDesc return an array of helm environment variables
+func (s *EnvSettings) EnvVarsWithDesc() []EnvironmentVariable {
+	return []EnvironmentVariable{
+		{Name: "HELM_BIN", Value: os.Args[0], Desc: "Path of the helm binary"},
+		{Name: "HELM_CACHE_HOME", Value: helmpath.CachePath(""), Desc: "Path of helm's cache files"},
+		{Name: "HELM_CONFIG_HOME", Value: helmpath.ConfigPath(""), Desc: "Path of helm's configuration files"},
+		{Name: "HELM_DATA_HOME", Value: helmpath.DataPath(""), Desc: "Path of helm's data files"},
+		{Name: "HELM_DEBUG", Value: fmt.Sprint(s.Debug), Desc: "Indicates if debug statements should be printed (true/false)"},
+		{Name: "HELM_PLUGINS", Value: s.PluginsDirectory, Desc: "Path of helm's plugin files"},
+		{Name: "HELM_REGISTRY_CONFIG", Value: s.RegistryConfig, Desc: "Path to the registry configuration file"},
+		{Name: "HELM_REPOSITORY_CACHE", Value: s.RepositoryCache, Desc: "Path to the file containing cached repository indexes"},
+		{Name: "HELM_REPOSITORY_CONFIG", Value: s.RepositoryConfig, Desc: "Path to the file containing repository names and URLs"},
+		{Name: "HELM_NAMESPACE", Value: s.Namespace(), Desc: "Kubernetes namespace to which this helm command applies"},
+		{Name: "HELM_MAX_HISTORY", Value: strconv.Itoa(s.MaxHistory), Desc: "Maximum number of revisions to configure for release history"},
 
 		// broken, these are populated from helm flags and not kubeconfig.
-		"HELM_KUBECONTEXT":   s.KubeContext,
-		"HELM_KUBETOKEN":     s.KubeToken,
-		"HELM_KUBEASUSER":    s.KubeAsUser,
-		"HELM_KUBEASGROUPS":  strings.Join(s.KubeAsGroups, ","),
-		"HELM_KUBEAPISERVER": s.KubeAPIServer,
-		"HELM_KUBECAFILE":    s.KubeCaFile,
+		{Name: "HELM_KUBECONTEXT", Value: s.KubeContext, Desc: "Kubernetes context to which this helm command applies"},
+		{Name: "HELM_KUBETOKEN", Value: s.KubeToken, Desc: "Path to the token file helm should use to contact the Kubernetes API server"},
+		{Name: "HELM_KUBEASUSER", Value: s.KubeAsUser, Desc: "Username to impersonate for the operation"},
+		{Name: "HELM_KUBEASGROUPS", Value: strings.Join(s.KubeAsGroups, ","), Desc: "Comma-separated list of groups to impersonate for the operation"},
+		{Name: "HELM_KUBEAPISERVER", Value: s.KubeAPIServer, Desc: "<IP>:<port> helm should use to reach the Kubernetes API server"},
+		{Name: "HELM_KUBECAFILE", Value: s.KubeCaFile, Desc: "Path to the certificate authority file helm should use to contact the Kubernetes API server"},
+	}
+}
+
+// EnvVars returns a map of env var with their current values
+func (s *EnvSettings) EnvVars() map[string]string {
+	rawvars := s.EnvVarsWithDesc()
+	envvars := make(map[string]string, len(rawvars))
+	for _, v := range rawvars {
+		envvars[v.Name] = v.Value
 	}
+
 	if s.KubeConfig != "" {
 		envvars["KUBECONFIG"] = s.KubeConfig
 	}