feat: adds a `func environment` command (#1761)

* feat: adds a `func environment` command

Adds `func environment` to print the current function execution
environment as JSON.

See: https://github.com/knative/func/discussions/1676

Signed-off-by: Lance Ball <lball@redhat.com>

* fixup

Signed-off-by: Lance Ball <lball@redhat.com>

* fixup: add environment variables

Signed-off-by: Lance Ball <lball@redhat.com>

* fixup: add cluster host

Signed-off-by: Lance Ball <lball@redhat.com>

* fixup: review feedback

Signed-off-by: Lance Ball <lball@redhat.com>

---------

Signed-off-by: Lance Ball <lball@redhat.com>

cmd/environment.go

@@ -0,0 +1,163 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/ory/viper"
+	"github.com/spf13/cobra"
+
+	"knative.dev/func/pkg/config"
+	"knative.dev/func/pkg/functions"
+	"knative.dev/func/pkg/k8s"
+)
+
+func NewEnvironmentCmd(newClient ClientFactory, version *Version) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "environment",
+		Short: "Display function execution environment information",
+		Long: `
+NAME
+	{{rootCmdUse}} environment
+
+SYNOPSIS
+	{{rootCmdUse}} environment - display function execution environment information
+
+DESCRIPTION
+	Display information about the function execution environment, including
+	the version of func, the version of the function spec, the default builder,
+	available runtimes, and available templates.
+`,
+		SuggestFor: []string{"env", "environemtn", "enviroment", "enviornment", "enviroment"},
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runEnvironment(cmd, newClient, version)
+		},
+	}
+	cfg, err := config.NewDefault()
+	if err != nil {
+		fmt.Fprintf(cmd.OutOrStdout(), "error loading config at '%v'. %v\n", config.File(), err)
+	}
+
+	addVerboseFlag(cmd, cfg.Verbose)
+
+	return cmd
+}
+
+type Environment struct {
+	Version     string
+	GitRevision string
+	BuildDate   string
+	SpecVersion string
+	SocatImage  string
+	TarImage    string
+	Languages   []string
+	Templates   map[string][]string
+	Environment []string
+	Cluster     string
+	Defaults    config.Global
+}
+
+func runEnvironment(cmd *cobra.Command, newClient ClientFactory, v *Version) (err error) {
+	cfg, err := newEnvironmentConfig()
+	if err != nil {
+		return
+	}
+
+	// Create a client to get runtimes and templates
+	client := functions.New(functions.WithVerbose(cfg.Verbose))
+
+	r, err := getRuntimes(client)
+	if err != nil {
+		return
+	}
+	t, err := getTemplates(client, r)
+	if err != nil {
+		return
+	}
+
+	// Get all environment variables that start with FUNC_
+	var envs []string
+	for _, e := range os.Environ() {
+		if strings.HasPrefix(e, "FUNC_") {
+			envs = append(envs, e)
+		}
+	}
+
+	// If no environment variables are set, make sure we return an empty array
+	// otherwise the output is "null" instead of "[]"
+	if len(envs) == 0 {
+		envs = make([]string, 0)
+	}
+
+	// Get global defaults
+	defaults, err := config.NewDefault()
+	if err != nil {
+		return
+	}
+
+	// Gets the cluster host
+	var host string
+	cc, err := k8s.GetClientConfig().ClientConfig()
+	if err != nil {
+		fmt.Printf("error getting client config %v\n", err)
+	} else {
+		host = cc.Host
+	}
+
+	environment := Environment{
+		Version:     v.String(),
+		GitRevision: v.Hash,
+		BuildDate:   v.Date,
+		SpecVersion: functions.LastSpecVersion(),
+		SocatImage:  k8s.SocatImage,
+		TarImage:    k8s.TarImage,
+		Languages:   r,
+		Templates:   t,
+		Environment: envs,
+		Cluster:     host,
+		Defaults:    defaults,
+	}
+
+	if s, err := json.MarshalIndent(environment, "", "  "); err != nil {
+		return err
+	} else {
+		fmt.Fprintln(cmd.OutOrStdout(), string(s))
+	}
+
+	return nil
+}
+
+func getRuntimes(client *functions.Client) ([]string, error) {
+	runtimes, err := client.Runtimes()
+	if err != nil {
+		return nil, err
+	}
+	return runtimes, nil
+}
+
+func getTemplates(client *functions.Client, runtimes []string) (map[string][]string, error) {
+	templateMap := make(map[string][]string)
+	for _, runtime := range runtimes {
+		templates, err := client.Templates().List(runtime)
+		if err != nil {
+			return nil, err
+		}
+		templateMap[runtime] = templates
+	}
+	return templateMap, nil
+}
+
+type environmentConfig struct {
+	Verbose bool
+	// TODO: add format (e.g. JSON/YAML)
+}
+
+func newEnvironmentConfig() (cfg environmentConfig, err error) {
+	cfg = environmentConfig{
+		Verbose: viper.GetBool("verbose"),
+	}
+
+	return
+}

cmd/root.go

@@ -90,6 +90,7 @@ Learn more about Knative at: https://knative.dev`, cfg.Name),
 				NewLanguagesCmd(newClient),
 				NewTemplatesCmd(newClient),
 				NewRepositoryCmd(newClient),
+				NewEnvironmentCmd(newClient, &cfg.Version),
 			},
 		},
 		{

docs/reference/func.md

@@ -30,6 +30,7 @@ Learn more about Knative at: https://knative.dev
 * [func delete](func_delete.md)	 - Undeploy a function
 * [func deploy](func_deploy.md)	 - Deploy a function
 * [func describe](func_describe.md)	 - Describe a function
+* [func environment](func_environment.md)	 - Display function execution environment information
 * [func invoke](func_invoke.md)	 - Invoke a local or remote function
 * [func languages](func_languages.md)	 - List available function language runtimes
 * [func list](func_list.md)	 - List deployed functions

docs/reference/func_environment.md

@@ -0,0 +1,34 @@
+## func environment
+
+Display function execution environment information
+
+### Synopsis
+
+
+NAME
+	func environment
+
+SYNOPSIS
+	func environment - display function execution environment information
+
+DESCRIPTION
+	Display information about the function execution environment, including
+	the version of func, the version of the function spec, the default builder,
+	available runtimes, and available templates.
+
+
+```
+func environment
+```
+
+### Options
+
+```
+  -h, --help      help for environment
+  -v, --verbose   Print verbose logs ($FUNC_VERBOSE)
+```
+
+### SEE ALSO
+
+* [func](func.md)	 - func manages Knative Functions
+