feat: 'describe' sub-command for faas cli

client/client.go

@@ -32,6 +32,7 @@ type Client struct {
 	runner            Runner      // Runs the function locally
 	remover           Remover     // Removes remote services
 	lister            Lister      // Lists remote services
+	describer         Describer
 }
 
 // ConfigFileName is an optional file checked for in the function root.
@@ -105,6 +106,22 @@ type Lister interface {
 	List() ([]string, error)
 }
 
+type Subscription struct {
+	Source string `json:"source" yaml:"source"`
+	Type string `json:"type" yaml:"type"`
+	Broker string `json:"broker" yaml:"broker"`
+}
+
+type FunctionDescription struct {
+	Name          string `json:"name" yaml:"name"`
+	Routes        []string `json:"routes" yaml:"routes"`
+	Subscriptions []Subscription `json:"subscriptions" yaml:"subscriptions"`
+}
+
+type Describer interface {
+	Describe(name string) (description FunctionDescription, err error)
+}
+
 // Option defines a function which when passed to the Client constructor optionally
 // mutates private members at time of instantiation.
 type Option func(*Client)
@@ -199,6 +216,12 @@ func WithLister(l Lister) Option {
 	}
 }
 
+func WithDescriber(describer Describer) Option {
+	return func(c *Client) {
+		c.describer = describer
+	}
+}
+
 // New client for a function service rooted at the given directory (default .) or
 // that explicitly set via the option.  Will fail if the directory already contains
 // config files or other non-hidden files.
@@ -370,6 +393,10 @@ func (c *Client) List() ([]string, error) {
 	return c.lister.List()
 }
 
+func (c *Client) Describe(name string) (FunctionDescription, error) {
+	return c.describer.Describe(name)
+}
+
 // Remove a function from remote, bringing the service funciton
 // to the same state as if it had been created --local only.
 // Name is the presently configured client's name, which was

cmd/describe.go

@@ -0,0 +1,76 @@
+package cmd
+
+import (
+	"encoding/json"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"gopkg.in/yaml.v2"
+
+	"github.com/boson-project/faas/client"
+	"github.com/boson-project/faas/knative"
+	"github.com/ory/viper"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	root.AddCommand(describeCmd)
+
+	describeCmd.Flags().StringP("output", "o", "yaml", "optionally specify output format (yaml,xml,json).")
+	viper.BindPFlag("output", describeCmd.Flags().Lookup("output"))
+}
+
+var describeCmd = &cobra.Command{
+	Use:        "describe",
+	Short:      "Describe Service Function",
+	Long:       `Describe Service Function`,
+	SuggestFor: []string{"desc"},
+	Args: 		cobra.ExactArgs(1),
+	RunE:       describe,
+}
+
+func describe(cmd *cobra.Command, args []string) (err error) {
+	var (
+		verbose      = viper.GetBool("verbose")
+		format 		 = viper.GetString("output")
+	)
+	name := args[0]
+
+	describer, err := knative.NewDescriber(client.FaasNamespace)
+	if err != nil {
+		return
+	}
+	describer.Verbose = verbose
+
+	client, err := client.New(".",
+		client.WithVerbose(verbose),
+		client.WithDescriber(describer),
+	)
+	if err != nil {
+		return
+	}
+
+	description, err := client.Describe(name)
+	if err != nil {
+		return
+	}
+
+
+	formatFunctions := map[string] func(interface{})([]byte, error) {
+		"json" : json.Marshal,
+		"yaml" : yaml.Marshal,
+		"xml"  : xml.Marshal,
+	}
+
+	formatFun, found := formatFunctions[format]
+	if !found {
+		return errors.New("unknown output format")
+	}
+	data, err := formatFun(description)
+	if err != nil {
+		return
+	}
+	fmt.Println(string(data))
+	
+	return
+}

cmd/list.go

@@ -9,14 +9,8 @@ import (
 	"github.com/spf13/cobra"
 )
 
-const (
-	nsFlag = "namespace"
-)
-
 func init() {
 	root.AddCommand(listCmd)
-	listCmd.Flags().StringP(nsFlag, "n", "", "optionally specify a namespace")
-	viper.BindPFlag(nsFlag, listCmd.Flags().Lookup(nsFlag))
 }
 
 var listCmd = &cobra.Command{
@@ -29,11 +23,10 @@ var listCmd = &cobra.Command{
 
 func list(cmd *cobra.Command, args []string) (err error) {
 	var (
-		namespace = viper.GetString(nsFlag)
 		verbose   = viper.GetBool("verbose")
 	)
 
-	lister, err := knative.NewLister(namespace)
+	lister, err := knative.NewLister(client.FaasNamespace)
 	if err != nil {
 		return
 	}

go.mod

@@ -9,12 +9,14 @@ require (
 	github.com/google/go-containerregistry v0.0.0-20200423114255-8f808463544c // indirect
 	github.com/openzipkin/zipkin-go v0.2.2 // indirect
 	github.com/ory/viper v1.7.4
+	github.com/robfig/cron v1.2.0 // indirect
 	github.com/spf13/cobra v1.0.0
 	golang.org/x/net v0.0.0-20200421231249-e086a090c8fd
 	gomodules.xyz/jsonpatch/v2 v2.1.0 // indirect
 	gopkg.in/yaml.v2 v2.2.8
 	k8s.io/apimachinery v0.17.4
 	k8s.io/client-go v0.17.4
+	knative.dev/eventing v0.14.1
 	knative.dev/pkg v0.0.0-20200414233146-0eed424fa4ee // indirect
 	knative.dev/serving v0.14.0
 )

go.sum

@@ -320,6 +320,8 @@ github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsT
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/remyoudompheng/bigfft v0.0.0-20170806203942-52369c62f446/go.mod h1:uYEyJGbgTkfkS4+E/PavXkNJcbFIpEtjt2B0KDQ5+9M=
+github.com/robfig/cron v1.2.0 h1:ZjScXvvxeQ63Dbyxy76Fj3AT3Ut0aKsyd2/tl3DTMuQ=
+github.com/robfig/cron v1.2.0/go.mod h1:JGuDeoQd7Z6yL4zQhZ3OPEVHB7fL6Ka6skscFHfmt2k=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rubiojr/go-vhd v0.0.0-20160810183302-0bfd3b39853c/go.mod h1:DM5xW0nvfNNm2uytzsvhI3OnX8uzaRAg8UX/CnDqbto=
@@ -581,8 +583,6 @@ gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gotest.tools v2.2.0+incompatible h1:VsBPFP1AI068pPrMxtb/S8Zkgf9xEmTLJjfM+P5UIEo=
 gotest.tools v2.2.0+incompatible/go.mod h1:DsYFclhRJ6vuDpmuTbkuFWG+y2sxOXAzmJt81HFBacw=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
@@ -612,6 +612,8 @@ k8s.io/kube-openapi v0.0.0-20191107075043-30be4d16710a/go.mod h1:1TqjTSzOxsLGIKf
 k8s.io/legacy-cloud-providers v0.17.4/go.mod h1:FikRNoD64ECjkxO36gkDgJeiQWwyZTuBkhu+yxOc1Js=
 k8s.io/utils v0.0.0-20191114184206-e782cd3c129f h1:GiPwtSzdP43eI1hpPCbROQCCIgCuiMMNF8YUVLF3vJo=
 k8s.io/utils v0.0.0-20191114184206-e782cd3c129f/go.mod h1:sZAwmy6armz5eXlNoLmJcl4F1QuKu7sr+mFQ0byX7Ew=
+knative.dev/eventing v0.14.1 h1:YmnEl3IBVRkBcVYWPMWZegRGifeI7ibcA9xuhHWvAaw=
+knative.dev/eventing v0.14.1/go.mod h1:UxweNv8yXhsdHJitcb9R6rmfNaUD2DFi9GWwNRyIs58=
 knative.dev/pkg v0.0.0-20200414233146-0eed424fa4ee h1:G1QedLB/RxF4QTyL1Pq9M1QK1uj8khQgTypofUXrG20=
 knative.dev/pkg v0.0.0-20200414233146-0eed424fa4ee/go.mod h1:pgODObA1dTyhNoFxPZTTjNWfx6F0aKsKzn+vaT9XO/Q=
 knative.dev/serving v0.14.0 h1:9iDyOqTciNuAh2D5KJP0soOq23FDR4HQHdIQNBQ/rAE=

knative/describer.go

@@ -0,0 +1,100 @@
+package knative
+
+import (
+	"fmt"
+	"github.com/boson-project/faas/client"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+	"knative.dev/eventing/pkg/apis/eventing/v1alpha1"
+	eventingv1client "knative.dev/eventing/pkg/client/clientset/versioned/typed/eventing/v1alpha1"
+	servingv1client "knative.dev/serving/pkg/client/clientset/versioned/typed/serving/v1alpha1"
+)
+
+type Describer struct {
+	Verbose        bool
+	namespace      string
+	servingClient  *servingv1client.ServingV1alpha1Client
+	eventingClient *eventingv1client.EventingV1alpha1Client
+	config 		   *rest.Config
+}
+
+func NewDescriber(namespace string) (describer *Describer, err error) {
+	describer = &Describer{namespace: namespace}
+	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
+	clientConfig := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, &clientcmd.ConfigOverrides{})
+	if describer.namespace == "" {
+		namespace, _, err := clientConfig.Namespace()
+		if err == nil {
+			describer.namespace = namespace
+		}
+	}
+	config, err := clientConfig.ClientConfig()
+	if err != nil {
+		return
+	}
+	describer.servingClient, err = servingv1client.NewForConfig(config)
+	if err != nil {
+		return
+	}
+	describer.eventingClient, err = eventingv1client.NewForConfig(config)
+	if err != nil {
+		return
+	}
+	describer.config = config
+	return
+}
+
+func (describer *Describer) Describe(name string) (description client.FunctionDescription, err error) {
+
+	namespace := describer.namespace
+	servingClient := describer.servingClient
+	eventingClient := describer.eventingClient
+
+	service, err := servingClient.Services(namespace).Get(name, metav1.GetOptions{})
+	if err != nil {
+		return
+	}
+
+	serviceLabel := fmt.Sprintf("serving.knative.dev/service=%s", name)
+	routes, err := servingClient.Routes(namespace).List(metav1.ListOptions{LabelSelector: serviceLabel})
+	if err != nil {
+		return
+	}
+
+	routeURLs := make([]string, 0, len(routes.Items))
+	for _, route := range routes.Items {
+		routeURLs = append(routeURLs, route.Status.URL.String())
+	}
+
+	triggers, err := eventingClient.Triggers(namespace).List(metav1.ListOptions{})
+	if err != nil {
+		return
+	}
+
+	triggerMatches := func(t *v1alpha1.Trigger) bool {
+		return (t.Spec.Subscriber.Ref != nil && t.Spec.Subscriber.Ref.Name == service.Name) ||
+			(t.Spec.Subscriber.URI != nil && service.Status.Address != nil && service.Status.Address.URL != nil &&
+				t.Spec.Subscriber.URI.Path == service.Status.Address.URL.Path)
+
+	}
+
+	subscriptions := make([]client.Subscription, 0, len(triggers.Items))
+	for _, trigger := range triggers.Items {
+		if triggerMatches(&trigger) {
+			filterAttrs := *trigger.Spec.Filter.Attributes
+			subscription := client.Subscription{
+				Source: filterAttrs["source"],
+				Type:   filterAttrs["type"],
+				Broker: trigger.Spec.Broker,
+			}
+			subscriptions = append(subscriptions, subscription)
+		}
+	}
+
+	description.Name = service.Name
+	description.Routes = routeURLs
+	description.Subscriptions = subscriptions
+
+	return
+}