Implement auto complete for --image(-i) flag (#2449)

Author: phanimarupaka

internal/cmdcomplete/complete.go

@@ -18,6 +18,7 @@ package cmdcomplete
 import (
 	"strings"
 
+	"github.com/GoogleContainerTools/kpt/internal/util/cmdutil"
 	kptfilev1 "github.com/GoogleContainerTools/kpt/pkg/api/kptfile/v1"
 	"github.com/posener/complete/v2"
 	"github.com/posener/complete/v2/predict"
@@ -67,6 +68,12 @@ func Complete(cmd *cobra.Command, skipHelp bool, visitFlags VisitFlags) *complet
 			cc.Flags[flag.Name] = predict.Options(predict.OptValues("%k_%n.yaml"))
 			return
 		}
+		if flag.Name == "image" || flag.Shorthand == "i" {
+			fnImages := cmdutil.FetchFunctionImages()
+			cc.Flags[flag.Name] = predict.Options(predict.OptValues(fnImages...))
+			cc.Flags[flag.Shorthand] = predict.Options(predict.OptValues(fnImages...))
+			return
+		}
 		cc.Flags[flag.Name] = predict.Nothing
 	})
 

internal/util/cmdutil/cmdutil.go

@@ -17,6 +17,7 @@ package cmdutil
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
 	"io"
 	"os"
@@ -26,6 +27,7 @@ import (
 	"time"
 
 	"github.com/GoogleContainerTools/kpt/internal/fnruntime"
+	"github.com/GoogleContainerTools/kpt/internal/util/httputil"
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/kyaml/kio"
 	"sigs.k8s.io/kustomize/kyaml/kio/kioutil"
@@ -37,6 +39,7 @@ const (
 	Stdout                             = "stdout"
 	Unwrap                             = "unwrap"
 	dockerVersionTimeout time.Duration = 5 * time.Second
+	FunctionsCatalogURL                = "https://catalog.kpt.dev/catalog.json"
 )
 
 // FixDocs replaces instances of old with new in the docs for c
@@ -178,3 +181,33 @@ func CheckDirectoryNotPresent(outDir string) error {
 	}
 	return nil
 }
+
+// FetchFunctionImages returns the list of latest function images from catalog.kpt.dev
+func FetchFunctionImages() []string {
+	content, err := httputil.FetchContent(FunctionsCatalogURL)
+	if err != nil {
+		return nil
+	}
+
+	return listImages(content)
+}
+
+// listImages returns the list of latest images from the input catalog content
+func listImages(content string) []string {
+	var result []string
+	jsonData := map[string]map[string]interface{}{}
+	err := json.Unmarshal([]byte(content), &jsonData)
+	if err != nil {
+		return result
+	}
+	for fnName, fnInfo := range jsonData {
+		var latestVersion string
+		for version := range fnInfo {
+			if latestVersion < version {
+				latestVersion = version
+			}
+		}
+		result = append(result, fmt.Sprintf("%s:%s", fnName, latestVersion))
+	}
+	return result
+}

internal/util/cmdutil/cmdutil_test.go

@@ -19,6 +19,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"sort"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -305,3 +306,35 @@ metadata:
 		})
 	}
 }
+
+func TestListImages(t *testing.T) {
+	result := listImages(`{
+  "apply-setters": {
+    "v0.1": {
+      "apply-setters-simple": {
+        "LocalExamplePath": "/apply-setters/v0.1/apply-setters-simple",
+        "RemoteExamplePath": "https://github.com/GoogleContainerTools/kpt-functions-catalog/tree/apply-setters/v0.1/examples/apply-setters-simple",
+        "RemoteSourcePath": "https://github.com/GoogleContainerTools/kpt-functions-catalog/tree/apply-setters/v0.1/functions/go/apply-setters"
+      }
+    }
+  },
+  "gatekeeper": {
+    "v0.1": {
+      "gatekeeper-warning-only": {
+        "LocalExamplePath": "/gatekeeper/v0.1/gatekeeper-warning-only",
+        "RemoteExamplePath": "https://github.com/GoogleContainerTools/kpt-functions-catalog/tree/gatekeeper/v0.1/examples/gatekeeper-warning-only",
+        "RemoteSourcePath": "https://github.com/GoogleContainerTools/kpt-functions-catalog/tree/gatekeeper/v0.1/functions/go/gatekeeper"
+      }
+    },
+    "v0.2": {
+      "gatekeeper-warning-only": {
+        "LocalExamplePath": "/gatekeeper/v0.2/gatekeeper-warning-only",
+        "RemoteExamplePath": "https://github.com/GoogleContainerTools/kpt-functions-catalog/tree/gatekeeper/v0.2/examples/gatekeeper-warning-only",
+        "RemoteSourcePath": "https://github.com/GoogleContainerTools/kpt-functions-catalog/tree/gatekeeper/v0.2/functions/go/gatekeeper"
+      }
+    }
+  }
+}`)
+	sort.Strings(result)
+	assert.Equal(t, []string{"apply-setters:v0.1", "gatekeeper:v0.2"}, result)
+}

internal/util/httputil/httputil.go

@@ -0,0 +1,24 @@
+package httputil
+
+import (
+	"io/ioutil"
+	"net/http"
+)
+
+// FetchContent fetches the content from the input url
+func FetchContent(url string) (string, error) {
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return "", err
+	}
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer res.Body.Close()
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return "", err
+	}
+	return string(body), nil
+}