[installer]: output all images to allow easy mirroring of containers

The output gives the original image name and tag and generates the new
image name to be used

Author: Simon Emms

installer/cmd/render-mirror.go

@@ -0,0 +1,220 @@
+// Copyright (c) 2021 Gitpod GmbH. All rights reserved.
+// Licensed under the GNU Affero General Public License (AGPL).
+// See License-AGPL.txt in the project root for license information.
+
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+
+	"github.com/docker/distribution/reference"
+	"github.com/gitpod-io/gitpod/installer/pkg/common"
+	"github.com/spf13/cobra"
+	"sigs.k8s.io/yaml"
+)
+
+type mirrorRepo struct {
+	Original string `json:"original"`
+	Target   string `json:"target"`
+}
+
+var mirrorOpts struct {
+	ExcludeThirdParty bool
+	Output            string
+}
+
+var outputTypes = []string{"yaml", "json"}
+
+// mirrorCmd represents the mirror command
+var mirrorCmd = &cobra.Command{
+	Use:   "mirror",
+	Short: "Renders a list of images used so they can be mirrored to a third-party registry",
+	Long: `Renders a list of images used so they can be mirrored to a third-party registry
+
+A config file is required which can be generated with the init command.
+The "repository" field must be set to your container repository server
+address and this value will be used to generate the mirrored image names
+and tags.
+
+The output can then be used to iterate over each image. A script can
+be written to pull from the "original" path and then tag and push the
+image to the "target" repo`,
+	Example: `
+  # YAML
+  gitpod-installer render mirror --config config.yaml > mirror.yaml
+
+  # JSON
+  gitpod-installer render mirror --config config.yaml -o json > mirror.json
+
+  # Pull original and push to target
+  for row in $(gitpod-installer render mirror --config ./config.yaml -o json | jq -c '.[]'); do
+    original=$(echo $row | jq -r '.original')
+    target=$(echo $row | jq -r '.target')
+    docker pull $original
+    docker tag $original $target
+    docker push $target
+  done`,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		// Validate output type
+		var output string
+		for _, i := range outputTypes {
+			if mirrorOpts.Output == i {
+				output = i
+			}
+		}
+		if output == "" {
+			return fmt.Errorf("unknown output type: %s", mirrorOpts.Output)
+		}
+
+		_, cfgVersion, cfg, err := loadConfig(renderOpts.ConfigFN)
+		if err != nil {
+			return err
+		}
+
+		// Throw error if set to the default Gitpod repository
+		if cfg.Repository == common.GitpodContainerRegistry {
+			return fmt.Errorf("cannot mirror images to repository %s", common.GitpodContainerRegistry)
+		}
+
+		// Get the target repository from the config
+		targetRepo := strings.TrimRight(cfg.Repository, "/")
+
+		// Use the default Gitpod registry to pull from
+		cfg.Repository = common.GitpodContainerRegistry
+
+		k8s, err := renderKubernetesObjects(cfgVersion, cfg)
+		if err != nil {
+			return err
+		}
+
+		// Map of images used for deduping
+		allImages := make(map[string]bool)
+
+		rawImages := make([]string, 0)
+		for _, item := range k8s {
+			rawImages = append(rawImages, getPodImages(item)...)
+			rawImages = append(rawImages, getGenericImages(item)...)
+		}
+
+		images := make([]mirrorRepo, 0)
+		for _, img := range rawImages {
+			// Dedupe
+			if _, ok := allImages[img]; ok {
+				continue
+			}
+			allImages[img] = true
+
+			// Convert target
+			target := img
+			if strings.Contains(img, cfg.Repository) {
+				// This is the Gitpod registry
+				target = strings.Replace(target, cfg.Repository, targetRepo, 1)
+			} else if !mirrorOpts.ExcludeThirdParty {
+				// Amend third-party images - remove the first part
+				thirdPartyImg := strings.Join(strings.Split(img, "/")[1:], "/")
+				target = fmt.Sprintf("%s/%s", targetRepo, thirdPartyImg)
+			} else {
+				// Excluding third-party images - just skip this one
+				continue
+			}
+
+			images = append(images, mirrorRepo{
+				Original: img,
+				Target:   target,
+			})
+		}
+
+		// Sort it by the Original
+		sort.Slice(images, func(i, j int) bool {
+			scoreI := images[i].Original
+			scoreJ := images[j].Original
+
+			return scoreI < scoreJ
+		})
+
+		switch output {
+		case "yaml":
+			fc, err := yaml.Marshal(images)
+			if err != nil {
+				return err
+			}
+
+			fmt.Printf(string(fc))
+		case "json":
+			fc, err := json.MarshalIndent(images, "", "  ")
+			if err != nil {
+				return err
+			}
+
+			fmt.Println(string(fc))
+		}
+
+		return nil
+	},
+}
+
+func init() {
+	renderCmd.AddCommand(mirrorCmd)
+
+	mirrorCmd.Flags().BoolVar(&mirrorOpts.ExcludeThirdParty, "exclude-third-party", false, "exclude non-Gitpod images")
+	mirrorCmd.Flags().StringVarP(&mirrorOpts.Output, "output", "o", "yaml", fmt.Sprintf("output type - [%s]", strings.Join(outputTypes, ", ")))
+}
+
+// getGenericImages this is a bit brute force - anything starting "docker.io" or with Gitpod repo is found
+// this will be in ConfigMaps and could be anything, so will need cleaning up
+func getGenericImages(k8sObj string) []string {
+	var images []string
+
+	// Search for anything that matches docker.io or the Gitpod repo - docker.io needed for gitpod/workspace-full
+	re := regexp.MustCompile(fmt.Sprintf("%s(.*)|%s(.*)", "docker.io", common.GitpodContainerRegistry))
+	img := re.FindAllString(k8sObj, -1)
+
+	if len(img) > 0 {
+		for _, i := range img {
+			// Remove whitespace
+			i = strings.TrimSpace(i)
+			// Remove end commas
+			i = strings.TrimRight(i, ",")
+			// Remove wrapping quotes
+			i = strings.Trim(i, "\"")
+			// Validate the image - assumes images are already fully qualified names
+			_, err := reference.ParseNamed(i)
+			if err != nil {
+				// Invalid - ignore
+				continue
+			}
+
+			images = append(images, i)
+		}
+	}
+
+	return images
+}
+
+// getPodImages these are images that are found in the "image:" tag in a PodSpec
+// may be multiple tags in a file
+func getPodImages(k8sObj string) []string {
+	var images []string
+
+	re := regexp.MustCompile("image:(.*)")
+	img := re.FindAllString(k8sObj, -1)
+
+	if len(img) > 0 {
+		for _, i := range img {
+			// Remove "image":
+			i = re.ReplaceAllString(i, "$1")
+			// Remove whitespace
+			i = strings.TrimSpace(i)
+			// Remove wrapping quotes
+			i = strings.Trim(i, "\"")
+
+			images = append(images, i)
+		}
+	}
+
+	return images
+}