hack/rhcos: add cmd to populate marketplace json

Adds a standalone go program that generates
data/data/coreos/marketplace-rhcos.json

This file is combined with rhcos.json to create the coreos stream,
but the files are updated at different cadences by different teams.

Author: patrickdillon

hack/rhcos/populate-marketplace-imagestream.go

@@ -0,0 +1,116 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+
+	"github.com/coreos/stream-metadata-go/stream"
+	"github.com/coreos/stream-metadata-go/stream/rhcos"
+
+	"github.com/openshift/installer/pkg/rhcos/marketplace/azure"
+)
+
+const (
+	streamRHCOSJSON            = "data/data/coreos/rhcos.json"
+	streamMarketplaceRHCOSJSON = "data/data/coreos/marketplace-rhcos.json"
+
+	x86   = "x86_64"
+	arm64 = "aarch64"
+)
+
+// arch -> marketplace
+type marketplaceStream map[string]*rhcos.Marketplace
+
+func main() {
+	ctx := context.Background()
+	stream := marketplaceStream{}
+
+	if err := stream.populate(ctx); err != nil {
+		log.Fatalln("Failed to populate marketplace stream:", err)
+	}
+
+	if err := stream.write(); err != nil {
+		log.Fatalln("Failed to write marketplace stream:", err)
+	}
+	log.Printf("Successfully wrote marketplace stream to %s", streamMarketplaceRHCOSJSON)
+}
+
+// populate gathers the marketplace images for each cloud
+// and adds them to the marketplace stream data structure.
+func (s marketplaceStream) populate(ctx context.Context) error {
+	clouds := []func(ctx context.Context, arch string) error{
+		s.azure,
+	}
+
+	for _, supportedArch := range []string{arm64, x86} {
+		s[supportedArch] = &rhcos.Marketplace{}
+		for _, populateCloud := range clouds {
+			if err := populateCloud(ctx, supportedArch); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// write serializes the marketplace stream to disk.
+func (s marketplaceStream) write() error {
+	contents, err := json.MarshalIndent(s, "", "    ")
+	if err != nil {
+		return fmt.Errorf("error marshaling stream: %w", err)
+	}
+
+	// TODO(padillon): dumb question time, git is still complaining \ No newline at end of file
+	// what am I doing wrong?
+	contents = append(contents, []byte("\n")...)
+
+	if err := os.WriteFile(streamMarketplaceRHCOSJSON, contents, 0644); err != nil {
+		return fmt.Errorf("error writing stream: %w", err)
+	}
+	return nil
+}
+
+func (s marketplaceStream) azure(ctx context.Context, arch string) error {
+	var err error
+
+	s[arch].Azure = &rhcos.AzureMarketplace{}
+
+	rel, err := getReleaseFromStream()
+	if err != nil {
+		return fmt.Errorf("failed to get release from rhcos stream: %w", err)
+	}
+
+	azClient, err := azure.NewStreamClient()
+	if err != nil {
+		return fmt.Errorf("failed to initialize azure client: %w", err)
+	}
+
+	if s[arch].Azure, err = azClient.Populate(ctx, arch, rel); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// getXYFromStream obtains the X.Y version from rhcos.json.
+func getReleaseFromStream() (string, error) {
+	if rel, ok := os.LookupEnv("STREAM_RELEASE_OVERRIDE"); ok {
+		log.Printf("Found STREAM_RELEASE_OVERRIDE %s", rel)
+		return rel, nil
+	}
+	fileContents, err := os.ReadFile(streamRHCOSJSON)
+	if err != nil {
+		return "", err
+	}
+
+	st := &stream.Stream{}
+	if err := json.Unmarshal(fileContents, st); err != nil {
+		return "", fmt.Errorf("failed to unmarshal RHCOS stream: %w", err)
+	}
+
+	return strings.Split(st.Stream, "-")[1], nil
+}