ce7cb702218693d08ea6d83464d2457c9250027c

services/mirrored-image/controller/main.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"k8s.io/client-go/dynamic"
+	"k8s.io/client-go/rest"
+)
+
+func main() {
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+	if err := run(ctx, os.Args[1:]); err != nil && !errors.Is(err, context.Canceled) {
+		slog.Error("image mirror", "error", err)
+		os.Exit(1)
+	}
+}
+
+func run(ctx context.Context, arguments []string) error {
+	if len(arguments) != 1 {
+		return errors.New("expected one command: run")
+	}
+	if arguments[0] != "run" {
+		return fmt.Errorf("unknown command %q", arguments[0])
+	}
+	clientConfig, err := rest.InClusterConfig()
+	if err != nil {
+		return fmt.Errorf("load Kubernetes configuration: %w", err)
+	}
+	client, err := dynamic.NewForConfig(clientConfig)
+	if err != nil {
+		return fmt.Errorf("create Kubernetes client: %w", err)
+	}
+	config, err := loadConfig()
+	if err != nil {
+		return err
+	}
+	registry, err := loadRegistry()
+	if err != nil {
+		return err
+	}
+	return (&controller{client: client, registry: registry, config: config}).run(ctx)
+}
+
+func loadConfig() (controllerConfig, error) {
+	namespace := os.Getenv("POD_NAMESPACE")
+	if namespace == "" {
+		return controllerConfig{}, errors.New("POD_NAMESPACE is required")
+	}
+	pollInterval, err := durationEnv("POLL_INTERVAL", 20*time.Second)
+	if err != nil {
+		return controllerConfig{}, err
+	}
+	return controllerConfig{
+		namespace:         namespace,
+		pollInterval:      pollInterval,
+		prepareTemplate:   valueOrDefault("PREPARE_TEMPLATE", "image-prepare"),
+		promotionTemplate: valueOrDefault("PROMOTION_TEMPLATE", "image-promote"),
+		cleanupTemplate:   valueOrDefault("CLEANUP_TEMPLATE", "image-cleanup"),
+	}, nil
+}
+
+func durationEnv(name string, fallback time.Duration) (time.Duration, error) {
+	value := os.Getenv(name)
+	if value == "" {
+		return fallback, nil
+	}
+	duration, err := time.ParseDuration(value)
+	if err != nil || duration <= 0 {
+		return 0, fmt.Errorf("%s must be a positive duration", name)
+	}
+	return duration, nil
+}
+
+func valueOrDefault(name, fallback string) string {
+	if value := os.Getenv(name); value != "" {
+		return value
+	}
+	return fallback
+}