add cache server command

README.md

@@ -7,10 +7,70 @@ Build k6 using one of the supported builders.
 
 ## Commands
 
+* [k6build cache](#k6build-cache)	 - k6 cache server
 * [k6build client](#k6build-client)	 - build k6 using a remote build server
 * [k6build local](#k6build-local)	 - build using a local builder
 * [k6build server](#k6build-server)	 - k6 build service
 
+---
+# k6build cache
+
+k6 cache server
+
+## Synopsis
+
+
+Starts a k6build cache server. 
+
+The cache server offers a REST API for storing and downloading objects.
+
+Objects can be retrieved by a download url returned when the object is stored.
+
+The --download-url specifies the base URL for downloading objects. This is necessary to allow
+downloading the objects from different machines.
+
+
+```
+k6build cache [flags]
+```
+
+## Examples
+
+```
+
+# start the cache server serving an external url
+k6build cache --download0url http://external.url
+
+# store object from same host
+curl -x POST http://localhost:9000/cache/objectID -d "object content" | jq .
+{
+	"Error": "",
+	"Object": {
+	  "ID": "objectID",
+	  "Checksum": "17d3eb873fe4b1aac4f9d2505aefbb5b53b9a7f34a6aadd561be104c0e9d678b",
+	  "URL": "http://external.url:9000/cache/objectID/download"
+	}
+      }
+
+# download object from another machine using the external url
+curl http://external.url:9000/cache/objectID/download
+
+```
+
+## Flags
+
+```
+  -c, --cache-dir string      cache directory (default "/tmp/cache/objectstore")
+  -d, --download-url string   base url used for downloading objects. If not specified http://localhost:<port> is used
+  -h, --help                  help for cache
+  -l, --log-level string      log level (default "INFO")
+  -p, --port int              port server will listen (default 9000)
+```
+
+## SEE ALSO
+
+* [k6build](#k6build)	 - Build k6 with various builders.
+
 ---
 # k6build client
 
@@ -161,7 +221,7 @@ k6 build service
 ## Synopsis
 
 
-starts a k6build server that server
+starts a k6build server
 
 
 ```
@@ -183,6 +243,7 @@ k6build server -e GOPROXY=http://localhost:80
 
 ```
   -f, --cache-dir string     cache dir (default "/tmp/buildservice")
+      --cache-url string     cache server url. If not specified, a local cache server is started
   -c, --catalog string       dependencies catalog (default "catalog.json")
   -g, --copy-go-env          copy go environment (default true)
   -e, --env stringToString   build environment variables (default [])

cmd/cache.go

@@ -0,0 +1,121 @@
+package cmd
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+
+	"github.com/grafana/k6build"
+	"github.com/spf13/cobra"
+)
+
+const (
+	cacheLong = `
+Starts a k6build cache server. 
+
+The cache server offers a REST API for storing and downloading objects.
+
+Objects can be retrieved by a download url returned when the object is stored.
+
+The --download-url specifies the base URL for downloading objects. This is necessary to allow
+downloading the objects from different machines.
+`
+
+	cacheExample = `
+# start the cache server serving an external url
+k6build cache --download0url http://external.url
+
+# store object from same host
+curl -x POST http://localhost:9000/cache/objectID -d "object content" | jq .
+{
+	"Error": "",
+	"Object": {
+	  "ID": "objectID",
+	  "Checksum": "17d3eb873fe4b1aac4f9d2505aefbb5b53b9a7f34a6aadd561be104c0e9d678b",
+	  "URL": "http://external.url:9000/cache/objectID/download"
+	}
+      }
+
+# download object from another machine using the external url
+curl http://external.url:9000/cache/objectID/download
+`
+)
+
+// NewCache creates new cobra command for cache command.
+func NewCache() *cobra.Command {
+	var (
+		cacheDir    string
+		cacheSrvURL string
+		port        int
+		logLevel    string
+	)
+
+	cmd := &cobra.Command{
+		Use:     "cache",
+		Short:   "k6 cache server",
+		Long:    cacheLong,
+		Example: cacheExample,
+		// prevent the usage help to printed to stderr when an error is reported by a subcommand
+		SilenceUsage: true,
+		// this is needed to prevent cobra to print errors reported by subcommands in the stderr
+		SilenceErrors: true,
+		RunE: func(_ *cobra.Command, _ []string) error {
+			// set log
+			ll, err := k6build.ParseLogLevel(logLevel)
+			if err != nil {
+				return fmt.Errorf("parsing log level %w", err)
+			}
+
+			log := slog.New(
+				slog.NewTextHandler(
+					os.Stderr,
+					&slog.HandlerOptions{
+						Level: ll,
+					},
+				),
+			)
+
+			cache, err := k6build.NewFileCache(cacheDir)
+			if err != nil {
+				return fmt.Errorf("creating cache %w", err)
+			}
+
+			// FIXME: this will not work across machines
+			if cacheSrvURL == "" {
+				cacheSrvURL = fmt.Sprintf("http://localhost:%d/cache", port)
+			}
+			config := k6build.CacheServerConfig{
+				BaseURL: cacheSrvURL,
+				Cache:   cache,
+				Log:     log,
+			}
+			cacheSrv := k6build.NewCacheServer(config)
+
+			srv := http.NewServeMux()
+			srv.Handle("/cache/", http.StripPrefix("/cache", cacheSrv))
+
+			listerAddr := fmt.Sprintf("localhost:%d", port)
+			log.Info("starting server", "address", listerAddr)
+			err = http.ListenAndServe(listerAddr, srv) //nolint:gosec
+			if err != nil {
+				log.Info("server ended", "error", err.Error())
+			}
+			log.Info("ending server")
+
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVarP(&cacheDir, "cache-dir", "c", "/tmp/cache/objectstore", "cache directory")
+	cmd.Flags().IntVarP(&port, "port", "p", 9000, "port server will listen")
+	cmd.Flags().StringVarP(&cacheSrvURL,
+		"download-url",
+		"d",
+		"",
+		"base url used for downloading objects. If not specified http://localhost:<port> is used",
+	)
+	cmd.Flags().StringVarP(&logLevel, "log-level", "l", "INFO", "log level")
+
+	return cmd
+}

cmd/cmd.go

@@ -17,6 +17,7 @@ func New() *cobra.Command {
 
 	root.AddCommand(NewLocal())
 	root.AddCommand(NewServer())
+	root.AddCommand(NewCache())
 	root.AddCommand(NewClient())
 
 	return root

cmd/server.go

@@ -14,7 +14,7 @@ import (
 
 const (
 	serverLong = `
-starts a k6build server that server
+starts a k6build server
 `
 
 	serverExample = `
@@ -25,16 +25,17 @@ k6build server -c /path/to/catalog.json
 k6build server -e GOPROXY=http://localhost:80`
 )
 
-// NewServer creates new cobra command for resolve command.
+// NewServer creates new cobra command for server command.
 func NewServer() *cobra.Command { //nolint:funlen
 	var (
-		buildEnv  map[string]string
-		cacheDir  string
-		catalog   string
-		copyGoEnv bool
-		port      int
-		verbose   bool
-		logLevel  string
+		buildEnv    map[string]string
+		cacheDir    string
+		cacheSrvURL string
+		catalog     string
+		copyGoEnv   bool
+		port        int
+		verbose     bool
+		logLevel    string
 	)
 
 	cmd := &cobra.Command{
@@ -89,14 +90,19 @@ func NewServer() *cobra.Command { //nolint:funlen
 				return fmt.Errorf("creating cache %w", err)
 			}
 
+			srv := http.NewServeMux()
+
 			// FIXME: this will not work across machines
-			cacheSrvURL := fmt.Sprintf("http://localhost:%d/cache", port)
-			config := k6build.CacheServerConfig{
-				BaseURL: cacheSrvURL,
-				Cache:   cache,
-				Log:     log,
+			if cacheSrvURL == "" {
+				cacheSrvURL = fmt.Sprintf("http://localhost:%d/cache", port)
+				config := k6build.CacheServerConfig{
+					BaseURL: cacheSrvURL,
+					Cache:   cache,
+					Log:     log,
+				}
+				cacheSrv := k6build.NewCacheServer(config)
+				srv.Handle("/cache/", http.StripPrefix("/cache", cacheSrv))
 			}
-			cacheSrv := k6build.NewCacheServer(config)
 
 			cacheClientConfig := k6build.CacheClientConfig{
 				Server: cacheSrvURL,
@@ -118,9 +124,7 @@ func NewServer() *cobra.Command { //nolint:funlen
 			}
 			buildAPI := k6build.NewAPIServer(apiConfig)
 
-			srv := http.NewServeMux()
 			srv.Handle("POST /build/", http.StripPrefix("/build", buildAPI))
-			srv.Handle("/cache/", http.StripPrefix("/cache", cacheSrv))
 
 			listerAddr := fmt.Sprintf("localhost:%d", port)
 			log.Info("starting server", "address", listerAddr)
@@ -135,6 +139,12 @@ func NewServer() *cobra.Command { //nolint:funlen
 	}
 
 	cmd.Flags().StringVarP(&catalog, "catalog", "c", "catalog.json", "dependencies catalog")
+	cmd.Flags().StringVar(
+		&cacheSrvURL,
+		"cache-url",
+		"",
+		"cache server url. If not specified, a local cache server is started",
+	)
 	cmd.Flags().StringVarP(&cacheDir, "cache-dir", "f", "/tmp/buildservice", "cache dir")
 	cmd.Flags().BoolVarP(&verbose, "verbose", "v", false, "print build process output")
 	cmd.Flags().BoolVarP(&copyGoEnv, "copy-go-env", "g", true, "copy go environment")