Merge pull request #20 from carolynvs/fix-porter-runtime-check

Only download porter runtime when porter changes

porter/porter.go

@@ -33,9 +33,14 @@ func EnsurePorterAt(version string) {
 	runtimesDir := filepath.Join(home, "runtimes")
 	os.MkdirAll(runtimesDir, 0770)
 
+	var forceDownloadRuntime bool
+
 	clientPath := filepath.Join(home, "porter"+xplat.FileExt())
 	if clientFound, _ := pkg.IsCommandAvailable(clientPath, "--version", version); !clientFound {
-		log.Println("Porter client not found at", clientPath)
+		// When we download a new client, always download a new runtime
+		forceDownloadRuntime = true
+
+		log.Printf("Porter %s not found at %s\n", version, clientPath)
 		log.Println("Installing porter into", home)
 		opts := downloads.DownloadOptions{
 			UrlTemplate: "https://cdn.porter.sh/{{.VERSION}}/porter-{{.GOOS}}-{{.GOARCH}}{{.EXT}}",
@@ -50,9 +55,11 @@ func EnsurePorterAt(version string) {
 		mgx.Must(downloads.Download(home, opts))
 	}
 
+	// Only check if the runtime file _exists_ but don't try to check the version
+	// The binary isn't runnable in all cases because it will always be a linux binary, and the client could be windows or mac
+	// So we can't really check the version here...
 	runtimePath := filepath.Join(home, "runtimes", "porter-runtime")
-	if runtimeFound, _ := pkg.IsCommandAvailable(runtimePath, "--version", version); !runtimeFound {
-		log.Println("Porter runtime not found at", runtimePath)
+	if _, err := os.Stat(runtimePath); forceDownloadRuntime || os.IsNotExist(err) {
 		opts := downloads.DownloadOptions{
 			UrlTemplate: "https://cdn.porter.sh/{{.VERSION}}/porter-linux-amd64",
 			Name:        "porter-runtime",

porter/porter_test.go

@@ -41,9 +41,7 @@ func TestEnsurePorterAt(t *testing.T) {
 
 	for _, tc := range testcases {
 		t.Run(tc.name, func(t *testing.T) {
-			tmp, err := ioutil.TempDir("", "magefiles")
-			require.NoError(t, err)
-			defer os.RemoveAll(tmp)
+			tmp := t.TempDir()
 
 			UsePorterHome(tmp)
 			EnsurePorterAt(tc.wantVersion)
@@ -55,4 +53,37 @@ func TestEnsurePorterAt(t *testing.T) {
 			assert.True(t, ok, "could not resolve the desired porter version")
 		})
 	}
+
+	// when the runtime binary already exists, leave it
+	t.Run("runtime binary only downloaded when client is stale", func(t *testing.T) {
+		tmp := t.TempDir()
+
+		UsePorterHome(tmp)
+		EnsurePorter()
+
+		porterPath := filepath.Join(tmp, "porter"+xplat.FileExt())
+		runtimePath := filepath.Join(tmp, "runtimes", "porter-runtime")
+		origPorterStat, err := os.Stat(porterPath)
+		require.NoError(t, err, "failed to stat the porter binary")
+		origRuntimeStat, err := os.Stat(runtimePath)
+		require.NoError(t, err, "failed to stat the porter-runtime binary")
+
+		// Nothing should be downloaded
+		EnsurePorterAt(DefaultPorterVersion)
+		newPorterStat, err := os.Stat(porterPath)
+		require.NoError(t, err, "failed to stat the porter binary")
+		require.Equal(t, origPorterStat.ModTime(), newPorterStat.ModTime(), "expected the porter binary to not be re-downloaded")
+		newRuntimeStat, err := os.Stat(runtimePath)
+		require.NoError(t, err, "failed to stat the porter-runtime binary")
+		require.Equal(t, origRuntimeStat.ModTime(), newRuntimeStat.ModTime(), "expected the porter-runtime binary to not be re-downloaded")
+
+		// Both should be re-downloaded
+		EnsurePorterAt("v1.0.0-rc.1")
+		newPorterStat, err = os.Stat(porterPath)
+		require.NoError(t, err, "failed to stat the porter binary")
+		require.Less(t, origPorterStat.ModTime(), newPorterStat.ModTime(), "expected the porter binary to be re-downloaded")
+		newRuntimeStat, err = os.Stat(runtimePath)
+		require.NoError(t, err, "failed to stat the porter-runtime binary")
+		require.Less(t, origRuntimeStat.ModTime(), newRuntimeStat.ModTime(), "expected the porter-runtime binary to be re-downloaded")
+	})
 }