Add an example of reading a local manifest file too

Author: tianon

manifest/example_test.go

@@ -126,7 +126,28 @@ i: g@h j
 	// Directory: j
 }
 
-func ExampleFetch() {
+func ExampleFetch_local() {
+	repoName, tagName, man, err := manifest.Fetch("testdata", "bash:4.4")
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Printf("%s:%s\n\n", repoName, tagName)
+
+	fmt.Println(man.GetTag(tagName))
+
+	// Output:
+	// bash:4.4
+	//
+	// Maintainers: Tianon Gravi <[email protected]> (@tianon)
+	// Tags: 4.4.12, 4.4, 4, latest
+	// GitRepo: https://github.com/tianon/docker-bash.git
+	// GitFetch: refs/heads/master
+	// GitCommit: 1cbb5cf49b4c53bd5a986abf7a1afeb9a80eac1e
+	// Directory: 4.4
+}
+
+func ExampleFetch_remote() {
 	repoName, tagName, man, err := manifest.Fetch("/home/jsmith/docker/official-images/library", "https://github.com/docker-library/official-images/raw/1a3c4cd6d5cd53bd538a6f56a69f94c5b35325a7/library/bash:4.4")
 	if err != nil {
 		panic(err)

manifest/testdata/bash

@@ -0,0 +1,38 @@
+# this is a snapshot of https://github.com/docker-library/official-images/raw/1a3c4cd6d5cd53bd538a6f56a69f94c5b35325a7/library/bash
+
+# this file is generated via https://github.com/tianon/docker-bash/blob/cd1de3dfc885b3395cd354ddb988922350b092a7/generate-stackbrew-library.sh
+
+Maintainers: Tianon Gravi <[email protected]> (@tianon)
+GitRepo: https://github.com/tianon/docker-bash.git
+
+Tags: 4.4.12, 4.4, 4, latest
+GitCommit: 1cbb5cf49b4c53bd5a986abf7a1afeb9a80eac1e
+Directory: 4.4
+
+Tags: 4.3.48, 4.3
+GitCommit: 1cbb5cf49b4c53bd5a986abf7a1afeb9a80eac1e
+Directory: 4.3
+
+Tags: 4.2.53, 4.2
+GitCommit: 1cbb5cf49b4c53bd5a986abf7a1afeb9a80eac1e
+Directory: 4.2
+
+Tags: 4.1.17, 4.1
+GitCommit: 1cbb5cf49b4c53bd5a986abf7a1afeb9a80eac1e
+Directory: 4.1
+
+Tags: 4.0.44, 4.0
+GitCommit: 4438745d601d10d300e363f24205a3ca75307803
+Directory: 4.0
+
+Tags: 3.2.57, 3.2, 3
+GitCommit: 1cbb5cf49b4c53bd5a986abf7a1afeb9a80eac1e
+Directory: 3.2
+
+Tags: 3.1.23, 3.1
+GitCommit: 1cbb5cf49b4c53bd5a986abf7a1afeb9a80eac1e
+Directory: 3.1
+
+Tags: 3.0.22, 3.0
+GitCommit: 1cbb5cf49b4c53bd5a986abf7a1afeb9a80eac1e
+Directory: 3.0