feat(helm): Add Files.Glob method to permit file organization

docs/chart_template_guide/accessing_files.md

@@ -9,6 +9,8 @@ Helm provides access to files through the `.Files` object. Before we get going w
 	- Files in `templates/` cannot be accessed.
 - Charts to not preserve UNIX mode information, so file-level permissions will have no impact on the availability of a file when it comes to the `.Files` object.
 
+## Basic example
+
 With those caveats behind, let's write a template that reads three files into our ConfigMap. To get started, we will add three files to the chart, putting all three directly inside of the `mychart/` directory.
 
 `config1.toml`:
@@ -65,6 +67,42 @@ data:
     message = Goodbye from config 3
 ```
 
+As your chart grows, you may find you have a greater need to organize your
+files more, and so we provide a `Files.Glob(pattern string)` method to assist
+in extracting certain files however you need.
+
+For example, imagine the directory structure:
+
+```
+foo/: 
+  foo.txt foo.yaml
+
+bar/:
+  bar.go bar.conf baz.yaml
+```
+
+## Glob patterns
+
+You have multiple options with Globs:
+
+
+```yaml
+{{ range $path := .Files.Glob "**.yaml" }}
+{{ $path }}: |
+{{ .Files.Get $path }}
+{{ end }}
+```
+
+Or
+
+```yaml
+{{ range $path, $bytes := .Files.Glob "foo/*" }}
+{{ $path }}: '{{ b64enc $bytes }}'
+{{ end }}
+```
+
+## Secrets
+
 When working with a Secret resource, you can import a file and have the template base-64 encode it for you:
 
 ```yaml

glide.lock

-hash: 89695daf5f2de706b79fdd8e8b095f9514f418c0fbcf80d7fdca4c208d114d19
-updated: 2016-11-29T14:56:31.55726541-07:00
+hash: 707ac6d1785d0029397f2f9a3b0bc45f7d8ce819f14f6c246967b0a404627a2c
+updated: 2016-12-01T09:07:51.289370422-07:00
 imports:
 - name: cloud.google.com/go
   version: 3b1ae45394a234c385be014e9a488f2bb6eef821
@@ -103,6 +103,16 @@ imports:
   version: 465937c80b3c07a7c7ad20cc934898646a91c1de
 - name: github.com/ghodss/yaml
   version: 73d445a93680fa1a78ae23a5839bad48f32ba1ee
+- name: github.com/gobwas/glob
+  version: 0354991b92587e2742549d3036f3b5bae5ab03f2
+  subpackages:
+  - compiler
+  - match
+  - syntax
+  - syntax/ast
+  - syntax/lexer
+  - util/runes
+  - util/strings
 - name: github.com/gogo/protobuf
   version: e18d7aa8f8c624c915db340349aad4c49b10d173
   subpackages:

glide.yaml

@@ -49,3 +49,5 @@ import:
 - package: golang.org/x/crypto
   subpackages:
   - openpgp
+- package: github.com/gobwas/glob
+  version: ^0.2.1

pkg/chartutil/files.go

@@ -16,6 +16,7 @@ limitations under the License.
 package chartutil
 
 import (
+	"github.com/gobwas/glob"
 	"github.com/golang/protobuf/ptypes/any"
 )
 
@@ -26,8 +27,10 @@ type Files map[string][]byte
 // Given an []*any.Any (the format for files in a chart.Chart), extract a map of files.
 func NewFiles(from []*any.Any) Files {
 	files := map[string][]byte{}
-	for _, f := range from {
-		files[f.TypeUrl] = f.Value
+	if from != nil {
+		for _, f := range from {
+			files[f.TypeUrl] = f.Value
+		}
 	}
 	return files
 }
@@ -56,3 +59,26 @@ func (f Files) GetBytes(name string) []byte {
 func (f Files) Get(name string) string {
 	return string(f.GetBytes(name))
 }
+
+// Glob takes a glob pattern and returns another files object only containing
+// matched  files.
+//
+// This is designed to be called from a template.
+// {{ range $name, $content := .Files.Glob("foo/**") }}
+// {{ $name }}: |
+// {{ .Files.Get($name) | indent 4 }}{{ end }}
+func (f Files) Glob(pattern string) Files {
+	g, err := glob.Compile(pattern, '/')
+	if err != nil {
+		g, _ = glob.Compile("**")
+	}
+
+	nf := NewFiles(nil)
+	for name, contents := range f {
+		if g.Match(name) {
+			nf[name] = contents
+		}
+	}
+
+	return nf
+}

pkg/chartutil/files_test.go

@@ -21,23 +21,25 @@ import (
 	"github.com/golang/protobuf/ptypes/any"
 )
 
-func TestNewFiles(t *testing.T) {
-
-	cases := []struct {
-		path, data string
-	}{
-		{"ship/captain.txt", "The Captain"},
-		{"ship/stowaway.txt", "Legatt"},
-		{"story/name.txt", "The Secret Sharer"},
-		{"story/author.txt", "Joseph Conrad"},
-	}
+var cases = []struct {
+	path, data string
+}{
+	{"ship/captain.txt", "The Captain"},
+	{"ship/stowaway.txt", "Legatt"},
+	{"story/name.txt", "The Secret Sharer"},
+	{"story/author.txt", "Joseph Conrad"},
+}
 
+func getTestFiles() []*any.Any {
 	a := []*any.Any{}
 	for _, c := range cases {
 		a = append(a, &any.Any{TypeUrl: c.path, Value: []byte(c.data)})
 	}
+	return a
+}
 
-	files := NewFiles(a)
+func TestNewFiles(t *testing.T) {
+	files := NewFiles(getTestFiles())
 	if len(files) != len(cases) {
 		t.Errorf("Expected len() = %d, got %d", len(cases), len(files))
 	}
@@ -51,3 +53,18 @@ func TestNewFiles(t *testing.T) {
 		}
 	}
 }
+
+func TestFileGlob(t *testing.T) {
+	f := NewFiles(getTestFiles())
+
+	matched := f.Glob("story/**")
+
+	if len(matched) != 2 {
+		t.Errorf("Expected two files in glob story/**, got %d", len(matched))
+	}
+
+	m, expect := matched.Get("story/author.txt"), "Joseph Conrad"
+	if m != expect {
+		t.Errorf("Wrong globbed file content. Expected %s, got %s", expect, m)
+	}
+}