first cut of fetch

cmd/helm/fetch.go

@@ -4,8 +4,11 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"os"
+	"strings"
 
+	"github.com/kubernetes/helm/pkg/repo"
 	"github.com/spf13/cobra"
 )
 
@@ -14,23 +17,37 @@ func init() {
 }
 
 var fetchCmd = &cobra.Command{
-	Use:   "fetch",
-	Short: "Download a chart from a repository and unpack it in local directory.",
+	Use:   "fetch [chart URL | repo/chartname]",
+	Short: "Download a chart from a repository and (optionally) unpack it in local directory.",
 	Long:  "",
 	RunE:  fetch,
 }
 
 func fetch(cmd *cobra.Command, args []string) error {
-	// parse args
+	if len(args) == 0 {
+		return fmt.Errorf("This command needs at least one argument, url or repo/name of the chart.")
+	}
+
+	f, err := repo.LoadRepositoriesFile(repositoriesFile())
+	if err != nil {
+		return err
+	}
+
 	// get download url
-	// call download url
-	out, err := os.Create("nginx-2.0.0.tgz")
+	u, err := mapRepoArg(args[0], f.Repositories)
+	if err != nil {
+		return err
+	}
+
+	// Grab the package name that we'll use for the name of the file to download to.
+	p := strings.Split(u.String(), "/")
+	chartName := p[len(p)-1]
+	out, err := os.Create(chartName)
 	if err != nil {
 		return err
 	}
 	defer out.Close()
-	resp, err := http.Get("http://localhost:8879/charts/nginx-2.0.0.tgz")
-	fmt.Println("after req")
+	resp, err := http.Get(u)
 	// unpack file
 	if err != nil {
 		return err
@@ -44,3 +61,32 @@ func fetch(cmd *cobra.Command, args []string) error {
 	}
 	return nil
 }
+
+// mapRepoArg figures out which format the argument is given, and creates a fetchable
+// url from it.
+func mapRepoArg(arg string, r map[string]string) (*url.URL, error) {
+	// See if it's already a full URL.
+	u, err := url.ParseRequestURI(arg)
+	if err == nil {
+		// If it has a scheme and host and path, it's a full URL
+		if u.IsAbs() && len(u.Host) > 0 && len(u.Path) > 0 {
+			return u, nil
+		} else {
+			return nil, fmt.Errorf("Invalid chart url format: %s", arg)
+		}
+	}
+	// See if it's of the form: repo/path_to_chart
+	p := strings.Split(arg, "/")
+	if len(p) > 1 {
+		if baseUrl, ok := r[p[0]]; ok {
+			if !strings.HasSuffix(baseUrl, "/") {
+				baseUrl = baseUrl + "/"
+			}
+			return url.ParseRequestURI(baseUrl + strings.Join(p[1:], "/"))
+		} else {
+			return nil, fmt.Errorf("No such repo: %s", p[0])
+		}
+	} else {
+		return nil, fmt.Errorf("Invalid chart url format: %s", arg)
+	}
+}

cmd/helm/fetch_test.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"fmt"
+	//	"io"
+	//	"net/http"
+	//"net/url"
+	//	"os"
+
+	"testing"
+)
+
+type testCase struct {
+	in          string
+	expectedErr error
+	expectedOut string
+}
+
+var repos = map[string]string{
+	"local":     "http://localhost:8879/charts",
+	"someother": "http://storage.googleapis.com/mycharts",
+}
+
+var testCases = []testCase{
+	{"bad", fmt.Errorf("Invalid chart url format: bad"), ""},
+	{"http://", fmt.Errorf("Invalid chart url format: http://"), ""},
+	{"http://example.com", fmt.Errorf("Invalid chart url format: http://example.com"), ""},
+	{"http://example.com/foo/bar", nil, "http://example.com/foo/bar"},
+	{"local/nginx-2.0.0.tgz", nil, "http://localhost:8879/charts/nginx-2.0.0.tgz"},
+	{"nonexistentrepo/nginx-2.0.0.tgz", fmt.Errorf("No such repo: nonexistentrepo"), ""},
+}
+
+func testRunner(t *testing.T, tc testCase) {
+	u, err := mapRepoArg(tc.in, repos)
+	if (tc.expectedErr == nil && err != nil) ||
+		(tc.expectedErr != nil && err == nil) ||
+		(tc.expectedErr != nil && err != nil && tc.expectedErr.Error() != err.Error()) {
+		t.Errorf("Expected mapRepoArg to fail with input %s %v but got %v", tc.in, tc.expectedErr, err)
+	}
+
+	if (u == nil && len(tc.expectedOut) != 0) ||
+		(u != nil && len(tc.expectedOut) == 0) ||
+		(u != nil && tc.expectedOut != u.String()) {
+		t.Errorf("Expected %s to map to fetch url %v but got %v", tc.in, tc.expectedOut, u)
+	}
+
+}
+
+func TestMappings(t *testing.T) {
+	for _, tc := range testCases {
+		testRunner(t, tc)
+	}
+}