added code for parsing Docker image names and returning owner, name and tag

pkg/build/util.go

@@ -5,6 +5,7 @@ import (
 	"crypto/sha1"
 	"fmt"
 	"io"
+	"strings"
 )
 
 // createUID is a helper function that will
@@ -26,3 +27,57 @@ func createRandom() []byte {
 	}
 	return k
 }
+
+// list of service aliases and their full, canonical names
+var defaultServices = map[string]string{
+	"cassandra":     "relateiq/cassandra:latest",
+	"couchdb":       "bradrydzewski/couchdb:1.5",
+	"elasticsearch": "bradrydzewski/elasticsearch:0.90",
+	"memcached":     "bradrydzewski/memcached",
+	"mongodb":       "bradrydzewski/mongodb:2.4",
+	"mysql":         "bradrydzewski/mysql:5.5",
+	"neo4j":         "bradrydzewski/neo4j:1.9",
+	"postgres":      "bradrydzewski/postgres:9.1",
+	"redis":         "bradrydzewski/redis:2.8",
+	"rabbitmq":      "bradrydzewski/rabbitmq:3.2",
+	"riak":          "guillermo/riak:latest",
+	"zookeeper":     "jplock/zookeeper:3.4.5",
+}
+
+// parseImageName parses a Docker image name, in the format owner/name:tag,
+// and returns each segment.
+//
+// If the owner is blank, it is assumed to be an official drone image,
+// and will be prefixed with the appropriate owner name.
+//
+// If the tag is empty, it is assumed to be the latest version.
+func parseImageName(image string) (owner, name, tag string) {
+	owner = "bradrydzewski" // this will eventually change to drone
+	name = image
+	tag = "latest"
+
+	// first we check to see if the image name is an alias
+	// for a known service.
+	//
+	// TODO I'm not a huge fan of this code here. Maybe it
+	//      should get handled when the yaml is parsed, and
+	//      convert the image and service names in the yaml
+	//      to fully qualified names?
+	if cname, ok := defaultServices[image]; ok {
+		name = cname
+	}
+
+	parts := strings.Split(name, "/")
+	if len(parts) == 2 {
+		owner = parts[0]
+		name = parts[1]
+	}
+
+	parts = strings.Split(name, ":")
+	if len(parts) == 2 {
+		name = parts[0]
+		tag = parts[1]
+	}
+
+	return
+}

pkg/build/util_test.go

@@ -0,0 +1,36 @@
+package build
+
+import "testing"
+
+func TestParseImageName(t *testing.T) {
+	images := []struct {
+		owner string
+		name  string
+		tag   string
+		cname string
+	}{
+		// full image name with all 3 sections present
+		{"johnsmith", "redis", "2.8", "johnsmith/redis:2.8"},
+		// image name with no tag specified
+		{"johnsmith", "redis", "latest", "johnsmith/redis"},
+		// image name with no owner specified
+		{"bradrydzewski", "redis", "2.8", "redis:2.8"},
+		// image name with ownly name specified
+		{"bradrydzewski", "redis2", "latest", "redis2"},
+		// image name that is a known alias
+		{"relateiq", "cassandra", "latest", "cassandra"},
+	}
+
+	for _, img := range images {
+		owner, name, tag := parseImageName(img.cname)
+		if owner != img.owner {
+			t.Errorf("Expected image %s with owner %s, got %s", img.cname, img.owner, owner)
+		}
+		if name != img.name {
+			t.Errorf("Expected image %s with name %s, got %s", img.cname, img.name, name)
+		}
+		if tag != img.tag {
+			t.Errorf("Expected image %s with tag %s, got %s", img.cname, img.tag, tag)
+		}
+	}
+}