From dc9d6c1c1f52eefba95920059f0607d3d57b2d07 Mon Sep 17 00:00:00 2001
From: "Guillaume J. Charmes" <guillaume@dotcloud.com>
Date: Wed, 15 May 2013 13:22:57 -0700
Subject: [PATCH] Upload images only when necessary

---
 registry/registry.go | 11 +++++------
 server.go            | 18 ++++++++++++++----
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/registry/registry.go b/registry/registry.go
index 03e977c374..d79b3e9f20 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -3,6 +3,7 @@ package registry
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"github.com/dotcloud/docker/auth"
 	"github.com/dotcloud/docker/utils"
@@ -14,6 +15,8 @@ import (
 	"strings"
 )
 
+var ErrAlreadyExists error = errors.New("Image already exists")
+
 func doWithCookies(c *http.Client, req *http.Request) (*http.Response, error) {
 	for _, cookie := range c.Jar.Cookies(req.URL) {
 		req.AddCookie(cookie)
@@ -291,15 +294,13 @@ func (r *Registry) PushImageJsonRegistry(imgData *ImgData, jsonRaw []byte, regis
 	if res.StatusCode != 200 {
 		errBody, err := ioutil.ReadAll(res.Body)
 		if err != nil {
-			return fmt.Errorf("HTTP code %d while uploading metadata and error when"+
-				" trying to parse response body: %v", res.StatusCode, err)
+			return fmt.Errorf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err)
 		}
 		var jsonBody map[string]string
 		if err := json.Unmarshal(errBody, &jsonBody); err != nil {
 			errBody = []byte(err.Error())
 		} else if jsonBody["error"] == "Image already exists" {
-			utils.Debugf("Image %s already uploaded ; skipping\n", imgData.Id)
-			return nil
+			return ErrAlreadyExists
 		}
 		return fmt.Errorf("HTTP code %d while uploading metadata: %s", res.StatusCode, errBody)
 	}
@@ -338,8 +339,6 @@ func (r *Registry) PushRegistryTag(remote, revision, tag, registry string, token
 	revision = "\"" + revision + "\""
 	registry = "https://" + registry + "/v1"
 
-	utils.Debugf("Pushing tags for rev [%s] on {%s}\n", revision, registry+"/users/"+remote+"/"+tag)
-
 	req, err := http.NewRequest("PUT", registry+"/repositories/"+remote+"/tags/"+tag, strings.NewReader(revision))
 	if err != nil {
 		return err
diff --git a/server.go b/server.go
index 35c3599093..05be2a9167 100644
--- a/server.go
+++ b/server.go
@@ -478,10 +478,15 @@ func (srv *Server) pushRepository(out io.Writer, name string, localRepo map[stri
 		fmt.Fprintf(out, "Pushing repository %s to %s (%d tags)\r\n", name, ep, len(localRepo))
 		// For each image within the repo, push them
 		for _, elem := range imgList {
+			if _, exists := repoData.ImgList[elem.Id]; exists {
+				fmt.Fprintf(out, "Image %s already on registry, skipping\n", name)
+				continue
+			}
 			if err := srv.pushImage(out, name, elem.Id, ep, repoData.Tokens); err != nil {
 				// FIXME: Continue on error?
 				return err
 			}
+			fmt.Fprintf(out, "Pushing tags for rev [%s] on {%s}\n", elem.Id, ep+"/users/"+name+"/"+elem.Tag)
 			if err := srv.registry.PushRegistryTag(name, elem.Id, elem.Tag, ep, repoData.Tokens); err != nil {
 				return err
 			}
@@ -511,6 +516,15 @@ func (srv *Server) pushImage(out io.Writer, remote, imgId, ep string, token []st
 		Checksum: checksum,
 	}
 
+	// Send the json
+	if err := srv.registry.PushImageJsonRegistry(imgData, jsonRaw, ep, token); err != nil {
+		if err == registry.ErrAlreadyExists {
+			fmt.Fprintf(out, "Image %s already uploaded ; skipping\n", imgData.Id)
+			return nil
+		}
+		return err
+	}
+
 	// Retrieve the tarball to be sent
 	var layerData *TempArchive
 	// If the archive exists, use it
@@ -537,10 +551,6 @@ func (srv *Server) pushImage(out io.Writer, remote, imgId, ep string, token []st
 		}
 	}
 
-	// Send the json
-	if err := srv.registry.PushImageJsonRegistry(imgData, jsonRaw, ep, token); err != nil {
-		return err
-	}
 	// Send the layer
 	if err := srv.registry.PushImageLayerRegistry(imgData.Id, utils.ProgressReader(layerData, int(layerData.Size), out, ""), ep, token); err != nil {
 		return err