Merge pull request moby#5951 from vieux/pr5919

Fix remote add cache

Author: vieux

integration-cli/build_tests/TestBuildCacheADD/1/Dockerfile

@@ -0,0 +1,2 @@
+FROM busybox
+ADD https://index.docker.io/robots.txt /

integration-cli/build_tests/TestBuildCacheADD/2/Dockerfile

@@ -0,0 +1,2 @@
+FROM busybox
+ADD http://example.com/index.html /

integration-cli/docker_cli_build_test.go

@@ -9,6 +9,37 @@ import (
 	"testing"
 )
 
+func TestBuildCacheADD(t *testing.T) {
+	buildDirectory := filepath.Join(workingDirectory, "build_tests", "TestBuildCacheADD", "1")
+	buildCmd := exec.Command(dockerBinary, "build", "-t", "testcacheadd1", ".")
+	buildCmd.Dir = buildDirectory
+	exitCode, err := runCommand(buildCmd)
+	errorOut(err, t, fmt.Sprintf("build failed to complete: %v", err))
+
+	if err != nil || exitCode != 0 {
+		t.Fatal("failed to build the image")
+	}
+
+	buildDirectory = filepath.Join(workingDirectory, "build_tests", "TestBuildCacheADD", "2")
+	buildCmd = exec.Command(dockerBinary, "build", "-t", "testcacheadd2", ".")
+	buildCmd.Dir = buildDirectory
+	out, exitCode, err := runCommandWithOutput(buildCmd)
+	errorOut(err, t, fmt.Sprintf("build failed to complete: %v %v", out, err))
+
+	if err != nil || exitCode != 0 {
+		t.Fatal("failed to build the image")
+	}
+
+	if strings.Contains(out, "Using cache") {
+		t.Fatal("2nd build used cache on ADD, it shouldn't")
+	}
+
+	deleteImages("testcacheadd1")
+	deleteImages("testcacheadd2")
+
+	logDone("build - build two images with ADD")
+}
+
 func TestBuildSixtySteps(t *testing.T) {
 	buildDirectory := filepath.Join(workingDirectory, "build_tests", "TestBuildSixtySteps")
 	buildCmd := exec.Command(dockerBinary, "build", "-t", "foobuildsixtysteps", ".")

server/buildfile.go

@@ -16,11 +16,13 @@ import (
 	"regexp"
 	"sort"
 	"strings"
+	"syscall"
 
 	"github.com/dotcloud/docker/archive"
 	"github.com/dotcloud/docker/daemon"
 	"github.com/dotcloud/docker/nat"
 	"github.com/dotcloud/docker/pkg/symlink"
+	"github.com/dotcloud/docker/pkg/system"
 	"github.com/dotcloud/docker/registry"
 	"github.com/dotcloud/docker/runconfig"
 	"github.com/dotcloud/docker/utils"
@@ -563,14 +565,22 @@ func (b *buildFile) CmdAdd(args string) error {
 		}
 		tmpFile.Close()
 
+		// Remove the mtime of the newly created tmp file
+		if err := system.UtimesNano(tmpFileName, make([]syscall.Timespec, 2)); err != nil {
+			return err
+		}
+
 		origPath = path.Join(filepath.Base(tmpDirName), filepath.Base(tmpFileName))
 
 		// Process the checksum
 		r, err := archive.Tar(tmpFileName, archive.Uncompressed)
 		if err != nil {
 			return err
 		}
-		tarSum := utils.TarSum{Reader: r, DisableCompression: true}
+		tarSum := &utils.TarSum{Reader: r, DisableCompression: true}
+		if _, err := io.Copy(ioutil.Discard, tarSum); err != nil {
+			return err
+		}
 		remoteHash = tarSum.Sum(nil)
 		r.Close()