use layer cache when building images

to more closely mimic docker default behavior, the --layers
cli option is set to true by default for podman.  the buildah
environment variable of BUILDAH_LAYERS is still honored and will
override the command line input.

this should be considered in place of PR #1383.

Many thanks for Scott McCarty for inspiring this welcome change.

Signed-off-by: baude <bbaude@redhat.com>

Closes: #1422
Approved by: rhatdan

1 files changed, 35 insertions, 6 deletions

diff --git a/vendor/github.com/projectatomic/buildah/run.go b/vendor/github.com/projectatomic/buildah/run.go
index 71a76862e..12560de3c 100644
--- a/vendor/github.com/projectatomic/buildah/run.go
+++ b/vendor/github.com/projectatomic/buildah/run.go
@@ -973,8 +973,7 @@ func (b *Builder) Run(command []string, options RunOptions) error {
 	} else if b.WorkDir() != "" {
 		g.SetProcessCwd(b.WorkDir())
 	}
-	g.SetProcessSelinuxLabel(b.ProcessLabel)
-	g.SetLinuxMountLabel(b.MountLabel)
+	setupSelinux(g, b.ProcessLabel, b.MountLabel)
 	mountPoint, err := b.Mount(b.MountLabel)
 	if err != nil {
 		return err
@@ -1017,6 +1016,7 @@ func (b *Builder) Run(command []string, options RunOptions) error {
 	if spec.Process.Cwd == "" {
 		spec.Process.Cwd = DefaultWorkingDir
 	}
+	logrus.Debugf("ensuring working directory %q exists", filepath.Join(mountPoint, spec.Process.Cwd))
 	if err = os.MkdirAll(filepath.Join(mountPoint, spec.Process.Cwd), 0755); err != nil {
 		return errors.Wrapf(err, "error ensuring working directory %q exists", spec.Process.Cwd)
 	}
@@ -1760,11 +1760,14 @@ func runCopyStdio(stdio *sync.WaitGroup, copyPipes bool, stdioPipe [][]int, copy
 		writeDesc[unix.Stderr] = "stderr"
 	}
 	// Set our reading descriptors to non-blocking.
-	for fd := range relayMap {
-		if err := unix.SetNonblock(fd, true); err != nil {
-			logrus.Errorf("error setting %s to nonblocking: %v", readDesc[fd], err)
+	for rfd, wfd := range relayMap {
+		if err := unix.SetNonblock(rfd, true); err != nil {
+			logrus.Errorf("error setting %s to nonblocking: %v", readDesc[rfd], err)
 			return
 		}
+		if err := unix.SetNonblock(wfd, false); err != nil {
+			logrus.Errorf("error setting descriptor %d (%s) blocking: %v", wfd, writeDesc[wfd], err)
+		}
 	}
 	// A helper that returns false if err is an error that would cause us
 	// to give up.
@@ -1837,7 +1840,33 @@ func runCopyStdio(stdio *sync.WaitGroup, copyPipes bool, stdioPipe [][]int, copy
 				}
 				if n > 0 {
 					// Buffer the data in case we get blocked on where they need to go.
-					relayBuffer[writeFD].Write(buf[:n])
+					nwritten, err := relayBuffer[writeFD].Write(buf[:n])
+					if err != nil {
+						logrus.Debugf("buffer: %v", err)
+						continue
+					}
+					if nwritten != n {
+						logrus.Debugf("buffer: expected to buffer %d bytes, wrote %d", n, nwritten)
+						continue
+					}
+					// If this is the last of the data we'll be able to read from this
+					// descriptor, read all that there is to read.
+					for pollFd.Revents&unix.POLLHUP == unix.POLLHUP {
+						nr, err := unix.Read(readFD, buf)
+						logIfNotRetryable(err, fmt.Sprintf("read %s: %v", readDesc[readFD], err))
+						if nr <= 0 {
+							break
+						}
+						nwritten, err := relayBuffer[writeFD].Write(buf[:nr])
+						if err != nil {
+							logrus.Debugf("buffer: %v", err)
+							break
+						}
+						if nwritten != nr {
+							logrus.Debugf("buffer: expected to buffer %d bytes, wrote %d", nr, nwritten)
+							break
+						}
+					}
 				}
 			}
 		}