Unshare the thread's file system attributes and, if applicable, mount
namespace so that the chroot operation does not affect the rest of the
process.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The applyLayer implementation in pkg/chrootarchive has to set the TMPDIR
environment variable so that archive.UnpackLayer() can successfully
create the whiteout-file temp directory. Change UnpackLayer to create
the temporary directory under the destination path so that environment
variables do not need to be touched.
Signed-off-by: Cory Snider <csnider@mirantis.com>
It was only used in a couple of places, and in most places shouldn't be used
as those locations were in unix/linux-only files, so didn't need the wrapper.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
On Linux, when (os/exec.Cmd).SysProcAttr.Pdeathsig is set, the signal
will be sent to the process when the OS thread on which cmd.Start() was
executed dies. The runtime terminates an OS thread when a goroutine
exits after being wired to the thread with runtime.LockOSThread(). If
other goroutines are allowed to be scheduled onto a thread which called
cmd.Start(), an unrelated goroutine could cause the thread to be
terminated and prematurely signal the command. See
https://github.com/golang/go/issues/27505 for more information.
Prevent started subprocesses with Pdeathsig from getting signaled
prematurely by wiring the starting goroutine to the OS thread until the
subprocess has exited. No other goroutines can be scheduled onto a
locked thread so it will remain alive until unlocked or the daemon
process exits.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The io/ioutil package has been deprecated in Go 1.16. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
The implementation in libcontainer/system is quite complicated,
and we only use it to detect if user-namespaces are enabled.
In addition, the implementation in containerd uses a sync.Once,
so that detection (and reading/parsing `/proc/self/uid_map`) is
only performed once.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This patch fixed below 4 types of code line
1. Remove unnecessary variable assignment
2. Use variables declaration instead of explicit initial zero value
3. Change variable name to underbar when variable not used
4. Add erro check and return for ignored error
Signed-off-by: Daehyeok Mun <daehyeok@gmail.com>
The `archive` package defines aliases for `io.ReadCloser` and
`io.Reader`. These don't seem to provide an benefit other than type
decoration. Per this change, several unnecessary type cases were
removed.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
If we are running in a user namespace, don't try to mknod as
it won't be allowed. libcontainer will bind-mount the host's
devices over files in the container anyway, so it's not needed.
The chrootarchive package does a chroot (without mounting /proc) before
its work, so we cannot check /proc/self/uid_map when we need to. So
compute it in advance and pass it along with the tar options.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
pkg/chrootarchive/diff_unix.go erroneously calls flush on stdout, which tries to read from stdout returning an error.
This has been fixed by removing the call and by modifying flush to return errors and checking for these errors on calls to flush.
Signed-off-by: Amit Krishnan <krish.amit@gmail.com>
Adds support for the daemon to handle user namespace maps as a
per-daemon setting.
Support for handling uid/gid mapping is added to the builder,
archive/unarchive packages and functions, all graphdrivers (except
Windows), and the test suite is updated to handle user namespace daemon
rootgraph changes.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
In `ApplyLayer` and `Untar`, the stream is magically decompressed. Since
this is not able to be toggled, rather than break this ./pkg/ API, add
an `ApplyUncompressedLayer` and `UntarUncompressed` that does not
magically decompress the layer stream.
Signed-off-by: Vincent Batts <vbatts@redhat.com>
