In the case the container has a console with a valid slave pty file descriptor
we duplicate std{in,out,err} to the slave file descriptor so console logging
works correctly. When the container does not have a valid slave pty file
descriptor for its console and is started daemonized we should dup to
/dev/null.
Closes #1646.
Signed-off-by: Li Feng <lifeng68@huawei.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
we made std{err,in,out} a duplicate of the slave file descriptor of the console
if it existed. This meant we also duplicated all of them when we executed
application containers in the foreground even if some std{err,in,out} file
descriptor did not refer to a {p,t}ty. This blocked use cases such as:
echo foo | lxc-execute -n -- cat
which are very valid and common with application containers but less common
with system containers where we don't have to care about this. So my suggestion
is to unconditionally duplicate std{err,in,out} to the console file descriptor
if we are either running daemonized - this ensures that daemonized application
containers with a single bash shell keep on working - or when we are not
running an application container. In other cases we only duplicate those file
descriptors that actually refer to a {p,t}ty. This logic is similar to what we
do for lxc-attach already.
Refers to #1690.
Closes #2028.
Reported-by: Felix Abecassis <fabecassis@nvidia.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Detaching network namespaces as an unprivileged user is currently not possible
and attaching to the user namespace will mean we are not allowed to move the
network device into an ancestor network namespace.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
tools: block using lxc-execute without config file
Moving away from internal symbols we can't do hacks like we currently do in
lxc-start and call internal functions like lxc_conf_init(). This is unsafe
anyway. Instead, we should simply error out if the user didn't give us a
configuration file to use. lxc-start refuses to start in that case already.
Relates to discussion in https://github.com/lxc/go-lxc/pull/96#discussion_r155075560 .
Closes #2023.
Reported-by: Felix Abecassis <fabecassis@nvidia.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
It doesn't make sense to error out when an app container doesn't pass explicit
arguments through c->start{l}(). This is especially true since we implemented
lxc.execute.cmd. However, even before we could have always relied on
lxc.init.cmd and errored out after that.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Callers can then make a decision whether they want to consider the peer closing
the connection an error or not. For example, a c->wait(c, "STOPPED", -1) call
can then consider a ECONNRESET not an error but rather see it - correctly - as
a container exiting before being able to register a state client.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Take the lock on the list after we've done all necessary work and check state.
If we are in requested state, do cleanup and return without adding the state
client to the state client list.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
- setting the handler->state value is atomic on any POSIX implementation since
we're dealing with an integer (enum/lxc_state_t)
- while the state clients are served it is not possible for lxc_set_state() to
transition to the next state anyway so there's no danger in moving to the
next state with clients missing it
- we only care about the list being modified
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
There are multiple reasons why this is not required:
- every command is transactional
- we only care about the list being modified not the memory allocation and
other costly operations
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
We're dealing with an integer (lxc_state_t which is an enum). Any POSIX
implementation makes those operations atomic so there's not need in locking
this.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Abbas Ally [Sun, 3 Dec 2017 05:51:44 +0000 (05:51 +0000)]
Add bash completion to list backing store types for lxc-create -B
- Backing Store types are hard-coded (Not sure how to get programmatically)
- Closes #1236
CC-Hsu [Sat, 2 Dec 2017 11:27:34 +0000 (19:27 +0800)]
Add new dependency to Slackware template
I followed the [changelog of Slackware-current]<http://www.slackware.com/changelog/>,
and found that Slackware-current split hostname utility from util-linux package in Nov 17 2017.
So I add the new package to the template.
Change conf.c to export function write_id_mapping, which will now be
called inside main function of lxc_unshare.c.
This is required because setuid syscalls only permits a new userns to
set a new uid if the uid of parameter is mapped inside the ns using
uid_map file[1]. So, just after the clone invocation, map the uid passed as
parameter into the newly created user namespace, and put the current uid
as the ID-outside-ns. After the mapping is done, setuid call succeeds.
Po-Hsu Lin [Wed, 22 Nov 2017 08:11:34 +0000 (03:11 -0500)]
lxc-test-unpriv: check user existence before removing it
Check the test user (lxcunpriv) before calling deluser command,
otherwise it will print unnecessary error message:
/usr/sbin/deluser: The user 'lxcunpriv' does not exist.
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Remove dead state clients from state client list. Consider the following
scenario:
01 start container
02 issue shutdown request
03 state_client_fd is added to lxc_handler
03 container doesn't respond to shutdown request
04 user aborts shutdown request
05 lxc_cmd_fd_cleanup() removes state_client_fd from lxc_mainloop
06 invalid state_client_fd is still recorded in the lxc_handler
07 user issues lxc_cmd_stop() request via SIGKILL
08 container reaches STOPPED state and sends message to state_client_fd
09 state_client_fd number has been reused by lxc_cmd_stop_callback()
10 invalid data gets dumped to lxc_cmd_stop()
Reproducer:
Set an invalid shutdown signal to which the init system does not respond with a
shutdown via lxc.signal.halt e.g. "lxc.signal.halt = SIGUSR1". Then do:
2. try to shutdown container
root@conventiont|~
> lxc-stop -n a1
3. abort shutdown
^C
4. SIGKILL the container (lxc.signal.stop = SIGKILL)
root@conventiont|~
> lxc-stop -n a1 -k
lxc-stop: a1: commands.c: lxc_cmd_rsp_recv: 165 File too large - Response data for command "stop" is too long: 12641 bytes > 8192
To not let this happen we remove the state_client_fd from the lxc_handler when
we detect a cleanup event in lxc_cmd_fd_cleanup().
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>