28 Commits

Author SHA1 Message Date
1e3ff69502 rootless: call IsRootless just once
we are calling this function several times, it is worth to store its
result and re-use it.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2018-11-14 10:13:50 +01:00
542d8fe95f Better document rootless containers
Need to return an error pointing user in right direction if rootless podman
fails, because of no /etc/subuid or /etc/subgid files.

Also fix up man pages to better describe rootless podman.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
2018-11-10 04:46:06 -05:00
55c9b03baf rootless: detect when user namespaces are not enabled
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2018-10-11 17:49:16 +02:00
2933c3b980 rootless: report more error messages from the startup phase
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2018-10-11 17:09:19 +02:00
48f6f9254d rootless: fix an hang on older versions of setresuid/setresgid
the issue is caused by the Go Runtime that messes up with the process
signals, overriding SIGSETXID and SIGCANCEL which are used internally
by glibc.  They are used to inform all the threads to update their
stored uid/gid information.  This causes a hang on the set*id glibc
wrappers since the handler installed by glibc is never invoked.

Since we are running with only one thread, we don't really need to
update other threads or even the current thread as we are not using
getuid/getgid before the execvp.

Closes: https://github.com/containers/libpod/issues/1625

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2018-10-11 17:09:18 +02:00
4f42fe2e9e rootless: error out if there are not enough UIDs/GIDs available
Most container images assume there are at least 65536 UIDs/GIDs
available.  Raise an error if there are not enough IDs allocated to
the current user.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1520
Approved by: rhatdan
2018-09-21 14:34:58 +00:00
37b2601a81 rootless: skip usage of filepath.Join
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1507
Approved by: rhatdan
2018-09-21 10:13:39 +00:00
6d1eecf7cf create, rootless: join the userns of ns:PATH
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1507
Approved by: rhatdan
2018-09-21 10:13:39 +00:00
807f6f8d8f rootless: check uid with Geteuid() instead of Getuid()
change the tests to use chroot to set a numeric UID/GID.

Go syscall.Credential doesn't change the effective UID/GID of the
process.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1372
Approved by: mheon
2018-09-04 14:36:57 +00:00
86aefb5de2 rootless: unexport GetUserNSForPid
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1371
Approved by: rhatdan
2018-08-29 16:25:20 +00:00
1789242933 rootless: add new function to join existing namespace
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1371
Approved by: rhatdan
2018-08-29 16:25:20 +00:00
c5753f57c1 rootless: exec handle processes that create an user namespace
Manage the case where the main process of the container creates and
joins a new user namespace.

In this case we want to join only the first child in the new
hierarchy, which is the user namespace that was used to create the
container.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1331
Approved by: rhatdan
2018-08-26 07:22:42 +00:00
720eb85ba5 rootless: fix exec
We cannot re-exec into a new user namespace to gain privileges and
access an existing as the new namespace is not the owner of the
existing container.

"unshare" is used to join the user namespace of the target container.

The current implementation assumes that the main process of the
container didn't create a new user namespace.

Since in the setup phase we are not running with euid=0, we must skip
the setup for containers/storage.

Closes: https://github.com/containers/libpod/issues/1329

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1331
Approved by: rhatdan
2018-08-26 07:22:42 +00:00
9e06478d83 rootless: fix user lookup if USER= is not set
Lookup the current username by UID if the USER env variable is not
set.

Reported in: https://github.com/projectatomic/libpod/issues/1092

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1217
Approved by: rhatdan
2018-08-08 09:27:27 +00:00
71af51e723 Check for missing arguments in /proc/self/cmdline
Closes: #1206
Approved by: giuseppe
2018-08-03 07:39:25 +00:00
13b1845214 rootless: do not set setgroups to deny when using newuidmap
It is required only when directly configuring the user namespace.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1200
Approved by: rhatdan
2018-08-02 18:49:55 +00:00
c7b6403ae5 rootless: do not segfault if the parent already died
Closes: https://github.com/projectatomic/libpod/issues/1189

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2018-08-02 14:29:50 +02:00
6372c977ea rootless: require subids to be present
Most images won't work without multiple ids/gids.  Error out
immediately if there are no multiple ids available.

The error code when the user is not present in /etc/sub{g,u}id looks
like:

$ bin/podman run --rm -ti alpine echo hello
ERRO[0000] No subuid ranges found for user "gscrivano"

Closes: https://github.com/projectatomic/libpod/issues/1087

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1097
Approved by: rhatdan
2018-07-16 13:40:40 +00:00
14a6d51a84 Merge pull request #1091 from giuseppe/rootless-unshare-mount-ns
rootless: unshare mount namespace
2018-07-13 14:16:24 -04:00
62e48e5b71 rootless: correctly propagate the exit status from the container
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2018-07-13 16:41:11 +02:00
6ffcb98a70 rootless: unshare mount namespace
unshare the mount namespace as well when creating an user namespace so
that we are the owner of the mount namespace and we can mount FUSE
file systems on Linux 4.18.  Tested on Fedora Rawhide:

podman --storage-opt overlay.fuse_program=/usr/bin/fuse-overlayfs run alpine echo hello
hello

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2018-07-13 16:37:37 +02:00
84cfdb2061 rootless: fix when argv[0] is not an absolute path
use execvp instead of exec so that we keep the PATH environment
variable and the lookup for the "podman" executable works.

Closes: https://github.com/projectatomic/libpod/issues/1070

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1072
Approved by: mheon
2018-07-10 16:13:43 +00:00
83968de28c rootless: Merge rootless.go back into rootless_linux.go
The files were split apart by b96be3af (changes to allow for darwin
compilation, 2018-06-20, #1015), but the C import and two functions
left in rootless.go are all Linux-specific as well.  This commit moves
all of the pre-b96be3af rootless.go into rootless_linux.go, just
adding the '// +build linux' header (b96be3af also scrambled the + in
that header) and keeping the new GetRootlessUID from a1545fe6
(rootless: add function to retrieve the original UID, 2018-07-05, #1048).

Signed-off-by: W. Trevor King <wking@tremily.us>

Closes: #1034
Approved by: baude
2018-07-06 00:48:39 +00:00
cc6f0e85f9 more changes to compile darwin
this should represent the last major changes to get darwin to **compile**.  again,
the purpose here is to get darwin to compile so that we can eventually implement a
ci task that would protect against regressions for darwin compilation.

i have left the manual darwin compilation largely static still and in fact now only
interject (manually) two build tags to assist with the build.  trevor king has great
ideas on how to make this better and i will defer final implementation of those
to him.

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

Closes: #1047
Approved by: rhatdan
2018-07-05 16:05:12 +00:00
a1545fe6e4 rootless: add function to retrieve the original UID
After we re-exec in the userNS os.Getuid() returns the new UID (= 0)
which is not what we want to use.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #1048
Approved by: mheon
2018-07-05 13:30:15 +00:00
b96be3af1b changes to allow for darwin compilation
Signed-off-by: baude <bbaude@redhat.com>

Closes: #1015
Approved by: baude
2018-06-29 20:44:09 +00:00
20862c9746 rootless: do not configure additional groups
Additional groups are not allowed in an userNS.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #936
Approved by: rhatdan
2018-06-27 14:07:17 +00:00
5ff90677c8 rootless: add management for the userNS
When running podman as non root user always create an userNS and let
the OCI runtime use it.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Closes: #936
Approved by: rhatdan
2018-06-27 14:07:17 +00:00