We were relying on time.UnixNano, but that was causing collisions.
Now we generate 20 bytes of entropy from rand.Read, and base32-encode it to get
a valid container id.
PiperOrigin-RevId: 222313867
Change-Id: Iaeea9b9582d36de55f9f02f55de6a5de3f739371
sandbox.Wait is racey, as the sandbox may have exited before it is called, or
even during.
We already had code to handle the case that the sandbox exits during the Wait
call, but we were not properly handling the case where the sandbox has exited
before the call.
The best we can do in such cases is return the sandbox exit code as the
application exit code.
PiperOrigin-RevId: 221702517
Change-Id: I290d0333cc094c7c1c3b4ce0f17f61a3e908d787
SetupContainerInRoot was setting Config.RootDir unnecessarily
and causing a --race violation in TestMultiContainerDestroyStarting.
PiperOrigin-RevId: 220580073
Change-Id: Ie0b28c19846106c7458a92681b708ae70f87d25a
More tests will come, but it's worth getting what's done so far reviewed.
PiperOrigin-RevId: 219734531
Change-Id: If15ca6e6855e3d1cc28c83b5f9c3a72cb65b2e59
From https://golang.org/pkg/net/http/#Get:
"When err is nil, resp always contains a non-nil resp.Body. Caller should close
resp.Body when done reading from it."
PiperOrigin-RevId: 219658052
Change-Id: I556e88ac4f2c90cd36ab16cd3163d1a52afc32b7
It's hard to resolve symlinks inside the sandbox because rootfs and mounts
may be read-only, forcing us to create mount points inside lower layer of an
overlay, **before** the volumes are mounted.
Since the destination must already be resolved outside the sandbox when creating
mounts, take this opportunity to rewrite the spec with paths resolved.
"runsc boot" will use the "resolved" spec to load mounts. In addition, symlink
traversals were disabled while mounting containers inside the sandbox.
It haven't been able to write a good test for it. So I'm relying on manual tests
for now.
PiperOrigin-RevId: 217749904
Change-Id: I7ac434d5befd230db1488446cda03300cc0751a9
Sandbox was setting chroot, but was not chaging the working
dir. Added test to ensure this doesn't happen in the future.
PiperOrigin-RevId: 215676270
Change-Id: I14352d3de64a4dcb90e50948119dc8328c9c15e1
Terminal support in runsc relies on host tty file descriptors that are imported
into the sandbox. Application tty ioctls are sent directly to the host fd.
However, those host tty ioctls are associated in the host kernel with a host
process (in this case runsc), and the host kernel intercepts job control
characters like ^C and send signals to the host process. Thus, typing ^C into a
"runsc exec" shell will send a SIGINT to the runsc process.
This change makes "runsc exec" handle all signals, and forward them into the
sandbox via the "ContainerSignal" urpc method. Since the "runsc exec" is
associated with a particular container process in the sandbox, the signal must
be associated with the same container process.
One big difficulty is that the signal should not necessarily be sent to the
sandbox process started by "exec", but instead must be sent to the foreground
process group for the tty. For example, we may exec "bash", and from bash call
"sleep 100". A ^C at this point should SIGINT sleep, not bash.
To handle this, tty files inside the sandbox must keep track of their
foreground process group, which is set/get via ioctls. When an incoming
ContainerSignal urpc comes in, we look up the foreground process group via the
tty file. Unfortunately, this means we have to expose and cache the tty file in
the Loader.
Note that "runsc exec" now handles signals properly, but "runs run" does not.
That will come in a later CL, as this one is complex enough already.
Example:
root@:/usr/local/apache2# sleep 100
^C
root@:/usr/local/apache2# sleep 100
^Z
[1]+ Stopped sleep 100
root@:/usr/local/apache2# fg
sleep 100
^C
root@:/usr/local/apache2#
PiperOrigin-RevId: 215334554
Change-Id: I53cdce39653027908510a5ba8d08c49f9cf24f39
Some tests check current capabilities and re-run the tests as root inside
userns if required capabibilities are missing. It was checking for
CAP_SYS_ADMIN only, CAP_SYS_CHROOT is also required now.
PiperOrigin-RevId: 214949226
Change-Id: Ic81363969fa76c04da408fae8ea7520653266312
Reap children more systematically in container tests. Previously,
container_test was taking ~5 mins to run because constainer.Destroy()
would timeout waiting for the sandbox process to exit. Now the test
running in less than a minute.
Also made the contract around Container and Sandbox destroy clearer.
PiperOrigin-RevId: 213527471
Change-Id: Icca84ee1212bbdcb62bdfc9cc7b71b12c6d1688d
It was used before gofer was implemented and it's not
supported anymore.
BREAKING CHANGE: proxy-shared and proxy-exclusive options
are now: shared and exclusive.
PiperOrigin-RevId: 212017643
Change-Id: If029d4073fe60583e5ca25f98abb2953de0d78fd
We construct a dir with the executable bind-mounted at /exe, and proc mounted
at /proc. Runsc now executes the sandbox process inside this chroot, thus
limiting access to the host filesystem. The mounts and chroot dir are removed
when the sandbox is destroyed.
Because this requires bind-mounts, we can only do the chroot if we have
CAP_SYS_ADMIN.
PiperOrigin-RevId: 211994001
Change-Id: Ia71c515e26085e0b69b833e71691830148bc70d1
When starting a sandbox without direct file or network access, we create an
empty user namespace and run the sandbox in there. However, the root user in
that namespace is still mapped to the root user in the parent namespace.
This CL maps the "nobody" user from the parent namespace into the child
namespace, and runs the sandbox process as user "nobody" inside the new
namespace.
PiperOrigin-RevId: 211572223
Change-Id: I1b1f9b1a86c0b4e7e5ca7bc93be7d4887678bab6
This is a prereq for running the sandbox process as user "nobody", when it may
not have permissions to open these files.
Instead, we must open then before starting the sandbox process, and pass them
by FD.
The specutils.ReadSpecFromFile method was fixed to always seek to the beginning
of the file before reading. This allows Files from the same FD to be read
multiple times, as we do in the boot command when the apply-caps flag is set.
Tested with --network=host.
PiperOrigin-RevId: 211570647
Change-Id: I685be0a290aa7f70731ebdce82ebc0ebcc9d475c
This is a prereq for running the sandbox process as user "nobody", when it may
not have permissions to open these files.
Instead, we must open then before starting the sandbox process, and pass them
by FD.
PiperOrigin-RevId: 210995199
Change-Id: I715875a9553290b4a49394a8fcd93be78b1933dd
Now each container gets its own dedicated gofer that is chroot'd to the
rootfs path. This is done to add an extra layer of security in case the
gofer gets compromised.
PiperOrigin-RevId: 210396476
Change-Id: Iba21360a59dfe90875d61000db103f8609157ca0
Tests get a readonly rootfs mapped to / (which was the case before)
and writable TEST_TMPDIR. This makes it easier to setup containers to
write to files and to share state between test and containers.
PiperOrigin-RevId: 209453224
Change-Id: I4d988e45dc0909a0450a3bb882fe280cf9c24334
Bazel adds the build type in front of directories making it hard to
refer to binaries in code.
PiperOrigin-RevId: 209010854
Change-Id: I6c9da1ac3bbe79766868a3b14222dd42d03b4ec5
Previously, gofer filesystems were configured with the default "fscache"
policy, which caches filesystem metadata and contents aggressively. While this
setting is best for performance, it means that changes from inside the sandbox
may not be immediately propagated outside the sandbox, and vice-versa.
This CL changes volumes and the root fs configuration to use a new
"remote-revalidate" cache policy which tries to retain as much caching as
possible while still making fs changes visible across the sandbox boundary.
This cache policy is enabled by default for the root filesystem. The default
value for the "--file-access" flag is still "proxy", but the behavior is
changed to use the new cache policy.
A new value for the "--file-access" flag is added, called "proxy-exclusive",
which turns on the previous aggressive caching behavior. As the name implies,
this flag should be used when the sandbox has "exclusive" access to the
filesystem.
All volume mounts are configured to use the new cache policy, since it is
safest and most likely to be correct. There is not currently a way to change
this behavior, but it's possible to add such a mechanism in the future. The
configurability is a smaller issue for volumes, since most of the expensive
application fs operations (walking + stating files) will likely served by the
root fs.
PiperOrigin-RevId: 208735037
Change-Id: Ife048fab1948205f6665df8563434dbc6ca8cfc9
integration_test runs manually and breakage wasn't detected. Added test to
kokoro to ensure breakages are detected in the future.
PiperOrigin-RevId: 207772835
Change-Id: Iada81b579b558477d4db3516b38366ef6a2e933d
Unit tests call runsc directly now, so all command line arguments
are valid. On the other hand, enabling debug in the test binary
doesn't affect runsc. It needs to be set in the config.
PiperOrigin-RevId: 200237706
Change-Id: I0b5922db17f887f58192dbc2f8dd2fd058b76ec7
Just a UI/usability addition. It's a lot easier to type "60" than
"60185c721d7e10c00489f1fa210ee0d35c594873d6376b457fb1815e4fdbfc2c".
PiperOrigin-RevId: 199547932
Change-Id: I19011b5061a88aba48a9ad7f8cf954a6782de854
Common code to setup and run sandbox is moved to testutil. Also, don't
link "boot" and "gofer" commands with test binary. Instead, use runsc
binary from the build. This not only make the test setup simpler, but
also resolves a dependency issue with sandbox_tests not depending on
container package.
PiperOrigin-RevId: 199164478
Change-Id: I27226286ca3f914d4d381358270dd7d70ee8372f
Fabricio Voznika
Nicolas Lacasse
Kevin Krakauer
Ian Gudger
Lantao Liu