172 Commits

Author SHA1 Message Date
51fbf3da9e enable gocritic linter
The linter ensures a common code style.
- use switch/case instead of else if
- use if instead of switch/case for single case statement
- add space between comment and text
- detect the use of defer with os.Exit()
- use short form var += "..." instead of var = var + "..."
- detect problems with append()
```
newSlice := append(orgSlice, val)
```
  This could lead to nasty bugs because the orgSlice will be changed in
  place if it has enough capacity too hold the new elements. Thus we
  newSlice might not be a copy.

Of course most of the changes are just cosmetic and do not cause any
logic errors but I think it is a good idea to enforce a common style.
This should help maintainability.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2022-04-26 18:12:22 +02:00
b0d36f6351 Implements Windows volume/mount support
Based on WSL2 9p support: remaps windows paths to /mnt/<drive> locations for
both podman and Docker API clients.

Signed-off-by: Jason T. Greene <jason.greene@redhat.com>
2022-04-25 13:52:27 -05:00
3b6ffcd290 Update to use new common machine API
Signed-off-by: Jason T. Greene <jason.greene@redhat.com>
2022-04-25 13:52:27 -05:00
09ef4f2e22 Merge pull request #13978 from Luap99/unparam
enable unparam linter
2022-04-25 13:43:57 -04:00
c7b16645af enable unparam linter
The unparam linter is useful to detect unused function parameters and
return values.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2022-04-25 13:23:20 +02:00
44642bee87 libpod/networking_linux.go: switch to sha256 hashes
SHA-1 is prone to collisions.

This will likely break connectivity between old containers started
before update and containers started after update. It will also fail to
cleanup old netns. A reboot will fix this, so a reboot is recommended
after update.

[NO NEW TESTS NEEDED]

Signed-off-by: Lokesh Mandvekar <lsm5@fedoraproject.org>
2022-04-22 16:31:43 -04:00
cf1b0c1965 network dis-/connect: update /etc/hosts
When we connect or disconnect from a network we also have to update
/etc/hosts to ensure we only have valid entries in there.
This also fixes problems with docker-compose since this makes use of
network connect/disconnect.

Fixes #12533

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2022-04-22 13:05:53 +02:00
1f1cf7bd40 rootless netns: move process to scope only with systemd
When you run podman on a non systemd system we should not try to move the
process under a new systemd scope.

[NO NEW TESTS NEEDED]

Ref #13703

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2022-03-30 13:02:41 +02:00
7680211ede Remove error stutter
When podman gets an error it prints out "Error: " before
printing the error string.  If the error message starts with
error, we end up with

Error: error ...

This PR Removes all of these stutters.

logrus.Error() also prints out that this is an error, so no need for the
error stutter.

[NO NEW TESTS NEEDED]

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
2022-03-25 21:47:04 -04:00
68b94338ba linter: enable makezero
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>
2022-03-22 13:04:35 +01:00
ea08765f40 go fmt: use go 1.18 conditional-build syntax
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>
2022-03-18 09:11:53 +01:00
611b45c517 Inspect network info of a joined network namespace
Closes: https://github.com/containers/podman/issues/13150
Signed-off-by: 😎 Mostafa Emami <mustafaemami@gmail.com>
2022-03-08 11:00:36 +01:00
4a60319ecb Remove the runtime lock
This primarily served to protect us against shutting down the
Libpod runtime while operations (like creating a container) were
happening. However, it was very inconsistently implemented (a lot
of our longer-lived functions, like pulling images, just didn't
implement it at all...) and I'm not sure how much we really care
about this very-specific error case?

Removing it also removes a lot of potential deadlocks, which is
nice.

[NO NEW TESTS NEEDED]

Signed-off-by: Matthew Heon <mheon@redhat.com>
2022-02-22 11:05:26 -05:00
87cca4e5e3 Modify /etc/resolv.conf when connecting/disconnecting
The `podman network connect` and `podman network disconnect`
commands give containers access to different networks than the
ones they were created with; these networks can also have DNS
servers associated with them. Until now, however, we did not
modify resolv.conf as network membership changed.

With this PR, `podman network connect` will add any new
nameservers supported by the new network to the container's
/etc/resolv.conf, and `podman network disconnect` command will do
the opposite, removing the network's nameservers from
`/etc/resolv.conf`.

Fixes #9603

Signed-off-by: Matthew Heon <matthew.heon@pm.me>
2022-02-10 09:44:00 -05:00
8d0fb0a4ed move rootless netns slirp4netns process to systemd user.slice
When running podman inside systemd user units, it is possible that
systemd kills the rootless netns slirp4netns process because it was
started in the default unit cgroup. When the unit is stopped all
processes in that cgroup are killed. Since the slirp4netns process is
run once for all containers it should not be killed. To make sure
systemd will not kill the process we move it to the user.slice.

Fixes #13153

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2022-02-07 17:38:53 +01:00
865f0a1977 libpod: report slirp4netns network stats
by default slirp4netns uses the tap0 device.  When slirp4netns is
used, use that device by default instead of eth0.

Closes: https://github.com/containers/podman/issues/11695

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2022-02-01 16:23:58 +01:00
2f371cb12c container create: do not check for network dns support
We should not check if the network supports dns when we create a
container with network aliases. This could be the case for containers
created by docker-compose for example if the dnsname plugin is not
installed or the user uses a macvlan config where we do not support dns.

Fixes #12972

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2022-01-24 16:56:11 +01:00
bd09b7aa79 bump go module to version 4
Automated for .go files via gomove [1]:
`gomove github.com/containers/podman/v3 github.com/containers/podman/v4`

Remaining files via vgrep [2]:
`vgrep github.com/containers/podman/v3`

[1] https://github.com/KSubedi/gomove
[2] https://github.com/vrothberg/vgrep

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
2022-01-18 12:47:07 +01:00
918890a4d6 use netns package from c/common
The netns package was moved to c/common so we should use this and remove
the package from podman.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2022-01-12 17:40:24 +01:00
495884b319 use libnetwork from c/common
The libpod/network packages were moved to c/common so that buildah can
use it as well. To prevent duplication use it in podman as well and
remove it from here.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2022-01-12 17:07:30 +01:00
4791595b5c network connect allow ip, ipv6 and mac address
Network connect now supports setting a static ipv4, ipv6 and mac address
for the container network. The options are added to the cli and api.

Fixes #9883

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-12-14 15:23:39 +01:00
5490be67b3 network db rewrite: migrate existing settings
The new network db structure stores everything in the networks bucket.
Previously some network settings were not written the the network bucket
and only stored in the container config.
Instead of the old format which used the container ID as value in the
networks buckets we now use the PerNetworkoptions struct there.

To migrate existing users we use the state.GetNetworks() function. If it
fails to read the new format it will automatically migrate the old
config format to the new one. This is allows a flawless migration path.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-12-14 15:23:20 +01:00
3753347d62 rootless netns: resolve all path components for resolv.conf
We need to follow all symlinks in the /etc/resolv.conf path. Currently
we would only check the last file but it is possible that any directory
before that is also a link.

Unfortunately this code is very hard to maintain and not well tested. I
will try to come up with a unit test when I have more time. I think we
could utilize some for of chroot for this. For now we are stucked with
the default setup in the fedora/ubunutu test VMs.

[NO NEW TESTS NEEDED]

Fixes #12461

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-12-06 18:34:14 +01:00
3ff47748de Fix possible rootless netns cleanup race
rootlessNetNS.Cleanup() has an issue with how it detects if cleanup
is needed, reading the container state is not good ebough because
containers are first stopped and than cleanup will be called. So at one
time two containers could wait for cleanup but the second one will fail
because the first one triggered already the cleanup thus making rootless
netns unavailable for the second container resulting in an teardown
error. Instead of checking the container state we need to check the
netns state.

Secondly, podman unshare --rootless-netns should not do the cleanup.
This causes more issues than it is worth fixing. Users also might want
to use this to setup the namespace in a special way. If unshare also
cleans this up right away we cannot do this.

[NO NEW TESTS NEEDED]

Fixes #12459

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-12-01 19:19:44 +01:00
5432bb95f1 Merge pull request #12174 from fgimenez/fix-docker-networksettings-type-discrepancy
Introduces Address type to be used in secondary IPv4 and IPv6 inspect data structure
2021-11-19 13:57:13 +01:00
62d6b6bf74 rootless netns, one netns per libpod tmp dir
The netns cleanup code is checking if there are running containers, this
can fail if you run several libpod instances with diffrent root/runroot.
To fix it we use one netns for each libpod instances. To prevent name
conflicts we use a hash from the static dir as part of the name.

Previously this worked because we would use the CNI files to check if
the netns was still in use. but this is no longer possible with netavark.

[NO NEW TESTS NEEDED]

Fixes #12306

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-11-18 17:34:06 +01:00
2e5d3e8fb3 Introduce Address type to be used in secondary IPv4 and IPv6 inspect data
structure.

Resolves a discrepancy between the types used in inspect for docker and podman.
This causes a panic when using the docker client against podman when the
secondary IP fields in the `NetworkSettings` inspect field are populated.

Fixes containers#12165

Signed-off-by: Federico Gimenez <fgimenez@redhat.com>
2021-11-18 17:04:49 +01:00
97c6403a1b rename libpod nettypes fields
Some field names are confusing. Change them so that they make more sense
to the reader.
Since these fields are only in the main branch we can safely rename them
without worrying about backwards compatibility.
Note we have to change the field names in netavark too.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-11-16 19:19:04 +01:00
295d87bb0b podman machine improve port forwarding
This commits adds port forwarding logic directly into podman. The
podman-machine cni plugin is no longer needed.

The following new features are supported:
 - works with cni, netavark and slirp4netns
 - ports can use the hostIP to bind instead of hard coding 0.0.0.0
 - gvproxy no longer listens on 0.0.0.0:7777 (requires a new gvproxy
   version)
 - support the udp protocol

With this we no longer need podman-machine-cni and should remove it from
the packaging. There is also a change to make sure we are backwards
compatible with old config which include this plugin.

Fixes #11528
Fixes #11728

[NO NEW TESTS NEEDED] We have no podman machine test at the moment.
Please test this manually on your system.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-11-15 15:20:47 +01:00
216e2cb366 Fix rootless networking with userns and ports
A rootless container created with a custom userns and forwarded ports
did not work. I refactored the network setup to make the setup logic
more clear.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-11-09 15:58:57 +01:00
abbd6c167e Merge pull request #11890 from Luap99/ports
libpod: deduplicate ports in db
2021-11-06 10:39:16 +01:00
7f433df7e7 rename rootless cni ns to rootless netns
Since we want to use the rootless cni ns also for netavark we should
pick a more generic name. The name is now "rootless network namespace"
or short "rootless netns".

The rename might cause some issues after the update but when the
all containers are restarted or the host is rebooted it should work
correctly.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-11-05 15:44:37 +01:00
58f8c3d743 mount full XDG_RUNTIME_DIR in rootless cni ns
We should mount the full runtime directory into the namespace instead of
just the netns dir. This allows more use cases.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-11-05 15:41:04 +01:00
614c6f5970 Fix rootless cni netns cleanup logic
The check if cleanup is needed reads all container and checks if there
are running containers with bridge networking. If we do not find any we
have to cleanup the ns. However there was a problem with this because
the state is empty by default so the running check never worked.
Fortunately the was a second check which relies on the CNI files so we
still did cleanup anyway.

With netavark I noticed that this check is broken because the CNI files
were not present.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-11-05 00:20:10 +01:00
0136a66a83 libpod: deduplicate ports in db
The OCICNI port format has one big problem: It does not support ranges.
So if a users forwards a range of 1k ports with podman run -p 1001-2000
we have to store each of the thousand ports individually as array element.
This bloats the db and makes the JSON encoding and decoding much slower.
In many places we already use a better port struct type which supports
ranges, e.g. `pkg/specgen` or the new network interface.

Because of this we have to do many runtime conversions between the two
port formats. If everything uses the new format we can skip the runtime
conversions.

This commit adds logic to replace all occurrences of the old format
with the new one. The database will automatically migrate the ports
to new format when the container config is read for the first time
after the update.

The `ParsePortMapping` function is `pkg/specgen/generate` has been
reworked to better work with the new format. The new logic is able
to deduplicate the given ports. This is necessary the ensure we
store them efficiently in the DB. The new code should also be more
performant than the old one.

To prove that the code is fast enough I added go benchmarks. Parsing
1 million ports took less than 0.5 seconds on my laptop.

Benchmark normalize PortMappings in specgen:
Please note that the 1 million ports are actually 20x 50k ranges
because we cannot have bigger ranges than 65535 ports.
```
$ go test -bench=. -benchmem  ./pkg/specgen/generate/
goos: linux
goarch: amd64
pkg: github.com/containers/podman/v3/pkg/specgen/generate
cpu: Intel(R) Core(TM) i7-10850H CPU @ 2.70GHz
BenchmarkParsePortMappingNoPorts-12             480821532                2.230 ns/op           0 B/op          0 allocs/op
BenchmarkParsePortMapping1-12                      38972             30183 ns/op          131584 B/op          9 allocs/op
BenchmarkParsePortMapping100-12                    18752             60688 ns/op          141088 B/op        315 allocs/op
BenchmarkParsePortMapping1k-12                      3104            331719 ns/op          223840 B/op       3018 allocs/op
BenchmarkParsePortMapping10k-12                      376           3122930 ns/op         1223650 B/op      30027 allocs/op
BenchmarkParsePortMapping1m-12                         3         390869926 ns/op        124593840 B/op   4000624 allocs/op
BenchmarkParsePortMappingReverse100-12             18940             63414 ns/op          141088 B/op        315 allocs/op
BenchmarkParsePortMappingReverse1k-12               3015            362500 ns/op          223841 B/op       3018 allocs/op
BenchmarkParsePortMappingReverse10k-12               343           3318135 ns/op         1223650 B/op      30027 allocs/op
BenchmarkParsePortMappingReverse1m-12                  3         403392469 ns/op        124593840 B/op   4000624 allocs/op
BenchmarkParsePortMappingRange1-12                 37635             28756 ns/op          131584 B/op          9 allocs/op
BenchmarkParsePortMappingRange100-12               39604             28935 ns/op          131584 B/op          9 allocs/op
BenchmarkParsePortMappingRange1k-12                38384             29921 ns/op          131584 B/op          9 allocs/op
BenchmarkParsePortMappingRange10k-12               29479             40381 ns/op          131584 B/op          9 allocs/op
BenchmarkParsePortMappingRange1m-12                  927           1279369 ns/op          143022 B/op        164 allocs/op
PASS
ok      github.com/containers/podman/v3/pkg/specgen/generate    25.492s
```

Benchmark convert old port format to new one:
```
go test -bench=. -benchmem  ./libpod/
goos: linux
goarch: amd64
pkg: github.com/containers/podman/v3/libpod
cpu: Intel(R) Core(TM) i7-10850H CPU @ 2.70GHz
Benchmark_ocicniPortsToNetTypesPortsNoPorts-12          663526126                1.663 ns/op           0 B/op          0 allocs/op
Benchmark_ocicniPortsToNetTypesPorts1-12                 7858082               141.9 ns/op            72 B/op          2 allocs/op
Benchmark_ocicniPortsToNetTypesPorts10-12                2065347               571.0 ns/op           536 B/op          4 allocs/op
Benchmark_ocicniPortsToNetTypesPorts100-12                138478              8641 ns/op            4216 B/op          4 allocs/op
Benchmark_ocicniPortsToNetTypesPorts1k-12                   9414            120964 ns/op           41080 B/op          4 allocs/op
Benchmark_ocicniPortsToNetTypesPorts10k-12                   781           1490526 ns/op          401528 B/op          4 allocs/op
Benchmark_ocicniPortsToNetTypesPorts1m-12                      4         250579010 ns/op        40001656 B/op          4 allocs/op
PASS
ok      github.com/containers/podman/v3/libpod  11.727s
```

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-10-27 18:59:56 +02:00
1c8926285d move network alias validation to container create
Podman 4.0 currently errors when you use network aliases for a network which
has dns disabled. Because the error happens on network setup this can
cause regression for old working containers. The network backend should not
validate this. Instead podman should check this at container create time
and also for network connect.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-09-28 13:40:27 +02:00
05614ee139 always add short container id as net alias
This matches what docker does. Also make sure the net aliases are also
shown when the container is stopped.

docker-compose uses this special alias entry to check if it is already
correctly connected to the network. [1]
Because we do not support static ips on network connect at the moment
calling disconnect && connect will loose the static ip.

Fixes #11748

[1] 0bea52b18d/compose/service.py (L663-L667)

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-09-28 13:40:22 +02:00
1c4e6d8624 standardize logrus messages to upper case
Remove ERROR: Error stutter from logrus messages also.

[ NO TESTS NEEDED] This is just code cleanup.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
2021-09-22 15:29:34 -04:00
b906b9d858 Drop OCICNI dependency
We do not use the ocicni code anymore so let's get rid of it. Only the
port struct is used but we can copy this into libpod network types so
we can debloat the binary.

The next step is to remove the OCICNI port mapping form the container
config and use the better PortMapping struct everywhere.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-09-15 20:00:28 +02:00
85e8fbf7f3 Wire network interface into libpod
Make use of the new network interface in libpod.

This commit contains several breaking changes:
- podman network create only outputs the new network name and not file
  path.
- podman network ls shows the network driver instead of the cni version
  and plugins.
- podman network inspect outputs the new network struct and not the cni
  conflist.
- The bindings and libpod api endpoints have been changed to use the new
  network structure.

The container network status is stored in a new field in the state. The
status should be received with the new `c.getNetworkStatus`. This will
migrate the old status to the new format. Therefore old containers should
contine to work correctly in all cases even when network connect/
disconnect is used.

New features:
- podman network reload keeps the ip and mac for more than one network.
- podman container restore keeps the ip and mac for more than one
  network.
- The network create compat endpoint can now use more than one ipam
  config.

The man pages and the swagger doc are updated to reflect the latest
changes.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-09-15 20:00:20 +02:00
6221f269a8 fix restart always with rootlessport
When a container is automatically restarted due its restart policy and
the container uses rootless cni networking with ports forwarded we have
to start a new rootlessport process since it exits with conmon.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-09-13 22:52:39 +02:00
06f94dd09e rootless cni: resolve absolute symlinks correctly
When /etc/resolv.conf is a symlink to an absolute path use it and not
join it the the previous path.

[NO TESTS NEEDED] This depends on the host layout.

Fixes #11358

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-08-30 16:55:26 +02:00
d28e85741f InfraContainer Rework
InfraContainer should go through the same creation process as regular containers. This change was from the cmd level
down, involving new container CLI opts and specgen creating functions. What now happens is that both container and pod
cli options are populated in cmd and used to create a podSpecgen and a containerSpecgen. The process then goes as follows

FillOutSpecGen (infra) -> MapSpec (podOpts -> infraOpts) -> PodCreate -> MakePod -> createPodOptions -> NewPod -> CompleteSpec (infra) -> MakeContainer -> NewContainer -> newContainer -> AddInfra (to pod state)

Signed-off-by: cdoern <cdoern@redhat.com>
2021-08-26 16:05:16 -04:00
4b2dc48d0b podman inspect show exposed ports
Podman inspect has to show exposed ports to match docker. This requires
storing the exposed ports in the container config.
A exposed port is shown as `"80/tcp": null` while a forwarded port is
shown as `"80/tcp": [{"HostIp": "", "HostPort": "8080" }]`.

Also make sure to add the exposed ports to the new image when the
container is commited.

Fixes #10777

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-08-24 15:44:26 +02:00
2a8c414488 Fix rootless cni dns without systemd stub resolver
When a host uses systemd-resolved but not the resolved stub resolver the
following symlinks are created: `/etc/resolv.conf` ->
`/run/systemd/resolve/stub-resolv.conf` -> `/run/systemd/resolve/resolv.conf`.
Because the code uses filepath.EvalSymlinks we put the new resolv.conf
to `/run/systemd/resolve/resolv.conf` but the `/run/systemd/resolve/stub-resolv.conf`
link does not exists in the mount ns.
To fix this we will walk the symlinks manually until we reach the first
one under `/run` and use this for the resolv.conf file destination.

This fixes a regression which was introduced in e73d4829900c.

Fixes #11222

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-08-16 11:30:11 +02:00
404488a087 Run codespell to fix spelling
[NO TESTS NEEDED] Just fixing spelling.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
2021-08-11 16:41:45 -04:00
e88d8dbeae fix rootless port forwarding with network dis-/connect
The rootlessport forwarder requires a child IP to be set. This must be a
valid ip in the container network namespace. The problem is that after a
network disconnect and connect the eth0 ip changed. Therefore the
packages are dropped since the source ip does no longer exists in the
netns.
One solution is to set the child IP to 127.0.0.1, however this is a
security problem. [1]

To fix this we have to recreate the ports after network connect and
disconnect. To make this work the rootlessport process exposes a socket
where podman network connect/disconnect connect to and send to new child
IP to rootlessport. The rootlessport process will remove all ports and
recreate them with the new correct child IP.

Also bump rootlesskit to v0.14.3 to fix a race with RemovePort().

Fixes #10052

[1] https://nvd.nist.gov/vuln/detail/CVE-2021-20199

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-08-03 16:29:09 +02:00
d24fc6b843 Merge pull request #10939 from Luap99/rootless-cni
Fix race conditions in rootless cni setup
2021-07-15 11:11:10 -04:00
0007c98ddb Fix race conditions in rootless cni setup
There was an race condition when calling `GetRootlessCNINetNs()`. It
created the rootless cni directory before it got locked. Therefore
another process could have called cleanup and removed this directory
before it was used resulting in errors. The lockfile got moved into the
XDG_RUNTIME_DIR directory to prevent a panic when the parent dir was
removed by cleanup.

Fixes #10930
Fixes #10922

To make this even more robust `GetRootlessCNINetNs()` will now return
locked. This guarantees that we can run `Do()` after `GetRootlessCNINetNs()`
before another process could have called `Cleanup()` in between.

[NO TESTS NEEDED] CI is flaking, hopefully this will fix it.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
2021-07-15 14:33:56 +02:00
e73d482990 CNI-in-slirp4netns: fix bind-mount for /run/systemd/resolve/stub-resolv.conf
Fix issue 10929 : `[Regression in 3.2.0] CNI-in-slirp4netns DNS gets broken when running a rootful container after running a rootless container`

When /etc/resolv.conf on the host is a symlink to /run/systemd/resolve/stub-resolv.conf,
we have to mount an empty filesystem on /run/systemd/resolve in the child namespace,
so as to isolate the directory from the host mount namespace.

Otherwise our bind-mount for /run/systemd/resolve/stub-resolv.conf is unmounted
when systemd-resolved unlinks and recreates /run/systemd/resolve/stub-resolv.conf on the host.

[NO TESTS NEEDED]

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
2021-07-15 17:25:09 +09:00