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| author | Paul Holzinger <pholzing@redhat.com> | 2022-04-29 15:01:56 +0200 |
|---|---|---|
| committer | Paul Holzinger <pholzing@redhat.com> | 2022-04-29 15:37:14 +0200 |
| commit | 01acc2565ac6bba44da270d59b90231a0bca3319 (patch) | |
| tree | 2d5694f2133962eccab7832ec4ba1c20042e6f48 | |
| parent | 5198209269eb8248eb001e02d39b3dd0dfce6c19 (diff) | |
| download | podman-01acc2565ac6bba44da270d59b90231a0bca3319.tar.gz podman-01acc2565ac6bba44da270d59b90231a0bca3319.tar.bz2 podman-01acc2565ac6bba44da270d59b90231a0bca3319.zip | |
libpod: host netns keep same /etc/resolv.conf
When a container is run in the host network namespace we have to keep
the same resolv.conf content and not use the systemd-resolve detection
logic.
But also make sure we still allow --dns options.
Fixes #14055
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
| -rw-r--r-- | libpod/container_internal_linux.go | 6 | ||||
| -rw-r--r-- | test/system/500-networking.bats | 9 |
2 files changed, 13 insertions, 2 deletions
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index af6e7417b..13670bc86 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -2279,9 +2279,11 @@ func (c *Container) generateResolvConf() error { networkSearchDomains []string ) + hostns := true resolvConf := "/etc/resolv.conf" for _, namespace := range c.config.Spec.Linux.Namespaces { if namespace.Type == spec.NetworkNamespace { + hostns = false if namespace.Path != "" && !strings.HasPrefix(namespace.Path, "/proc/") { definedPath := filepath.Join("/etc/netns", filepath.Base(namespace.Path), "resolv.conf") _, err := os.Stat(definedPath) @@ -2303,7 +2305,7 @@ func (c *Container) generateResolvConf() error { ns := resolvconf.GetNameservers(contents) // check if systemd-resolved is used, assume it is used when 127.0.0.53 is the only nameserver - if len(ns) == 1 && ns[0] == "127.0.0.53" { + if !hostns && len(ns) == 1 && ns[0] == "127.0.0.53" { // read the actual resolv.conf file for systemd-resolved resolvedContents, err := ioutil.ReadFile("/run/systemd/resolve/resolv.conf") if err != nil { @@ -2336,7 +2338,7 @@ func (c *Container) generateResolvConf() error { // Ensure that the container's /etc/resolv.conf is compatible with its // network configuration. - resolv, err := resolvconf.FilterResolvDNS(contents, ipv6, c.config.CreateNetNS) + resolv, err := resolvconf.FilterResolvDNS(contents, ipv6, !hostns) if err != nil { return errors.Wrapf(err, "error parsing host resolv.conf") } diff --git a/test/system/500-networking.bats b/test/system/500-networking.bats index c7007741b..3db0804d1 100644 --- a/test/system/500-networking.bats +++ b/test/system/500-networking.bats @@ -656,6 +656,15 @@ EOF run_podman run --network $netname --rm $IMAGE cat /etc/resolv.conf is "$output" "search dns.podman.*" "correct search domain" is "$output" ".*nameserver $subnet.1.*" "integrated dns nameserver is set" + + # host network should keep localhost nameservers + if grep 127.0.0. /etc/resolv.conf >/dev/null; then + run_podman run --network host --rm $IMAGE cat /etc/resolv.conf + is "$output" ".*nameserver 127\.0\.0.*" "resolv.conf contains localhost nameserver" + fi + # host net + dns still works + run_podman run --network host --dns 1.1.1.1 --rm $IMAGE cat /etc/resolv.conf + is "$output" ".*nameserver 1\.1\.1\.1.*" "resolv.conf contains 1.1.1.1 nameserver" } @test "podman run port forward range" { |