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-rw-r--r--libpod/container.go9
-rw-r--r--libpod/container_internal.go80
-rw-r--r--libpod/container_internal_linux.go228
-rw-r--r--libpod/container_internal_linux_test.go28
-rw-r--r--libpod/networking_linux.go70
5 files changed, 168 insertions, 247 deletions
diff --git a/libpod/container.go b/libpod/container.go
index bc3cab439..6e2b7f528 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -628,6 +628,15 @@ func (c *Container) RuntimeName() string {
// Hostname gets the container's hostname
func (c *Container) Hostname() string {
+ if c.config.UTSNsCtr != "" {
+ utsNsCtr, err := c.runtime.GetContainer(c.config.UTSNsCtr)
+ if err != nil {
+ // should we return an error here?
+ logrus.Errorf("unable to lookup uts namespace for container %s: %v", c.ID(), err)
+ return ""
+ }
+ return utsNsCtr.Hostname()
+ }
if c.config.Spec.Hostname != "" {
return c.config.Spec.Hostname
}
diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index b051b7f2d..6c0d51df3 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -1,7 +1,6 @@
package libpod
import (
- "bufio"
"bytes"
"context"
"fmt"
@@ -17,8 +16,10 @@ import (
"github.com/containers/buildah/copier"
"github.com/containers/buildah/pkg/overlay"
butil "github.com/containers/buildah/util"
+ "github.com/containers/common/libnetwork/etchosts"
"github.com/containers/common/pkg/cgroups"
"github.com/containers/common/pkg/chown"
+ "github.com/containers/common/pkg/config"
"github.com/containers/podman/v4/libpod/define"
"github.com/containers/podman/v4/libpod/events"
"github.com/containers/podman/v4/pkg/ctime"
@@ -31,6 +32,7 @@ import (
"github.com/containers/storage"
"github.com/containers/storage/pkg/archive"
"github.com/containers/storage/pkg/idtools"
+ "github.com/containers/storage/pkg/lockfile"
"github.com/containers/storage/pkg/mount"
"github.com/coreos/go-systemd/v22/daemon"
securejoin "github.com/cyphar/filepath-securejoin"
@@ -1006,17 +1008,14 @@ func (c *Container) completeNetworkSetup() error {
}
}
// check if we have a bindmount for /etc/hosts
- if hostsBindMount, ok := state.BindMounts["/etc/hosts"]; ok && len(c.cniHosts()) > 0 {
- ctrHostPath := filepath.Join(c.state.RunDir, "hosts")
- if hostsBindMount == ctrHostPath {
- // read the existing hosts
- b, err := ioutil.ReadFile(hostsBindMount)
- if err != nil {
- return err
- }
- if err := ioutil.WriteFile(hostsBindMount, append(b, []byte(c.cniHosts())...), 0644); err != nil {
- return err
- }
+ if hostsBindMount, ok := state.BindMounts[config.DefaultHostsFile]; ok {
+ entries, err := c.getHostsEntries()
+ if err != nil {
+ return err
+ }
+ // add new container ips to the hosts file
+ if err := etchosts.Add(hostsBindMount, entries); err != nil {
+ return err
}
}
@@ -1041,18 +1040,6 @@ func (c *Container) completeNetworkSetup() error {
return ioutil.WriteFile(resolvBindMount, []byte(strings.Join(outResolvConf, "\n")), 0644)
}
-func (c *Container) cniHosts() string {
- var hosts string
- for _, status := range c.getNetworkStatus() {
- for _, netInt := range status.Interfaces {
- for _, netAddress := range netInt.Subnets {
- hosts += fmt.Sprintf("%s\t%s %s\n", netAddress.IPNet.IP.String(), c.Hostname(), c.config.Name)
- }
- }
- }
- return hosts
-}
-
// Initialize a container, creating it in the runtime
func (c *Container) init(ctx context.Context, retainRetries bool) error {
// Unconditionally remove conmon temporary files.
@@ -1894,6 +1881,24 @@ func (c *Container) cleanup(ctx context.Context) error {
lastError = errors.Wrapf(err, "error removing container %s network", c.ID())
}
+ // cleanup host entry if it is shared
+ if c.config.NetNsCtr != "" {
+ if hoststFile, ok := c.state.BindMounts[config.DefaultHostsFile]; ok {
+ if _, err := os.Stat(hoststFile); err == nil {
+ // we cannot use the dependency container lock due ABBA deadlocks
+ if lock, err := lockfile.GetLockfile(hoststFile); err == nil {
+ lock.Lock()
+ // make sure to ignore ENOENT error in case the netns container was cleanup before this one
+ if err := etchosts.Remove(hoststFile, getLocalhostHostEntry(c)); err != nil && !errors.Is(err, os.ErrNotExist) {
+ // this error is not fatal we still want to do proper cleanup
+ logrus.Errorf("failed to remove hosts entry from the netns containers /etc/hosts: %v", err)
+ }
+ lock.Unlock()
+ }
+ }
+ }
+ }
+
// Remove the container from the runtime, if necessary.
// Do this *before* unmounting storage - some runtimes (e.g. Kata)
// apparently object to having storage removed while the container still
@@ -2030,33 +2035,6 @@ func (c *Container) writeStringToStaticDir(filename, contents string) (string, e
return destFileName, nil
}
-// appendStringToRunDir appends the provided string to the runtimedir file
-func (c *Container) appendStringToRunDir(destFile, output string) (string, error) {
- destFileName := filepath.Join(c.state.RunDir, destFile)
-
- f, err := os.OpenFile(destFileName, os.O_APPEND|os.O_RDWR, 0600)
- if err != nil {
- return "", err
- }
- defer f.Close()
-
- compareStr := strings.TrimRight(output, "\n")
- scanner := bufio.NewScanner(f)
- scanner.Split(bufio.ScanLines)
-
- for scanner.Scan() {
- if strings.Compare(scanner.Text(), compareStr) == 0 {
- return filepath.Join(c.state.RunDir, destFile), nil
- }
- }
-
- if _, err := f.WriteString(output); err != nil {
- return "", errors.Wrapf(err, "unable to write %s", destFileName)
- }
-
- return filepath.Join(c.state.RunDir, destFile), nil
-}
-
// saveSpec saves the OCI spec to disk, replacing any existing specs for the container
func (c *Container) saveSpec(spec *spec.Spec) error {
// If the OCI spec already exists, we need to replace it
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index 6ffd99649..9d0c8ff8c 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -28,6 +28,7 @@ import (
"github.com/containers/buildah/pkg/chrootuser"
"github.com/containers/buildah/pkg/overlay"
butil "github.com/containers/buildah/util"
+ "github.com/containers/common/libnetwork/etchosts"
"github.com/containers/common/libnetwork/types"
"github.com/containers/common/pkg/apparmor"
"github.com/containers/common/pkg/cgroups"
@@ -49,6 +50,7 @@ import (
"github.com/containers/podman/v4/version"
"github.com/containers/storage/pkg/archive"
"github.com/containers/storage/pkg/idtools"
+ "github.com/containers/storage/pkg/lockfile"
securejoin "github.com/cyphar/filepath-securejoin"
runcuser "github.com/opencontainers/runc/libcontainer/user"
spec "github.com/opencontainers/runtime-spec/specs-go"
@@ -2079,23 +2081,25 @@ func (c *Container) makeBindMounts() error {
// check if dependency container has an /etc/hosts file.
// It may not have one, so only use it if it does.
- hostsPath, exists := bindMounts["/etc/hosts"]
+ hostsPath, exists := bindMounts[config.DefaultHostsFile]
if !c.config.UseImageHosts && exists {
- depCtr.lock.Lock()
- // generate a hosts file for the dependency container,
- // based on either its old hosts file, or the default,
- // and add the relevant information from the new container (hosts and IP)
- hostsPath, err = depCtr.appendHosts(hostsPath, c)
+ // we cannot use the dependency container lock due ABBA deadlocks in cleanup()
+ lock, err := lockfile.GetLockfile(hostsPath)
+ if err != nil {
+ return fmt.Errorf("failed to lock hosts file: %w", err)
+ }
+ lock.Lock()
+ // add the newly added container to the hosts file
+ // we always use 127.0.0.1 as ip since they have the same netns
+ err = etchosts.Add(hostsPath, getLocalhostHostEntry(c))
+ lock.Unlock()
if err != nil {
- depCtr.lock.Unlock()
return errors.Wrapf(err, "error creating hosts file for container %s which depends on container %s", c.ID(), depCtr.ID())
}
- depCtr.lock.Unlock()
// finally, save it in the new container
- err := c.mountIntoRootDirs("/etc/hosts", hostsPath)
-
+ err = c.mountIntoRootDirs(config.DefaultHostsFile, hostsPath)
if err != nil {
return errors.Wrapf(err, "error assigning mounts to container %s", c.ID())
}
@@ -2123,7 +2127,7 @@ func (c *Container) makeBindMounts() error {
}
if !c.config.UseImageHosts {
- if err := c.updateHosts("/etc/hosts"); err != nil {
+ if err := c.createHosts(); err != nil {
return errors.Wrapf(err, "error creating hosts file for container %s", c.ID())
}
}
@@ -2142,7 +2146,7 @@ func (c *Container) makeBindMounts() error {
}
} else {
if !c.config.UseImageHosts && c.state.BindMounts["/etc/hosts"] == "" {
- if err := c.updateHosts("/etc/hosts"); err != nil {
+ if err := c.createHosts(); err != nil {
return errors.Wrapf(err, "error creating hosts file for container %s", c.ID())
}
}
@@ -2528,169 +2532,79 @@ func (c *Container) removeNameserver(ips []string) error {
return nil
}
-// updateHosts updates the container's hosts file
-func (c *Container) updateHosts(path string) error {
- var hosts string
-
- orig, err := ioutil.ReadFile(path)
- if err != nil {
- // Ignore if the path does not exist
- if !os.IsNotExist(err) {
- return err
- }
- } else {
- hosts = string(orig)
- }
-
- hosts += c.getHosts()
- hosts = c.appendLocalhost(hosts)
-
- newHosts, err := c.writeStringToRundir("hosts", hosts)
- if err != nil {
- return err
- }
-
- if err = c.mountIntoRootDirs("/etc/hosts", newHosts); err != nil {
- return err
- }
-
- return nil
+func getLocalhostHostEntry(c *Container) etchosts.HostEntries {
+ return etchosts.HostEntries{{IP: "127.0.0.1", Names: []string{c.Hostname(), c.config.Name}}}
}
-// based on networking mode we may want to append the localhost
-// if there isn't any record for it and also this should happen
-// in slirp4netns and similar network modes.
-func (c *Container) appendLocalhost(hosts string) string {
- if !strings.Contains(hosts, "localhost") &&
- !c.config.NetMode.IsHost() {
- hosts += "127.0.0.1\tlocalhost\n::1\tlocalhost\n"
- }
-
- return hosts
-}
-
-// appendHosts appends a container's config and state pertaining to hosts to a container's
-// local hosts file. netCtr is the container from which the netNS information is
-// taken.
-// path is the basis of the hosts file, into which netCtr's netNS information will be appended.
-// FIXME. Path should be used by this function,but I am not sure what is correct; remove //lint
-// once this is fixed
-func (c *Container) appendHosts(path string, netCtr *Container) (string, error) { //nolint
- return c.appendStringToRunDir("hosts", netCtr.getHosts())
-}
-
-// getHosts finds the pertinent information for a container's host file in its config and state
-// and returns a string in a format that can be written to the host file
-func (c *Container) getHosts() string {
- var hosts string
-
- if len(c.config.HostAdd) > 0 {
- for _, host := range c.config.HostAdd {
- // the host format has already been verified at this point
- fields := strings.SplitN(host, ":", 2)
- hosts += fmt.Sprintf("%s %s\n", fields[1], fields[0])
- }
- }
-
- hosts += c.cniHosts()
-
- // Add hostname for slirp4netns
- if c.Hostname() != "" {
- if c.config.NetMode.IsSlirp4netns() {
- // When using slirp4netns, the interface gets a static IP
- slirp4netnsIP, err := GetSlirp4netnsIP(c.slirp4netnsSubnet)
- if err != nil {
- logrus.Warnf("Failed to determine slirp4netnsIP: %v", err.Error())
- } else {
- hosts += fmt.Sprintf("# used by slirp4netns\n%s\t%s %s\n", slirp4netnsIP.String(), c.Hostname(), c.config.Name)
- }
+// getHostsEntries returns the container ip host entries for the correct netmode
+func (c *Container) getHostsEntries() (etchosts.HostEntries, error) {
+ var entries etchosts.HostEntries
+ names := []string{c.Hostname(), c.config.Name}
+ switch {
+ case c.config.NetMode.IsBridge():
+ entries = etchosts.GetNetworkHostEntries(c.state.NetworkStatus, names...)
+ case c.config.NetMode.IsSlirp4netns():
+ ip, err := GetSlirp4netnsIP(c.slirp4netnsSubnet)
+ if err != nil {
+ return nil, err
}
-
- // Do we have a network namespace?
- netNone := false
- if c.config.NetNsCtr == "" && !c.config.CreateNetNS {
+ entries = etchosts.HostEntries{{IP: ip.String(), Names: names}}
+ default:
+ // check for net=none
+ if !c.config.CreateNetNS {
for _, ns := range c.config.Spec.Linux.Namespaces {
if ns.Type == spec.NetworkNamespace {
if ns.Path == "" {
- netNone = true
+ entries = etchosts.HostEntries{{IP: "127.0.0.1", Names: names}}
}
break
}
}
}
- // If we are net=none (have a network namespace, but not connected to
- // anything) add the container's name and hostname to localhost.
- if netNone {
- hosts += fmt.Sprintf("127.0.0.1 %s %s\n", c.Hostname(), c.config.Name)
- }
}
+ return entries, nil
+}
- // Add gateway entry if we are not in a machine. If we use podman machine
- // the gvproxy dns server will take care of host.containers.internal.
- // https://github.com/containers/gvisor-tap-vsock/commit/1108ea45162281046d239047a6db9bc187e64b08
- if !c.runtime.config.Engine.MachineEnabled {
- var depCtr *Container
- netStatus := c.getNetworkStatus()
- if c.config.NetNsCtr != "" {
- // ignoring the error because there isn't anything to do
- depCtr, _ = c.getRootNetNsDepCtr()
- } else if len(netStatus) != 0 {
- depCtr = c
+func (c *Container) createHosts() error {
+ var containerIPsEntries etchosts.HostEntries
+ var err error
+ // if we configure the netns after the container create we should not add
+ // the hosts here since we have no information about the actual ips
+ // instead we will add them in c.completeNetworkSetup()
+ if !c.config.PostConfigureNetNS {
+ containerIPsEntries, err = c.getHostsEntries()
+ if err != nil {
+ return fmt.Errorf("failed to get container ip host entries: %w", err)
}
+ }
+ baseHostFile, err := etchosts.GetBaseHostFile(c.runtime.config.Containers.BaseHostsFile, c.state.Mountpoint)
+ if err != nil {
+ return err
+ }
- // getLocalIP returns the non loopback local IP of the host
- getLocalIP := func() string {
- addrs, err := net.InterfaceAddrs()
- if err != nil {
- return ""
- }
- for _, address := range addrs {
- // check the address type and if it is not a loopback the display it
- if ipnet, ok := address.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
- if ipnet.IP.To4() != nil {
- return ipnet.IP.String()
- }
- }
- }
- return ""
- }
+ targetFile := filepath.Join(c.state.RunDir, "hosts")
+ err = etchosts.New(&etchosts.Params{
+ BaseFile: baseHostFile,
+ ExtraHosts: c.config.HostAdd,
+ ContainerIPs: containerIPsEntries,
+ HostContainersInternalIP: etchosts.GetHostContainersInternalIP(c.runtime.config, c.state.NetworkStatus, c.runtime.network),
+ TargetFile: targetFile,
+ })
+ if err != nil {
+ return err
+ }
- if depCtr != nil {
- host := ""
- outer:
- for net, status := range depCtr.getNetworkStatus() {
- network, err := c.runtime.network.NetworkInspect(net)
- // only add the host entry for bridge networks
- // ip/macvlan gateway is normally not on the host
- if err != nil || network.Driver != types.BridgeNetworkDriver {
- continue
- }
- for _, netInt := range status.Interfaces {
- for _, netAddress := range netInt.Subnets {
- if netAddress.Gateway != nil {
- host = fmt.Sprintf("%s host.containers.internal\n", netAddress.Gateway.String())
- break outer
- }
- }
- }
- }
- // if no bridge gw was found try to use a local ip
- if host == "" {
- if ip := getLocalIP(); ip != "" {
- host = fmt.Sprintf("%s\t%s\n", ip, "host.containers.internal")
- }
- }
- hosts += host
- } else if c.config.NetMode.IsSlirp4netns() {
- if ip := getLocalIP(); ip != "" {
- hosts += fmt.Sprintf("%s\t%s\n", ip, "host.containers.internal")
- }
- } else {
- logrus.Debug("Network configuration does not support host.containers.internal address")
- }
+ if err := os.Chown(targetFile, c.RootUID(), c.RootGID()); err != nil {
+ return err
+ }
+ if err := label.Relabel(targetFile, c.MountLabel(), false); err != nil {
+ return err
}
- return hosts
+ if err = c.mountIntoRootDirs(config.DefaultHostsFile, targetFile); err != nil {
+ return err
+ }
+ return nil
}
// generateGroupEntry generates an entry or entries into /etc/group as
diff --git a/libpod/container_internal_linux_test.go b/libpod/container_internal_linux_test.go
index a7dd0fc31..2c1193445 100644
--- a/libpod/container_internal_linux_test.go
+++ b/libpod/container_internal_linux_test.go
@@ -8,7 +8,6 @@ import (
"os"
"testing"
- "github.com/containers/podman/v4/pkg/namespaces"
spec "github.com/opencontainers/runtime-spec/specs-go"
"github.com/stretchr/testify/assert"
)
@@ -70,30 +69,3 @@ func TestGenerateUserGroupEntry(t *testing.T) {
}
assert.Equal(t, group, "567:x:567:567\n")
}
-
-func TestAppendLocalhost(t *testing.T) {
- {
- c := Container{
- config: &ContainerConfig{
- ContainerNetworkConfig: ContainerNetworkConfig{
- NetMode: namespaces.NetworkMode("slirp4netns"),
- },
- },
- }
-
- assert.Equal(t, "127.0.0.1\tlocalhost\n::1\tlocalhost\n", c.appendLocalhost(""))
- assert.Equal(t, "127.0.0.1\tlocalhost", c.appendLocalhost("127.0.0.1\tlocalhost"))
- }
- {
- c := Container{
- config: &ContainerConfig{
- ContainerNetworkConfig: ContainerNetworkConfig{
- NetMode: namespaces.NetworkMode("host"),
- },
- },
- }
-
- assert.Equal(t, "", c.appendLocalhost(""))
- assert.Equal(t, "127.0.0.1\tlocalhost", c.appendLocalhost("127.0.0.1\tlocalhost"))
- }
-}
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go
index 71e29f18f..41beaf41d 100644
--- a/libpod/networking_linux.go
+++ b/libpod/networking_linux.go
@@ -20,7 +20,9 @@ import (
"time"
"github.com/containernetworking/plugins/pkg/ns"
+ "github.com/containers/common/libnetwork/etchosts"
"github.com/containers/common/libnetwork/types"
+ "github.com/containers/common/pkg/config"
"github.com/containers/common/pkg/netns"
"github.com/containers/podman/v4/libpod/define"
"github.com/containers/podman/v4/libpod/events"
@@ -1282,15 +1284,35 @@ func (c *Container) NetworkDisconnect(nameOrID, netName string, force bool) erro
for _, ip := range oldStatus.DNSServerIPs {
stringIPs = append(stringIPs, ip.String())
}
- if len(stringIPs) == 0 {
- return nil
+ if len(stringIPs) > 0 {
+ logrus.Debugf("Removing DNS Servers %v from resolv.conf", stringIPs)
+ if err := c.removeNameserver(stringIPs); err != nil {
+ return err
+ }
}
- logrus.Debugf("Removing DNS Servers %v from resolv.conf", stringIPs)
- if err := c.removeNameserver(stringIPs); err != nil {
- return err
+
+ // update /etc/hosts file
+ if file, ok := c.state.BindMounts[config.DefaultHostsFile]; ok {
+ // sync the names with c.getHostsEntries()
+ names := []string{c.Hostname(), c.config.Name}
+ rm := etchosts.GetNetworkHostEntries(map[string]types.StatusBlock{netName: oldStatus}, names...)
+ if len(rm) > 0 {
+ // make sure to lock this file to prevent concurrent writes when
+ // this is used a net dependency container
+ lock, err := lockfile.GetLockfile(file)
+ if err != nil {
+ return fmt.Errorf("failed to lock hosts file: %w", err)
+ }
+ logrus.Debugf("Remove /etc/hosts entries %v", rm)
+ lock.Lock()
+ err = etchosts.Remove(file, rm)
+ lock.Unlock()
+ if err != nil {
+ return err
+ }
+ }
}
}
-
return nil
}
@@ -1361,6 +1383,13 @@ func (c *Container) NetworkConnect(nameOrID, netName string, netOpts types.PerNe
return errors.New("when adding aliases, results must be of length 1")
}
+ // we need to get the old host entries before we add the new one to the status
+ // if we do not add do it here we will get the wrong existing entries which will throw of the logic
+ // we could also copy the map but this does not seem worth it
+ // sync the hostNames with c.getHostsEntries()
+ hostNames := []string{c.Hostname(), c.config.Name}
+ oldHostEntries := etchosts.GetNetworkHostEntries(networkStatus, hostNames...)
+
// update network status
if networkStatus == nil {
networkStatus = make(map[string]types.StatusBlock, 1)
@@ -1394,12 +1423,31 @@ func (c *Container) NetworkConnect(nameOrID, netName string, netOpts types.PerNe
}
stringIPs = append(stringIPs, ip.String())
}
- if len(stringIPs) == 0 {
- return nil
+ if len(stringIPs) > 0 {
+ logrus.Debugf("Adding DNS Servers %v to resolv.conf", stringIPs)
+ if err := c.addNameserver(stringIPs); err != nil {
+ return err
+ }
}
- logrus.Debugf("Adding DNS Servers %v to resolv.conf", stringIPs)
- if err := c.addNameserver(stringIPs); err != nil {
- return err
+
+ // update /etc/hosts file
+ if file, ok := c.state.BindMounts[config.DefaultHostsFile]; ok {
+ // make sure to lock this file to prevent concurrent writes when
+ // this is used a net dependency container
+ lock, err := lockfile.GetLockfile(file)
+ if err != nil {
+ return fmt.Errorf("failed to lock hosts file: %w", err)
+ }
+ new := etchosts.GetNetworkHostEntries(results, hostNames...)
+ logrus.Debugf("Add /etc/hosts entries %v", new)
+ // use special AddIfExists API to make sure we only add new entries if an old one exists
+ // see the AddIfExists() comment for more information
+ lock.Lock()
+ err = etchosts.AddIfExists(file, oldHostEntries, new)
+ lock.Unlock()
+ if err != nil {
+ return err
+ }
}
return nil
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-11-20 05:40:20 +0000