diff options
Diffstat (limited to 'libpod/container_internal_linux.go')
-rw-r--r-- | libpod/container_internal_linux.go | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index e6071945d..ffb82cc94 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -11,6 +11,7 @@ import ( "os" "path" "path/filepath" + "strconv" "strings" "sync" "syscall" @@ -21,8 +22,11 @@ import ( crioAnnotations "github.com/containers/libpod/pkg/annotations" "github.com/containers/libpod/pkg/criu" "github.com/containers/libpod/pkg/lookup" + "github.com/containers/libpod/pkg/resolvconf" "github.com/containers/libpod/pkg/rootless" + "github.com/containers/libpod/pkg/secrets" "github.com/containers/storage/pkg/idtools" + "github.com/opencontainers/runc/libcontainer/user" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/opencontainers/runtime-tools/generate" "github.com/opencontainers/selinux/go-selinux/label" @@ -132,6 +136,9 @@ func (c *Container) prepare() (err error) { // cleanupNetwork unmounts and cleans up the container's network func (c *Container) cleanupNetwork() error { + if c.NetworkDisabled() { + return nil + } if c.state.NetNS == nil { logrus.Debugf("Network is already cleaned up, skipping...") return nil @@ -169,6 +176,11 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) { g.AddOrReplaceLinuxNamespace(spec.NetworkNamespace, c.state.NetNS.Path()) } } + + if err := c.makeBindMounts(); err != nil { + return nil, err + } + // Check if the spec file mounts contain the label Relabel flags z or Z. // If they do, relabel the source directory and then remove the option. for _, m := range g.Mounts() { @@ -347,8 +359,34 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) { // Mounts need to be sorted so paths will not cover other paths mounts := sortMounts(g.Mounts()) g.ClearMounts() + + // Determine property of RootPropagation based on volume properties. If + // a volume is shared, then keep root propagation shared. This should + // work for slave and private volumes too. + // + // For slave volumes, it can be either [r]shared/[r]slave. + // + // For private volumes any root propagation value should work. + rootPropagation := "" for _, m := range mounts { g.AddMount(m) + for _, opt := range m.Options { + switch opt { + case MountShared, MountRShared: + if rootPropagation != MountShared && rootPropagation != MountRShared { + rootPropagation = MountShared + } + case MountSlave, MountRSlave: + if rootPropagation != MountShared && rootPropagation != MountRShared && rootPropagation != MountSlave && rootPropagation != MountRSlave { + rootPropagation = MountRSlave + } + } + } + } + + if rootPropagation != "" { + logrus.Debugf("set root propagation to %q", rootPropagation) + g.SetLinuxRootPropagation(rootPropagation) } return g.Config, nil } @@ -593,3 +631,226 @@ func (c *Container) restore(ctx context.Context, keep bool) (err error) { return c.save() } + +// Make standard bind mounts to include in the container +func (c *Container) makeBindMounts() error { + if err := os.Chown(c.state.RunDir, c.RootUID(), c.RootGID()); err != nil { + return errors.Wrapf(err, "cannot chown run directory %s", c.state.RunDir) + } + + if c.state.BindMounts == nil { + c.state.BindMounts = make(map[string]string) + } + + if !c.NetworkDisabled() { + // Make /etc/resolv.conf + if _, ok := c.state.BindMounts["/etc/resolv.conf"]; ok { + // If it already exists, delete so we can recreate + delete(c.state.BindMounts, "/etc/resolv.conf") + } + newResolv, err := c.generateResolvConf() + if err != nil { + return errors.Wrapf(err, "error creating resolv.conf for container %s", c.ID()) + } + c.state.BindMounts["/etc/resolv.conf"] = newResolv + + // Make /etc/hosts + if _, ok := c.state.BindMounts["/etc/hosts"]; ok { + // If it already exists, delete so we can recreate + delete(c.state.BindMounts, "/etc/hosts") + } + newHosts, err := c.generateHosts() + if err != nil { + return errors.Wrapf(err, "error creating hosts file for container %s", c.ID()) + } + c.state.BindMounts["/etc/hosts"] = newHosts + + } + + // SHM is always added when we mount the container + c.state.BindMounts["/dev/shm"] = c.config.ShmDir + + newPasswd, err := c.generatePasswd() + if err != nil { + return errors.Wrapf(err, "error creating temporary passwd file for container %s", c.ID()) + } + if newPasswd != "" { + // Make /etc/passwd + if _, ok := c.state.BindMounts["/etc/passwd"]; ok { + // If it already exists, delete so we can recreate + delete(c.state.BindMounts, "/etc/passwd") + } + logrus.Debugf("adding entry to /etc/passwd for non existent default user") + c.state.BindMounts["/etc/passwd"] = newPasswd + } + + // Make /etc/hostname + // This should never change, so no need to recreate if it exists + if _, ok := c.state.BindMounts["/etc/hostname"]; !ok { + hostnamePath, err := c.writeStringToRundir("hostname", c.Hostname()) + if err != nil { + return errors.Wrapf(err, "error creating hostname file for container %s", c.ID()) + } + c.state.BindMounts["/etc/hostname"] = hostnamePath + } + + // Make .containerenv + // Empty file, so no need to recreate if it exists + if _, ok := c.state.BindMounts["/run/.containerenv"]; !ok { + // Empty string for now, but we may consider populating this later + containerenvPath, err := c.writeStringToRundir(".containerenv", "") + if err != nil { + return errors.Wrapf(err, "error creating containerenv file for container %s", c.ID()) + } + c.state.BindMounts["/run/.containerenv"] = containerenvPath + } + + // Add Secret Mounts + secretMounts := secrets.SecretMountsWithUIDGID(c.config.MountLabel, c.state.RunDir, c.runtime.config.DefaultMountsFile, c.state.DestinationRunDir, c.RootUID(), c.RootGID()) + for _, mount := range secretMounts { + if _, ok := c.state.BindMounts[mount.Destination]; !ok { + c.state.BindMounts[mount.Destination] = mount.Source + } + } + + return nil +} + +// generateResolvConf generates a containers resolv.conf +func (c *Container) generateResolvConf() (string, error) { + // Determine the endpoint for resolv.conf in case it is a symlink + resolvPath, err := filepath.EvalSymlinks("/etc/resolv.conf") + if err != nil { + return "", err + } + + contents, err := ioutil.ReadFile(resolvPath) + if err != nil { + return "", errors.Wrapf(err, "unable to read %s", resolvPath) + } + + // Process the file to remove localhost nameservers + // TODO: set ipv6 enable bool more sanely + resolv, err := resolvconf.FilterResolvDNS(contents, true) + if err != nil { + return "", errors.Wrapf(err, "error parsing host resolv.conf") + } + + // Make a new resolv.conf + nameservers := resolvconf.GetNameservers(resolv.Content) + if len(c.config.DNSServer) > 0 { + // We store DNS servers as net.IP, so need to convert to string + nameservers = []string{} + for _, server := range c.config.DNSServer { + nameservers = append(nameservers, server.String()) + } + } + + search := resolvconf.GetSearchDomains(resolv.Content) + if len(c.config.DNSSearch) > 0 { + search = c.config.DNSSearch + } + + options := resolvconf.GetOptions(resolv.Content) + if len(c.config.DNSOption) > 0 { + options = c.config.DNSOption + } + + destPath := filepath.Join(c.state.RunDir, "resolv.conf") + + if err := os.Remove(destPath); err != nil && !os.IsNotExist(err) { + return "", errors.Wrapf(err, "error removing resolv.conf for container %s", c.ID()) + } + + // Build resolv.conf + if _, err = resolvconf.Build(destPath, nameservers, search, options); err != nil { + return "", errors.Wrapf(err, "error building resolv.conf for container %s") + } + + // Relabel resolv.conf for the container + if err := label.Relabel(destPath, c.config.MountLabel, false); err != nil { + return "", err + } + + return filepath.Join(c.state.DestinationRunDir, "resolv.conf"), nil +} + +// generateHosts creates a containers hosts file +func (c *Container) generateHosts() (string, error) { + orig, err := ioutil.ReadFile("/etc/hosts") + if err != nil { + return "", errors.Wrapf(err, "unable to read /etc/hosts") + } + hosts := string(orig) + 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]) + } + } + if len(c.state.NetworkStatus) > 0 && len(c.state.NetworkStatus[0].IPs) > 0 { + ipAddress := strings.Split(c.state.NetworkStatus[0].IPs[0].Address.String(), "/")[0] + hosts += fmt.Sprintf("%s\t%s\n", ipAddress, c.Hostname()) + } + return c.writeStringToRundir("hosts", hosts) +} + +// generatePasswd generates a container specific passwd file, +// iff g.config.User is a number +func (c *Container) generatePasswd() (string, error) { + var ( + groupspec string + group *user.Group + gid int + ) + if c.config.User == "" { + return "", nil + } + spec := strings.SplitN(c.config.User, ":", 2) + userspec := spec[0] + if len(spec) > 1 { + groupspec = spec[1] + } + // If a non numeric User, then don't generate passwd + uid, err := strconv.ParseUint(userspec, 10, 32) + if err != nil { + return "", nil + } + // Lookup the user to see if it exists in the container image + _, err = lookup.GetUser(c.state.Mountpoint, userspec) + if err != nil && err != user.ErrNoPasswdEntries { + return "", err + } + if err == nil { + return "", nil + } + if groupspec != "" { + if !c.state.Mounted { + return "", errors.Wrapf(ErrCtrStateInvalid, "container %s must be mounted in order to translate group field for passwd record", c.ID()) + } + group, err = lookup.GetGroup(c.state.Mountpoint, groupspec) + if err != nil { + if err == user.ErrNoGroupEntries { + return "", errors.Wrapf(err, "unable to get gid %s from group file", groupspec) + } + return "", err + } + gid = group.Gid + } + originPasswdFile := filepath.Join(c.state.Mountpoint, "/etc/passwd") + orig, err := ioutil.ReadFile(originPasswdFile) + if err != nil && !os.IsNotExist(err) { + return "", errors.Wrapf(err, "unable to read passwd file %s", originPasswdFile) + } + + pwd := fmt.Sprintf("%s%d:x:%d:%d:container user:%s:/bin/sh\n", orig, uid, uid, gid, c.WorkingDir()) + passwdFile, err := c.writeStringToRundir("passwd", pwd) + if err != nil { + return "", errors.Wrapf(err, "failed to create temporary passwd file") + } + if os.Chmod(passwdFile, 0644); err != nil { + return "", err + } + return passwdFile, nil +} |