diff options
Diffstat (limited to 'libpod/container_internal_linux.go')
| -rw-r--r-- | libpod/container_internal_linux.go | 156 |
1 files changed, 124 insertions, 32 deletions
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index 86d8586d0..afa351c17 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -2045,19 +2045,8 @@ func (c *Container) generateResolvConf() (string, error) { } } - ipv6 := false - // If network status is set check for ipv6 and dns namesevers netStatus := c.getNetworkStatus() for _, status := range netStatus { - for _, netInt := range status.Interfaces { - for _, netAddress := range netInt.Subnets { - // Note: only using To16() does not work since it also returns a valid ip for ipv4 - if netAddress.IPNet.IP.To4() == nil && netAddress.IPNet.IP.To16() != nil { - ipv6 = true - } - } - } - if status.DNSServerIPs != nil { for _, nsIP := range status.DNSServerIPs { networkNameServers = append(networkNameServers, nsIP.String()) @@ -2070,16 +2059,9 @@ func (c *Container) generateResolvConf() (string, error) { } } - if c.config.NetMode.IsSlirp4netns() { - ctrNetworkSlipOpts := []string{} - if c.config.NetworkOptions != nil { - ctrNetworkSlipOpts = append(ctrNetworkSlipOpts, c.config.NetworkOptions["slirp4netns"]...) - } - slirpOpts, err := parseSlirp4netnsNetworkOptions(c.runtime, ctrNetworkSlipOpts) - if err != nil { - return "", err - } - ipv6 = slirpOpts.enableIPv6 + ipv6, err := c.checkForIPv6(netStatus) + if err != nil { + return "", err } // Ensure that the container's /etc/resolv.conf is compatible with its @@ -2099,38 +2081,38 @@ func (c *Container) generateResolvConf() (string, error) { } dnsServers := append(dns, c.config.DNSServer...) // If the user provided dns, it trumps all; then dns masq; then resolv.conf + var search []string switch { case len(dnsServers) > 0: - // We store DNS servers as net.IP, so need to convert to string for _, server := range dnsServers { nameservers = append(nameservers, server.String()) } - case len(networkNameServers) > 0: - nameservers = append(nameservers, networkNameServers...) default: // Make a new resolv.conf - nameservers = resolvconf.GetNameservers(resolv.Content) - // slirp4netns has a built in DNS server. + // first add the nameservers from the networks status + nameservers = append(nameservers, networkNameServers...) + // when we add network dns server we also have to add the search domains + search = networkSearchDomains + // slirp4netns has a built in DNS forwarder. if c.config.NetMode.IsSlirp4netns() { slirp4netnsDNS, err := GetSlirp4netnsDNS(c.slirp4netnsSubnet) if err != nil { logrus.Warn("Failed to determine Slirp4netns DNS: ", err.Error()) } else { - nameservers = append([]string{slirp4netnsDNS.String()}, nameservers...) + nameservers = append(nameservers, slirp4netnsDNS.String()) } } + nameservers = append(nameservers, resolvconf.GetNameservers(resolv.Content)...) } - var search []string - if len(c.config.DNSSearch) > 0 || len(c.runtime.config.Containers.DNSSearches) > 0 || len(networkSearchDomains) > 0 { + if len(c.config.DNSSearch) > 0 || len(c.runtime.config.Containers.DNSSearches) > 0 { if !util.StringInSlice(".", c.config.DNSSearch) { - search = c.runtime.config.Containers.DNSSearches + search = append(search, c.runtime.config.Containers.DNSSearches...) search = append(search, c.config.DNSSearch...) - search = append(search, networkSearchDomains...) } } else { - search = resolvconf.GetSearchDomains(resolv.Content) + search = append(search, resolvconf.GetSearchDomains(resolv.Content)...) } var options []string @@ -2160,6 +2142,116 @@ func (c *Container) generateResolvConf() (string, error) { return destPath, nil } +// Check if a container uses IPv6. +func (c *Container) checkForIPv6(netStatus map[string]types.StatusBlock) (bool, error) { + for _, status := range netStatus { + for _, netInt := range status.Interfaces { + for _, netAddress := range netInt.Subnets { + // Note: only using To16() does not work since it also returns a valid ip for ipv4 + if netAddress.IPNet.IP.To4() == nil && netAddress.IPNet.IP.To16() != nil { + return true, nil + } + } + } + } + + if c.config.NetMode.IsSlirp4netns() { + ctrNetworkSlipOpts := []string{} + if c.config.NetworkOptions != nil { + ctrNetworkSlipOpts = append(ctrNetworkSlipOpts, c.config.NetworkOptions["slirp4netns"]...) + } + slirpOpts, err := parseSlirp4netnsNetworkOptions(c.runtime, ctrNetworkSlipOpts) + if err != nil { + return false, err + } + return slirpOpts.enableIPv6, nil + } + + return false, nil +} + +// Add a new nameserver to the container's resolv.conf, ensuring that it is the +// first nameserver present. +// Usable only with running containers. +func (c *Container) addNameserver(ips []string) error { + // Take no action if container is not running. + if !c.ensureState(define.ContainerStateRunning, define.ContainerStateCreated) { + return nil + } + + // Do we have a resolv.conf at all? + path, ok := c.state.BindMounts["/etc/resolv.conf"] + if !ok { + return nil + } + + // Read in full contents, parse out existing nameservers + contents, err := ioutil.ReadFile(path) + if err != nil { + return err + } + ns := resolvconf.GetNameservers(contents) + options := resolvconf.GetOptions(contents) + search := resolvconf.GetSearchDomains(contents) + + // We could verify that it doesn't already exist + // but extra nameservers shouldn't harm anything. + // Ensure we are the first entry in resolv.conf though, otherwise we + // might be after user-added servers. + ns = append(ips, ns...) + + // We're rewriting the container's resolv.conf as part of this, but we + // hold the container lock, so there should be no risk of parallel + // modification. + if _, err := resolvconf.Build(path, ns, search, options); err != nil { + return errors.Wrapf(err, "error adding new nameserver to container %s resolv.conf", c.ID()) + } + + return nil +} + +// Remove an entry from the existing resolv.conf of the container. +// Usable only with running containers. +func (c *Container) removeNameserver(ips []string) error { + // Take no action if container is not running. + if !c.ensureState(define.ContainerStateRunning, define.ContainerStateCreated) { + return nil + } + + // Do we have a resolv.conf at all? + path, ok := c.state.BindMounts["/etc/resolv.conf"] + if !ok { + return nil + } + + // Read in full contents, parse out existing nameservers + contents, err := ioutil.ReadFile(path) + if err != nil { + return err + } + ns := resolvconf.GetNameservers(contents) + options := resolvconf.GetOptions(contents) + search := resolvconf.GetSearchDomains(contents) + + toRemove := make(map[string]bool) + for _, ip := range ips { + toRemove[ip] = true + } + + newNS := make([]string, 0, len(ns)) + for _, server := range ns { + if !toRemove[server] { + newNS = append(newNS, server) + } + } + + if _, err := resolvconf.Build(path, newNS, search, options); err != nil { + return errors.Wrapf(err, "error removing nameservers from container %s resolv.conf", c.ID()) + } + + return nil +} + // updateHosts updates the container's hosts file func (c *Container) updateHosts(path string) error { var hosts string |