func TestDnsOptionsBasedOnHostResolvConf(t *testing.T) { resolvConf, err := ioutil.ReadFile("/etc/resolv.conf") if os.IsNotExist(err) { t.Fatalf("/etc/resolv.conf does not exist") } hostNamservers := resolvconf.GetNameservers(resolvConf) hostSearch := resolvconf.GetSearchDomains(resolvConf) cmd := exec.Command(dockerBinary, "run", "--dns=127.0.0.1", "busybox", "cat", "/etc/resolv.conf") out, _, err := runCommandWithOutput(cmd) if err != nil { t.Fatal(err, out) } if actualNameservers := resolvconf.GetNameservers([]byte(out)); string(actualNameservers[0]) != "127.0.0.1" { t.Fatalf("expected '127.0.0.1', but says: '%s'", string(actualNameservers[0])) } actualSearch := resolvconf.GetSearchDomains([]byte(out)) if len(actualSearch) != len(hostSearch) { t.Fatalf("expected '%s' search domain(s), but it has: '%s'", len(hostSearch), len(actualSearch)) } for i := range actualSearch { if actualSearch[i] != hostSearch[i] { t.Fatalf("expected '%s' domain, but says: '%s'", actualSearch[i], hostSearch[i]) } } cmd = exec.Command(dockerBinary, "run", "--dns-search=mydomain", "busybox", "cat", "/etc/resolv.conf") out, _, err = runCommandWithOutput(cmd) if err != nil { t.Fatal(err, out) } actualNameservers := resolvconf.GetNameservers([]byte(out)) if len(actualNameservers) != len(hostNamservers) { t.Fatalf("expected '%s' nameserver(s), but it has: '%s'", len(hostNamservers), len(actualNameservers)) } for i := range actualNameservers { if actualNameservers[i] != hostNamservers[i] { t.Fatalf("expected '%s' nameserver, but says: '%s'", actualNameservers[i], hostNamservers[i]) } } if actualSearch = resolvconf.GetSearchDomains([]byte(out)); string(actualSearch[0]) != "mydomain" { t.Fatalf("expected 'mydomain', but says: '%s'", string(actualSearch[0])) } deleteAllContainers() logDone("run - dns options based on host resolv.conf") }
func (container *Container) setupContainerDns() error { if container.ResolvConfPath != "" { return nil } var ( config = container.hostConfig daemon = container.daemon ) resolvConf, err := resolvconf.Get() if err != nil { return err } container.ResolvConfPath, err = container.getRootResourcePath("resolv.conf") if err != nil { return err } if config.NetworkMode != "host" { // check configurations for any container/daemon dns settings if len(config.Dns) > 0 || len(daemon.config.Dns) > 0 || len(config.DnsSearch) > 0 || len(daemon.config.DnsSearch) > 0 { var ( dns = resolvconf.GetNameservers(resolvConf) dnsSearch = resolvconf.GetSearchDomains(resolvConf) ) if len(config.Dns) > 0 { dns = config.Dns } else if len(daemon.config.Dns) > 0 { dns = daemon.config.Dns } if len(config.DnsSearch) > 0 { dnsSearch = config.DnsSearch } else if len(daemon.config.DnsSearch) > 0 { dnsSearch = daemon.config.DnsSearch } return resolvconf.Build(container.ResolvConfPath, dns, dnsSearch) } // replace any localhost/127.* nameservers resolvConf = utils.RemoveLocalDns(resolvConf) // if the resulting resolvConf is empty, use DefaultDns if !bytes.Contains(resolvConf, []byte("nameserver")) { log.Infof("No non localhost DNS resolver found in resolv.conf and containers can't use it. Using default external servers : %v", DefaultDns) // prefix the default dns options with nameserver resolvConf = append(resolvConf, []byte("\nnameserver "+strings.Join(DefaultDns, "\nnameserver "))...) } } return ioutil.WriteFile(container.ResolvConfPath, resolvConf, 0644) }
func (container *Container) setupContainerDns() error { if container.ResolvConfPath != "" { return nil } var ( config = container.hostConfig daemon = container.daemon ) if config.NetworkMode == "host" { container.ResolvConfPath = "/etc/resolv.conf" return nil } resolvConf, err := resolvconf.Get() if err != nil { return err } // If custom dns exists, then create a resolv.conf for the container if len(config.Dns) > 0 || len(daemon.config.Dns) > 0 || len(config.DnsSearch) > 0 || len(daemon.config.DnsSearch) > 0 { var ( dns = resolvconf.GetNameservers(resolvConf) dnsSearch = resolvconf.GetSearchDomains(resolvConf) ) if len(config.Dns) > 0 { dns = config.Dns } else if len(daemon.config.Dns) > 0 { dns = daemon.config.Dns } if len(config.DnsSearch) > 0 { dnsSearch = config.DnsSearch } else if len(daemon.config.DnsSearch) > 0 { dnsSearch = daemon.config.DnsSearch } resolvConfPath, err := container.getRootResourcePath("resolv.conf") if err != nil { return err } container.ResolvConfPath = resolvConfPath return resolvconf.Build(container.ResolvConfPath, dns, dnsSearch) } else { container.ResolvConfPath = "/etc/resolv.conf" } return nil }
func (container *Container) setupContainerDns() error { if container.ResolvConfPath != "" { return nil } var ( config = container.hostConfig daemon = container.daemon ) resolvConf, err := resolvconf.Get() if err != nil { return err } container.ResolvConfPath, err = container.getRootResourcePath("resolv.conf") if err != nil { return err } if config.NetworkMode != "host" && (len(config.Dns) > 0 || len(daemon.config.Dns) > 0 || len(config.DnsSearch) > 0 || len(daemon.config.DnsSearch) > 0) { var ( dns = resolvconf.GetNameservers(resolvConf) dnsSearch = resolvconf.GetSearchDomains(resolvConf) ) if len(config.Dns) > 0 { dns = config.Dns } else if len(daemon.config.Dns) > 0 { dns = daemon.config.Dns } if len(config.DnsSearch) > 0 { dnsSearch = config.DnsSearch } else if len(daemon.config.DnsSearch) > 0 { dnsSearch = daemon.config.DnsSearch } return resolvconf.Build(container.ResolvConfPath, dns, dnsSearch) } return ioutil.WriteFile(container.ResolvConfPath, resolvConf, 0644) }
func (container *Container) setupContainerDns() error { if container.ResolvConfPath != "" { // check if this is an existing container that needs DNS update: if container.UpdateDns { // read the host's resolv.conf, get the hash and call updateResolvConf log.Debugf("Check container (%s) for update to resolv.conf - UpdateDns flag was set", container.ID) latestResolvConf, latestHash := resolvconf.GetLastModified() // clean container resolv.conf re: localhost nameservers and IPv6 NS (if IPv6 disabled) updatedResolvConf, modified := resolvconf.FilterResolvDns(latestResolvConf, container.daemon.config.EnableIPv6) if modified { // changes have occurred during resolv.conf localhost cleanup: generate an updated hash newHash, err := utils.HashData(bytes.NewReader(updatedResolvConf)) if err != nil { return err } latestHash = newHash } if err := container.updateResolvConf(updatedResolvConf, latestHash); err != nil { return err } // successful update of the restarting container; set the flag off container.UpdateDns = false } return nil } var ( config = container.hostConfig daemon = container.daemon ) resolvConf, err := resolvconf.Get() if err != nil { return err } container.ResolvConfPath, err = container.getRootResourcePath("resolv.conf") if err != nil { return err } if config.NetworkMode != "host" { // check configurations for any container/daemon dns settings if len(config.Dns) > 0 || len(daemon.config.Dns) > 0 || len(config.DnsSearch) > 0 || len(daemon.config.DnsSearch) > 0 { var ( dns = resolvconf.GetNameservers(resolvConf) dnsSearch = resolvconf.GetSearchDomains(resolvConf) ) if len(config.Dns) > 0 { dns = config.Dns } else if len(daemon.config.Dns) > 0 { dns = daemon.config.Dns } if len(config.DnsSearch) > 0 { dnsSearch = config.DnsSearch } else if len(daemon.config.DnsSearch) > 0 { dnsSearch = daemon.config.DnsSearch } return resolvconf.Build(container.ResolvConfPath, dns, dnsSearch) } // replace any localhost/127.*, and remove IPv6 nameservers if IPv6 disabled in daemon resolvConf, _ = resolvconf.FilterResolvDns(resolvConf, daemon.config.EnableIPv6) } //get a sha256 hash of the resolv conf at this point so we can check //for changes when the host resolv.conf changes (e.g. network update) resolvHash, err := utils.HashData(bytes.NewReader(resolvConf)) if err != nil { return err } resolvHashFile := container.ResolvConfPath + ".hash" if err = ioutil.WriteFile(resolvHashFile, []byte(resolvHash), 0644); err != nil { return err } return ioutil.WriteFile(container.ResolvConfPath, resolvConf, 0644) }