github/kubernetes
1
0
Fork 0
mirror of https://github.com/k3s-io/kubernetes.git synced 2025-11-02 06:47:34 +00:00
Code Issues Projects Releases Wiki Activity

rkt: Add DNS support.

Browse Source 
rkt is now able to populate /etc/resolv.conf with command line flags.
Update the runtime code to fix DNS issues.
This commit is contained in:
Yifan Gu
2016-01-28 16:01:01 -08:00
committed by Jonathan Boulle
parent e9139bb0e5
commit d27a635c4a
3 changed files with 159 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

51
pkg/kubelet/rkt/rkt.go
View File

@@ -90,6 +90,12 @@ const (
defaultImageTag = "latest"
defaultRktAPIServiceAddr = "localhost:15441"
defaultNetworkName = "rkt.kubernetes.io"
// ndots specifies the minimum number of dots that a domain name must contain for the resolver to consider it as FQDN (fully-qualified)
// we want to able to consider SRV lookup names like _dns._udp.kube-dns.default.svc to be considered relative.
// hence, setting ndots to be 5.
// TODO(yifan): Move this and dockertools.ndotsDNSOption to a common package.
defaultDNSOption = "ndots:5"
)
// Runtime implements the Containerruntime for rkt. The implementation
@@ -107,7 +113,7 @@ type Runtime struct {
dockerKeyring credentialprovider.DockerKeyring
containerRefManager *kubecontainer.RefManager
generator kubecontainer.RunContainerOptionsGenerator
runtimeHelper kubecontainer.RuntimeHelper
recorder record.EventRecorder
livenessManager proberesults.Manager
volumeGetter volumeGetter
@@ -131,7 +137,7 @@ type volumeGetter interface {
// It will test if the rkt binary is in the $PATH, and whether we can get the
// version of it. If so, creates the rkt container runtime, otherwise returns an error.
func New(config *Config,
generator kubecontainer.RunContainerOptionsGenerator,
runtimeHelper kubecontainer.RuntimeHelper,
recorder record.EventRecorder,
containerRefManager *kubecontainer.RefManager,
livenessManager proberesults.Manager,
@@ -169,7 +175,7 @@ func New(config *Config,
config: config,
dockerKeyring: credentialprovider.NewDockerKeyring(),
containerRefManager: containerRefManager,
generator: generator,
runtimeHelper: runtimeHelper,
recorder: recorder,
livenessManager: livenessManager,
volumeGetter: volumeGetter,
@@ -582,7 +588,7 @@ func (r *Runtime) newAppcRuntimeApp(pod *api.Pod, c api.Container, pullSecrets [
return err
}
opts, err := r.generator.GenerateRunContainerOptions(pod, &c)
opts, err := r.runtimeHelper.GenerateRunContainerOptions(pod, &c)
if err != nil {
return err
}
@@ -702,6 +708,35 @@ func serviceFilePath(serviceName string) string {
return path.Join(systemdServiceDir, serviceName)
}
// generateRunCommand crafts a 'rkt run-prepared' command with necessary parameters.
func (r *Runtime) generateRunCommand(pod *api.Pod, uuid string) (string, error) {
runPrepared := r.buildCommand("run-prepared").Args
// Setup network configuration.
if pod.Spec.SecurityContext != nil && pod.Spec.SecurityContext.HostNetwork {
runPrepared = append(runPrepared, "--net=host")
} else {
runPrepared = append(runPrepared, fmt.Sprintf("--net=%s", defaultNetworkName))
}
// Setup DNS.
dnsServers, dnsSearches, err := r.runtimeHelper.GetClusterDNS(pod)
if err != nil {
return "", err
}
for _, server := range dnsServers {
runPrepared = append(runPrepared, fmt.Sprintf("--dns=%s", server))
}
for _, search := range dnsSearches {
runPrepared = append(runPrepared, fmt.Sprintf("--dns-search=%s", search))
}
if len(dnsServers) > 0 || len(dnsSearches) > 0 {
runPrepared = append(runPrepared, fmt.Sprintf("--dns-opt=%s", defaultDNSOption))
}
runPrepared = append(runPrepared, uuid)
return strings.Join(runPrepared, " "), nil
}
// preparePod will:
//
// 1. Invoke 'rkt prepare' to prepare the pod, and get the rkt pod uuid.
@@ -754,11 +789,9 @@ func (r *Runtime) preparePod(pod *api.Pod, pullSecrets []api.Secret) (string, *k
glog.V(4).Infof("'rkt prepare' returns %q", uuid)
// Create systemd service file for the rkt pod.
var runPrepared string
if pod.Spec.SecurityContext != nil && pod.Spec.SecurityContext.HostNetwork {
runPrepared = fmt.Sprintf("%s run-prepared --mds-register=false --net=host %s", r.rktBinAbsPath, uuid)
} else {
runPrepared = fmt.Sprintf("%s run-prepared --mds-register=false --net=%s %s", r.rktBinAbsPath, defaultNetworkName, uuid)
runPrepared, err := r.generateRunCommand(pod, uuid)
if err != nil {
return "", nil, fmt.Errorf("failed to generate 'rkt run-prepared' command: %v", err)
}
// TODO handle pod.Spec.HostPID