// detachServiceContainer detaches the service container's endpoint during network delete
// - detach happens only if all other endpoints in the network are already removed
func detachServiceContainer(tenantName, networkName string) error {
docker, err := utils.GetDockerClient()
if err != nil {
log.Errorf("Unable to connect to docker. Error %v", err)
return errors.New("Unable to connect to docker")
}
dnsContName := getDNSName(tenantName)
cinfo, err := docker.InspectContainer(dnsContName)
if err != nil {
log.Errorf("Error inspecting the container %s. Err: %v", dnsContName, err)
return err
}
// Trim default tenant
dnetName := docknet.GetDocknetName(tenantName, networkName, "")
// inspect docker network
nwState, err := docker.InspectNetwork(dnetName)
if err != nil {
log.Errorf("Error while inspecting network: %+v", dnetName)
return err
}
log.Infof("Containers in network: %+v are {%+v}", dnetName, nwState.Containers)
dnsServerIP := strings.Split(nwState.Containers[cinfo.Id].IPv4Address, "/")[0]
stateDriver, err := utils.GetStateDriver()
if err != nil {
log.Errorf("Could not get StateDriver while trying to disconnect dnsContainer from %+v", networkName)
return err
}
// Read network config and get DNSServer information
nwCfg := &mastercfg.CfgNetworkState{}
nwCfg.StateDriver = stateDriver
networkID := networkName + "." + tenantName
err = nwCfg.Read(networkID)
if err != nil {
return err
}
log.Infof("dnsServerIP: %+v, nwCfg.dnsip: %+v", dnsServerIP, nwCfg.DNSServer)
// Remove dns container from network if all other endpoints are withdrawn
if len(nwState.Containers) == 1 && (dnsServerIP == nwCfg.DNSServer) {
log.Infof("Disconnecting dns container from network as all other endpoints are removed: %+v", networkName)
err = docker.DisconnectNetwork(dnetName, dnsContName, false)
if err != nil {
log.Errorf("Could not detach container(%s) from network %s. Error: %s",
dnsContName, dnetName, err)
return err
}
}
return nil
}
func attachServiceContainer(tenantName, networkName string, stateDriver core.StateDriver) error {
contName := getDNSName(tenantName)
docker, err := utils.GetDockerClient()
if err != nil {
log.Errorf("Unable to connect to docker. Error %v", err)
return err
}
cinfo, err := docker.InspectContainer(contName)
if err != nil {
if strings.Contains(err.Error(), "no such id") {
// DNS container not started for this tenant. Start skydns container
err = startServiceContainer(tenantName)
if err != nil {
log.Warnf("Error starting service container. "+
"Continuing without DNS provider. Error: %v", err)
return nil
}
cinfo, err = docker.InspectContainer(contName)
if err != nil {
log.Warnf("Error fetching container info after starting %s"+
"Continuing without DNS provider. Error: %s", contName, err)
return nil
}
}
}
// If it's not in running state, restart the container.
// This case can occur if the host is reloaded
if !cinfo.State.Running {
log.Debugf("Container %s not running. Restarting the container", contName)
err = docker.RestartContainer(contName, 0)
if err != nil {
log.Warnf("Error restarting service container %s. "+
"Continuing without DNS provider. Error: %v",
contName, err)
return nil
}
// Refetch container info after restart
cinfo, err = docker.InspectContainer(contName)
if err != nil {
log.Warnf("Error fetching container info after restarting %s"+
"Continuing without DNS provider. Error: %s", contName, err)
return nil
}
}
log.Debugf("Container info: %+v\n Hostconfig: %+v", cinfo, cinfo.HostConfig)
// Trim default tenant
dnetName := docknet.GetDocknetName(tenantName, networkName, "")
err = docker.ConnectNetwork(dnetName, contName)
if err != nil {
log.Warnf("Could not attach container(%s) to network %s. "+
"Continuing without DNS provider. Error: %s",
contName, dnetName, err)
return nil
}
ninfo, err := docker.InspectNetwork(dnetName)
if err != nil {
log.Errorf("Error getting network info for %s. Err: %v", dnetName, err)
return err
}
log.Debugf("Network info: %+v", ninfo)
// find the container in network info
epInfo, ok := ninfo.Containers[cinfo.Id]
if !ok {
log.Errorf("Could not find container %s in network info", cinfo.Id)
return errors.New("Endpoint not found")
}
// read network Config
nwCfg := &mastercfg.CfgNetworkState{}
networkID := networkName + "." + tenantName
nwCfg.StateDriver = stateDriver
err = nwCfg.Read(networkID)
if err != nil {
return err
}
// set the dns server Info
nwCfg.DNSServer = strings.Split(epInfo.IPv4Address, "/")[0]
log.Infof("Dns server for network %s: %s", networkName, nwCfg.DNSServer)
// write the network config
err = nwCfg.Write()
if err != nil {
return err
}
return nil
}