Deployment Manager Detail

When an instance of a Deployment Manager is initialized the run method is called with the deploymentManager struct passed in.

func newDeploymentManager(s *service, lease mtypes.LeaseID, mgroup *manifest.Group, isNewLease bool) *deploymentManager {
    ...
    go dm.run(context.Background())
    ...
}

The run method calls the startDeploy method to initialize the depployment creation in the Kubernetes cluster.

The retrurned value from the startDeloy method is placed onto the runch channel.

func (dm *deploymentManager) run(ctx context.Context) {
    ....
    runch := dm.startDeploy(ctx)
    ....

The startDeploy method sets the deploymentManager struct state field to dsDeployActive.

The startDeploy method exists in provider/cluster/manager.go.

A Go routine is launched calling the doDeploy method which will conduct the Kubernetes API post for new service and deployment creation.

func (dm *deploymentManager) startDeploy(ctx context.Context) <-chan error {
    ....
    dm.state = dsDeployActive

    chErr := make(chan error, 1)

    go func() {
        hostnames, endpoints, err := dm.doDeploy(ctx)
        ....
    }()
    ....
}

The doDeploy method makes several validations and queries then eventually creates the deployment in Kubernetes via a call of the dm.client.Deploy method. The lease and manifest info is passed into this method as arguments.

The doDeploy method exists in provider/cluster/manager.go.

func (dm *deploymentManager) doDeploy(ctx context.Context) ([]string, []string, error) {
    ....

    if err = dm.checkLeaseActive(ctx); err != nil {
        return nil, nil, err
    }

    currentIPs, err := dm.client.GetDeclaredIPs(ctx, dm.lease)
    if err != nil {
        return nil, nil, err
    }

    // Either reserve the hostnames, or confirm that they already are held
    allHostnames := sdlutil.AllHostnamesOfManifestGroup(*dm.mgroup)
    withheldHostnames, err := dm.hostnameService.ReserveHostnames(ctx, allHostnames, dm.lease)

    if err != nil {
        deploymentCounter.WithLabelValues("reserve-hostnames", "err").Inc()
        dm.log.Error("deploy hostname reservation error", "state", dm.state, "err", err)
        return nil, nil, err
    }
    deploymentCounter.WithLabelValues("reserve-hostnames", "success").Inc()

    dm.log.Info("hostnames withheld", "cnt", len(withheldHostnames))

    hostnamesInThisRequest := make(map[string]struct{})
    for _, hostname := range allHostnames {
        hostnamesInThisRequest[hostname] = struct{}{}
    }

    ....

    err = dm.client.Deploy(deployCtx, dm.lease, dm.mgroup)
    label := "success"
    if err != nil {
        label = "fail"
    }
    ....
}