createNode: copy as many details as possible from existing

- we now use the full containerJSON details when getting a node
- we now use as many details as possible to copy k3d settings from an
existing node when adding a new node to a running cluster

docs/usage/.pages

@@ -2,4 +2,5 @@ title: Usage
 arrange:
   - commands.md
   - kubeconfig.md
+  - multimaster.md
   - guides

go.mod

@@ -21,7 +21,7 @@ require (
 	github.com/gogo/protobuf v1.3.1 // indirect
 	github.com/golang/protobuf v1.4.0 // indirect
 	github.com/heroku/docker-registry-client v0.0.0-20190909225348-afc9e1acc3d5
-	github.com/imdario/mergo v0.3.9 // indirect
+	github.com/imdario/mergo v0.3.9
 	github.com/liggitt/tabwriter v0.0.0-20181228230101-89fcab3d43de
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/morikuni/aec v0.0.0-20170113033406-39771216ff4c // indirect

pkg/cluster/node.go

@@ -25,10 +25,10 @@ package cluster
 import (
 	"bytes"
 	"context"
-	"fmt"
 	"strings"
 	"time"
 
+	"github.com/imdario/mergo"
 	"github.com/rancher/k3d/pkg/runtimes"
 	k3d "github.com/rancher/k3d/pkg/types"
 	log "github.com/sirupsen/logrus"
@@ -70,27 +70,21 @@ func AddNodeToCluster(runtime runtimes.Runtime, node *k3d.Node, cluster *k3d.Clu
 		}
 	}
 
+	// get node details
+	chosenNode, err = GetNode(chosenNode, runtime)
+	if err != nil {
+		return err
+	}
+
 	log.Debugf("Copying configuration from existing node %+v", chosenNode)
 
-	// get config from labels
-	for k, v := range chosenNode.Labels {
-		if strings.HasPrefix(k, "k3d") {
-			node.Labels[k] = v
-		}
-		if k == "k3d.cluster.url" {
-			node.Env = append(node.Env, fmt.Sprintf("K3S_URL=%s", v))
-		}
-		if k == "k3d.cluster.secret" {
-			node.Env = append(node.Env, fmt.Sprintf("K3S_TOKEN=%s", v))
-		}
+	// merge node config of new node into existing node config
+	if err := mergo.MergeWithOverwrite(chosenNode, *node); err != nil {
+		log.Errorln("Failed to merge new node config into existing node config")
+		return err
 	}
 
-	// backup: get config from environment variables
-	for _, env := range chosenNode.Env {
-		if strings.HasPrefix(env, "K3S_") {
-			node.Env = append(node.Env, env)
-		}
-	}
+	node = chosenNode
 
 	log.Debugf("Resulting node %+v", node)
 

pkg/runtimes/docker/node.go

@@ -38,7 +38,6 @@ import (
 
 // CreateNode creates a new container
 func (d Docker) CreateNode(node *k3d.Node) error {
-	log.Debugln("docker.CreateNode...")
 
 	// translate node spec to docker container specs
 	dockerNode, err := TranslateNodeToContainer(node)
@@ -172,9 +171,30 @@ func getContainersByLabel(labels map[string]string) ([]types.Container, error) {
 		log.Errorln("Failed to list containers")
 		return nil, err
 	}
+
 	return containers, nil
 }
 
+// getContainer details returns the containerjson with more details
+func getContainerDetails(containerID string) (types.ContainerJSON, error) {
+	// (0) create docker client
+	ctx := context.Background()
+	docker, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
+	if err != nil {
+		return types.ContainerJSON{}, fmt.Errorf("Failed to create docker client. %+v", err)
+	}
+	defer docker.Close()
+
+	containerDetails, err := docker.ContainerInspect(ctx, containerID)
+	if err != nil {
+		log.Errorln("Failed to get details for container '%s'", containerID)
+		return types.ContainerJSON{}, err
+	}
+
+	return containerDetails, nil
+
+}
+
 // GetNode tries to get a node container by its name
 func (d Docker) GetNode(node *k3d.Node) (*k3d.Node, error) {
 	container, err := getNodeContainer(node)
@@ -183,9 +203,14 @@ func (d Docker) GetNode(node *k3d.Node) (*k3d.Node, error) {
 		return nil, err
 	}
 
-	node, err = TranslateContainerToNode(container)
+	containerDetails, err := getContainerDetails(container.ID)
 	if err != nil {
-		log.Errorf("Failed to translate container for node '%s' to node object", node.Name)
+		return nil, err
+	}
+
+	node, err = TranslateContainerDetailsToNode(containerDetails)
+	if err != nil {
+		log.Errorf("Failed to translate container details for node '%s' to node object", node.Name)
 		return nil, err
 	}
 

pkg/runtimes/docker/translate.go

@@ -23,6 +23,7 @@ THE SOFTWARE.
 package docker
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/docker/docker/api/types"
@@ -117,3 +118,79 @@ func TranslateContainerToNode(cont *types.Container) (*k3d.Node, error) {
 	}
 	return node, nil
 }
+
+// TranslateContainerDetailsToNode translates a docker containerJSON object into a k3d node representation
+func TranslateContainerDetailsToNode(containerDetails types.ContainerJSON) (*k3d.Node, error) {
+
+	// translate portMap to string representation
+	ports := []string{}
+	for containerPort, portBindingList := range containerDetails.HostConfig.PortBindings {
+		for _, hostInfo := range portBindingList {
+			ports = append(ports, fmt.Sprintf("%s:%s:%s", hostInfo.HostIP, hostInfo.HostPort, containerPort))
+		}
+	}
+
+	// restart -> we only set 'unless-stopped' upon cluster creation
+	restart := false
+	if containerDetails.HostConfig.RestartPolicy.IsAlways() || containerDetails.HostConfig.RestartPolicy.IsUnlessStopped() {
+		restart = true
+	}
+
+	// get the clusterNetwork
+	clusterNetwork := ""
+	for networkName := range containerDetails.NetworkSettings.Networks {
+		if strings.HasPrefix(networkName, fmt.Sprintf("%s-%s", k3d.DefaultObjectNamePrefix, containerDetails.Config.Labels["k3d.cluster"])) { // FIXME: catch error if label 'k3d.cluster' does not exist, but this should also never be the case
+			clusterNetwork = networkName
+		}
+	}
+
+	// masterOpts
+	masterOpts := k3d.MasterOpts{IsInit: false}
+	for k, v := range containerDetails.Config.Labels {
+		/*
+			node.Labels["k3d.master.api.hostIP"] = node.MasterOpts.ExposeAPI.HostIP // TODO: maybe get docker machine IP here
+			node.Labels["k3d.master.api.host"] = node.MasterOpts.ExposeAPI.Host
+			node.Labels["k3d.master.api.port"] = node.MasterOpts.ExposeAPI.Port
+		*/
+		if k == "k3d.master.api.hostIP" {
+			masterOpts.ExposeAPI.HostIP = v
+		} else if k == "k3d.master.api.host" {
+			masterOpts.ExposeAPI.Host = v
+		} else if k == "k3d.master.api.port" {
+			masterOpts.ExposeAPI.Port = v
+		}
+	}
+
+	// env vars: only copy K3S_* and K3D_* // FIXME: should we really do this? Might be unexpected, if user has e.g. HTTP_PROXY vars
+	env := []string{}
+	for _, envVar := range containerDetails.Config.Env {
+		if strings.HasPrefix(envVar, "K3D_") || strings.HasPrefix(envVar, "K3S_") {
+			env = append(env, envVar)
+		}
+	}
+
+	// labels: only copy k3d.* labels
+	labels := map[string]string{}
+	for k, v := range containerDetails.Config.Labels {
+		if strings.HasPrefix(k, "k3d") {
+			labels[k] = v
+		}
+	}
+
+	node := &k3d.Node{
+		Name:       strings.TrimPrefix(containerDetails.Name, "/"), // container name with leading '/' cut off
+		Role:       k3d.NodeRoles[containerDetails.Config.Labels["k3d.role"]],
+		Image:      containerDetails.Image,
+		Volumes:    containerDetails.HostConfig.Binds,
+		Env:        env,
+		Cmd:        containerDetails.Config.Cmd,
+		Args:       []string{}, // empty, since Cmd already contains flags
+		Ports:      ports,
+		Restart:    restart,
+		Labels:     labels,
+		Network:    clusterNetwork,
+		MasterOpts: masterOpts,
+		WorkerOpts: k3d.WorkerOpts{},
+	}
+	return node, nil
+}