implement get nodes

cmd/get/getCluster.go

@@ -104,7 +104,6 @@ func parseGetClusterCmd(cmd *cobra.Command, args []string) (*k3d.Cluster, runtim
 	return cluster, runtime, headersOff
 }
 
-// TODO: improve (tabular output or output similar to kubectl)
 func printClusters(clusters []*k3d.Cluster, headersOff bool) {
 
 	tabwriter := tabwriter.NewWriter(os.Stdout, 6, 4, 3, ' ', tabwriter.RememberWidths)

cmd/get/getNode.go

@@ -22,6 +22,15 @@ THE SOFTWARE.
 package get
 
 import (
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+
+	"github.com/liggitt/tabwriter"
+	"github.com/rancher/k3d/pkg/cluster"
+	"github.com/rancher/k3d/pkg/runtimes"
+	k3d "github.com/rancher/k3d/pkg/types"
 	"github.com/spf13/cobra"
 
 	log "github.com/sirupsen/logrus"
@@ -32,16 +41,86 @@ func NewCmdGetNode() *cobra.Command {
 
 	// create new command
 	cmd := &cobra.Command{
-		Use:   "node",
-		Short: "Get node",
-		Long:  `Get node.`,
+		Use:     "node",
+		Short:   "Get node",
+		Aliases: []string{"nodes"},
+		Long:    `Get node.`,
 		Run: func(cmd *cobra.Command, args []string) {
 			log.Debugln("get node called")
+			node, runtime, headersOff := parseGetNodeCmd(cmd, args)
+			var existingNodes []*k3d.Node
+			if node == nil { // Option a)  no name specified -> get all nodes
+				found, err := cluster.GetNodes(runtime)
+				if err != nil {
+					log.Fatalln(err)
+				}
+				existingNodes = append(existingNodes, found...)
+			} else { // Option b) cluster name specified -> get specific cluster
+				found, err := cluster.GetNode(node, runtime)
+				if err != nil {
+					log.Fatalln(err)
+				}
+				existingNodes = append(existingNodes, found)
+			}
+			// print existing clusters
+			printNodes(existingNodes, headersOff)
 		},
 	}
 
+	// add flags
+	cmd.Flags().Bool("no-headers", false, "Disable headers")
+
 	// add subcommands
 
 	// done
 	return cmd
 }
+
+func parseGetNodeCmd(cmd *cobra.Command, args []string) (*k3d.Node, runtimes.Runtime, bool) {
+	// --runtime
+	rt, err := cmd.Flags().GetString("runtime")
+	if err != nil {
+		log.Fatalln("No runtime specified")
+	}
+	runtime, err := runtimes.GetRuntime(rt)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	// --no-headers
+	headersOff, err := cmd.Flags().GetBool("no-headers")
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	// Args = node name
+	if len(args) == 0 {
+		return nil, runtime, headersOff
+	}
+
+	node := &k3d.Node{Name: args[0]} // TODO: validate name first?
+
+	return node, runtime, headersOff
+}
+
+func printNodes(nodes []*k3d.Node, headersOff bool) {
+
+	tabwriter := tabwriter.NewWriter(os.Stdout, 6, 4, 3, ' ', tabwriter.RememberWidths)
+	defer tabwriter.Flush()
+
+	if !headersOff {
+		headers := []string{"NAME", "ROLE", "CLUSTER"} // TODO: add status
+		_, err := fmt.Fprintf(tabwriter, "%s\n", strings.Join(headers, "\t"))
+		if err != nil {
+			log.Fatalln("Failed to print headers")
+		}
+	}
+
+	sort.Slice(nodes, func(i, j int) bool {
+		return nodes[i].Name < nodes[j].Name
+	})
+
+	for _, node := range nodes {
+		fmt.Fprintf(tabwriter, "%s\t%s\t%s\n", strings.TrimPrefix(node.Name, "/"), string(node.Role), node.Labels["k3d.cluster"])
+	}
+}

pkg/cluster/node.go

@@ -135,3 +135,25 @@ func patchMasterSpec(node *k3d.Node) error {
 	node.Ports = append(node.Ports, fmt.Sprintf("%s:%s:6443/tcp", hostIP, apiPort)) // TODO: get '6443' from defaultport variable
 	return nil
 }
+
+// GetNodes returns a list of all existing clusters
+func GetNodes(runtime k3drt.Runtime) ([]*k3d.Node, error) {
+	nodes, err := runtime.GetNodesByLabel(k3d.DefaultObjectLabels)
+	if err != nil {
+		log.Errorln("Failed to get nodes")
+		return nil, err
+	}
+
+	return nodes, nil
+}
+
+// GetNode returns an existing cluster
+func GetNode(node *k3d.Node, runtime k3drt.Runtime) (*k3d.Node, error) {
+	// get node
+	node, err := runtime.GetNode(node)
+	if err != nil {
+		log.Errorf("Failed to get node '%s'", node.Name)
+	}
+
+	return node, nil
+}

pkg/runtimes/containerd/node.go

@@ -114,3 +114,8 @@ func (d Containerd) StopNode(node *k3d.Node) error {
 func (d Containerd) GetNodesByLabel(labels map[string]string) ([]*k3d.Node, error) {
 	return nil, nil
 }
+
+// GetNode tries to get a node container by its name
+func (d Containerd) GetNode(node *k3d.Node) (*k3d.Node, error) {
+	return nil, nil
+}

pkg/runtimes/docker/node.go

@@ -167,3 +167,21 @@ func getContainersByLabel(labels map[string]string) ([]types.Container, error) {
 	}
 	return containers, 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)
+	if err != nil {
+		log.Errorf("Failed to get container for node '%s'", node.Name)
+		return nil, err
+	}
+
+	node, err = TranslateContainerToNode(container)
+	if err != nil {
+		log.Errorf("Failed to translate container for node '%s' to node object", node.Name)
+		return nil, err
+	}
+
+	return node, nil
+
+}

pkg/runtimes/runtime.go

@@ -41,6 +41,7 @@ type Runtime interface {
 	CreateNode(*k3d.Node) error
 	DeleteNode(*k3d.Node) error
 	GetNodesByLabel(map[string]string) ([]*k3d.Node, error)
+	GetNode(*k3d.Node) (*k3d.Node, error)
 	CreateNetworkIfNotPresent(name string) (string, bool, error) // @return NETWORK_NAME, EXISTS, ERROR
 	GetKubeconfig(*k3d.Node) (io.ReadCloser, error)
 	DeleteNetwork(ID string) error