add exec command

cmd/exec.go

@@ -0,0 +1,77 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+	"github.com/srl-wim/container-lab/clab"
+)
+
+var labels []string
+
+// execCmd represents the exec command
+var execCmd = &cobra.Command{
+	Use:   "exec",
+	Short: "execute a command on one or multiple containers",
+
+	Run: func(cmd *cobra.Command, args []string) {
+		if prefix == "" && topo == "" {
+			fmt.Println("provide either lab prefix (--prefix) or topology file path (--topo)")
+			return
+		}
+		log.Debugf("raw command: %v", args)
+		if len(args) == 0 {
+			fmt.Println("provide command to execute")
+			return
+		}
+		c := clab.NewContainerLab(debug)
+		err := c.Init()
+		if err != nil {
+			log.Fatal(err)
+		}
+		if prefix == "" {
+			if err = c.GetTopology(&topo); err != nil {
+				log.Fatal(err)
+			}
+			prefix = c.Conf.Prefix
+		}
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+		labels = append(labels, "containerlab=lab-"+prefix)
+		containers, err := c.ListContainers(ctx, labels)
+		if err != nil {
+			log.Fatalf("could not list containers: %v", err)
+		}
+		if len(containers) == 0 {
+			log.Println("no containers found")
+			return
+		}
+		cmds := make([]string, 0, len(args))
+		for _, a := range args {
+			cmds = append(cmds, strings.Split(a, " ")...)
+		}
+		for _, cont := range containers {
+			stdout, stderr, err := c.Exec(ctx, cont.ID, cmds)
+			if err != nil {
+				log.Errorf("%s: failed to execute cmd: %v", cont.Names, err)
+				continue
+			}
+			if len(stdout) > 0 {
+				log.Infof("%s: stdout:\n%s", cont.Names, string(stdout))
+			}
+			if len(stderr) > 0 {
+				log.Infof("%s: stderr:\n%s", cont.Names, string(stderr))
+			}
+		}
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(execCmd)
+	execCmd.Flags().StringVarP(&topo, "topo", "t", "/etc/containerlab/lab-examples/wan-topo.yml", "path to the file with topology information")
+	execCmd.Flags().StringVarP(&prefix, "prefix", "p", "", "lab name prefix")
+	execCmd.Flags().StringSliceVarP(&labels, "label", "", []string{}, "labels to filter container subset")
+}