Add service logs command to faasd ce from faasd-pro

A more limited version is added, for continuity.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Author: alexellis

cmd/root.go

@@ -17,6 +17,7 @@ func init() {
 	rootCommand.AddCommand(installCmd)
 	rootCommand.AddCommand(makeProviderCmd())
 	rootCommand.AddCommand(collectCmd)
+	rootCommand.AddCommand(makeServiceCmd())
 }
 
 func RootCommand() *cobra.Command {

cmd/service.go

@@ -0,0 +1,22 @@
+package cmd
+
+import "github.com/spf13/cobra"
+
+func makeServiceCmd() *cobra.Command {
+	var command = &cobra.Command{
+		Use:   "service",
+		Short: "Manage services",
+		Long:  `Manage services created by faasd from the docker-compose.yml file`,
+	}
+
+	command.RunE = runServiceE
+
+	command.AddCommand(makeServiceLogsCmd())
+	return command
+}
+
+func runServiceE(cmd *cobra.Command, args []string) error {
+
+	return cmd.Help()
+
+}

cmd/service_logs.go

@@ -0,0 +1,89 @@
+package cmd
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"time"
+
+	goexecute "github.com/alexellis/go-execute/v2"
+	"github.com/spf13/cobra"
+)
+
+func makeServiceLogsCmd() *cobra.Command {
+	var command = &cobra.Command{
+		Use:   "logs",
+		Short: "View logs for a service",
+		Long:  `View logs for a service created by faasd from the docker-compose.yml file.`,
+		Example: `  ## View logs for the gateway for the last hour
+  faasd service logs gateway --since 1h
+
+  ## View logs for the cron-connector, and tail them
+  faasd service logs cron-connector -f
+`,
+	}
+
+	command.Flags().Duration("since", 10*time.Minute, "How far back in time to include logs")
+	command.Flags().BoolP("follow", "f", false, "Follow the logs")
+
+	command.RunE = runServiceLogsE
+	command.PreRunE = preRunServiceLogsE
+
+	return command
+}
+
+func runServiceLogsE(cmd *cobra.Command, args []string) error {
+	name := args[0]
+
+	namespace, _ := cmd.Flags().GetString("namespace")
+	follow, _ := cmd.Flags().GetBool("follow")
+	since, _ := cmd.Flags().GetDuration("since")
+
+	journalTask := goexecute.ExecTask{
+		Command:     "journalctl",
+		Args:        []string{"-o", "cat", "-t", fmt.Sprintf("%s:%s", namespace, name)},
+		StreamStdio: true,
+	}
+
+	if follow {
+		journalTask.Args = append(journalTask.Args, "-f")
+	}
+
+	if since != 0 {
+		// Calculate the timestamp that is 'age' duration ago
+		sinceTime := time.Now().Add(-since)
+		// Format according to journalctl's expected format: "2012-10-30 18:17:16"
+		formattedTime := sinceTime.Format("2006-01-02 15:04:05")
+		journalTask.Args = append(journalTask.Args, fmt.Sprintf("--since=%s", formattedTime))
+	}
+
+	res, err := journalTask.Execute(context.Background())
+	if err != nil {
+		return err
+	}
+
+	if res.ExitCode != 0 {
+		return fmt.Errorf("failed to get logs for service %s: %s", name, res.Stderr)
+	}
+
+	return nil
+}
+
+func preRunServiceLogsE(cmd *cobra.Command, args []string) error {
+
+	if os.Geteuid() != 0 {
+		return errors.New("this command must be run as root")
+	}
+
+	if len(args) == 0 {
+		return errors.New("service name is required as an argument")
+	}
+
+	namespace, _ := cmd.Flags().GetString("namespace")
+	if namespace == "" {
+		return errors.New("namespace is required")
+	}
+
+	return nil
+}