feat(journal): add journal support

Author: Gabriel Monroy

client/api.go

@@ -9,4 +9,5 @@ type Client interface {
 	Scale(string, int) error
 	List() error
 	Status(string) error
+	Journal(string) error
 }

client/journal.go

@@ -0,0 +1,38 @@
+package client
+
+import (
+	"fmt"
+	"os"
+)
+
+// Journal prints the systemd journal of target unit(s)
+func (c *FleetClient) Journal(target string) (err error) {
+	units, err := c.getUnits(target)
+	if err != nil {
+		return
+	}
+	for _, unit := range units {
+		runJournal(unit)
+	}
+	return
+}
+
+// runJournal tails the systemd journal for a given unit
+func runJournal(jobName string) (exit int) {
+
+	j, err := cAPI.Job(jobName)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error retrieving Job %s: %v", jobName, err)
+		return 1
+	}
+	if j == nil {
+		fmt.Fprintf(os.Stderr, "Job %s does not exist.\n", jobName)
+		return 1
+	} else if j.UnitState == nil {
+		fmt.Fprintf(os.Stderr, "Job %s does not appear to be running.\n", jobName)
+		return 1
+	}
+
+	command := fmt.Sprintf("journalctl --unit %s --no-pager -n 40 -f", jobName)
+	return runCommand(command, j.UnitState.MachineID)
+}

cmd/cmd.go

@@ -2,11 +2,12 @@ package cmd
 
 import (
 	"fmt"
-	"github.com/deis/deisctl/client"
-	"github.com/deis/deisctl/utils"
 	"regexp"
 	"strconv"
 	"strings"
+
+	"github.com/deis/deisctl/client"
+	"github.com/deis/deisctl/utils"
 )
 
 func List(c client.Client) error {
@@ -68,6 +69,16 @@ func Status(c client.Client, targets []string) error {
 	return nil
 }
 
+func Journal(c client.Client, targets []string) error {
+	for _, target := range targets {
+		err := c.Journal(target)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func Install(c client.Client, targets []string) error {
 	// if targets, install all services
 	if len(targets) == 0 {

deisctl.go

@@ -77,6 +77,7 @@ Example Commands:
   deisctl start router@2
   deisctl stop router builder
   deisctl status controller
+  deisctl journal controller
 
 Options:
   --debug                     print debug information to stderr
@@ -112,6 +113,8 @@ Options:
 		err = cmd.Stop(c, targets)
 	case "status":
 		err = cmd.Status(c, targets)
+	case "journal":
+		err = cmd.Journal(c, targets)
 	case "install":
 		err = cmd.Install(c, targets)
 	case "uninstall":