Add events command to view ECS events for a service

app/app.go

@@ -707,6 +707,28 @@ func (a *App) DescribeTasks() ([]*ecs.Task, error) {
 	return appTasks, nil
 }
 
+func (a *App) GetECSEvents(service string) ([]*ecs.ServiceEvent, error) {
+	ecsSvc := ecs.New(a.Session)
+	a.LoadSettings()
+	logrus.WithFields(logrus.Fields{"service": service}).Debug("fetching service events")
+	serviceStatus, err := ecsSvc.DescribeServices(&ecs.DescribeServicesInput{
+		Cluster:  &a.Settings.Cluster.ARN,
+		Services: aws.StringSlice([]string{fmt.Sprintf("%s-%s", a.Name, service)}),
+	})
+	if err != nil {
+		return nil, err
+	}
+	if len(serviceStatus.Services) == 0 {
+		return nil, fmt.Errorf("could not find service %s", service)
+	}
+	events := serviceStatus.Services[0].Events
+	// reverse events so the oldest is first
+	for i, j := 0, len(events)-1; i < j; i, j = i+1, j-1 {
+		events[i], events[j] = events[j], events[i]
+	}
+	return events, nil
+}
+
 func (a *App) DBDumpLocation(prefix string) (*s3.GetObjectInput, error) {
 	currentTime := time.Now()
 	username, err := auth.WhoAmI()

cmd/events.go

@@ -0,0 +1,106 @@
+/*
+Copyright © 2021 NAME HERE <EMAIL ADDRESS>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package cmd
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/apppackio/apppack/app"
+	"github.com/aws/aws-sdk-go/service/ecs"
+	"github.com/logrusorgru/aurora"
+	"github.com/spf13/cobra"
+)
+
+func printEvent(event *ecs.ServiceEvent) {
+	fmt.Println(aurora.Faint(event.CreatedAt.Local().Format("Jan 02, 2006 15:04:05 MST")), *event.Message)
+}
+
+// eventsCmd represents the events command
+var eventsCmd = &cobra.Command{
+	Use:     "events <service>",
+	Short:   "Show recent events for the given service",
+	Example: "apppack -a my-app events web",
+	Args:    cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		startSpinner()
+		a, err := app.Init(AppName, UseAWSCredentials, SessionDurationSeconds)
+		checkErr(err)
+		events, err := a.GetECSEvents(args[0])
+		checkErr(err)
+		waitForSteadyState := cmd.Flag("wait-for-steady").Value.String() == "true"
+		Spinner.Stop()
+		fmt.Println("⏳", aurora.Blue(fmt.Sprintf("waiting for `%s` service to reach a steady state...", args[0])))
+		for _, event := range events {
+			// when waiting for steady, only show the last minute of events to start
+			if !waitForSteadyState || event.CreatedAt.After(time.Now().Add(-time.Minute)) {
+				printEvent(event)
+			}
+		}
+		if !waitForSteadyState {
+			return
+		}
+		startSpinner()
+		// if no events, wait for some to come in
+		if len(events) == 0 {
+			for {
+				events, err = a.GetECSEvents(args[0])
+				checkErr(err)
+				if len(events) > 0 {
+					break
+				}
+				time.Sleep(time.Second * 5)
+			}
+		}
+		cursor := *events[len(events)-1].Id
+		startEventTime := events[0].CreatedAt
+		for {
+			events, err := a.GetECSEvents(args[0])
+			checkErr(err)
+			lastEvent := events[len(events)-1]
+			// no new events, sleep and check again
+			if *lastEvent.Id == cursor {
+				time.Sleep(time.Second * 5)
+				continue
+			}
+			Spinner.Stop()
+			display := false
+			// loop through events, only printing new ones and break on steady state
+			for _, event := range events {
+				if display {
+					printEvent(event)
+					if strings.Contains(*event.Message, "has reached a steady state") && event.CreatedAt.After(*startEventTime) {
+						return
+					}
+				} else if *event.Id == cursor {
+					display = true
+				}
+			}
+			startSpinner()
+			cursor = *lastEvent.Id
+			time.Sleep(time.Second * 5)
+		}
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(eventsCmd)
+	eventsCmd.PersistentFlags().StringVarP(&AppName, "app-name", "a", "", "app name (required)")
+	eventsCmd.MarkPersistentFlagRequired("app-name")
+	eventsCmd.PersistentFlags().BoolVar(&UseAWSCredentials, "aws-credentials", false, "use AWS credentials instead of AppPack.io federation")
+	eventsCmd.Flags().BoolP("wait-for-steady", "w", false, "wait for service to reach a steady state")
+}