Merge pull request #2 from mlafeldt/wipe-state

Allow to wipe state of Chaos Monkey

README.md

@@ -41,6 +41,12 @@ Use the tool to:
     chaosmonkey -endpoint http://chaosmonkey.example.com:8080
     ```
 
+* List available chaos strategies, which you may pass to `-strategy`:
+
+    ```bash
+    chaosmonkey -list-strategies
+    ```
+
 * List all auto scaling groups for a given AWS account, which you may then pass to `-group`:
 
     ```bash
@@ -50,10 +56,13 @@ Use the tool to:
     chaosmonkey -list-groups
     ```
 
-* List available chaos strategies, which you may pass to `-strategy`:
+* Wipe state of Chaos Monkey by deleting its SimpleDB domain (named `SIMIAN_ARMY` by default):
 
     ```bash
-    chaosmonkey -list-strategies
+    export AWS_ACCESS_KEY_ID=...
+    export AWS_SECRET_ACCESS_KEY=...
+    export AWS_REGION=...
+    chaosmonkey -wipe-state SIMIAN_ARMY
     ```
 
 As always, invoke `chaosmonkey -h` for a list of all available options.

aws.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/autoscaling"
+	"github.com/aws/aws-sdk-go/service/simpledb"
+)
+
+func autoScalingGroups() ([]string, error) {
+	var groups []string
+	svc := autoscaling.New(session.New())
+	err := svc.DescribeAutoScalingGroupsPages(nil, func(out *autoscaling.DescribeAutoScalingGroupsOutput, last bool) bool {
+		for _, g := range out.AutoScalingGroups {
+			groups = append(groups, aws.StringValue(g.AutoScalingGroupName))
+		}
+		return !last
+	})
+	if err != nil {
+		return nil, err
+	}
+	sort.Strings(groups)
+	return groups, nil
+}
+
+func deleteSimpleDBDomain(domainName string) error {
+	var domainExists bool
+	svc := simpledb.New(session.New())
+	err := svc.ListDomainsPages(nil, func(out *simpledb.ListDomainsOutput, last bool) bool {
+		for _, n := range out.DomainNames {
+			if aws.StringValue(n) == domainName {
+				domainExists = true
+			}
+		}
+		return !last
+	})
+	if !domainExists {
+		return fmt.Errorf("SimpleDB domain %q does not exist", domainName)
+	}
+	_, err = svc.DeleteDomain(&simpledb.DeleteDomainInput{
+		DomainName: aws.String(domainName),
+	})
+	return err
+}

main.go

@@ -6,13 +6,9 @@ import (
 	"net/http"
 	"os"
 	"runtime"
-	"sort"
 	"strings"
 	"time"
 
-	"github.com/aws/aws-sdk-go/aws"
-	"github.com/aws/aws-sdk-go/aws/session"
-	"github.com/aws/aws-sdk-go/service/autoscaling"
 	"github.com/ryanuber/columnize"
 
 	chaosmonkey "github.com/mlafeldt/chaosmonkey/lib"
@@ -32,6 +28,7 @@ func main() {
 
 		listGroups     bool
 		listStrategies bool
+		wipeState      string
 		showVersion    bool
 	)
 
@@ -42,6 +39,7 @@ func main() {
 	flag.StringVar(&password, "password", "", "HTTP password")
 	flag.BoolVar(&listGroups, "list-groups", false, "List auto scaling groups")
 	flag.BoolVar(&listStrategies, "list-strategies", false, "List default chaos strategies")
+	flag.StringVar(&wipeState, "wipe-state", "", "Wipe Chaos Monkey state by deleting given SimpleDB domain")
 	flag.BoolVar(&showVersion, "version", false, "Show program version")
 	flag.Parse()
 
@@ -58,6 +56,11 @@ func main() {
 			fmt.Println(s)
 		}
 		return
+	case wipeState != "":
+		if err := deleteSimpleDBDomain(wipeState); err != nil {
+			abort("failed to wipe state: %s", err)
+		}
+		return
 	case showVersion:
 		fmt.Printf("chaosmonkey %s %s/%s %s\n", Version,
 			runtime.GOOS, runtime.GOARCH, runtime.Version())
@@ -90,22 +93,6 @@ func main() {
 	}
 }
 
-func autoScalingGroups() ([]string, error) {
-	var groups []string
-	svc := autoscaling.New(session.New())
-	err := svc.DescribeAutoScalingGroupsPages(nil, func(out *autoscaling.DescribeAutoScalingGroupsOutput, last bool) bool {
-		for _, g := range out.AutoScalingGroups {
-			groups = append(groups, aws.StringValue(g.AutoScalingGroupName))
-		}
-		return !last
-	})
-	if err != nil {
-		return nil, err
-	}
-	sort.Strings(groups)
-	return groups, nil
-}
-
 func printEvents(event ...chaosmonkey.Event) {
 	lines := []string{"InstanceID|AutoScalingGroupName|Region|Strategy|TriggeredAt"}
 	for _, e := range event {