events: add Secrets Manager rotation event (#291)

events/README_SecretsManager_SecretRotationEvent.md

@@ -0,0 +1,38 @@
+# Sample Function
+
+The following is a sample Lambda function that handles a SecretsManager secret rotation event.
+
+```go
+package main
+
+import (
+ "fmt"
+ "context"
+
+ "github.com/aws/aws-lambda-go/lambda"
+ "github.com/aws/aws-lambda-go/events"
+)
+
+func handler(ctx context.Context, event SecretsManagerSecretRotationEvent) error {
+ fmt.Printf("rotating secret %s with token %s\n", 
+ event.SecretID, event.ClientRequestToken)
+
+ switch event.Step {
+ case "createSecret":
+ // create
+ case "setSecret":
+ // set
+ case "finishSecret":
+ // finish
+ case "testSecret":
+ // test
+ }
+
+ return nil
+}
+
+
+func main() {
+ lambda.Start(handler)
+}
+```

events/secretsmanager.go

@@ -0,0 +1,11 @@
+package events
+
+// SecretsManagerSecretRotationEvent is the event passed to a Lambda function to handle
+// automatic secret rotation.
+//
+// https://docs.aws.amazon.com/secretsmanager/latest/userguide/rotating-secrets.html#rotate-secrets_how
+type SecretsManagerSecretRotationEvent struct {
+ Step string `json:"Step"`
+ SecretID string `json:"SecretId"`
+ ClientRequestToken string `json:"ClientRequestToken"`
+}

events/secretsmanager_test.go

@@ -0,0 +1,30 @@
+package events
+
+import (
+ "encoding/json"
+ "testing"
+
+ "github.com/aws/aws-lambda-go/events/test"
+ "github.com/stretchr/testify/assert"
+)
+
+func TestSecretsManagerSecretRotationEventMarshaling(t *testing.T) {
+
+ // 1. read JSON from file
+ inputJSON := test.ReadJSONFromFile(t, "./testdata/secretsmanager-secret-rotation-event.json")
+
+ // 2. de-serialize into Go object
+ var inputEvent SecretsManagerSecretRotationEvent
+ if err := json.Unmarshal(inputJSON, &inputEvent); err != nil {
+ t.Errorf("could not unmarshal event. details: %v", err)
+ }
+
+ // 3. serialize to JSON
+ outputJSON, err := json.Marshal(inputEvent)
+ if err != nil {
+ t.Errorf("could not marshal event. details: %v", err)
+ }
+
+ // 4. check result
+ assert.JSONEq(t, string(inputJSON), string(outputJSON))
+}

events/testdata/secretsmanager-secret-rotation-event.json

@@ -0,0 +1,5 @@
+{
+ "Step": "createSecret",
+ "SecretId": "arn:aws:secretsmanager:us-east-1:111122223333:secret:id-ABCD1E",
+ "ClientRequestToken": "1ab23456-cde7-8912-34fg-h56i78j9k12l"
+}