Format extract cloudfront distribution id from arn

Author: nmorsman

format/aws.go

@@ -12,6 +12,7 @@ import "regexp"
 
 var arnEc2InstanceRe = regexp.MustCompile(`^arn:aws:ec2:.+/([^/]+)`)
 var arnEcsTaskToClusterRe = regexp.MustCompile(`^(arn:aws:ecs:[^:]+:\d+):task/([^/]+)/.*`)
+var arnCloudFrontDistributionRe = regexp.MustCompile(`^arn:aws:cloudfront::\d+:distribution/([^/]+)`)
 
 func Ec2InstanceIdFromArn(arn string) string {
 	return arnEc2InstanceRe.ReplaceAllString(arn, "${1}")
@@ -20,3 +21,7 @@ func Ec2InstanceIdFromArn(arn string) string {
 func EcsTaskArnToClusterArn(arn string) string {
 	return arnEcsTaskToClusterRe.ReplaceAllString(arn, "${1}:cluster/${2}")
 }
+
+func CloudFrontDistributionIdFromArn(arn string) string {
+	return arnCloudFrontDistributionRe.ReplaceAllString(arn, "${1}")
+}

format/aws_test.go

@@ -27,3 +27,14 @@ func TestEcsTaskArnToClusterArnErr(t *testing.T) {
 	result := EcsTaskArnToClusterArn(arn)
 	assert.Equal(t, arn, result)
 }
+
+func TestCloudFrontDistributionIdFromArn(t *testing.T) {
+	result := CloudFrontDistributionIdFromArn("arn:aws:cloudfront::1234567890:distribution/E1234567890ABC")
+	assert.Equal(t, "E1234567890ABC", result)
+}
+
+func TestCloudFrontDistributionIdFromArnErr(t *testing.T) {
+	arn := "invalid-arn"
+	result := CloudFrontDistributionIdFromArn(arn)
+	assert.Equal(t, arn, result)
+}