Add support for multiple AWS regions to Functionbeat (elastic#21065)

(cherry picked from commit ee95f3d)

CHANGELOG.next.asciidoc

@@ -650,6 +650,7 @@ port. {pull}19209[19209]
 *Functionbeat*
 
 - Provide more ways to set AWS credentials. {issue}12464[12464] {pull}23344[23344]
+- Add support for multiple regions {pull}21065[21065]
 
 *Winlogbeat*
 

x-pack/functionbeat/config/config.go

@@ -16,7 +16,14 @@ import (
 )
 
 var (
-	functionPattern = "^[A-Za-z][A-Za-z0-9\\-]{0,139}$"
+	// We're appending the function name to the role name.
+	// Limiting this to 30 because, we're prefixing the role name
+	// with "functionbeat-lambda-"(20 chars) and suffixing with
+	// the region, the max of which is "ap-southeast-2" (14 chars)
+	// Length constraints for roleName in AWS is 64 characters max per
+	// https://docs.aws.amazon.com/IAM/latest/APIReference/API_CreateRole.html
+
+	functionPattern = "^[A-Za-z][A-Za-z0-9\\-]{0,30}$"
 	functionRE      = regexp.MustCompile(functionPattern)
 	configOverrides = common.MustNewConfigFrom(map[string]interface{}{
 		"path.data":              "/tmp",
@@ -103,7 +110,7 @@ type functionName string
 func (f *functionName) Unpack(s string) error {
 	if !functionRE.MatchString(s) {
 		return fmt.Errorf(
-			"invalid name: '%s', name must match [a-zA-Z0-9-] and be at most 140 characters",
+			"invalid name: '%s', name must match [a-zA-Z0-9-] and be at most 30 characters",
 			s,
 		)
 	}

x-pack/functionbeat/config/config_test.go

@@ -105,9 +105,24 @@ func TestFunctionName(t *testing.T) {
 		assert.Equal(t, functionName("hello-world"), f)
 	})
 
+	t.Run("valid function name: length of 30 chars", func(t *testing.T) {
+		f := functionName("")
+		err := f.Unpack("something-which-is--30--chars")
+		if !assert.NoError(t, err) {
+			return
+		}
+		assert.Equal(t, functionName("something-which-is--30--chars"), f)
+	})
+
 	t.Run("invalid function name", func(t *testing.T) {
 		f := functionName("")
 		err := f.Unpack("hello world")
 		assert.Error(t, err)
 	})
+
+	t.Run("invalid function name: length", func(t *testing.T) {
+		f := functionName("")
+		err := f.Unpack("something-which-is-greater-than-thirty-characters")
+		assert.Error(t, err)
+	})
 }

x-pack/functionbeat/manager/aws/template_builder.go

@@ -264,7 +264,7 @@ func (d *defaultTemplateBuilder) roleTemplate(function installer, name string) *
 			},
 		},
 		Path:     "/",
-		RoleName: "functionbeat-lambda-" + name,
+		RoleName: "functionbeat-lambda-" + name + "-" + cloudformation.Ref("AWS::Region"),
 		// Allow the lambda to write log to cloudwatch logs.
 		// doc: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-iam-policy.html
 		Policies: policies,