Create strong typed awsInstanceID

pkg/cloudprovider/providers/aws/BUILD

@@ -18,6 +18,7 @@ go_library(
         "aws_routes.go",
         "aws_utils.go",
         "device_allocator.go",
+        "instances.go",
         "log_handler.go",
         "regions.go",
         "retry_handler.go",
@@ -58,6 +59,7 @@ go_test(
     srcs = [
         "aws_test.go",
         "device_allocator_test.go",
+        "instances_test.go",
         "regions_test.go",
         "retry_handler_test.go",
         "tags_test.go",

pkg/cloudprovider/providers/aws/instances.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+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 aws
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+
+	"github.com/aws/aws-sdk-go/aws"
+)
+
+// awsInstanceID represents the ID of the instance in the AWS API, e.g. i-12345678
+// The "traditional" format is "i-12345678"
+// A new longer format is also being introduced: "i-12345678abcdef01"
+// We should not assume anything about the length or format, though it seems
+// reasonable to assume that instances will continue to start with "i-".
+type awsInstanceID string
+
+func (i awsInstanceID) awsString() *string {
+	return aws.String(string(i))
+}
+
+// kubernetesInstanceID represents the id for an instance in the kubernetes API;
+// the following form
+//  * aws:///<zone>/<awsInstanceId>
+//  * aws:////<awsInstanceId>
+//  * <awsInstanceId>
+type kubernetesInstanceID string
+
+// mapToAWSInstanceID extracts the awsInstanceID from the kubernetesInstanceID
+func (name kubernetesInstanceID) mapToAWSInstanceID() (awsInstanceID, error) {
+	s := string(name)
+
+	if !strings.HasPrefix(s, "aws://") {
+		// Assume a bare aws volume id (vol-1234...)
+		// Build a URL with an empty host (AZ)
+		s = "aws://" + "/" + "/" + s
+	}
+	url, err := url.Parse(s)
+	if err != nil {
+		return "", fmt.Errorf("Invalid instance name (%s): %v", name, err)
+	}
+	if url.Scheme != "aws" {
+		return "", fmt.Errorf("Invalid scheme for AWS instance (%s)", name)
+	}
+
+	awsID := ""
+	tokens := strings.Split(strings.Trim(url.Path, "/"), "/")
+	if len(tokens) == 1 {
+		// instanceId
+		awsID = tokens[0]
+	} else if len(tokens) == 2 {
+		// az/instanceId
+		awsID = tokens[1]
+	}
+
+	// We sanity check the resulting volume; the two known formats are
+	// i-12345678 and i-12345678abcdef01
+	// TODO: Regex match?
+	if awsID == "" || strings.Contains(awsID, "/") || !strings.HasPrefix(awsID, "i-") {
+		return "", fmt.Errorf("Invalid format for AWS instance (%s)", name)
+	}
+
+	return awsInstanceID(awsID), nil
+}

pkg/cloudprovider/providers/aws/instances_test.go

@@ -0,0 +1,89 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+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 aws
+
+import (
+	"testing"
+)
+
+func TestParseInstance(t *testing.T) {
+	tests := []struct {
+		Kubernetes  kubernetesInstanceID
+		Aws         awsInstanceID
+		ExpectError bool
+	}{
+		{
+			Kubernetes: "aws:///us-east-1a/i-12345678",
+			Aws:        "i-12345678",
+		},
+		{
+			Kubernetes: "aws:////i-12345678",
+			Aws:        "i-12345678",
+		},
+		{
+			Kubernetes: "i-12345678",
+			Aws:        "i-12345678",
+		},
+		{
+			Kubernetes: "aws:///us-east-1a/i-12345678abcdef01",
+			Aws:        "i-12345678abcdef01",
+		},
+		{
+			Kubernetes: "aws:////i-12345678abcdef01",
+			Aws:        "i-12345678abcdef01",
+		},
+		{
+			Kubernetes: "i-12345678abcdef01",
+			Aws:        "i-12345678abcdef01",
+		},
+		{
+			Kubernetes:  "vol-123456789",
+			ExpectError: true,
+		},
+		{
+			Kubernetes:  "aws:///us-east-1a/vol-12345678abcdef01",
+			ExpectError: true,
+		},
+		{
+			Kubernetes:  "aws://accountid/us-east-1a/vol-12345678abcdef01",
+			ExpectError: true,
+		},
+		{
+			Kubernetes:  "aws:///us-east-1a/vol-12345678abcdef01/suffix",
+			ExpectError: true,
+		},
+		{
+			Kubernetes:  "",
+			ExpectError: true,
+		},
+	}
+
+	for _, test := range tests {
+		awsID, err := test.Kubernetes.mapToAWSInstanceID()
+		if err != nil {
+			if !test.ExpectError {
+				t.Errorf("unexpected error parsing %s: %v", test.Kubernetes, err)
+			}
+		} else {
+			if test.ExpectError {
+				t.Errorf("expected error parsing %s", test.Kubernetes)
+			} else if test.Aws != awsID {
+				t.Errorf("unexpected value parsing %s, got %s", test.Kubernetes, awsID)
+			}
+		}
+	}
+}

pkg/cloudprovider/providers/aws/volumes.go

@@ -24,7 +24,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws"
 )
 
-// awsVolumeID represents the ID of the volume in the AWS API, e.g. vol-12345678a
+// awsVolumeID represents the ID of the volume in the AWS API, e.g. vol-12345678
 // The "traditional" format is "vol-12345678"
 // A new longer format is also being introduced: "vol-12345678abcdef01"
 // We should not assume anything about the length or format, though it seems