Fix #195 and #196 - issues with creating VPCs in regions with < 3 ava…

…ilability zones

common/stack.go

@@ -40,6 +40,11 @@ type ImageFinder interface {
 	FindLatestImageID(namePattern string) (string, error)
 }
 
+// AZCounter for counting availability zones in a region
+type AZCounter interface {
+	CountAZs() (int, error)
+}
+
 // StackManager composite of all stack capabilities
 type StackManager interface {
 	StackUpserter
@@ -48,4 +53,5 @@ type StackManager interface {
 	StackGetter
 	StackDeleter
 	ImageFinder
+	AZCounter
 }

provider/aws/cloudformation.go

@@ -446,6 +446,25 @@ func (cfnMgr *cloudformationStackManager) GetStack(stackName string) (*common.St
 	return stack, nil
 }
 
+// CountAZs for current region
+func (cfnMgr *cloudformationStackManager) CountAZs() (int, error) {
+	ec2Api := cfnMgr.ec2API
+	resp, err := ec2Api.DescribeAvailabilityZones(&ec2.DescribeAvailabilityZonesInput{
+		Filters: []*ec2.Filter{
+			{
+				Name: aws.String("state"),
+				Values: []*string{
+					aws.String("available"),
+				},
+			},
+		},
+	})
+	if err != nil {
+		return 0, err
+	}
+	return len(resp.AvailabilityZones), nil
+}
+
 // FindLatestImageID for a given
 func (cfnMgr *cloudformationStackManager) FindLatestImageID(namePattern string) (string, error) {
 	ec2Api := cfnMgr.ec2API

templates/assets/vpc-target.yml

@@ -11,6 +11,10 @@ Parameters:
   ElbSubnetIds:
     Description: ELB subnet ids
     Type: CommaDelimitedList
+  AZCount:
+    Description: Number of availability zones to use
+    Type: String
+    Default: '3'
 Resources:
   WaitHandle:
     Type: "AWS::CloudFormation::WaitConditionHandle"

templates/assets/vpc.yml

@@ -99,6 +99,10 @@ Parameters:
     Description: SSH Key to add to bastion
     Type: String
     Default: ''
+  AZCount:
+    Description: Number of availability zones to use
+    Type: String
+    Default: '3'
 Conditions:
   HasElbSubnetAZ1:
     "Fn::Not":
@@ -111,10 +115,14 @@ Conditions:
         - !Ref ElbSubnetAZ2CidrBlock
         - ''
   HasElbSubnetAZ3:
-    "Fn::Not":
+    "Fn::And":
       - "Fn::Equals":
-        - !Ref ElbSubnetAZ3CidrBlock
-        - ''
+        - !Ref AZCount
+        - '3'
+      - "Fn::Not":
+        - "Fn::Equals":
+          - !Ref ElbSubnetAZ3CidrBlock
+          - ''
   HasInstanceSubnetAZ1:
     "Fn::Not":
       - "Fn::Equals":
@@ -126,10 +134,14 @@ Conditions:
         - !Ref InstanceSubnetAZ2CidrBlock
         - ''
   HasInstanceSubnetAZ3:
-    "Fn::Not":
+    "Fn::And":
       - "Fn::Equals":
-        - !Ref InstanceSubnetAZ3CidrBlock
-        - ''
+        - !Ref AZCount
+        - '3'
+      - "Fn::Not":
+        - "Fn::Equals":
+          - !Ref InstanceSubnetAZ3CidrBlock
+          - ''
   IsPublicElb:
     "Fn::Not":
       - "Fn::Equals":

workflows/environment_upsert.go

@@ -24,7 +24,7 @@ func NewEnvironmentUpserter(ctx *common.Context, environmentName string) Executo
 	return newPipelineExecutor(
 		workflow.environmentFinder(&ctx.Config, environmentName),
 		workflow.environmentRolesetUpserter(ctx.RolesetManager, ctx.RolesetManager, consulStackParams, ecsStackParams),
-		workflow.environmentVpcUpserter(ctx.Config.Namespace, ecsStackParams, elbStackParams, consulStackParams, ctx.StackManager, ctx.StackManager, ctx.StackManager),
+		workflow.environmentVpcUpserter(ctx.Config.Namespace, ecsStackParams, elbStackParams, consulStackParams, ctx.StackManager, ctx.StackManager, ctx.StackManager, ctx.StackManager),
 		workflow.environmentElbUpserter(ctx.Config.Namespace, ecsStackParams, elbStackParams, ctx.StackManager, ctx.StackManager, ctx.StackManager),
 		newConditionalExecutor(workflow.isConsulEnabled(), workflow.environmentConsulUpserter(ctx.Config.Namespace, consulStackParams, ecsStackParams, ctx.StackManager, ctx.StackManager, ctx.StackManager), nil),
 		workflow.environmentUpserter(ctx.Config.Namespace, ecsStackParams, ctx.StackManager, ctx.StackManager, ctx.StackManager),
@@ -48,7 +48,7 @@ func (workflow *environmentWorkflow) environmentFinder(config *common.Config, en
 	}
 }
 
-func (workflow *environmentWorkflow) environmentVpcUpserter(namespace string, ecsStackParams map[string]string, elbStackParams map[string]string, consulStackParams map[string]string, imageFinder common.ImageFinder, stackUpserter common.StackUpserter, stackWaiter common.StackWaiter) Executor {
+func (workflow *environmentWorkflow) environmentVpcUpserter(namespace string, ecsStackParams map[string]string, elbStackParams map[string]string, consulStackParams map[string]string, imageFinder common.ImageFinder, stackUpserter common.StackUpserter, stackWaiter common.StackWaiter, azCounter common.AZCounter) Executor {
 	return func() error {
 		environment := workflow.environment
 		vpcStackParams := make(map[string]string)
@@ -89,6 +89,15 @@ func (workflow *environmentWorkflow) environmentVpcUpserter(namespace string, ec
 			vpcStackParams["InstanceSubnetIds"] = strings.Join(environment.VpcTarget.InstanceSubnetIds, ",")
 		}
 
+		azCount, err := azCounter.CountAZs()
+		if err != nil {
+			return err
+		}
+		if azCount < 2 {
+			return fmt.Errorf("Only found %v availability zones...need at least 2", azCount)
+		}
+		vpcStackParams["AZCount"] = strconv.Itoa(azCount)
+
 		log.Noticef("Upserting VPC environment '%s' ...", environment.Name)
 
 		tags := createTagMap(&EnvironmentTags{

workflows/environment_upsert_test.go

@@ -2,11 +2,12 @@ package workflows
 
 import (
 	"bytes"
+	"testing"
+
 	"github.com/stelligent/mu/common"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 	"gopkg.in/yaml.v2"
-	"testing"
 )
 
 func TestEnvironmentFinder(t *testing.T) {
@@ -70,6 +71,10 @@ func (m *mockedStackManagerForUpsert) FindLatestImageID(pattern string) (string,
 	args := m.Called()
 	return args.String(0), args.Error(1)
 }
+func (m *mockedStackManagerForUpsert) CountAZs() (int, error) {
+	args := m.Called()
+	return args.Int(0), nil
+}
 
 func TestEnvironmentEcsUpserter(t *testing.T) {
 	assert := assert.New(t)
@@ -196,8 +201,9 @@ func TestEnvironmentVpcUpserter(t *testing.T) {
 	stackManager.On("AwaitFinalStatus", "mu-vpc-foo").Return(&common.Stack{Status: common.StackStatusCreateComplete})
 	stackManager.On("UpsertStack", "mu-vpc-foo", mock.AnythingOfType("map[string]string")).Return(nil)
 	stackManager.On("FindLatestImageID").Return("ami-00000", nil)
+	stackManager.On("CountAZs").Return(3)
 
-	err := workflow.environmentVpcUpserter("mu", vpcInputParams, vpcInputParams, vpcInputParams, stackManager, stackManager, stackManager)()
+	err := workflow.environmentVpcUpserter("mu", vpcInputParams, vpcInputParams, vpcInputParams, stackManager, stackManager, stackManager, stackManager)()
 	assert.Nil(err)
 	assert.Equal("mu-vpc-foo-VpcId", vpcInputParams["VpcId"])
 	assert.Equal("mu-vpc-foo-InstanceSubnetIds", vpcInputParams["InstanceSubnetIds"])
@@ -221,8 +227,9 @@ func TestEnvironmentVpcUpserter_NoBastion(t *testing.T) {
 	stackManager := new(mockedStackManagerForUpsert)
 	stackManager.On("AwaitFinalStatus", "mu-vpc-foo").Return(&common.Stack{Status: common.StackStatusCreateComplete})
 	stackManager.On("UpsertStack", "mu-vpc-foo", mock.AnythingOfType("map[string]string")).Return(nil)
+	stackManager.On("CountAZs").Return(3)
 
-	err := workflow.environmentVpcUpserter("mu", vpcInputParams, vpcInputParams, vpcInputParams, stackManager, stackManager, stackManager)()
+	err := workflow.environmentVpcUpserter("mu", vpcInputParams, vpcInputParams, vpcInputParams, stackManager, stackManager, stackManager, stackManager)()
 	assert.Nil(err)
 	assert.Equal("mu-vpc-foo-VpcId", vpcInputParams["VpcId"])
 	assert.Equal("mu-vpc-foo-InstanceSubnetIds", vpcInputParams["InstanceSubnetIds"])
@@ -254,11 +261,12 @@ environments:
 	stackManager := new(mockedStackManagerForUpsert)
 	stackManager.On("UpsertStack", "mu-target-dev", mock.AnythingOfType("map[string]string")).Return(nil)
 	stackManager.On("AwaitFinalStatus", "mu-target-dev").Return(&common.Stack{Status: common.StackStatusCreateComplete})
+	stackManager.On("CountAZs").Return(3)
 
 	workflow := new(environmentWorkflow)
 	workflow.environment = &config.Environments[0]
 
-	err = workflow.environmentVpcUpserter("mu", vpcInputParams, vpcInputParams, vpcInputParams, stackManager, stackManager, stackManager)()
+	err = workflow.environmentVpcUpserter("mu", vpcInputParams, vpcInputParams, vpcInputParams, stackManager, stackManager, stackManager, stackManager)()
 	assert.Nil(err)
 	assert.Equal("mu-target-dev-VpcId", vpcInputParams["VpcId"])
 	assert.Equal("mu-target-dev-InstanceSubnetIds", vpcInputParams["InstanceSubnetIds"])