Add support to EC2 Spot instances

Author: vyncentk

ecs-cli/modules/cli/cluster/cluster_app.go

@@ -58,6 +58,7 @@ func init() {
 		flags.KeypairNameFlag:   cloudformation.ParameterKeyKeyPairName,
 		flags.ImageIdFlag:       cloudformation.ParameterKeyAmiId,
 		flags.InstanceRoleFlag:  cloudformation.ParameterKeyInstanceRole,
+		flags.SpotPriceFlag:	 cloudformation.ParameterKeySpotPrice,
 	}
 }
 

ecs-cli/modules/cli/cluster/cluster_app_test.go

@@ -262,6 +262,49 @@ func TestClusterUpWithUserData(t *testing.T) {
 	assert.ElementsMatch(t, []string{"some_file", "some_file2"}, userdataMock.files, "Expected userdata file list to match")
 }
 
+func TestClusterUpWithSpotPrice(t *testing.T) {
+	defer os.Clearenv()
+	mockECS, mockCloudformation, mockSSM := setupTest(t)
+	awsClients := &AWSClients{mockECS, mockCloudformation, mockSSM}
+
+	spotPrice := "0.03"
+
+	gomock.InOrder(
+		mockECS.EXPECT().CreateCluster(clusterName).Return(clusterName, nil),
+	)
+
+	gomock.InOrder(
+		mockSSM.EXPECT().GetRecommendedECSLinuxAMI().Return(amiMetadata(amiID), nil),
+	)
+
+	gomock.InOrder(
+		mockCloudformation.EXPECT().ValidateStackExists(stackName).Return(errors.New("error")),
+		mockCloudformation.EXPECT().CreateStack(gomock.Any(), stackName, gomock.Any()).Do(func(x, y, z interface{}) {
+			cfnParams := z.(*cloudformation.CfnStackParams)
+			param, err := cfnParams.GetParameter(cloudformation.ParameterKeySpotPrice)
+			assert.NoError(t, err, "Expected Spot Price parameter to be set")
+			assert.Equal(t, spotPrice, aws.StringValue(param.ParameterValue), "Expected spot price to match")
+		}).Return("", nil),
+		mockCloudformation.EXPECT().WaitUntilCreateComplete(stackName).Return(nil),
+	)
+
+	globalSet := flag.NewFlagSet("ecs-cli", 0)
+	globalContext := cli.NewContext(nil, globalSet, nil)
+
+	flagSet := flag.NewFlagSet("ecs-cli-up", 0)
+	flagSet.Bool(flags.CapabilityIAMFlag, true, "")
+	flagSet.String(flags.KeypairNameFlag, "default", "")
+	flagSet.String(flags.SpotPriceFlag, spotPrice, "")
+
+	context := cli.NewContext(nil, flagSet, globalContext)
+	rdwr := newMockReadWriter()
+	commandConfig, err := newCommandConfig(context, rdwr)
+	assert.NoError(t, err, "Unexpected error creating CommandConfig")
+
+	err = createCluster(context, awsClients, commandConfig)
+	assert.NoError(t, err, "Unexpected error bringing up cluster")
+}
+
 func TestClusterUpWithVPC(t *testing.T) {
 	defer os.Clearenv()
 	mockECS, mockCloudformation, mockSSM := setupTest(t)

ecs-cli/modules/clients/aws/cloudformation/params.go

@@ -38,6 +38,7 @@ const (
 	ParameterKeyInstanceRole             = "InstanceRole"
 	ParameterKeyIsFargate                = "IsFargate"
 	ParameterKeyUserData                 = "UserData"
+	ParameterKeySpotPrice                = "SpotPrice"
 )
 
 var ParameterNotFoundError = errors.New("Parameter not found")
@@ -72,6 +73,7 @@ func init() {
 		ParameterKeyCluster,
 		ParameterKeyAmiId,
 		ParameterKeyAssociatePublicIPAddress,
+		ParameterKeySpotPrice,
 	}
 }
 

ecs-cli/modules/clients/aws/cloudformation/template.go

@@ -184,6 +184,11 @@ var template = `
       ],
       "ConstraintDescription": "must be a valid EC2 instance type."
     },
+    "SpotPrice": {
+      "Type": "Number",
+      "Description": "If greater than 0, then a EC2 Spot instance will be requested",
+      "Default": "0"
+    },
     "KeyName": {
       "Type": "String",
       "Description": "Optional - Name of an existing EC2 KeyPair to enable SSH access to the ECS instances",
@@ -340,6 +345,18 @@ var template = `
           ]
         }
       ]
+    },
+    "UseSpotInstances": {
+      "Fn::Not": [
+      {
+        "Fn::Equals": [
+        {
+          "Ref": "SpotPrice"
+        },
+        0
+        ]
+      }
+      ]
     }
   },
   "Resources": {
@@ -565,6 +582,17 @@ var template = `
         "InstanceType": {
           "Ref": "EcsInstanceType"
         },
+        "SpotPrice": {
+          "Fn::If": [
+            "UseSpotInstances",
+            {
+              "Ref": "SpotPrice"
+            },
+            {
+              "Ref": "AWS::NoValue"
+            }
+          ]
+        },
         "AssociatePublicIpAddress": {
           "Ref": "AssociatePublicIpAddress"
         },

ecs-cli/modules/commands/cluster/cluster_command.go

@@ -86,6 +86,10 @@ func clusterUpFlags() []cli.Flag {
 			Name:  flags.InstanceTypeFlag,
 			Usage: "[Optional] Specifies the EC2 instance type for your container instances. Defaults to t2.micro. NOTE: Not applicable for launch type FARGATE.",
 		},
+		cli.StringFlag{
+			Name:  flags.SpotPriceFlag,
+			Usage: "[Optional] If filled and greater than 0, EC2 Spot instances will be requested.",
+		},
 		cli.StringFlag{
 			Name:  flags.ImageIdFlag,
 			Usage: "[Optional] Specify the AMI ID for your container instances. Defaults to amazon-ecs-optimized AMI. NOTE: Not applicable for launch type FARGATE.",

ecs-cli/modules/commands/flags/flags.go

@@ -77,6 +77,7 @@ const (
 	SubnetIdsFlag                   = "subnets"
 	VpcIdFlag                       = "vpc"
 	InstanceTypeFlag                = "instance-type"
+	SpotPriceFlag                   = "spot-price"
 	InstanceRoleFlag                = "instance-role"
 	ImageIdFlag                     = "image-id"
 	KeypairNameFlag                 = "keypair"
@@ -221,5 +222,6 @@ func CFNResourceFlags() []string {
 		InstanceRoleFlag,
 		ImageIdFlag,
 		KeypairNameFlag,
+		SpotPriceFlag,
 	}
 }