fix(ecs): correct logic of healthcheck command (aws#2462)

Adding a healthcheck command to an ECS container definition
results in an invalid command after synthesizing.

Before:

    Input: ['CMD', 'command']
    Output:
          HealthCheck:
            Command:
              - CMD
              - CMD
              - echo
              - z

    Input: ['CMD-SHELL', 'command']
    Output:
          HealthCheck:
            Command:
              - CMD
              - CMD-SHELL
              - echo
              - z

After:

    Input: ['CMD', 'command']
    Output:
          HealthCheck:
            Command:
              - CMD
              - echo
              - z

    Input: ['CMD-SHELL', 'command']
    Output:
          HealthCheck:
            Command:
              - CMD-SHELL
              - echo
              - z

fixes aws#2461

Signed-off-by: Chris Lahaye <dev@chrislahaye.com>

packages/@aws-cdk/aws-ecs/lib/container-definition.ts

@@ -478,7 +478,7 @@ function getHealthCheckCommand(hc: HealthCheck): string[] {
     return hcCommand;
   }
 
-  if (cmd[0] !== "CMD" || cmd[0] !== 'CMD-SHELL') {
+  if (cmd[0] !== "CMD" && cmd[0] !== 'CMD-SHELL') {
     hcCommand.push('CMD');
   }
 

packages/@aws-cdk/aws-ecs/test/test.container-definition.ts

@@ -360,7 +360,7 @@ export = {
     test.done();
   },
 
-  'can specify Health Check values'(test: Test) {
+  'can specify Health Check values in shell form'(test: Test) {
     // GIVEN
     const stack = new cdk.Stack();
     const taskDefinition = new ecs.Ec2TaskDefinition(stack, 'TaskDef');
@@ -396,6 +396,78 @@ export = {
     test.done();
   },
 
+  'can specify Health Check values in array form starting with CMD-SHELL'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const taskDefinition = new ecs.Ec2TaskDefinition(stack, 'TaskDef');
+    const hcCommand = "curl localhost:8000";
+
+    // WHEN
+    taskDefinition.addContainer('cont', {
+      image: ecs.ContainerImage.fromRegistry('test'),
+      memoryLimitMiB: 1024,
+      healthCheck: {
+        command: ["CMD-SHELL", hcCommand],
+        intervalSeconds: 20,
+        retries: 5,
+        startPeriod: 10
+      }
+    });
+
+    // THEN
+    expect(stack).to(haveResourceLike('AWS::ECS::TaskDefinition', {
+      ContainerDefinitions: [
+        {
+          HealthCheck: {
+            Command: ["CMD-SHELL", hcCommand],
+            Interval: 20,
+            Retries: 5,
+            Timeout: 5,
+            StartPeriod: 10
+          },
+        }
+      ]
+    }));
+
+    test.done();
+  },
+
+  'can specify Health Check values in array form starting with CMD'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const taskDefinition = new ecs.Ec2TaskDefinition(stack, 'TaskDef');
+    const hcCommand = "curl localhost:8000";
+
+    // WHEN
+    taskDefinition.addContainer('cont', {
+      image: ecs.ContainerImage.fromRegistry('test'),
+      memoryLimitMiB: 1024,
+      healthCheck: {
+        command: ["CMD", hcCommand],
+        intervalSeconds: 20,
+        retries: 5,
+        startPeriod: 10
+      }
+    });
+
+    // THEN
+    expect(stack).to(haveResourceLike('AWS::ECS::TaskDefinition', {
+      ContainerDefinitions: [
+        {
+          HealthCheck: {
+            Command: ["CMD", hcCommand],
+            Interval: 20,
+            Retries: 5,
+            Timeout: 5,
+            StartPeriod: 10
+          },
+        }
+      ]
+    }));
+
+    test.done();
+  },
+
   'can specify private registry credentials'(test: Test) {
     // GIVEN
     const stack = new cdk.Stack();