Set proper dependencies for the ECS containers (#67)

This will prevent the web container from starting before downloading the S3 keys or initializing the DB

ecs-web/main.tf

@@ -74,8 +74,10 @@ data "template_file" "concourse_web_task_template" {
     concourse_prometheus_bind_port              = var.concourse_prometheus_bind_port
     concourse_prometheus_bind_ip                = var.concourse_prometheus_bind_ip
     volumes_from_concourse_db                   = var.auto_create_db ? ",{ \"sourceContainer\": \"create_db\" }" : ""
+    db_container_dependency                     = var.auto_create_db ? ",{ \"containerName\": \"create_db\", \"condition\": \"COMPLETE\" }" : ""
     volumes_from_vault_auth                     = var.vault_server_url != null ? ",{ \"sourceContainer\": \"vault_auth\" }" : ""
     vault_command_args                          = var.vault_server_url != null ? "--vault-client-token=`cat /concourse_vault/token`" : ""
+    vault_container_dependency                  = var.vault_server_url != null ? ",{ \"containerName\": \"create_db\", \"condition\": \"SUCCESS\" }" : ""
     concourse_extra_args                        = var.concourse_extra_args != null ? var.concourse_extra_args : ""
     concourse_extra_env                         = var.concourse_extra_env != null ? join("", data.template_file.concourse_extra_env.*.rendered) : ""
     concourse_default_build_logs_to_retain      = var.concourse_default_build_logs_to_retain

ecs-web/task-definitions/concourse_web_service.json

@@ -84,6 +84,14 @@
       ${volumes_from_concourse_db}
       ${volumes_from_vault_auth}
     ],
+    "dependsOn": [
+      {
+        "containerName": "download_keys",
+        "condition": "SUCCESS"
+      }
+      ${db_container_dependency}
+      ${vault_container_dependency}
+    ],
     "logConfiguration": {
       "logDriver": "awslogs",
       "options"  : {