# How to make Docker Compose wait for container X before starting Y?

You can make Docker Compose wait for a container X to be fully up and running before starting container Y by using the `depends_on` option in your `docker-compose.yml` file.

The `depends_on` option allows you to specify dependencies between services. By default, Docker Compose starts all services simultaneously, but you can use `depends_on` to specify that a service should wait for another service to be fully up and running before starting.

Here is an example `docker-compose.yml` file that shows how to use the `depends_on` option:

```yaml
version: "3"

services:
  service-x:
    build: .
    ports:
      - "8080:8080"
  service-y:
    build: .
    ports:
      - "8081:8081"
    depends_on:
      - service-x
```

In this example, we have two services, `service-x` and `service-y`. The `depends_on` option is used to specify that `service-y` should wait for `service-x` to be fully up and running before starting. This means that Docker Compose will start `service-x` first and wait for it to be fully up and running before starting `service-y`.

Note that the `depends_on` option does not guarantee that the dependent service is fully up and running, it only waits for the container to be started. It is recommended to use a health check to make sure that the dependent service is fully up and running before starting the dependent service.