github.com/drud/ddev@v1.21.5-alpha1.0.20230226034409-94fcc4b94453/docs/content/users/extend/custom-compose-files.md (about)

     1  # Defining Additional Services with Docker Compose
     2  
     3  ## Prerequisite
     4  
     5  Much of DDEV’s customization ability and extensibility comes from leveraging features and functionality provided by [Docker](https://docs.docker.com/) and [Docker Compose](https://docs.docker.com/compose/overview/). Some working knowledge of these tools is required in order to customize or extend the environment DDEV provides.
     6  
     7  There are [many examples of custom docker-compose files](https://github.com/drud/ddev-contrib#additional-services-added-via-docker-composeserviceyaml) available on [ddev-contrib](https://github.com/drud/ddev-contrib).
     8  
     9  ## Background
    10  
    11  Under the hood, DDEV uses a private copy of docker-compose to define and run the multiple containers that make up the local environment for a project. docker-compose supports defining multiple compose files to facilitate [sharing Compose configurations between files and projects](https://docs.docker.com/compose/extends/), and DDEV is designed to leverage this ability.
    12  
    13  To add custom configuration or additional services to your project, create docker-compose files in the `.ddev` directory. DDEV will process any files with the `docker-compose.[servicename].yaml` naming convention and include them in executing docker-compose functionality. You can optionally create a `docker-compose.override.yaml` to override any configurations from the main `.ddev/.ddev-docker-compose-base.yaml` or any additional docker-compose files added to your project.
    14  
    15  !!!warning "Don’t modify `.ddev-docker-compose-base.yaml` or `.ddev-docker-compose-full.yaml`!"
    16  
    17      The main docker-compose file is `.ddev/.ddev-docker-compose-base.yaml`, reserved exclusively for DDEV’s use. It’s overwritten every time a project is started, so any edits will be lost. If you need to override configuration provided by `.ddev/.ddev-docker-compose-base.yaml`, use an additional `docker-compose.<whatever>.yaml` file instead.
    18  
    19  ## `docker-compose.*.yaml` Examples
    20  
    21  * Expose an additional port 9999 to host port 9999, in a file perhaps called `docker-compose.ports.yaml`:
    22  
    23  ```yaml
    24  services:
    25    someservice:
    26      ports:
    27      - "9999:9999"
    28  ```
    29  
    30  That approach usually isn’t sustainable because two projects might want to use the same port, so we *expose* the additional port to the Docker network and then use `ddev-router` to bind it to the host. This works only for services with an HTTP API, but results in having both HTTP and HTTPS ports (9998 and 9999).
    31  
    32  ```yaml
    33  services:
    34    someservice:
    35      container_name: "ddev-${DDEV_SITENAME}-someservice"
    36      labels:
    37        com.ddev.site-name: ${DDEV_SITENAME}
    38        com.ddev.approot: ${DDEV_APPROOT}
    39      expose:
    40        - "9999"
    41      environment:
    42        - VIRTUAL_HOST=$DDEV_HOSTNAME
    43        - HTTP_EXPOSE=9998:9999
    44        - HTTPS_EXPOSE=9999:9999
    45  ```
    46  
    47  ## Confirming docker-compose Configurations
    48  
    49  To better understand how DDEV parses your custom docker-compose files, run `ddev debug compose-config`. This prints the final, DDEV-generated docker-compose configuration when starting your project.
    50  
    51  ## Conventions for Defining Additional Services
    52  
    53  When defining additional services for your project, we recommended following these conventions to ensure DDEV handles your service the same way DDEV handles default services.
    54  
    55  * The container name should be `ddev-${DDEV_SITENAME}-<servicename>`.
    56  * Provide containers with required labels:
    57  
    58      ```yaml
    59          labels:
    60            com.ddev.site-name: ${DDEV_SITENAME}
    61            com.ddev.approot: ${DDEV_APPROOT}
    62      ```
    63  
    64  * Exposing ports for service: you can expose the port for a service to be accessible as `projectname.ddev.site:portNum` while your project is running. This is achieved by the following configurations for the container(s) being added:
    65  
    66      * Define only the internal port in the `expose` section for docker-compose; use `ports:` only if the port will be bound directly to `localhost`, as may be required for non-HTTP services.
    67  
    68      * To expose a web interface to be accessible over HTTP, define the following environment variables in the `environment` section for docker-compose:
    69  
    70          * `VIRTUAL_HOST=$DDEV_HOSTNAME`
    71          * `HTTP_EXPOSE=portNum` The `hostPort:containerPort` convention may be used here to expose a container’s port to a different external port. To expose multiple ports for a single container, define the ports as comma-separated values.
    72          * `HTTPS_EXPOSE=<exposedPortNumber>:portNum` This will expose an HTTPS interface on `<exposedPortNumber>` to the host (and to the `web` container) as `https://<project>.ddev.site:exposedPortNumber`. To expose multiple ports for a single container, use comma-separated definitions, as in `HTTPS_EXPOSE=9998:80,9999:81`, which would expose HTTP port 80 from the container as `https://<project>.ddev.site:9998` and HTTP port 81 from the container as `https://<project>.ddev.site:9999`.
    73  
    74  ## Interacting with Additional Services
    75  
    76  [`ddev exec`](../usage/commands.md#exec), [`ddev ssh`](../usage/commands.md#ssh), and [`ddev logs`](../usage/commands.md#logs) interact with containers on an individual basis.
    77  
    78  By default, these commands interact with the `web` container for a project. All of these commands, however, provide a `--service` or `-s` flag allowing you to specify the service name of the container to interact with. For example, if you added a service to provide Apache Solr, and the service was named `solr`, you would be able to run `ddev logs --service solr` to retrieve the Solr container’s logs.