Remember to commit updated docs...

```yaml

# /my/esgf/config/group_vars/all.yml

image_defaults:

# Use the images that were built for a particular commit

  tag: a031a2ca

image_tag: a031a2ca

# If using an immutable tag, don't do unnecessary pulls

  pull: false

image_pull: false

```

### Setting the web address

By default, the web address is the FQDN of the host (i.e. the output of `hostname --fqdn`). This can

be changed on a host-by-host basis using the variable `hostname`. For convenience, this can be set directly

in the inventory file:

be changed on a host-by-host basis using the variable `hostname`. For convenience, this can be set

directly in the inventory file:

```ini

# /my/esgf/config/inventory.ini

esgf-data02.example.org  hostname=esgf-data.example.org

```

The Ansible playbook does **not** configure the DNS load-balancing automatically - you will need to separately

configure [Round-robin DNS](https://en.wikipedia.org/wiki/Round-robin_DNS) or a more sophisticated service like

[AWS Route 53](https://aws.amazon.com/route53/) to do this.

The Ansible playbook does **not** configure the DNS load-balancing automatically - you will need to

separately configure [Round-robin DNS](https://en.wikipedia.org/wiki/Round-robin_DNS) or a more sophisticated

service like [AWS Route 53](https://aws.amazon.com/route53/) to do this.

### Configuring the available datasets

The Docker-based data node uses a catalog-free configuration to serve data - the available data is defined simply

by a series of datasets, under which all files will be served using both OPeNDAP (for NetCDF files) and plain

HTTP. The browsable interface and OPeNDAP are provided by THREDDS and, direct file serving is provided by Nginx.

The data node uses a catalog-free configuration where the available data is defined simply by a

series of datasets. For each dataset, all files under the specified path will be served using both

OPeNDAP (for NetCDF files) and plain HTTP. The browsable interface and OPeNDAP are provided by

THREDDS and direct file serving is provided by Nginx.

The configuration of the datasets is done using two variables:

  * `data.mounts`: List of directories to mount from the host into the container. Each item should contain

  * `data_mounts`: List of directories to mount from the host into the container. Each item should contain

    the keys:

    * `hostPath`: The path on the host

    * `mountPath`: The path in the container

  * `data.datasets`: List of datasets to expose via THREDDS/Nginx. Each item should contain the keys:

    * `host_path`: The path on the host

    * `mount_path`: The path in the container

  * `data_datasets`: List of datasets to expose. Each item should contain the keys:

    * `name`: The human-readable name of the dataset, displayed in the THREDDS UI

    * `path`: The URL path part for the dataset

    * `location`: The directory path to the root of the dataset

These variables should be defined in your configuration directory using `/my/esgf/config/group_vars/data.yml`, e.g.:

These variables should be defined in your configuration directory using

`/my/esgf/config/group_vars/data.yml`, e.g.:

```yaml

# /my/esgf/config/group_vars/data.yml

data:

  mounts:

data_mounts:

  # This will mount /datacentre/archive on the host as /data in the containers

    - hostPath: /datacentre/archive

      mountPath: /data

  - host_path: /datacentre/archive

    mount_path: /data

  datasets:

data_datasets:

  # This will expose files at /data/cmip6/[path]

  # as http://esgf-data.example.org/thredds/{dodsC,fileServer}/esg_cmip6/[path]

  - name: CMIP6