Environment Variables and Datacube_OWS

The behaviour of datacube_ows can be modified by a number of environment variables.

Datacube_ows configuration

The location of the datacube configuration object is set via the $DATACUBE_OWS_CFG environment variable as described here. To enable the retrieval of a json configuration file from AWS S3, the $DATACUBE_OWS_CFG_ALLOW_S3 environment variable needs to be set to YES.

Open DataCube Database Connection

The preferred method of configuring the ODC database is with the $ODC_DEFAULT_DB_URL environment variable. The format of postgres connection URL is:

postgresql://<username>:<password>@<hostname>:<port>/<database>

If you are using an ODC environment other than default or are using multiple ODC environments, you can specify the url for other environments in the same fashion, e.g. for environment myenv use $ODC_MYENV_DB_URL.

If you want to use a postgis based ODC index, you should also specify the index driver by setting e.g. $ODC_MYENV_INDEX_DRIVER to postgis.

Other valid methods for configuring an OpenDatacube instance (e.g. a .datacube.conf file) should also work. As of the 1.9.0 release, OWS supports both the postgres and postgis drivers.

The old $DB_HOSTNAME, $DB_DATABASE etc. environment variables are now STRONGLY DEPRECATED as they only work in a single-index environment.

An ODC environment other than default can be used by setting the env option in the global OWS configuration.

For Running Integration Tests

The integration tests need to be able to call a running a OWS server connected the test database and running the version of the OWS codebase being tested.

SERVER_URL:

The URL of the test server. Defaults to http://localhost:5000

SERVER_DB_USERNAME:

This is the database username used by the test server to connect to the test database. Defaults to the same database username being used by the integration tests themselves.

Note that docker-compose arrangement used for integration testing on github

Configuring AWS Access

Environment variables for AWS access are mostly read through the boto3 library - please refer to their documentation for details.

Of particular note are:

AWS_DEFAULT_REGION:

S3 access by datacube_ows will be disabled unless this is set.

AWS_NO_SIGN_REQUEST:

S3 access will be unsigned if this environment variable is set to “y”, “t”, “yes”, “true” or “1”.

If requests are signed then you will also need to ensure that boto3 has access to appropriate AWS credentials - typically the $AWS_ACCESS_KEY_ID and $AWS_SECRET_ACCESS_KEY environment variables.

N.B. Signed requests are the default behaviour - explicitly set $AWS_NO_SIGN_REQUEST to ‘yes’ to use unsigned request. The default behaviour for this variable changed in version 1.8.17.

AWS_REQUEST_PAYER:

Set to “requester” if accessing requester-pays S3 buckets. Default behaviour is to prevent access to requester-pays buckets.

AWS_S3_ENDPOINT:

Set to the DNS host name of the S3 endpoint. Required for accessing non-Amazon implementations of the S3 protocol, and for some newer AWS regions (e.g. Africa).

Configuring Flask

Datacube_ows uses the Flask web application framework which can read from several environment variables, most notably:

FLASK_APP:

Should point to the datacube_ows/ogc.py file in your deployment.

The $FLASK_ENV environment variable also has a significant effect on the way datacube_ows runs. Refer to the Flask documentation for further details.

Dev-ops Tools

The following deployment tools are configured via environment variables:

SENTRY_DSN:

The `Sentry application monitoring and error tracking system`_ system is activated and configured with the $SENTRY_DSN environment variables.

PROMETHEUS_MULTIPROC_DIR:

The Prometheus event monitoring system is activated by setting this environment variable.

PROXY_FIX:

If $PROXY_FIX is set to “true”, “yes”, “on” or “1”, the Flask application will trust the X-Forwarded-For and other headers from a proxy server.

This is useful when running behind a reverse proxy server such as Nginx or CloudFront.

NEVER use in production without a reverse proxy server.

Dev Tools

PYDEV_DEBUG:

If set to anything other than “n”, “f”, “no” or “false” (case insensitive), activates PyDev remote debugging.

NEVER use in production.

DEFER_CFG_PARSE:

If set, the configuration file is not read and parsed at startup. This is mostly useful for creating test fixtures.

Docker and Docker-compose

The provided Dockerfile and docker-compose.yaml read additional environment variables at build time. Please refer to the README for further details.

Environment variables exclusive for docker-compose

OWS_CFG_DIR:

path to a folder containing ows config files anywhere on the local machine

OWS_CFG_MOUNT_DIR:

path the OWS_CFG_FOLDER will mount to inside docker container

PYTHONPATH:

PYTHONPATH to ows config file

POSTGRES_DB: POSTGRES_USER: POSTGRES_PASSWORD:

The db superuser name and password for the postgis database container. If multiple databases are required, use a comma-separated list of database names

POSTGRES_HOSTNAME:

The name of the database server/container.

READY_PROBE_DB:

The (single) database to use for the startup database readiness probe. Should be set to one of the values in $POSTGRES_DB