Using env vars in a docker cmd?

I have this line in my Dockerfile:

CMD [“rqworker”, “–host=$REDIS_MASTER_SERVICE_HOST”]

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  • REDIS_MASTER_SERVICE_HOST is set by Kubernetes, and works fine when accessed within my python app. I need to point rqworker to it, but it doesn’t seem to be expanded:

    redis.exceptions.ConnectionError: Error -2 connecting to $REDIS_MASTER_SERVICE_HOST:6379. Name or service not known.

    How can I get docker to expand it into the actual value?

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  • One Solution collect form web for “Using env vars in a docker cmd?”

    Variable expansion is supported in kubernetes with the $(VAR) syntax. Please see this doc:

    http://docs.k8s.io/v1.0/user-guide/configuring-containers.html#environment-variables-and-variable-expansion

    Docker will be the best open platform for developers and sysadmins to build, ship, and run distributed applications.