Are app environment vars available at build time?

Configuration
1

We need to pass our AWS credentials to a grunt task in our Dockerfile, but it doesn’t seem that convox build (or a build created by an automated workflow) can access any of the environment variables set in the convox.yml or the app’s Environment tab.

Is there a best-practice method for achieving this?

2

You should be able to accomplish this with Convox Build Variables.

For example, here’s how you can parametrize the version of Bundler for your Ruby app. In your Dockerfile:

FROM ubuntu:16.04
...
ARG BUNDLER_VERSION=2.0.0
RUN gem install bundler -v ${BUNDLER_VERSION} && rbenv rehash
...

This sets a default value for BUNDLER_VERSION which you can then override by setting an environment variable using the Convox CLI, Environment Tab, or convox.yml:

$ convox env set BUNDLER_VERSION=2.00

You can also use declare a build variable without a default value.

3

Thanks for the prompt reply, Nick.

Does convox env set only need to be run once, and it will then apply for future builds both local and in production?