Switch to using a .env file for setting environment variables

[wlach]

This allows us to modify variables for our development instance
(e.g. to use production presto)

[codecov-io]

Codecov Report

Merging #107 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #107   +/-   ##
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  Coverage   46.29%   46.29%           
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  Files          13       13           
  Lines         270      270           
  Branches       30       30           
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  Hits          125      125           
  Misses        143      143           
  Partials        2        2

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[maurodoglio]

Using a .env file seems to be almost equivalent to using the docker-compose environment directive. Am I missing something?

[wlach]

@maurodoglio it's equivalent, it's just easier to modify an .env file without worrying about accidentally committing stuff.

[whd]

The approach seems fine in that ATMO is doing this, but see comment.

[whd]

This should probably be [ ! -f .env ] && cp .env-dist .env. Additionally I don't think this needs to be part of the build step. ATMO has it as an instruction in the README (not ideal because it requires another manual step) and also in bin/test but as I understand it this file is meant to be used by docker-compose and not as an artifact in the container. We should exclude it from being copied to the container if we want to keep it in the build script.

[wlach]

@whd just to confirm, none of the variables in .env-dist would be applicable for a production deployment?

[whd]

Correct.

[maurodoglio]

I noticed that @jezdez wants to move away from .env files in mozilla/telemetry-analysis-service#225. Maybe we should hold on on this?

[wlach]

@maurodoglio As @whd pointed out above, we don't actually use the .env file in production so I don't see the issue here. In fact I would think that modifying the docker-compose file would be more of a security risk (since there's a chance of accidentally checking in aws credentials)

[wlach]

I removed the changes to bin/build