Add Google Translate documentation and simplify setup process

[patcon]

Re-ticketed from #263

To Do

• add documentation for setting up Google Translate
• add e2e tests for Google Translating comments
• create test credentials for Google Translate API -- @patcon
  • Add $10 credit (more than enough for tests)
• Improve GitHub Actions workflow to run certain tests only when secrets are provided
• Add GOOGLE_CREDENTIALS_BASE64 secret in forked repo and test -- @patcon
• optional: Add GOOGLE_CREDENTIALS_BASE64 secret in upstream repo (can merge without)
  • optional: transfer ownership of Google service account key to Team Polis chris@mathdem.org

[patcon]

We could actually enable comment translation in the e2e tests by storing the envvar as a secret.

Assuming the secret is available in the PR's workflow run (i.e. if we're building a PR from a branch on the main repo instead of a fork), then we should be able to append the enabling envvars to the end of server/docker-dev.env.

We'll also need to ensure that the tests against the comment translation features only run in that same scenario.

diff --git a/.github/workflows/cypress-tests.yml b/.github/workflows/cypress-tests.yml
index 048493ee..86665ceb 100644
--- a/.github/workflows/cypress-tests.yml
+++ b/.github/workflows/cypress-tests.yml
@@ -39,16 +39,35 @@ jobs:
           # and so newest version of client apps may not have been copied in.
           docker-compose build file-server
 
+      - name: Enable comment translation
+        # If we're in a pull_request from a main repo branch, NOT a fork.
+        if: github.event.pull_request.head.repo.full_name == github.repository
+        run: |
+          echo GOOGLE_CREDENTIALS_BASE64=${{ secrets.GOOGLE_CREDENTIALS_BASE64 }} >> server/docker-dev.env
+          echo SHOULD_USE_TRANSLATION_API=true >> server/docker-dev.env
+
       - name: Serve app via docker-compose
         run: docker-compose up --detach
 
-      - name: Run Cypress tests
+      - name: Run Cypress tests: default
         uses: cypress-io/github-action@v1
         env:
           CYPRESS_BASE_URL: http://localhost
         with:
           working-directory: ./e2e
           spec: cypress/integration/polis/**/*
+          config: ignoreTestFiles='**/polis/comment-translation/*'
+          browser: chrome
+
+      - name: Run Cypress tests: comment translation
+        # If we're in a pull_request from a main repo branch, NOT a fork.
+        if: github.event.pull_request.head.repo.full_name == github.repository
+        uses: cypress-io/github-action@v1
+        env:
+          CYPRESS_BASE_URL: http://localhost
+        with:
+          working-directory: ./e2e
+          spec: cypress/integration/polis/comment-translation/*
           browser: chrome
 
       # NOTE: screenshots will be generated only if E2E test failed

[patcon]

I feel I should re-ticket the e2e tasks, since there are some slower coordination tasks related to getting secrets in the repo. So this is ready for review as-is.

[patcon]

This was undocumented before, but I think it was required to set this envvar in the environment (or app, like we've done), in order to tell the Google client libs where to find the credentials. This allows the lib to load the credentials, since .google_creds_temp is a nonstandard place to look.

[colinmegill]

cc @metasoarous as to whether this is the right path going forward — is disk required here?

[patcon]

to clarify, disk was always required :)

We were writing this file before:
https://github.com/pol-is/polisServer/pull/319/files#diff-ea75b530d74f94670cea053feb8b961bL231-L233

but we weren't hardcoding this envvar, that tells the Google client library where to find the credentials we'd written to disk -- presumably we were setting GOOGLE_APPLICATION_CREDENTIALS as a heroku envvar (e.g., GOOGLE_APPLICATION_CREDENTIALS=.google_creds_temp) or else the google library would've had no way to pick up the credentials that were written to this filepath by the old server code.

[patcon]

Made changes suggested by @colinmegill and ready for review by @metasoarous

[patcon]

From Gitter, re GOOGLE_CREDENTIALS_BASE64 envvar: https://gitter.im/pol-is/polisDeployment?at=5eeeb347613d3b3394fb9c8d

ah, ok, the easy task to minimize comms burden is I can just add it back so both are supported (and then it's more a question of "is supporting base64 ok?") -- @patcon

Yes, this is the right thing to do. As long as what's currently running on heroku is still supported, I'm fine with it (that is, until if/when we come off heroku ourselves) -- @metasoarous

Merged my own suggestions that added this back in.

[colinmegill]

One comment, but excellent to have this documented! Thanks @patcon

[patcon]

Ok, got this working with e2e tests for Google Translation button feature.

Here's a run with the Google credential available to the workflow:
https://github.com/patcon/polisServer/pull/44/checks?check_run_id=821053022

Here's the video artefact of the comment translation test run, for download:
https://github.com/patcon/polisServer/actions/runs/152303142

For now, I've created a service account and added $10 to pay for some Google Translate API use. Should last for a very long time. This can be merged without adding a GOOGLE_CREDENTIALS_BASE64 secret to the upstream repo, as it will simply skip those tests if the envvar is missing. I'm happy to send you mine to add in the short term, and assign you ownership of the service account. You can then swap it out for your own when you get time.

Pls merge this, and then I can DM you the secret value on Gitter (if interested). Or alternatively leave it as-is, and we'll add credentials for Google later :)

[patcon]

@colinmegill @metasoarous This is ready for review and merge -- bonus points if we do it synchronously on a call, so we can ensure the new e2e tests run after merging upstream :)

[metasoarous]

LGTM! Thanks!