dnscontrol/documentation/byo-secrets.md

Bring-Your-Own-Secrets for automated testing

Goal: Enable automated integration testing without accidentally leaking our API keys and other secrets; at the same time permit anyone to automate their own tests without having to share their API keys and secrets.

• PR from a project member:
  • Automated tests run for a long list of providers. All officially supported providers have automated tests, plus a few others too.
• PR from an external person
  • Automated tests run for a short list of providers. Any test that requires secrets are skipped in the fork. They will run after the fact though once the PR has been merged to into the master branch of StackExchange/dnscontrol.
• PR from an external person that wants automated tests for their provider.
  • They can set up secrets in their own GitHub account for any tests they'd like to automate without sharing their secrets.
  • Note: These tests can always be run outside of GitHub at the command line.

Background: How GitHub Actions protects secrets

GitHub Actions has a secure secrets storage system. Those secrets are available to GitHub Actions and are required for the integration tests to communicate with the various DNS providers that DNSControl supports.

For security reasons, those secrets are unavailable if the PR comes from outside the project (a forked repo). This is a good thing. If it didn't work that way, a third-party could write a PR that leaks the secrets without the owners of the project knowing.

The docs (and many blog posts) describe this as forked repos don't have access to secrets, and instead receive null strings. That's not actually what's happening.

Actually what happens is the secrets come from the forked repo. Or, more precisely, the secrets offered to a PR come from the repo that the PR came from. A PR from DNSControl's owners gets secrets from github.com/StackExchange/dnscontrol's secret store but a PR from a fork, such as https://github.com/TomOnTime/dnscontrol gets its secrets from TomOnTime's secrets.

Our automated integration tests leverages this info to have tests only run if they have access to the secrets they will need.

How it works

Tests are executed if *_DOMAIN exists where * is the name of the provider. If the value is empty or unset, the test is skipped.
For example, if a provider is called FANCYDNS, there must be a secret called FANCYDNS_DOMAIN.

Bring your own secrets

This section describes how to add a provider to the testing system.

Step 1: Create a branch

Create a branch as you normally would to submit a PR to the project.

Step 2: Update build.yml

In this branch, edit .github/workflows/build.yml:

1. In the integration-test-providers section, the name of the provider.

Add your provider's name (alphabetically). The line looks something like:

{% code title=".github/workflows/build.yml" %}

        PROVIDERS: "['BIND','HEXONET','AZURE_DNS','CLOUDFLAREAPI','GCLOUD','NAMEDOTCOM','ROUTE53','CLOUDNS','DIGITALOCEAN','GANDI_V5','HEDNS','INWX','NS1','POWERDNS','TRANSIP']"

{% endcode %}

2. Add your providers _DOMAIN env variable:

Add it to the env section of integrtests-diff1 and again in integrtests-diff2.

For example, the entry for BIND looks like:

{% code title=".github/workflows/build.yml" %}

        BIND_DOMAIN: ${{ vars.BIND_DOMAIN }}

{% endcode %}

3. Add your providers other ENV variables:

If there are other env variables (for example, for an API key), add that as a "secret".

For example, the entry for CLOUDFLAREAPI looks like this:

{% code title=".github/workflows/build.yml" %}

        CLOUDFLAREAPI_ACCOUNTID: ${{ secrets.CLOUDFLAREAPI_ACCOUNTID }}
        CLOUDFLAREAPI_TOKEN: ${{ secrets.CLOUDFLAREAPI_TOKEN }}

{% endcode %}

Step 3. Submit this PR like any other.

Caveats

Sadly there is no locking to prevent two PRs from running the same test on the same domain at the same time. When that happens, both PRs running the tests fail. In the future we hope to add some locking.

Also, maintaining a fork requires keeping it up to date. That's a bit more Git knowledge than I can describe here. (I'm not a Git expert by any stretch of the imagination!)