checklist-gist-example.md

Adding a Simple Config Field for Client Agents

• Add the field to the Config struct (or an appropriate sub-struct) in agent/config/config.go.
• Add the field to the actual RuntimeConfig struct in agent/config/runtime.go.
• Add an appropriate parser/setter in agent/config/builder.go to translate.
• Add the new field with a random value to both the JSON and HCL blobs in TestFullConfig in agent/config/runtime_test.go, it should fail now, then add the same random value to the expected struct in that test so it passes again.
• Add the new field and it's default value to TestSanitize in the same file. (Running the test first gives you a nice diff which can save working out where etc.)
• If your new config field needed some validation as it's only valid in some cases or with some values (often true).
  • Add validation to Validate in builder.go.
  • Add a test case to the table test TestConfigFlagsAndEdgeCases in runtime_test.go.
• If your new config field needs a non-zero-value default.
  • Add that to DefaultSource in defaults.go.
  • Add a test case to the table test TestConfigFlagsAndEdgeCases in runtime_test.go.
• If your config should take effect on a reload/HUP.
  • Add necessary code to to trigger a safe (locked or atomic) update to any state the feature needs changing. This needs to be added to one or more of the following places:
    • ReloadConfig in agent/agent.go if it needs to affect the local client state or another client agent component.
    • ReloadConfig in agent/consul/client.go if it needs to affect state for client agent's RPC client.
  • Add a test to agent/agent_test.go similar to others with prefix TestAgent_reloadConfig*.
• If the new config field(s) include an array of structs or maps.
  • Add the path to the call to lib.PatchSliceOfMaps in Parse in config.go.
  • If none of the tests in runtime_test.go failed before you did that, then you didn't actually test the slice part yet, go back and add tests that populate that slice.
• Add documentation to website/source/docs/agent/options.html.md.