Adding Maintenance Mode Toggle

[madflojo]

Having a maintenance mode can be very useful for applications. This toggle will essentially allow users to set their services as "not ready," which, when combined with readiness probes, will cause traffic to divert from the instances that are "not ready".

A very useful feature to have.

Summary by CodeRabbit

• New Features

  • Introduced a Maintenance Mode feature that returns a 503 status for requests to /ready when enabled.

• Documentation

  • Updated configuration documentation to include the new APP_ENABLE_MAINTENANCE_MODE environment variable.

• Tests

  • Added tests to verify the functionality of the new Maintenance Mode.

[coderabbitai]

Walkthrough

The changes introduce a new maintenance mode to Tarmac via the environment variable APP_ENABLE_MAINTENANCE_MODE. When this mode is enabled, the server's /ready endpoint returns a 503 status, indicating that the server is not ready to handle requests. This update includes modifying the Ready method in the Server struct and corresponding tests to verify the new functionality.

Changes

File	Change Summary
docs/running-tarmac/configuration.md	Added documentation for the new APP_ENABLE_MAINTENANCE_MODE environment variable.
pkg/app/server.go	Updated Server.Ready method to check if maintenance mode is enabled and return a 503 status if so.
pkg/app/server_test.go	Added TestMaintenanceMode to test the server's behavior when maintenance mode is activated.

Poem

When Tarmac dreams of soothing rest,
A maintenance mode will aid its quest.
With checks for readiness at its core,
A 503 will be its score.
When gears align and all is right,
The server wakes to serve the night.
🌙✨

---

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[coderabbitai]

Actionable comments posted: 0

Outside diff range and nitpick comments (1)

docs/running-tarmac/configuration.md (1)

36-36: Correct punctuation and formatting

There seems to be a missing punctuation mark in the description of the new environment variable. Ensure the description is clear and correctly punctuated.

- | `APP_ENABLE_MAINTENANCE_MODE` | `enable_maintenance_mode` | `bool` | Enable Maintenance Mode. When enabled, Tarmac will return a 503 for requests to `/ready` allowing the service to go into "maintenance mode". |
+ | `APP_ENABLE_MAINTENANCE_MODE` | `enable_maintenance_mode` | `bool` | Enable Maintenance Mode. When enabled, Tarmac will return a 503 for requests to `/ready`, allowing the service to go into "maintenance mode". |

Review details

Configuration used: CodeRabbit UI
Review profile: CHILL

Commits

Files that changed from the base of the PR and between 96c339c and a0af90a.

Files selected for processing (3)

• docs/running-tarmac/configuration.md (1 hunks)
• pkg/app/server.go (1 hunks)
• pkg/app/server_test.go (1 hunks)

Additional context used

LanguageTool

docs/running-tarmac/configuration.md

[uncategorized] ~34-~34: A punctuation mark might be missing here.
Context: ...e to use (Options: postgres, mysql)| | APP_RUN_MODE | run_mode | string...

(AI_EN_LECTOR_MISSING_PUNCTUATION)

Additional comments not posted (2)

pkg/app/server.go (1)

28-32: Ensure correct implementation of maintenance mode

The check for maintenance mode is correctly implemented. Ensure that the srv.cfg.GetBool("enable_maintenance_mode") correctly fetches the configuration value. The logic is sound, but verify that the configuration is properly loaded.

pkg/app/server_test.go (1)

93-124: Test case for maintenance mode looks good

The TestMaintenanceMode test case is well-structured and correctly tests the maintenance mode functionality. Ensure the test environment is correctly set up and the assertions are valid.