This is a fairly simple addition of a Redis-backed TokenPersistence. When GithubConstellation is initialized, it will create a FsTokenPersistence or a RedisTokenPersistence based on configuration. Have added tests of the Redis backend as an integration test, and ensured the server starts up correctly when a `REDIS_URL` is configured.
Ref: #1848
Make a clear distinction between programmer errors ("internal errors") and runtime errors, and allow configuring the server to let the programmer errors bubble up in development and unit testing. This saves a huge amount of time because it generates ordinary stack traces when things go wrong. And, if these errors occur in production, we'll catch them, and display **shields | internal error** which is the equivalent of a 500 error.
Ref: #1379
This takes a naive approach to font-width computation, the most compute-intensive part of rendering badges.
1. Add the widths of the individual characters.
- These widths are measured on startup using PDFKit.
2. For each character pair, add a kerning adjustment
- The difference between the width of each character pair, and the sum of the characters' separate widths.
- These are computed for each character pair on startup using PDFKit.
3. For a string with characters outside the printable ASCII character set, fall back to PDFKit.
This branch averaged 0.041 ms in `makeBadge`, compared to 0.144 ms on master, a speedup of 73%. That was on a test of 10,000 consecutive requests (using the `benchmark-performance.sh` script, now checked in).
The speedup applies to badges containing exclusively printable ASCII characters. It wouldn't be as dramatic on non-ASCII text. Though, we could add some frequently used non-ASCII characters to the cached set.
- Periodically log github auth information
- Tokens are hashed which reduces the security risk inherent in the logs
- A consistent hash is used so tokens can be correlated across the three data structures and across the three servers
- Add an admin endpoint for github auth information
- Tokens are returned as-is to enable troubleshooting (e.g. comparing our reqRemaining to github’s)
- Support single-server testing and a local dev server (like Next) that is on a different port from the shields server
- Refactor config schema
With this change, the suggestions work locally in #1273.
