github-badge-cache-buster

A small tool that uses curl to PURGE the github cache for badges displayed in README.md files

Unfortunately github caches badges ( on a server called camo.githubusercontent.com ) quite agressively. This leads to badge data being out of date a lot of the time.

Theoretically if the src badge image correctly sets.... Cache-Control: no-cache, no-store Expire: Mon, 01 Jan 1990 00:00:00 GMT Last-Modified: Mon, 01 Jan 2999 00:00:00 GMT and a unique to each request etag Etag: $UUID Everything should work just fine. However, many people find that not to be the case.

I found another possible workaround that calls for adding a dummy paramater to the URL of the badge. This may or may not work for all badge sources.

[tv-nightly-image]: https://jimtru1979.blob.core.windows.net/badges/DailyBuildStatus.svg?dummy=unused
[![Coverage Status](https://coveralls.io/repos/github/ledgersmb/LedgerSMB/badge.svg?branch=master)](https://coveralls.io/github/ledgersmb/LedgerSMB?branch=master&dummy=unused)

There is a large list of bugs open (and incorrectly closed) relating to this. The main issue is

• #224 - Aggressive image caching breaks image badges

Some of the others are.....

• #9 - GitHub Image Proxy breaking Nodei.co images in markdown
• #15 - Badges do not update with GitHubs caching
• #111 - can't find the URL for this one
• #116 - can't find the URL for this one
• #134 - Serve cached images upon request timeout
• #137 - Travis badges seem to be broken
• #218 - GitHub caching affecting my badge
• #220 - Set Cache-Control or Expires on S3 assets
• #257 - Badge caching
• #414 - Incorrect coverage badge
• #1970 - Build status image cached by GitHub
• #3122 - Code Coverage Status Badge is cached
• #3150 - Unix nightly badge is inaccurate
• #6040 - fix coveralls badge issue in README
• #17057 - Aggressive GitHub caching breaks Gitlab badge images.