Brotli for Caddy

This package implements a brotli encoder for Caddy.

Requires Caddy 2+.

Uses the pure go brotli implementation https://github.com/andybalholm/brotli

This implementation is NOT high performance, so it is not recommended to use this encoding as primary compression algorithm. Use gzip or zstd instead.

The new matchfinder algorithm implementation in andybalholm/brotli is also supported, use with v2.

Currently they [new compression algorithms] give better results than the old implementation (at least for compressing my test file, Newton’s Opticks) on levels 2 to 7.

quoted from the README of https://github.com/andybalholm/brotli.

Installation

xcaddy build --with github.com/ueffel/caddy-brotli

Syntax

There will be the new encoding br available within the encode directive

encode [<matcher>] <formats...> {
    br [[<level>] [v2]]
}

• level controls the compression level (ranges from 0 to 11), default is 4.
  for the new algorithm (v2) the levels range from 2 to 7, default is also 4.
• v2 if set the new brotli algorithm is used

Example usages could look like this:

encode br

encode {
    br 4
}

encode {
    br v2
}

encode {
    br 4 v2
}

or together with other encodings like gzip

encode gzip br

encode {
    gzip 5
    br 4
}

Remarks

Update 2: From Caddy v2.4.0 onwards preferred order is implied by definition order.

Update: Since Caddy v2.4.0-beta.2 the preferred order of encodings can be set via prefer setting.

There is currently no way to set a prefered order of content-encodings via caddy's configuration. The content-encoding is determined by the clients preference. In most cases that means a response is encoded with the first accepted encoding in the Accept-Encoding header of the request that the caddy also supports.

Example:

Caddyfile

encode gzip br

• Request:

  [...]
  Accept-Encoding: deflate, gzip, br
  [...]
  

  Response will be:

  [...]
  Content-Encoding: gzip
  [...]
  

• Request: (different order of encodings)

  [...]
  Accept-Encoding: deflate, br, gzip
  [...]
  

  Response will be:

  [...]
  Content-Encoding: br
  [...]