blog/source/_posts/caddy2-pre-compressed.md

---
title: Serving pre-compressed files in Caddy 2
excerpt: gzip and brotli files
date: 2020-11-12
tags:
- caddy
---

Caddy v0.9.4+ and v1.0.0+ support pre-compressed gzip and brotli files automatically. However, this feature is [not yet](https://github.com/caddyserver/caddy/issues/2665) implemented in v2 and requires manual configuration. Examples available at the Caddy forum are incomplete, it's either gzip or brotli. The config provided in this guide supports _both_, prioritising brotli if supported by the requesting web browser (and there are .br files), otherwise fallback to gzip.

## Default usage

This configuration supports URL normalisation; when a URL has a trailing slash `http://localhost:8080/about/`, Caddy will serve `http://localhost:8080/about/index.html` using _internal/transparent_ redirect (without 301/302 redirect). If you need to internal redirect `http://localhost:8080/bio` to `http://localhost:8080/bio.html`, refer to the [next section](#Pretty-URLs).

``` plain Caddyfile
http://localhost:8080 {
  bind 127.0.0.1 ::1

  root * /home/user/www
  file_server

  @brotli {
    header Accept-Encoding *br*
    file {
      try_files {path}.br {path}/index.html.br
    }
  }
  handle @brotli {
    header Content-Encoding br
    rewrite {http.matchers.file.relative}
  }

  @gzip {
    header Accept-Encoding *gzip*
    file {
      try_files {path}.gz {path}/index.html.gz
    }
  }
  handle @gzip {
    header Content-Encoding gzip
    rewrite {http.matchers.file.relative}
  }

  @html {
    file
    path *.html */
  }
  header @html Content-Type text/html

  @css {
    file
    path *.css
  }
  header @css Content-Type text/css

  @js {
    file
    path *.js
  }
  header @js Content-Type text/javascript

  @svg {
    file
    path *.svg
  }
  header @svg Content-Type image/svg+xml

  @xml {
    file
    path *.xml
  }
  header @xml Content-Type application/xmlr
  }

  @json {
    file
    path *.json
  }
  header @json Content-Type application/json
}
```

### Content-Type

```
@svg {
  file
  path *.svg
}
header @svg Content-Type image/svg+xml
```

`Content-Type` response header needs to be specified as a workaround, otherwise Caddy responses with `application/gzip`.

### URL normalisation

```
@html {
  file
  path *.html */
}
```

`*/` is to match path with a trailing slash `/path/` since that is (transparently) redirects to `/path/index.html`.

### Dummy files

```
root * /home/user/www
```

I prepared a set of dummy files with most common file extensions ([download](https://gitlab.com/curben/blog/-/raw/site/20201112/dummy.zip)). This enables you to test whether Caddy serves the correct file. `.gz` and `.br` files are _not_ compressed files, they are text files so that you can easily identify the file being served.

Unzip the dummy.zip and specify the folder in the `root` directive. Following are some sample tests after you start Caddy:

```
$ curl -i http://localhost:8080/foo.svg -H 'Accept-Encoding: gzip'

# /foo.svg.gz should be served
HTTP/1.1 200 OK
Content-Encoding: gzip
Content-Type: image/svg+xml

svg gz
```

```
$ curl -i http://localhost:8080/foo.svg -H 'Accept-Encoding: gzip,br'

# /foo.svg.br should be served
HTTP/1.1 200 OK
Content-Encoding: br
Content-Type: image/svg+xml

svg br
```

```
$ curl -i http://localhost:8080/foo.svg

# /foo.svg should be served
HTTP/1.1 200 OK
Content-Type: image/svg+xml

svg
```

## Pretty URLs

This configuration supports transparently redirect a URL without trailing slash and file extension, e.g. `http://localhost:8080/bio` to `http://localhost:8080/bio.html`. If you request "bio.html", Caddy still still serve it as usual, without any redirect. This feature is similar to [Netlify's](https://docs.netlify.com/routing/redirects/redirect-options/#trailing-slash).

``` plain Caddyfile
http://localhost:8080 {
  bind 127.0.0.1 ::1

  root * /home/user/www
  file_server
  try_files {path}.html

  @brotli {
    header Accept-Encoding *br*
    file {
      try_files {path}.br {path}/index.html.br {path}.html.br
    }
  }
  handle @brotli {
    header {
      Content-Encoding br
      Content-Type text/html
    }
    rewrite {http.matchers.file.relative}
  }

  @gzip {
    header Accept-Encoding *gzip*
    file {
      try_files {path}.gz {path}/index.html.gz {path}.html.gz
    }
  }
  handle @gzip {
    header {
      Content-Encoding gzip
      Content-Type text/html
    }
    rewrite {http.matchers.file.relative}
  }

  @html {
    file
    path *.html */
  }
  header @html {
    Content-Type text/html
    defer
  }

  @css {
    file
    path *.css
  }
  header @css {
    Content-Type text/css
    defer
  }

  @js {
    file
    path *.js
  }
  header @js {
    Content-Type text/javascript
    defer
  }

  @svg {
    file
    path *.svg
  }
  header @svg {
    Content-Type image/svg+xml
    defer
  }

  @xml {
    file
    path *.xml
  }
  header @xml {
    Content-Type application/xml
    defer
  }

  @json {
    file
    path *.json
  }
  header @json {
    Content-Type application/json
    defer
  }
}
```

Derived from [[1]](https://caddy.community/t/how-to-serve-pre-compressed-files-with-caddy-v2/8760), [[2]](https://caddy.community/t/how-to-serve-gzipped-files-automatically-in-caddy-v2/7311), [[3]](https://caddy.community/t/why-caddy-2-is-not-able-to-serve-static-brotli-files/7653).