gxy.io link shortening

This repository is for Galaxy Project members to create gxy.io short links that redirect to other URLs, e.g. for publications, conference slides, etc.

Usage

1. Add your link to gxy_io_rewrites in group_vars/all.yaml.

   See the Rewrite entry syntax section below for details.

2. Make a Pull Request with your changes. A test will make sure your syntax passes. Once your PR is approved and merged, the changes are automatically deployed.

Rewrite entry syntax

gxy_io_rewrites is a list of dictionaries with required keys src and dest and the optional key tests.

The value of src is the path (after gxy.io) of the short link you would like to create. It should start with a / and supports regular expressions; the path component of a gxy.io request is checked with re.match(src, path). Any trailing / is automatically stripped and /? appended, meaning that /example and /example/ are equivalent.

The value of dest is the URL to redirect to. It can contain regex backreferences.

The optional tests key can contain a list of paths to test as inputs to the rewrite function, to ensure they all rewrite to the value of dest. The default if tests is unset is to use the src as the test input value, so defining your own tests is required if src is a regular expression.

Alternatively, tests can be a list of dicts with src and dest keys, which is necessary if the rewrite dest contains a regex backreference.

A few examples are shown below, but all currently supported possibilities are represented in the current set of rewrites.

Examples

A simple example that does not use regex, rewrites http://gxy.io/example (with or without trailing slash) to http://example.org. The implied test ensures that the src value rewrites to dest:

- src: /example
  dest: http://example.org

Using regex to allow for some common variations in the src - all of /test-example, test_example, and /testexample will rewrite to http://example.org. At least one test definition is required since src contains a regex:

- src: /test[-_]?example
  dest: http://example.org
  tests:
    - /test-example
    - /testexample

Using backreferences in dest to rewrite any path after /example/ to another domain with the path intact, requires src and dest keys in tests:

- src: "/example/(.*)"
  dest: "http://example.org/\\1"
  tests:
    - src: /example/foo
      dest: http://example.org/foo
    - src: /example/foo/bar?baz=quux
      dest: http://example.org/foo/bar?baz=quux

Notes

Rewrites are performed via an AWS Lambda@Edge function via CloudFront. The function runs under the Python 3.9 runtime.

The initial gxy.io service (pre-automation) ran via nginx on an EC2 instance, so some work was done to support automated deployment under nginx, which is preserved in the nginx directory in case it would be useful in the future.