/Header transformation

Header transformation

v0.2.3

Header transformation plugin for traefik

This plugin allow to change on the fly header's value of a request.

Dev `traefik.yml` configuration file for traefik

pilot:
  token: [REDACTED]
experimental:
  devPlugin:
    goPath: /home/tm/go
    moduleName: github.com/tommoulard/htransformation
entryPoints:
  http:
    address: ":8000"
    forwardedHeaders:
      insecure: true
api:
  dashboard: true
  insecure: true
providers:
  file:
    filename: rules-htransformation.yaml

How to dev

$ docker run -d --network host containous/whoami -port 5000
# traefik --config-file traefik.yml

How to use

To choose a Rule you have to fill the Type field with either

'Rename' : to rename a header
'Set' : to Set a header
'Del' : to Delete a header
'Join' : to Join values on a header

Each Rule can be named with the Name field

Rename

A Rename rule need 2 arguments

Header, the regex of the header you want to replace
Value, the new header

# Example Rename
- Rule:
      Name: 'Header rename'
      Header: 'Cache-Control'
      Value: 'NewHeader'
      Type: 'Join'

# Old header:
Cache-Control: gzip, deflate
# New header:
NewHeader: gzip, deflate

- Rule:
      Name: 'Header Renaming'
      Header: 'X-Traefik-*'
      Value: 'X-Traefik-merged'
      Type: 'Join'

# Old header:
X-Traefik-uuid: 0
X-Traefik-date: mer. 21 oct. 2020 11:57:39 CEST
# New header:
X-Traefik-merged: 0 # A value from old headers

Set

A Set rule will either create or replace the header and value (if it already exist)

A rule Set need 2 arguments

Header, the header you want to create
Value, the value of the new header

# Example Join
- Rule:
      Name: 'Set Cache-Control'
      Header: 'Cache-Control'
      Value: 'Foo'
      Type: 'Join'

# New header:
Cache-Control: Foo

Delete

A rule Delete need 1 arguments

Header, the header you want to delete

# Example Del
- Rule:
      Name: 'Delete Cache-Control'
      Header: 'Cache-Control'
      Type: 'Del'

Join

A Join rule will concat the values of the existing header with the new one. If the header doesnt exist, it'll do nothing

It needs 3 arguments

Header, the header you want to join
Values, a list of values to add to the existing header
Sep, the separator you want to use

# Example Join
- Rule:
      Name: 'Header join'
      Header: 'Cache-Control'
      Sep: ','
      Values:
        - 'Foo'
        - 'Bar'
      Type: 'Join'

# Old header:
Cache-Control: gzip, deflate
# Joined header:
Cache-Control: gzip, deflate,Foo,Bar

Careful

The rules will be evaluated in the order of definition

#Example
- Rule:
  Name: 'Header addition'
  Header: 'X-Custom-2'
  Value: 'True'
  Type: 'Set'
- Rule:
  Name: 'Header deletion'
  Header: 'X-Custom-2'
  Type: 'Del'
- Rule:
  Name: 'Header join'
  Header: 'X-Custom-2'
  Value: 'False'
  Type: 'Set'

Will firstly set the header X-Custom-2 to 'True', then delete it and lastly set it again but with False

Authors

Tom Moulard	Clément David	Martin Huvelle	Alexandre Bossut-Lasry