simple-traefik-http-provider with openstack swift

Two use case of traefik-http-provider:

For some projects, i need to deploy instances behing loadbalancer with terraform in an openstack cloud without LBaas available.

So, here the workflow, i want:

• use provisionning tool (ex terraform or other tool) to provision instances app + lb stack (traefik + small httpd proxy + openstack swift object)
• terraform dynamically generates traefik template file dynamic_conf.json with IP of instances and Floating IP (or Host url) and store it in an openstack swift object
• traefik contact every X seconds, the intermediate httpd provider endpoint, which point to the Swift URL hosting the dynamic configuration

Benefits:

• You can increase (or delete/recreate) the number of traefik instances, configuration files is always in stores in swift
• the intermediate nginx container can act as a cache, in case of swift is unavailable
• the intermediate nginx container store tempurl URL. It is not exposed to public interface
• template configuration file is under your control without modifying traefik or httpd component

In this repository, you will find only the small docker-compose stack (traefik, nginx, and sample dynamic_conf.json).

You cand deploy this stack on a Loadbalancer instance with the ci/docker-deploy.sh script.

The terraform part is not described here, but you can find a version in my openstack-terraform-app repository reference

Design

scenario 1 (without swift openstack)

[ traefik ] -> [ httpd -> dynamic_conf file ]
[ traefik ] -(routing)-> [ whoami1 | whoami2 ]

• traefik container with http provider: listening on http://127.0.0.1:80/

• httpd container hosting dynamic_conf.json : http://httpd/dynamic_conf.json

• 2 whoami containers displaying usefull information (hostname IP) on http://whoami1 or http://whoami2

• docker-compose http file

• dynamic_conf.json file

scenario 2 (with swift openstack)

[ traefik ] -> [ httpd -> proxy_pass ] -> [Openstack Swift Container]/[Openstack Swift Object dynamic_conf.json]
[ traefik ] -(routing)-> [ whoami1 | whoami2 ]

• traefik container with http provider: listening on http://127.0.0.1:80/

• httpd container routing to Openstack swift object storage : http://httpd/lb-conf/dynamic_conf.json

• openstack swift container hosting dynamic_conf.json: OS_STORAGE_URL, OS_CONTAINER, OS_OBJECT

• 2 whoami container displaying usefull information (hostname IP) on http://whoami1 or http://whoami2

• docker-compose file

• nginx-dynamic_conf.template file

• .env file

• dynamic_conf.json file

Configuration

Create your .envi from dot-ev.sample, to define your configuration

Environement Variable	Description	Example
Traefik configuration
TRAEFIK_*	https://doc.traefik.io/traefik/v2.3/reference/static-configuration/env/	http://httpd/lb-conf/dynamic_conf.json
Nginx configuration
OS_STORAGE_URL	Swift Root URL	https://object-store.api.pi.dsic.minint.fr/v1/AUTH_XXXXXXXXX
OS_CONTAINER	Swift Container	lb-conf
OS_OBJECT	Swift Object (the real http config traefik file)	dynamic_conf.json

Deploy it

ci/docker-deploy.sh

Test the traefik/httpd/whoami version

#docker-compose -f docker-compose.http.yml up -d
Creating network "simpletraefikhttpprovider_traefik-network" with driver "bridge"
Creating simpletraefikhttpprovider_traefik_1 ... done
Creating simpletraefikhttpprovider_whoami1_1 ... done
Creating simpletraefikhttpprovider_whoami2_1 ... done
Creating simpletraefikhttpprovider_httpd_1   ... done

# curl -H 'Host: whoami.mydomain.local' http://127.0.0.1
Hostname: 14af84badd78
IP: 127.0.0.1
IP: 172.29.0.4
RemoteAddr: 172.29.0.2:36838
GET / HTTP/1.1
Host: whoami.mydomain.local
User-Agent: curl/7.52.1
Accept: */*
Accept-Encoding: gzip
X-Forwarded-For: 172.29.0.1
X-Forwarded-Host: whoami.mydomain.local
X-Forwarded-Port: 80
X-Forwarded-Proto: http
X-Forwarded-Server: 44cf085fbde8
X-Real-Ip: 172.29.0.1

# curl -H 'Host: whoami.mydomain.local' http://127.0.0.1
Hostname: 299346f0d50e
IP: 127.0.0.1
IP: 172.29.0.3
RemoteAddr: 172.29.0.2:54310
GET / HTTP/1.1
Host: whoami.mydomain.local
User-Agent: curl/7.52.1
Accept: */*
Accept-Encoding: gzip
X-Forwarded-For: 172.29.0.1
X-Forwarded-Host: whoami.mydomain.local
X-Forwarded-Port: 80
X-Forwarded-Proto: http
X-Forwarded-Server: 44cf085fbde8
X-Real-Ip: 172.29.0.1

#docker-compose -f docker-compose.http.yml down 

Sources/Inspirations

• https://www.grottedubarbu.fr/traefik-2-3-http-provider/
• https://github.com/NETWAYS/traefik-provider-openstack