nginx-consul-template

DockerHub Repository: https://registry.hub.docker.com/u/shufo/nginx-consul-template/

Overview

This repository contains a scripts for creating configurable load balancer Consul Key-Value store API with nginx and consul-template.

Requirements

Docker (Tested on 1.6.2)
Consul (Tested on 0.5.2)

Usage

docker run -d -p 80:80 \
    --link consul:consul \
    -e "CONSUL_KV_PREFIX=nginx" \
    shufo/nginx-consul-template

Custom nginx config

Inside the container there is a file config.json which contains default values for all of the configuration options that are read by the consul template. When this container starts these default values are pre-loaded into consul, so that when it comes to reading these values when the template is parsed, there are already default values.

However you can change these default values by providing your own config.json:

docker run -d -p 80:80 \
    -v /path/to/config.json:/config.json \
    --link consul:consul \
    -e "CONSUL_KV_PREFIX=nginx" \
    shufo/nginx-consul-template

Custom template

docker run -d -p 80:80 \
    -v $(pwd)/config.json:/config.json \
    -v /path/to/nginx.conf.ctmpl:/etc/nginx/nginx.conf.ctmpl \
    -e "CONSUL_KV_PREFIX=nginx" \
    shufo/nginx-consul-template

Dynamic configuration change via Consul API.

curl -X PUT -d "/var/log/nginx/error.log" http://consul_host:8500/v1/kv/nginx/error_log

Changing the consul hostname

By default this container tries to connect to a consul server running on localhost. If you want to specify a different location for the consul server, set the CONSUL_PORT_8500_TCP_ADDR environmental variable. If you are linking this container to the consul container then you should set the CONSUL_PORT_8500_TCP_ADDR variable to the alias of the consul container:

docker run -d -p 80:80 \
    -v /path/to/config.json:/config.json \
    --link consul:consul \
    -e "CONSUL_KV_PREFIX=nginx" \
    -e "CONSUL_PORT_8500_TCP_ADDR=consul" \
    shufo/nginx-consul-template

Example

This repository contains a example dockerize application build with vagrant machine.(Requires Vagrant and Ansible)

Setup VM and docker containers.

make install

Change configuration.

curl -X PUT -d "/var/log/nginx/error.log" http://172.17.9.101:8500/v1/kv/nginx/error_log

Ensure nginx conf is properly rewrited.

docker exec -it nodes_nginx_1 cat /etc/nginx/nginx.conf

Set tag to application upstream.

curl -X PUT -d "0.0.1" http://172.17.9.101:8500/v1/kv/nginx/http/server/httpd/upstream/current

This will set upstream of service named httpd to tagged with 0.0.1 containers. Service registration is automated by registrator.

If something goes wrong, restart all containers

make restart

How to

Consul data persistence

docker run -d -v /mnt:/data progrium/consul:latest -server -bootstrap -data-dir /data -ui-dir /ui

Set multiple value in same key

# Edit config.json
# Set JSON key-value pair as a Value.
"location": {
"proxy_set_header": "{\"X-Real-IP\": \"$remote_addr\", \"X-Forwarded-For\": \"$proxy_add_x_forwarded_for\", \"X-Forwarded-Proto\": \"$scheme\", \"Host\": \"$host\"}"
}

# Edit consul template file
{{ range $key, $pairs := tree "location" | byKey }}
  {{ range $pair := $pairs }}
    {{ range $key, $value := printf "location/%s"  $pair.Key | key | parseJSON }}
    	{{ $key }}{{ $value }}
    {{ end }}
  {{ end }}
{{ end }}

Run with Host networking

docker run -d --net host -v $(pwd)/config.json:/config.json -e "CONSUL_KV_PREFIX=nginx" -e "CONSUL_PORT_8500_TCP_ADDR=CONSUL_HOST_IP" shufo/nginx-consul-template