Tags and respective Dockerfile links

• 2.3.1, centos-7 (centos-7/Dockerfile)
• 1.3.1, centos-6 (centos-6/Dockerfile)

Overview

This build uses the base image jdeathe/centos-ssh so inherits it's features but with sshd disabled by default. Supervisor is used to start the haproxy daemon when a docker container based on this image is run.

To manage HAProxy both HATop and socat are included to provide both a UI and low level cli management interface respectively.

Image variants

• HAProxy 1.8 / HATop 0.7 - CentOS-7
• HAProxy 1.5 / HATop 0.7 - CentOS-6

Quick start

For production use, it is recommended to select a specific release tag as shown in the examples.

Run up a container named haproxy.1 from the docker image jdeathe/centos-ssh-haproxy on port 80 and 443 of your docker host. 2 backend hosts, httpd_1 and httpd_2, are defined with IP addresses 172.17.8.101 and 172.17.8.102; this is required to identify the backend hosts from within the HAProxy configuration file if not using docker network aliases.

Change 172.17.8.101 and 172.17.8.102 in the example below to IP addresses that resolve to valid web servers on your network.

$ docker run -d -t \
  --name haproxy.1 \
  -p 80:80 \
  -p 443:443 \
  --add-host httpd_1:172.17.8.101 \
  --add-host httpd_2:172.17.8.102 \
  jdeathe/centos-ssh-haproxy:2.3.1

Verify the named container's process status and health.

$ docker ps -a \
  -f "name=haproxy.1"

Verify successful initialisation of the named container.

$ docker logs haproxy.1

Instructions

Running

To run the a docker container from this image you can use the standard docker commands. Alternatively, there's a docker-compose.yml example.

In the following example the http service is bound to port 80 and https on port 443 of the docker host. Also, the environment variable HAPROXY_HOST_NAMES has been used to set a list of 3 hostnames to be added to the auto-generated self-signed SAN certificate.

Using environment variables

$ docker stop haproxy.1 && \
  docker rm haproxy.1; \
  docker run \
  --detach \
  --tty \
  --name haproxy.1 \
  --publish 80:80 \
  --publish 443:443 \
  --sysctl "net.core.somaxconn=32768" \
  --sysctl "net.ipv4.ip_local_port_range=1024 65535" \
  --sysctl "net.ipv4.route.flush=1" \
  --ulimit memlock=82000 \
  --ulimit nofile=131072 \
  --ulimit nproc=65535 \
  --env "HAPROXY_HOST_NAMES=www.app.local app.local localhost.localdomain" \
  --add-host httpd_1:172.17.8.101 \
  --add-host httpd_2:172.17.8.102 \
  jdeathe/centos-ssh-haproxy:2.3.1

Environment variables

There are several environmental variables defined at runtime which allows the operator to customise the running container.

HAPROXY_SSL_CERTIFICATE

The HAProxy SSL/TLS certificate can be defined using HAPROXY_SSL_CERTIFICATE. The value may be either a file path, a base64 encoded string of the certificate file contents or a multiline string containing a PEM formatted concatenation of private key and certificate. If set to a file path the contents may also be a base64 encoded string.

Note: If using a file path with base64 encoded content the on container path is not maintained so this feature is not suitable for use with orchestration secrets such as Docker Swarm secrets or config however use of unencoded file contents is.

HAPROXY_CONFIG

The HAProxy configuration file path, (or base64 encoded string of the configuration file contents), is set using HAPROXY_CONFIG. The default http configuration is located at the path /etc/haproxy/haproxy-http.example.cfg and will be copied into the running configuration path /etc/haproxy/haproxy.cfg. There's also an example tcp configuration in the path /etc/haproxy/haproxy-tcp.example.cfg.

Note: In most situations it will be necessary to define a custom configuration where the use of the base64 encoded string option is recommended. However if using a file path with base64 encoded content the on container path is not maintained so this feature is not suitable for use with orchestration secrets such as Docker Swarm secrets or config so when using these unencoded file contents is recommended.

HAPROXY_HOST_NAMES

The HAPROXY_HOST_NAMES can be used to set a, space separated, list of hostnames to be added to the automatically generated self-signed SAN certificate.

Note: The value is unused if HAPROXY_SSL_CERTIFICATE has a valid value set.