HAProxy Firehose Router

This is a HAProxy Docker image for Firehose. It is configured via keys in etcd.

Configuration

The HAProxy configuration is dynamically configured through confd. Every 30 seconds (configurable through CONFD_INTERVAL) it will look at certain keys in etcd. If there are keys changes it will update the configuration and reload HAProxy.

Environment

• CONFD_INTERVAL - The interval in seconds to check for key changes.
• CONFD_NODE - The backend servers address (defaults to 172.17.42.1:4001).
• CONFD_BACKEND - The backend type can be etcd or consul (defaults to etcd).

etcd

The HAProxy template looks for certain keys in etcd. Some are optional and some are required.

• /firehose/services/rainbows/* Required - The keys under this directory are used as the upstream servers. This is typically populated by registrator.
• /firehose/put_allow/* Required - The keys under this directory are used to allow PUT calls to Firehose. The key name can be anything. The value of the key should be a single IP or subnet in CIDR format. Examples of this would be 104.12.201.79 or 104.12.201.0/24.
• /firehose/healthcheck_path Required - This key should be set to the Firehose health check path. It is used by HAProxy to determine if a particular backend is healthy. The key is typically set to /firehose-healthcheck.
• /firehose/syslog_endpoint Optional - This is the syslog endpoint to log to such as logs.papertrailapp.com:46352.
• /firehose/accept_proxy Optional - If this key exists (can be set to anything) then we enable accept-proxy on the HAProxy frontend. See http://cbonte.github.io/haproxy-dconv/configuration-1.5.html#accept-proxy for more ifnormation. This is typically used with AWS ELB proxy protocol support to pass through client IP addresses to HAProxy for authorization.