Heroku buildpack: ssh-tunnel

This heroku buildpack makes it possible for an application to establish ssh tunnel to reach a remote host. This buildpack must be used with a language-specific buildpack as a supplement.

Usage

1. Add this buildpack before your language-specific buildpacks:

$ heroku buildpacks:set https://github.com/emartech/heroku-buildpack-ssh-tunnel

2. Add your language-specific buildpack (nodejs in this case):

$ heroku buildpacks:set heroku/nodejs

Configuration

Static configuration

Configuration	Value
openssh connect timeout	10 sec
keepalive interval	10 sec
maximum number of keepalives	3
reconnect after	5 sec

The buildpack creates an ssh tunnel on the basis of the environment variables configured for Heroku:

• SSHTUNNEL_PRIVATE_KEY: Private key for connecting to the tunnel host
• SSHTUNNEL_TUNNEL_CONFIG: Tunnel configuration (openssh -L syntax without the LOCAL_HOST) [LOCAL PORT]:[REMOTE_HOST]:[REMOTE_PORT]
• SSHTUNNEL_REMOTE_USER: Username for connecting to the tunnel server
• SSHTUNNEL_REMOTE_HOST: The tunnel server hostname
• SSHTUNNEL_REMOTE_PORT: (optional) Port for connecting the tunnel server. Default is 22.

Logging

The buildpack logs to the standard output with the 'ssh-tunnel' prefix.

Logged events:

Event	Description
starting	logged on dyno start
spawned	logged after "tunnel-daemon" starts
missing-configuration	logged on any missing configuration (tunnel-daemon is not started as variables are not defined properly)
ssh-connection-init	logged before initiating ssh connection
ssh-connection-end	logged after the ssh connection ends or there is a connection error