Using Teamocil To Manage Tmux Sessions

When I am wearing my operations hat at work I need ready access to a number of servers, 15 or so. I use tmux to create a “console” session that is broken into 5 separate windows, each further divided into panes (one per server). The windows are rough categories: production, alpha, web, ESB, etc. I also normally have a “tools” session in a separate Terminal instance that contains 4 more windows, each to utility servers that I use periodically throughout the day.

Rather than try to create these tmux sessions by hand I’ve been using a tool called teamocil to capture the session::window::pane configuration in YAML files. With a console.yml file I can setup the entire console session with a single command.

Here’s how I set things up.

First you need to install the teamocil Gem.

$ gem install teamocil

Next you’ll need a space to keep the YAML files that describe your tmux sessions. teamocil expects this to be called ~/.teamocil

$ mkdir ~/.teamocil

teamocil comes with a command that will use your $EDITOR to create new session configuration files.

$ teamocil —edit console

The teamocil web site has good documentation on the options and attributes required to setup a configuration. Here is a sanitized version of my console.yml file.

session:
  name: "console"
  windows:
    - name: "prod"
      root: "~"
      options:
        synchronize-panes: true
      layout: even-vertical
      panes:
        - cmd: "ssh prod1"
        - cmd: "ssh prod2"
        - cmd: "ssh prod3"
        - cmd: "ssh prod4"
    - name: "web"
      root: "~"
      options:
        synchronize-panes: true
      layout: even-vertical
      panes:
        - cmd: "ssh web1"
        - cmd: "ssh web2"
        - cmd: "ssh web3"
        - cmd: "ssh web4"
        - cmd: "ssh web5"
    - name: "esb"
      root: "~"
      options:
        synchronize-panes: true
      layout: even-vertical
      panes:
        - cmd: "ssh hub1"
        - cmd: "ssh hub2"
    - name: alpha
      root: "~"
      options:
        synchronize-panes: true
      layout: even-vertical
      panes:
        - cmd: "ssh alpha1"
        - cmd: "ssh alpha2"
        - cmd: "ssh alpha3"
        - cmd: "ssh alpha4"

The name attribute is the name that will appear in my tmux status bar. root sets the directory in which each pane will be created. The synchronize-panes option is particularly nice as it allows me to type commands in one pane and have them run in all panes. The layout attribute determines whether the panes are vertically stacked, horizontally arranges or tiled.

Since I have my terminal set to create or reattach to my base tmux session creating my console session is one command away.

$ teamocil console

In seconds I have 5 windows (the original, prod, alpha, web, and ESB), each subdivided in to as many panes as there are servers. Quick, simple, repeatable.