Edgar

edgar is a small utility to help one maintain their huge SSH config file. It’s heavilly inspired by concierge (even the tests are directly taken from the concierge examples!).

Installation

edgar only support python3. We are now in 2019!

python -m venv edgar-venv
source edgar-venv/bin/activate
python setup.py install

Unit tests can be run with python -m unittest.

Usage

Contrary to concierge, there is no inotify support. The main idea is that you are not always modifying your SSH config file and it’s not that hard to just call manually edgar when your config template is ready.

edgar rely on a config file stored in your ~/.config folder: ~/.config/edgar.yml. As its name show it, this is a YAML file.

This file should contain a list of host configurations. Thus the most simple config file may be:

---
- Host: m1
  Hostname: 192.168.1.42
  User: edgar
- Host: m2
  Hostname: 192.168.1.43
  User: edgar

Which will output the following:

Host m1
  Hostname 192.168.1.42
  User edgar

Host m2
  Hostname 192.168.1.43
  User edgar

If the main object is not a list, it is taken as a primary host configuration named *:

---
CheckHostIP: yes
Compression: yes
StrictHostKeyChecking: accept-new
ServerAliveInterval: 120
ServerAliveCountMax: 2
HashKnownHosts: yes
IdentitiesOnly: yes
AddKeysToAgent: yes

hosts:
  - Host: m1
    Hostname: 192.168.1.42
    User: edgar
  - Host: m2
    Hostname: 192.168.1.43
    User: edgar

Which will output the following:

Host m1
  Hostname 192.168.1.42
  User edgar

Host m2
  Hostname 192.168.1.43
  User edgar

Host *
  AddKeysToAgent yes
  CheckHostIP yes
  Compression yes
  HashKnownHosts yes
  IdentitiesOnly yes
  ServerAliveCountMax 2
  ServerAliveInterval 120
  StrictHostKeyChecking accept-new

Finally, edgar understands sub-hosts and ansible-like with_items processing:

---
CheckHostIP: yes
Compression: yes
StrictHostKeyChecking: accept-new
ServerAliveInterval: 120
ServerAliveCountMax: 2
HashKnownHosts: yes
IdentitiesOnly: yes
AddKeysToAgent: yes

hosts:
  - Host: m
    User: edgar
    hide: yes
    hosts:
      - Host: e{item}
        Hostname: 10.10.0.{item}
        ViaProxy: gw2
        with_items: range(2)
  - Host: blog
    User: sa

Which will output the following:

Host me0
  Hostname 10.10.0.0
  ProxyCommand ssh -W %h:%p gw2
  User edgar

Host me1
  Hostname 10.10.0.1
  ProxyCommand ssh -W %h:%p gw2
  User edgar

Host blog
  User sa

Host *
  AddKeysToAgent yes
  CheckHostIP yes
  Compression yes
  HashKnownHosts yes
  IdentitiesOnly yes
  ServerAliveCountMax 2
  ServerAliveInterval 120
  StrictHostKeyChecking accept-new

Reference

edgar understands all config options from an up-to-date OpenSSH config options list. As for OpenSSH itself, option names are case insensitive. However, during config generation process, option names will be written following the OpenSSH naming convention and alphabetically sorted under Host or Match blocks. The Host and Match blocks order is kept as provided, but all “orphaned” options are gathered inside a single Host * block, which is always output last.

It also understands the following supplementary options:

blocks

define a listing of Host or Match block, each of them will inherit from the current block parameters. For historical reason, this option can be named hosts, but this is deprecated.

hide

Whether a specific configuration for the current block should be output or if it should be only used for factorization purpose of its sub-block. Value must be a boolean. Default is no (false).

prefix

Whether the current block name should be concatenated with it’s sub-blocks name. Value must be a boolean. Default is yes (true).

with_items

define that the current block configuration must be duplicated for each item of this list. Value must be something python is able to iterate over (a list, a range expression…). You can use the {item} tag in any option value of the same block.

ViaProxy <host>

shortcut helper, which expands to ProxyCommand ssh -W %h:%p <host>.

FAQ

• Edgar crash with a weird error message about YAML parser
  1. Don’t forget to add the colon between the SSH parameter and its value.
  2. Some values must be protected, like the one with *. For exemple: Host: "*.toto.com".