update readme

README.md

@@ -9,6 +9,20 @@ Specifically, this script uses SSH forwarding to forward the Docker socket of a
 The benefit Harbor Master provides is that not only does it maintain the SSH tunnel for the remote socket, but it _also port forwards exposed container ports_. This is a severe
 oversight in the current Docker implementation, and Harbor Master just makes your life that much easier :^).
 
+## Pre-Installation
+
+Harbor Master requires Python3
+
+Before you can use Harbor Master, you must have a trusted host that is already running docker. In addition you _must_ be using passwordless SSH to connect to this host and have
+already done the key transfer. Harbor Master does not, and (probably) will not, manage/accept passwords for SSH connections. These are insecure and add unnecessary complexity. In
+addition, please read the SSH Configuration notes below to ensure your remote host has the proper configuration.
+
+## Installation
+
+Harbor Master is available on PiPY and can be installed via a `pip install harbormaster`, or `pip3 install harbormaster` if you have multiple python versions.
+
+Alternatively, you may clone this repository, install the docker python package as specified in the `requirements.txt`, and then copy `harbormaster.py` into your path.
+
 ## Usage
 
 ```
@@ -29,11 +43,27 @@ optional arguments:
 For example:
 
 ```
-./harbormaster.py dubey 192.168.1.111
+harbormaster.py dubey 192.168.1.111
 ```
 
 This would connect to a machine on the IP `192.168.1.111` as user `dubey`, establishing a Docker socket tunnel on port 2377. Once this command is run, you can let the Harbor Master manage all the SSH tunnels necessary as containers go up and down.
 
 ### Important Notes
 
+#### SSH Configuration
+
+Most \*Nix distros come with sane defaults for the number of SSH connections allowed to a host, usually 10 concurrent connections. If you plan to have more than 10 ports forwarded,
+then you must change the `sshd` config located at `/etc/ssh/sshd_config` and change the parameters:
+
+```
+MaxSessions 100
+MaxStartups 100
+```
+
+In the above example, the host will accept 100 concurrent connections, allowing you to port forward 100 ports.
+
+In addition it is highly recommended to disallow password SSH login, and only use SSH key files.
+
+### Version Notes
+
 As of `v0.1`, Harbor Master assumes that you are using `zsh` and will modify your `~/.zshrc` file by appending a `export` statement that lets any new shell sessions use the forwarded Docker socket. Harbor Master does cleanup on shutdown: all SSH tunnels that are open, and any changes to the `.zshrc` file.