move doc into README.md

(and modify example user-data to include a NIX_CHANNEL version)

README.md

@@ -0,0 +1,48 @@
+This script aims to install NixOS on Digital Ocean droplets
+(starting from one of the distros that Digital Ocean supports out of the box)
+
+These are the only supported Digital Ocean images:
+
+- Fedora 24 x64
+- Ubuntu 16.04 x64
+- Debian 8.5 x64
+
+YMMV with any other hoster + image combination.
+
+nixos-infect is so named because of the high likelihood of rendering a system
+inoperable. Use with caution and preferably only on newly-provisioned
+systems.
+
+*WARNING NB*: This script wipes out the targeted host's root filesystem when it
+runs to completion. Any errors halt execution. It's advised to run with
+`bash -x` to help debug, as often a failed run leaves the system in an
+inconsistent state, requiring a rebuild (in DigitalOcean panel: Droplet
+Settings -> "Destroy" -> "Rebuild from original").
+
+*TO USE:*
+- Add any custom config you want (see notes below)
+- Deploy the droplet indicated at the top of the file, enable ipv6, add your ssh key
+- cat customConfig.optional nixos-infect | ssh root@targethost
+
+Alternatively, use the user data mechamism by supplying the lines between the following
+cat and EOF in the Digital Ocean Web UI (or HTTP API):
+
+```yaml
+#cloud-config
+
+runcmd:
+  - curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | NIX_CHANNEL=nixos-16.09 bash 2>&1 | tee /tmp/infect.log
+```
+Potential tweaks:
+- `/etc/nixos/{,hardware-}configuration.nix`: rudimentary mostly static config
+- `/etc/nixos/networking.nix`, networking settings determined at runtime tweak
+  if no ipv6, different number of adapters, etc.
+
+Motivation for this script: nixos-assimilate should supplant this script
+entirely, if it's ever completed. nixos-in-place was quite broken when I
+tried it, and also took a pretty janky approach that was substantially more
+complex than this (although it supported more platforms): it didn't install
+to root (/nixos instead), left dregs of the old filesystem (almost always
+unnecessary since starting from a fresh deployment), and most importantly,
+simply didn't work for me! (old system was being because grub wasnt properly
+reinstalled)

nixos-infect

@@ -1,49 +1,6 @@
 #! /usr/bin/env bash
 
-# These are the only supported Digital Ocean images:
+# More info at: https://github.com/elitak/nixos-infect
-#
-#     Fedora 24 x64
-#     Ubuntu 16.04 x64
-#     Debian 8.5 x64
-#
-# YMMV with any other hoster + image combination.
-
-# nixos-infect is so named because of the high likelihood of rendering a system
-# inoperable. Use with caution and preferably only on newly-provisioned
-# systems.
-#
-# WARNING NB This script wipes out the targeted host's root filesystem when it
-# runs to completion. Any errors halt execution. It's advised to run with
-# `bash -x` to help debug, as often a failed run leaves the system in an
-# inconsistent state, requiring a rebuild (in DigitalOcean panel: Droplet
-# Settings -> "Destroy" -> "Rebuild from original").
-#
-# TO USE:
-#  - Add any custom config you want (see notes below)
-#  - Deploy the droplet indicated at the top of the file, enable ipv6, add your ssh key
-#  - cat customConfig.optional nixos-infect | ssh root@targethost
-#
-# Alternatively, use the user data mechamism by supplying the following lines (without >)
-# in the Digital Ocean Web UI (or HTTP API):
-#
-# > #cloud-config
-# >
-# > runcmd:
-# >   - curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | bash 2>&1 | tee /tmp/infect.log
-#
-# Potential tweaks:
-#  /etc/nixos/{,hardware-}configuration.nix : rudimentary mostly static config
-#  /etc/nixos/networking.nix, networking settings determined at runtime
-#    tweak if no ipv6, different number of adapters, etc.
-#
-# Motivation for this script: nixos-assimilate should supplant this script
-# entirely, if it's ever completed. nixos-in-place was quite broken when I
-# tried it, and also took a pretty janky approach that was substantially more
-# complex than this (although it supported more platforms): it didn't install
-# to root (/nixos instead), left dregs of the old filesystem (almost always
-# unnecessary since starting from a fresh deployment), and most importantly,
-# simply didn't work for me! (old system was being because grub wasnt properly
-# reinstalled)
 
 set -e -o pipefail