From d51a6ac06c9749c99bac46e653935db1d870d705 Mon Sep 17 00:00:00 2001
From: Jay Faulkner <jay@jvf.cc>
Date: Thu, 17 Apr 2014 10:06:11 -0700
Subject: [PATCH] Better documentation and defaults for coreos image

The existing coreos image required 20G+ of RAM, which isn't reasonable.
Also there was no documentation about how to get the image running, so a
sample configuration with iPXE was added. These changes are required to
help folks who want to use the agent now.

Change-Id: I845bebf17c62653521282863d596ac512dd6b82e
---
 coreos/README.md  | 27 ++++++++++++++++++++++++++-
 coreos/oem/run.sh |  8 +++++---
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/coreos/README.md b/coreos/README.md
index 60f6f1d..90151b1 100644
--- a/coreos/README.md
+++ b/coreos/README.md
@@ -11,7 +11,7 @@ Run the following locally or from a virtualenv to install the python requirement
 pip install -r requirements.txt
 ``` 
 
-# Instructions
+# Build Instructions
 
 To create a docker repository and embed it into a CoreOS pxe image:
 ```
@@ -31,3 +31,28 @@ oem/authorized_keys with the keys you need added before building the image.
 ```
 make coreos
 ```
+
+# Booting the agent with this image
+
+To boot the image, it should be booted via PXE. Here's an example ipxe 
+configuration (replace my-web-server with the IP/hostname of the http server
+hosting your image):
+
+```
+#!ipxe
+
+dhcp
+kernel http://my-web-server/coreos_production_pxe.vmlinuz root=squashfs: state=tmpfs:
+initrd http://my-web-server/coreos_production_pxe_image-oem.cpio.gz
+boot
+```
+
+You can either embed a configuration file into the image, or set configuration
+options via the kernel command line. Values most people will need are:
+
+  - `ipa-api-url=http://ironic-api-server:6385`
+  - `ipa-advertise-host=ip-of-server-running-agent`
+
+But any config value supported in the agent can be given to the agent via the
+kernel command line, which allows the use of the same agent image across
+environments because it contains no state.
diff --git a/coreos/oem/run.sh b/coreos/oem/run.sh
index 12be0b5..914a4a3 100755
--- a/coreos/oem/run.sh
+++ b/coreos/oem/run.sh
@@ -3,9 +3,11 @@
 set -e
 
 # CoreOS by default only has an OEM partition of 2GB. This isn't large enough
-# for some images. Remount it with a larger size. Note: When CoreOS changes to 
-# r/w /, instead of remounting here, we'll use rootflags= to set the size.
-mount -o remount,size=20G /media/state
+# for some images. If you need something larger, uncomment the following line
+# to remount it with a larger size.
+# Note: When CoreOS changes to r/w /, instead of remounting here, rootflags=
+# in the kernelk command line will be used to set the size.
+#mount -o remount,size=20G /media/state
 
 cd /usr/share/oem/