Difference between revisions of "Heat/ApplicationDeployment"

Revision as of 07:40, 7 May 2013

Images with cloud-init and heat-cfntools packages installed. It is easier to use the prebuild images from the Heat team.
Metadata server up and running

The user calls the Heat API to create a stack ("heat stack-create ... myStack")
Heat engine generates a mime multipart data blob that will be consumed by cloud-init
Heat engine asks nova to create an instance with the cloud-init data
Nova selects a compute node to run the instance and provisions the metadata server with the cloud-init data
When the instance boots up, it runs the cloud-init script:

Download the data from the metadata server
Splits the multiple parts into the /var/lib/cloud/ directory
Run the different cloud-init parts (resize the root filesystem, set the hostname, install the user's SSH key, etc.)
Runs the user's script (located at /var/lib/cloud/data/cfn-userdata), it can be any kind of script (Bash, Python, etc.) but at some point this script should call cfn-init.

cfn-init loads /var/lib/cloud/data/cfn-init-data (a copy of the Metadata->AWS::CloudFormation::Init->Config attribute from the AWS template) and can install packages, setup users & groups, create files, etc.

Note that heat-cfntools leverage the boto library and that the boto configuration is stored at /var/lib/heat-cfntools/cfn-boto-cfg on the instance.

If you can logged into the instance, look at the following files:

var/log/cloud-init.log => cloud-init logs
/var/log/part-handler.log => logs of the Heat-specific script managing data with content-type=text/x-cfninitdata
/var/log/heat-provision.log => logs of the user's script including cfn-init logs

You can also query the metadata server for the user's data generated by Heat:

@@ Line 1: / Line 1: @@
 == Pre-requisites ==
-* Images with cloud-init and heat-cfntools packages installed
+* Images with [https://help.ubuntu.com/community/CloudInit cloud-init] and [https://github.com/openstack/heat-cfntools heat-cfntools] packages installed. It is easier to use the [http://fedorapeople.org/groups/heat/prebuilt-jeos-images/ prebuild images] from the Heat team.
 * Metadata server up and running
@@ Line 14: / Line 14: @@
 :* Runs the user's script (located at /var/lib/cloud/data/cfn-userdata), it can be any kind of script (Bash, Python, etc.) but at some point this script should call cfn-init.
 ::* cfn-init loads /var/lib/cloud/data/cfn-init-data (a copy of the Metadata->AWS::CloudFormation::Init->Config attribute from the AWS template) and can install packages, setup users & groups, create files, etc.
+Note that heat-cfntools leverage the [https://github.com/boto/boto boto] library and that the boto configuration is stored at /var/lib/heat-cfntools/cfn-boto-cfg on the instance.
 == Troubleshooting ==