Difference between revisions of "Heat/ApplicationDeployment"
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If you can logged into the instance, look at the following files: | If you can logged into the instance, look at the following files: | ||
| − | * var/log/cloud-init.log => cloud-init logs | + | * /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/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 | * /var/log/heat-provision.log => logs of the user's script including cfn-init logs | ||
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Instead your script can get that information from the (Nova) metadata server: | Instead your script can get that information from the (Nova) metadata server: | ||
curl -s http://169.254.169.254/latest/meta-data/local-ipv4 | curl -s http://169.254.169.254/latest/meta-data/local-ipv4 | ||
| + | |||
| + | ===Installing cfn tools on Ubuntu cloud images=== | ||
| + | |||
| + | apt-get -y install python-argparse cloud-init python-psutil python-pip | ||
| + | apt-get -y remove python-boto | ||
| + | pip install 'boto==2.5.2' heat-cfntools | ||
| + | cfn-create-aws-symlinks -s /usr/local/bin/ | ||
== Resources == | == Resources == | ||
Revision as of 15:55, 21 May 2013
Contents
Pre-requisites
- Images with cloud-init and heat-cfntools packages installed. It is easier to use the prebuild images from the Heat team.
- Nova metadata server up and running
- Heat CFN API service up and running
Walk-through in a stack's lifetime
- 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.
Troubleshooting
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:
curl -s http://169.254.169.254/2009-04-04/user-data
Tips & tricks
Getting the private IP address within the instance
If the UserData script needs to know the private IP address of the instance, it can be resolved by Fn::GetAtt(instance, "PrivateIp") since it is not available when the UserData file is resolved by the Heat engine. Instead your script can get that information from the (Nova) metadata server:
curl -s http://169.254.169.254/latest/meta-data/local-ipv4
Installing cfn tools on Ubuntu cloud images
apt-get -y install python-argparse cloud-init python-psutil python-pip apt-get -y remove python-boto pip install 'boto==2.5.2' heat-cfntools cfn-create-aws-symlinks -s /usr/local/bin/
