Creating a custom elastic image

1. Requirements

First ensure that you have set up the following:

• Amazon Web Services (AWS) account with EC2 — if you are already using Elastic Bamboo, you should already have an AWS account with EC2 set up. If not, please read Getting started with Elastic Bamboo.

• Amazon EC2 API Tools — you must install the EC2 API tools on your local machine, otherwise you will not be able to start and access your AMI instance. Note: you need Java Runtime Environment to run these tools. You can install the EC2 API tools by executing the following commands:
  
  

  wget http://s3.amazonaws.com/ec2-downloads/ec2-api-tools.zip
  unzip ec2-api-tools.zip

• Environment Variables— you must set up the following environment variables on your local machine before creating a custom elastic image:
  • EC2_HOME — set this to the path to the installed EC2 API Tools
  • EC2_CERT — set this to the path to the certificate assigned to EC2 account
  • EC2_PRIVATE_KEY — set this to the path to the private key assigned to your AWS account

• Registered Key Pair— you need a registered EC2 key pair, which consists of a private key file and certificate file, to use the EC2 API tools with your AMI instance. If you have previously generated and registered an EC2 key pair (e.g. to use the EC2 API tools), you can re-use it. If you need to generate a new key pair, you can use the following command to do so:

  ec2-add-keypair <key_pair_name>

  The content of the private key will be displayed in the command-line output on your console. Save this content in a file , starting with the line:

  "--BEGIN RSA PRIVATE KEY--"

  and ending with the line:

  "--END RSA PRIVATE KEY--"

  This private key file will be used to access your AMI instance. Set up the appropriate permissions on the private key file by executing the following command:

  chmod 600 <private_key_file>

2. Selecting an existing AMI

We strongly recommend that you select an existing Linux/UNIX AMI to customise, rather than starting with a blank AMI. When choosing an AMI, decide whether you want to launch 32-bit or 64-bit instances from your custom elastic image and select an existing AMI matching your choice.

We recommend the following existing Linux/UNIX AMIs for customisation (in order of preference):

Atlassian's AMIs (and hence, their IDs) may change with each release of Bamboo, including both major and minor releases. To quickly access Atlassian's AMI IDs for your currently-running version of Bamboo, open that Bamboo site in a web browser and access its 'Image Configurations' page (see Managing your Elastic Image Configurations for more information). The AMI IDs of Atlassian's AMIs are labelled with "(stock image)".

3. Starting an instance

After you have selected an existing AMI to customise, the next step is to start an instance of the AMI.

3.1 Starting an instance of Atlassian's default AMI

If you chose to customise Atlassian's default AMI, you will have to start the instance from the admin section of Bamboo. See Starting an elastic instance.

Note that Atlassian's default AMI cannot be started using the command line ec2 tools. This is because, on start up, the Bamboo agent on Atlassian's AMI checks to see if it was started from a Bamboo server, and immediately shuts itself down if it was not.

Once started, see Accessing an elastic instance for details on how to access the running instance.

3.2 Starting an instance from the command line

Use the ec2-run-instances command to start your instance, as follows:

ec2-run-instances <image_name> -k <key_pair_name>

where <image_name> is the name of the AMI selected in the previous step and <key_pair_name> is the name of the registered key pair generated in '1. Requirements'. The public certificate of this key will be injected into your instance.

For example, if you wanted to start an instance of image ami-e55bbd8c using key pair my-keypair, you would run the following command:

ec2-run-instances ami-e55bbd8c -k my-keypair

This command would produce the following command-line output:

INSTANCE        i-25b86743   ami-e55bbd8c     running   my-keypair

i-25b86743 is the name of the new instance in the above example. You should note down the name of your new instance, as you will need that to access your instance in the next step.

3.3 Starting an instance from Bamboo

You can also start a fresh, uncustomised image from Bamboo and begin customisation. The drawback of this approach is that you have only 40 minutes before Bamboo shuts down your instance. The advantage is that you can customise the agent in a single step (as opposed to having to customise/create image/start from Bamboo/save image again).

4. Accessing your instance

Once your instance is running, you will need to obtain the address of the instance so you can access it. To do this, use the following command:

ec2-describe-instances <instance_name>

For example, if you wanted to find the address of instance i-25b86743, you would enter:

ec2-describe-instances i-25b86743

This command would produce the following command-line output similar to this:

RESERVATION	r-790f7210	121852097033	default
INSTANCE	i-25b86743	ami-e55bbd8c 	ec2-174-129-94-241.compute-1.amazonaws.com
domU-12-31-39-04-38-87.compute-1.internal	running	elasticbamboo	0		m1.small
2009-06-24T12:36:20+0000	us-east-1c	aki-a71cf9ce	ari-a51cf9cc
monitoring-disabled

The address of the instance in the above example is ec2-174-129-94-241.compute-1.amazonaws.com

You can then use this address to access the instance via SSH. See Accessing an elastic instance for instructions. If you are using the example command text from that document, you will need to adjust it as follows:

• replace /opt/bamboo/home/xml-data/configuration/elasticbamboo.pk in the example command text with the private key file you generated in '1. Requirements'.
• replace ec2-68-111-185-197.compute-1.amazonaws.com in the example command text with the address of your instance.

5. Customising your instance

Now that you have a running instance, customisation steps heavily depend on the operating system you're using. We've prepared separate pages with Linux-specific instructions and Windows-specific instructions. 

6. Creating an image of your customised instance

The process of creating a new image varies depending whether you based your image on an instance-store or EBS-root image. You can check your image type via AWS console or using ec2-describe-images.

Creating an image from EBS-root instances

See here for instructions: Amazon Tutorial

Creating an image from instance-store (S3) instances

The final step is to create an image from your customised instance. To do this, you will require the following information:

• Amazon Account Number
• Access Key ID
• Secret Access Key
• Amazon S3 bucket name that will be used to store image (if you don't have access to Amazon S3, you can sign up on this page.)

1. Transfer Amazon private key file and certificate to your instance
   Transfer the key files to your instance by running these commands on your local machine:
   
   

   scp -i <private_key_file> $EC2_PRIVATE_KEY root@<instance_address>:/mnt
   scp -i <private_key_file> $EC2_CERT root@<instance_address>:/mnt
   

   where <private_key_file> is the private key file from your local machine created in step 'Registered Key Pair' of 1. Requirements and the <instance_address> is the address of your instance from '4. Accessing your Instance'.

2. Set up EC2_HOME and JAVA_HOME environment variables
   Set up these environment variables by running the following commands on your instance:
   
   

   export EC2_HOME=<location of your EC2 tools installation>
   export EC2_PRIVATE_KEY=/mnt/<ec2_private_key_file>
   export EC2_CERT=/mnt/<ec2_certificate_file>
   export JAVA_HOME=<path to JRE used to start the agent>
   

3. You can create an image of your customised instance by using the ec2-bundle-vol command, as follows:
   
   

   ec2-bundle-vol -c $EC2_CERT -k $EC2_PRIVATE_KEY -u <amazon_account_number> -p <elastic_image_name> --batch --debug
   

   where <elastic_image_name> is the name that you want to assign to your custom image (e.g. 'CustomImage1')

4. Once the image is created, you need to upload it to Amazon S3 by running the command below:
   
   

   ec2-upload-bundle -b <s3_bucket_name> -m /tmp/<elastic_image_name>.manifest.xml -a <access_key_id> -s <secret_access_key> --retry --debug
   

   where <s3_bucket_name>, <access_key_id> and <secret_access_key> are the Amazon S3 bucket name, Access Key ID and Secret Access Key described previously, and <elastic_image_name> is the name that you want to assign to your custom image (e.g. 'CustomImage1').

   You will then need to register your image with Amazon EC2 by using the ec2-register command:
   
   

   ec2-register <s3_bucket_name>/<elastic_image_name>.manifest.xml
   

   where <s3_bucket_name> is the Amazon S3 bucket name described previously and <elastic_image_name> is the name that you want to assign to your custom image (e.g. 'CustomImage1'). The output of this command will show the AMI ID of your custom image.

7. Next steps

Now that you have created a custom elastic image, there are two more steps that you will need to complete before you can use it.

First, you will need to associate your custom elastic image with your Bamboo installation by creating an Elastic Image Configuration. Please note the AMI ID of your new custom image and read Managing your Elastic Image Configurations for further instructions.

Secondly, you will need to configure the capabilities of the elastic agents that will run on instances started from your image. This is done by adding the appropriate builder, JDK, Perforce and custom capabilities to your elastic image configuration, so that it reflects what your custom elastic image actually can do. For example, if you have created a custom elastic image with JDK 1.6 and Maven 2 installed, you will need to add capabilities for JDK 1.6 and Maven 2 to the elastic image configuration. Read Configuring Elastic Agent Capabilities for further instructions.

8. Need more help?

If you need more help, there are a number of resources that you can take advantage of:

• AWS Support Center — if you are having problems with any of your Amazon services, not specifically related to Bamboo, you can obtain basic support from the AWS Support Center. Note, you will need to sign up for Premium Support to get access to web/phone support.
• AWS Resource Center — the AWS Resource Center has links to online documentation, code samples and tools for AWS services.
• Bamboo Developer Forums — please feel free to discuss any useful tips or issues regarding this process in the Bamboo Developer Forums.