Bazaar Windows EC2 Server

We have an Amazon EC2 virtual machine called Desolation for building Windows packages and general testing on Windows. As of 2009-02-19, this is just experimental and this is a draft specification, but we aim to use it for the production Windows installer build of 1.13 in March.

See also:

Goals

  • The instance is only running (and incurring charges) when it’s needed for testing or packaging.
  • It can be started or stopped by anyone on the team using a straightforward script.
  • Multiple people can get into the same instance at the same time, e.g. if one person needs to pass work on to some one else.
  • We keep snapshot of the OS and tool chain so that we can roll back if we need to.
  • bzr branches and similar information are kept on stable storage that survives rollbacks of the OS state, and that can be backed up.

Later on we may try automated Windows testing in a similar setup.

Approach

The working disk and the AMI images are stored in one person’s account for billing purposes.

Ideally we want to give other people access to run this machine without giving full access to the account. I’m not sure if that’s feasible. If it’s not, we might need to allow people to launch the image within their own account; this may be problematic if the shared volume is already in use by someone else.

I don’t think it’s possible to have an EBS that’s shared across accounts, and they can’t be attached to multiple running instances. So for now it’s probably best to just ignore the concept and store the working data on the instance’s local storage, and to copy things up e.g. to Launchpad as required.

On this machine, C: should be used only for the Windows system files, D: for installed programs and working directories, and other drive letters can be used later for mounting EBS storage if desired.

Through ec2-modify-image-attribute we can allow nominated users to access an existing image. We need to have their AWS opaque ID.

Through ec2-bundle-image we can make a new snapshot at any point, which will be stored into the current user’s S3 account.

We’ll (probably) have one shared account for running builds which is also an administrator for ease of installing software.

You do need to have an RSA keypair to get the initial password for a Windows machine, even though you can’t use it to log in later. ec2-get-password takes the full path to the private key to obtain the password from Amazon, and ec2-add-keypair creates a named keypair at Amazon and returns the private path. One keypair is all that is needed. This is distinct from the account identifier - likely due to the different toolchains in use (the keypairs are used for unix SSH keys, and I (Robert) suspect a rather unix friendly core at Amazon). Once a custom image is made with a saved password, you can skip using ec2-get-password (which is only needed for Windows anyway).

It would be nice if rdesktop could use private key authentication but apparently not.

Should check how the Launchpad ec2test scripts work.

Procedures

Preparation

  • Be in the bzr core team. If you are interested in helping with Windows packaging, testing or development just ask.

  • Install the Amazon EC2 API tools (needs-packaging bug 330930)

  • Create an Amazon Web Services account, sign up for S3 and EC2, and do the various steps to create authentication devices.

  • Create a private key and certificate for yourself. Check these environment variables are set and exported, e.g. by setting them in the file ~/.aws. Make sure the files are private.:

    export EC2_PRIVATE_KEY=~/.ec2/pk-XXXXXX.pem
    export EC2_CERT=~/.ec2/cert-XXXXXX.pem
    export EC2_HOME=~/build/ec2-api-tools-1.3-30349
    export AWS_SECRET_ACCESS_KEY=XXXXXXXXX
    export AWS_ACCESS_KEY_ID=XXXXXXXXXXX
    export EC2_KEYPAIR_NAME=XXXXXXXXX
    export PATH=$PATH:$EC2_HOME/bin
    export JAVA_HOME=/usr/lib/jvm/java-6-openjdk
    ssh-add ~/.ec2/id_rsa

    You can now ‘. ~/.aws’ to get the ec2 commands available.

  • (Unix images only) run ec2-add-keypair SOMENAME, e.g. ‘bzr’. Put the result (minus the first line) somewhere like ~/.ec2/id_rsa and chmod go-rw.

  • A useful Unix image is ami-bdfe19d4, Eric Hammonds 64-bit Ubuntu image.

  • Install the rdesktop client, to actually access the machine.

  • Possibly read some of the EC2 documentation for background.

  • Create a security group for your that allows rdesktop access and icmp with:

    ec2-add-group desolation-group -d 'bzr win32 build machine'
    ec2-authorize desolation-group -p 3389 -s 1.2.3.4/32
    ec2-authorize desolation-group -t -1:-1 -P icmp

    Add your public IP there. You can repeat that command to allow others in.

To start up an instance

  1. Get the right AMI image ID from another developer.
  1. Start the instance:

    ec2-run-instances $image_id -g desolation-group

    This will print out some information including the image id, something like i-31a74258.

  1. Actually starting the machine will take a few minutes. Once it’s in the running state, get the machine’s public IP with

    ec2-describe-instances
    
  1. and then connect

    rdesktop -g 1200x850 -u Administrator $machine_ip

Don’t forget to shut it down when you’re done, and check with ec2-describe-instances that it did terminate.

To save a system snapshot as an image

  1. Bundle the current state. Doing this will reboot the machine. You need to choose a unique s3 bucket name, typically based on a domain or email address, which can contain any number of images. You also need a name unique within the bucket for this image, like desolation-vs2008-20090219. And finally it needs your AWS S3 access key and secret key, which should be set in ~/.aws:

    ec2-bundle-instance -b ec2.sourcefrog.net \
        -p desolation-vs2008-2009021 \
        -o "$AWS_ACCESS_KEY_ID" \
        -w "$AWS_SECRET_ACCESS_KEY"
  1. This will take several minutes: You can check progress with

    ec2-describe-bundle-tasks
    
  1. Register the files as an image, e.g.:

      ec2-register ec2.sourcefrog.net/desolation-vs2008-2009021
    
    This will give you an AMI id for the image.
  1. Give access to other team members identified by their Amazon account id:

    ec2-modify-image-attributes $ami_id -l -a 123412341234

Management console (useful!)

https://console.aws.amazon.com/ec2/home