Creating an Autonomous VM

The goal of this topic is to present one of the solutions to deploy self-configured virtual machines (VMs) on the OUTSCALE Cloud.

This solution is a proper alternative to tools like Ansible or Salt, since you do not need to add inbound rules in the security groups of your VM. However, do not forget to open outbound flows if you are in a Net, and create routes and an Internet gateway.

Step 1: Create an instance image executing user data

  1. Create a script that is executed only when necessary:

    To prevent from any further execution, we will end the execution by creating a file, which existence will be checked before re-executing itself.

    1. To create the script, run the following command:

      $ vim /opt/bootscript.sh

    2. Insert the following content for the script in the text editor:

      #!/usr/bin/bash
if [ ! -f /var/setup_vm ]; then
    curl 169.254.169.254/latest/user-data | bash
fi

  2. Ensure that this script will be executed as a service using the following command:

    1. To create the boot setup script, run the following command:

      $ vim /usr/lib/systemd/system/setup_boot.service

    2. Insert the following content for the script in the text editor:

      [Unit]
Description=Execute user-datas to setup the machine
After=network-online.target
[Service]
Type=oneshot
RemainAfterExit=no
ExecStart=/usr/bin/bash /opt/bootscript.sh
[Install]
WantedBy=multi-user.target

  3. Enable the service using the following command:

    command
    $ systemctl enable setup_boot.service

  4. Stop the VM and create an OMI from it. For more information, see Creating an OMI from a VM.

Step 2: Create an instance for a small python webserver

With Boto2, create a VM using the previously created OMI:

from boto.ec2.regioninfo import EC2RegionInfo
from boto.vpc import VPCConnection

your_ak, your_sk = "XXXXXAAAXXXXXX", "ZZZZZZBBBBBBZZZZZZBBBBBBBZZZZZZZ"
outscale_endpoint = EC2RegionInfo(endpoint="fcu.eu-west-2.outscale.com")    # you can change the region
outscale_fcu = VPCConnection( aws_access_key_id = your_ak, aws_secret_access_key = your_sk, region = outscale_endpoint)

userdatas = '''
    #!/usr/bin/bash
    yum install python supervisor -y
    wget https://oos.eu-west-2.outscale.com/BUCKET/package.tar.gz
    tar -xvf package.tar.gz
    mv package/* /root/
    pip install -r /root/requirements.txt
    mv /root/supervisord.conf /etc/supervisord.conf
    systemctl start supervisord
    touch /var/setup_vm
    '''
resa = outscale_fcu.run_instances(image_id=<you_new_omi>, key_name=keypair, instance_type='t2.medium', userdata=userdatas)
print resa.instances[0].ip_address

You can now connect to your VM and enjoy your brand-new webserver.

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