Running Pace Calculator App

Multipass cloud-init

Multipass is pretty useful but what a pain this was to figure out, due to Ubuntu’s Node.js package not working with AWS-CDK.

Multipass lets you manage VM in Ubuntu and can take cloud-init scripts as a parameter. I wanted an Ubuntu LTS instance with AWS CDK, which needs Node.js and python3-venv.

#cloud-config
packages:
  - python3-venv
  - unzip

package_update: true

package_upgrade: true

write_files:
  - path: "/etc/environment"
    append: true
    content: |
      export PATH=\
      /opt/node-v20.11.1-linux-x64/bin:\
      /usr/local/sbin:/usr/local/bin:\
      /usr/sbin:/usr/bin:/sbin:/bin:\
      /usr/games:/usr/local/games:\
      /snap/bin

runcmd:
  - wget https://nodejs.org/dist/v20.11.1/node-v20.11.1-linux-x64.tar.xz 
  - tar xvf node-v20.11.1-linux-x64.tar.xz -C /opt
  - export PATH=/opt/node-v20.11.1-linux-x64/bin:$PATH
  - npm install -g npm@latest
  - npm install -g aws-cdk
  - git config --system user.name "Dougie Richardson"
  - git config --system user.email "xx@xxxxxxxxx.com"
  - git config --system init.defaultBranch main
  - wget https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip
  - unzip awscli-exe-linux-x86_64.zip
  - ./aws/install

Save that as cdk.yaml and spin up an new instance:

multipass launch --name cdk --cloud-init cdk.yaml
Success!

There’s a couple useful things to note if you’re checking this out:

  • Inside the VM there’s a useful log to assist debugging /var/log/cloud-init-output.log.
  • While YAML has lots of ways to split text over multiple lines, when you don’t want space use a backslash.

Shell into the new VM with multipass shell cdk, then we can configure programmatic access and bootstrap CDK.

aws sso configure
aws sso login --profile profile_name
aws sts get-caller-identity --profile profile_name
aws configure get region --profile profile_name

The last two commands give the account and region to bootstrap:

cdk bootstrap aws://account_number/region --profile profile_name

Setup a Multipass CDK Environment

I want to be able to connect to the environment using Visual Studio Code, so first we need to create a SSH key:

ssh-keygen -t rsa

We need a configuration YAML, replace <generated ssh-rsa key> with the above key, saved as cloud-init.yaml:

groups:
  - vscode
runcmd:
  - adduser ubuntu vscode
ssh_authorized_keys:
  - ssh-rsa <generated ssh-rsa key>

Assuming you’ve got Multipass installed (if not sudo snap install multipass) then:

multipass launch mantic --name ubuntu-cdk --cloud-init

We’ll come back to Visual Studio Code later but first lets set everything up in the VM. We need to install aws-cli which I want to use with SSO (hence why we installed Mantic).

multipass shell ubuntu-cdk
sudo apt install awscli
aws configure sso

Follow the prompts and sign in to AWS as usual. Then install CDK:

sudo apt install nodejs npm
sudo npm install -g aws-cdk

Almost there, lets bootstrap1 (provisioning resources needed to make deployments) substituting the relevant values:

cdk bootstrap aws://<account>/<region> --profile <profile>

You should see a screen like this:

Create a new CDK application by creating a new folder, changing into it and initialising CDK:

cdk init app --language python
source .venv/bin/activate
python -m pip install -r requirements.txt

And that’s about it, except for Visual Studio Code. You’ll need to install Microsoft’s Remote-SSH extension:

You can get the IP address from multipass list, then in Code add a new SSH connection using ubuntu@<ip>:

Accept the various options presented and you’re there!

VSCode
  1. Bootstrapping provisions resources in your environment such as an Amazon Simple Storage Service (Amazon S3) bucket for storing files and AWS Identity and Access Management (IAM) roles that grant permissions needed to perform deployments. These resources get provisioned in an AWS CloudFormation stack, called the bootstrap stack. It is usually named CDKToolkit. Like any AWS CloudFormation stack, it will appear in the AWS CloudFormation console of your environment once it has been deployed. ↩︎