How to set Environment Variables on EC2 instance via User Data

Question

I am trying to set environment variables with EC2s user data, but nothing i do seems to work

here are the User data scripts i tried

#!/b         


        

Answer 1

This maynot be the exact answer to the OP's question but similar. I've thought of sharing this as I've wasted enough time searching for the answer and finally figured it out.

Example assuming - AWS EC2 running ubuntu.

If there is a scenario where you need to define the environment variables as well use it in the same bash session (same user-data process), then either you can add the variables to /etc/profile, /etc/environment or /home/ubuntu/.zshrc file. I have not tried /home/ubuntu/.profile file BTW.

Assuming adding to .zshrc file,

sudo su ubuntu -c "$(cat << EOF 
    echo 'export PATH="/tmp:\$PATH"' >> /home/ubuntu/.zshrc
    echo 'export ABC="XYZ"' >> /home/ubuntu/.zshrc
    echo 'export PY_VERSION=3.8.1' >> /home/ubuntu/.zshrc
    source /home/ubuntu/.zshrc
    echo printenv > /tmp/envvars  # To test
EOF
)"

Once the user data is finished running, you can see the environment variables which you have added in the script are echoed to the envvars file. Reloading the bash with source /home/ubuntu/.zshrc made the newly added variables available in the bash session.

(additional info) How to install zsh and oh-my-zsh?

sudo apt-get install -y zsh
sudo su ubuntu -c "$(cat << EOF 
    ssh-keyscan -H github.com >> /home/ubuntu/.ssh/known_hosts
    git clone https://github.com/robbyrussell/oh-my-zsh.git /home/ubuntu/.oh-my-zsh
    cp /home/ubuntu/.oh-my-zsh/templates/zshrc.zsh-template /home/ubuntu/.zshrc
    echo DISABLE_AUTO_UPDATE="true" >> /home/ubuntu/.zshrc
    cp /home/ubuntu/.oh-my-zsh/themes/robbyrussell.zsh-theme /home/ubuntu/.oh-my-zsh/custom
EOF
)"
sudo chsh -s /bin/zsh ubuntu

Wondering why I didn't added the environment variable in .bashrc? The scenario which I mentioned above (using the environment variables in the same user-data session) adding to .bashrc won't work. .bashrc is only sourced for interactive Bash shells so there should be no need for .bashrc to check if it is running in an interactive shell. So just like above,

source /home/ubuntu/.bashrc

won't reload the bash. You can check this out written right in the beginning of the .bashrc file,

# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac