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startup

GCP Compute Startup Script

How to add startup and shutdown scripts on GCP Compute Engine.

Startup Script

gcloud compute instances add-metadata servername \
--project project-id \
--zone us-central1-c \
--metadata=startup-script='#! /bin/bash
sudo -i
echo "Time: $(date)" >> /tmp/date.txt'

Shutdown Script

gcloud compute instances add-metadata servername \
--project project-id \
--zone us-central1-c \
--metadata=shutdown-script='#! /bin/bash
# Shuts down Apache server
/etc/init.d/apache2 stop'

Bash Script on Startup

How to add bash scripts on startup.

update-rc.d

sudo cp /path/to/yourscript.sh /etc/init.d/yourscript.sh
sudo update-rc.d /etc/init.d/yourscript.sh defaults
chmod +x /etc/init.d/yourscript.sh

Root Crontab

sudo crontab -e
@reboot /path/to/yourscript.sh

CloudFormation Userdata

Here’s another way to add startup scripts to your instance during creation.

      UserData:
        Fn::Base64: !Sub |
          #cloud-config
          repo_upgrade: none
 
          runcmd:
            # Cloud init startup script
            - "bash /root/setup.sh"
 
          write_files:
            # Cloud init startup script
            - owner: root:root
              permissions: '0644'
              path: /root/setup.sh
              content: |
                #! /bin/bash -x
          write_files:
            # Cloud init startup script
            - owner: root:root
              permissions: '0644'
              path: /root/setup.sh
              content: |
                #! /bin/bash -x
                # run your bash commands here
                date > log.txt
                uptime >>  log.txt

The above script creates a file setup.sh and executes it during instance creation. The output is dumped to log.txt file.