I need a Compute Engine instance to import the exact configuration (IP, services, files, etc...) of the original machine, without impacting the frontend if it concerns a web server for example. While running this machine, I would be able to shut down the original machine to increase its RAM or vCPUs before starting it again and deleting the cloned instance.
The problem is that I want to automate this process, and that's why I need the gcloud command. So is there a way to clone an entire gcp instance using the gcloud command or another tool?
This is not possible with the gcloud. This is possible with the cloud console, but as you can see in this documentation:
Restrictions
You can only use this feature in the Cloud Console; this feature is not supported in the gcloud tool or the API.
What you could do is create similar (not completely equal) instances from a custom image, using that all you have to do is use the following command:
gcloud compute instances create --image=IMAGE
More details on that command can be found here