Google ACE Deploying and Implementing a Cloud Solution Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  gcloud compute instances create my-instance --image-family=ubuntu-2004-lts --image-project=ubuntu-os-cloud

  Why it's wrong here

  The command uses the Ubuntu 20.04 LTS image family from the ubuntu-os-cloud project, which is a legitimate gcloud invocation but produces a standard Linux VM, not a Container-Optimized OS (COS) instance. COS is Google's hardened, minimal operating system specifically designed to run Docker containers with a read-only root filesystem and automatic security updates. If the developer's goal is a container-optimized environment, this command fails conceptually even though it would succeed technically.

• ✓

  gcloud compute instances create my-instance --image-family=cos-stable --image-project=cos-cloud

  Why this is correct

  This is the correct command because it explicitly selects the 'cos-stable' image family from the 'cos-cloud' project, which yields the latest stable release of Container-Optimized OS. COS is a Google-supported OS with Docker, containerd, and Kubernetes tools preinstalled, optimized for running containerized workloads. Including both --image-family and --image-project ensures that gcloud resolves the family from the proper project, avoiding ambiguity with the default compute project.

• ✗

  gcloud compute instances create my-instance --image-family=cos-stable

  Why it's wrong here

  Omitting the --image-project flag is a common mistake; by default, gcloud looks for the image family in the project configured as the current compute project (or the default project set in gcloud config). The 'cos-stable' family lives in the 'cos-cloud' project, not in the user's project, so the command would fail with an error like 'Could not find image: cos-stable' unless that project happens to have a family with that name. This error occurs at image resolution time, before instance creation begins.

• ✗

  gcloud compute instances create my-instance --image=cos-stable --image-project=cos-cloud

  Why it's wrong here

  Using --image instead of --image-family incorrectly treats 'cos-stable' as a specific image name rather than a family alias. The --image flag requires an exact image name (e.g., 'cos-stable-125-17-21'), which is version-specific and changes frequently, whereas --image-family allows automatic use of the latest image in that family. Since an image literally named 'cos-stable' does not exist in cos-cloud, gcloud would fail to find it and refuse to create the instance.

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