gcloud can only create instances using private image

Question

I have a private image called 'test-1' and I can use it to create an instance

$ gcloud compute instances create demo --image test-1

However I cannot use a public image:

$ gcloud compute instances create demo --image ubuntu-1804-bionic-v20190204 
ERROR: (gcloud.compute.instances.create) Could not fetch resource:
 - Invalid value for field 'resource.disks[0].initializeParams.sourceImage': 'https://www.googleapis.com/compute/v1/projects/szabgab-149/global/images/ubuntu-1804-bionic-v20190204'. The referenced image resource cannot be found.

Nor a public image family:

$ gcloud compute instances create demo --image-family ubuntu-1804-lts 
ERROR: (gcloud.compute.instances.create) Could not fetch resource:
 - The resource 'projects/szabgab-149/global/images/family/ubuntu-1804-lts' was not found

What am I doing wrong here?

Answer 1

I've noticed that in the generated error message, that you are generating the location of the image as if it is located in your project, which I understand it is named szabgab-149:

The resource 'projects/szabgab-149/global/images/family/ubuntu-1804-lts'

The thing is that public images are located in its own projects, see the output of the command gcloud compute images list.

For example, the ubuntu-1804-bionic-v20190204 is under the project ubuntu-os-cloud and the image family ubuntu-1804-lts.

To solve this, you can simply add the --image-project flag, from the information of the previous gcloud command, you execute this command, to use this specific image:

gcloud compute instances create demo \
--image ubuntu-1804-bionic-v20190204 \
--image-project ubuntu-os-cloud

Or this one, to use the default image under the project ubuntu-os-cloud and family ubuntu-1804-lts:

gcloud compute instances create demo \
--image-family ubuntu-1804-lts \
--image-project ubuntu-os-cloud