Before you can build anything you need a project. You can create one in the console (the project picker > New project), or from the CLI with gcloud projects create PROJECT_ID --name="Display name" --folder=FOLDER_ID. Creating projects requires the Project Creator role on the organization or folder, and the project must be linked to a billing account before you can use most paid services.
Every project has three identifiers, and exam questions like to test the difference. The project name is a friendly display label; you can change it at any time and it doesn't need to be unique. The project ID is a globally unique string of lowercase letters, digits and hyphens that you choose (or accept a generated one) when you create the project. It can never be changed, and it's what gcloud, APIs and many resource names use. The project number is assigned by Google, is also permanent, and shows up in places such as the default Compute Engine service account, PROJECT_NUMBER-compute@developer.gserviceaccount.com.
Services in Google Cloud are exposed as APIs, and most of them are disabled in a new project. If you try to use a service whose API is off, you get an error telling you the API has not been used in the project or is disabled. You enable it on the APIs and services page or with gcloud services enable compute.googleapis.com (or run.googleapis.com, container.googleapis.com and so on). gcloud services list --enabled shows what's on. Enabling an API costs nothing by itself; you pay for the resources you then create.
Enabling some APIs also creates Google-managed service accounts, called service agents, which let the service act in your project, for example to attach disks or pull images. Don't delete them or remove their roles, or the service will stop working.
When a project is no longer needed, shut it down with gcloud projects delete PROJECT_ID. It enters a pending deletion period during which an owner can restore it; after that it is deleted for good and its ID can't be reused.
Key terms
- Project ID
- The permanent, globally unique identifier you choose at creation and use in commands and APIs.
- Project number
- A permanent numeric identifier Google assigns, used in some service account names.
- Project name
- A changeable display label that doesn't need to be unique.
- Service agent
- A Google-managed service account that a Google Cloud service uses to act on resources in your project.
A developer creates a project with the ID shop-dev-4821 and the name Shop Dev. When she runs gcloud run deploy, gcloud offers to enable the Cloud Run API. Later the team renames the project to Shop Development in the console; all scripts keep working because they reference the unchanged project ID.
Check yourself
Which project identifier appears in the default Compute Engine service account's email address?
The project number, as in PROJECT_NUMBER-compute@developer.gserviceaccount.com.
How do you list the APIs enabled in the current project?
Run gcloud services list --enabled, or look at APIs and services in the console.