Configure the development environment

This document describes how to configure your API Gateway development environment.

Prerequisites

Before you can create an API on API Gateway, you must do the following:

Create a Google Cloud project in which you have the Editor or Owner role. After the initial deployment, you can grant the more restrictive Service Config Editor role to a user, group, or service account.
Prepare the Google Cloud CLI for deployment.
Enable the required Google services.
Configure the service account used to create API configs.

Prepare the Google Cloud CLI for deployment

To prepare gcloud for the deployment:

Install and initialize the gcloud CLI.
Update gcloud CLI:
```
gcloud components update
```
Make sure that gcloud CLI is authorized to access your data and services:
```
gcloud auth login
```
A new browser tab opens and you are prompted to choose an account.
Set the default project. Replace PROJECT_ID with your Google Cloud project ID:
```
gcloud config set project PROJECT_ID 
```

Enable the required Google services

API Gateway requires that you enable the following Google Cloud services:

Name	Service name
API Gateway API	`apigateway.googleapis.com`
Service Management API	`servicemanagement.googleapis.com`
Service Control API	`servicecontrol.googleapis.com`

To enable required services:

Google Cloud console

In the Google Cloud console, go to the APIs & Services > API Library page.

Go to API Library
On the API Library page, enter the required API name into the search bar.
In the search results, select the API page.
On the API page, click Enable.
Repeat these steps for each of the services listed in the preceding table.

Google Cloud CLI

Use the following commands to enable the services:

gcloud services enable apigateway.googleapis.com
gcloud services enable servicemanagement.googleapis.com
gcloud services enable servicecontrol.googleapis.com

For more information about the gcloud services, see gcloud services.

Configure the service account used to create API configs

An API config deployed on a gateway executes with the permissions associated with the gateway service account.

As a best practice, create a separate service account in the same project you are using for API Gateway. Then, assign the service account only the permissions necessary to access the backend service. In that way, you limit the permissions associated with the API config.

For API Gateway, the user creating or updating an API config or gateway requires the iam.serviceAccounts.actAs permission on the service account object. This permission is included in the Service Account User role.

To add the required role and permission to the gateway service account:

Google Cloud console

In the Google Cloud console, go to the IAM & Admin > Service Accounts page.

Go to Service accounts
Select the required project or create a new one.
Click the required service account.
Click the Permissions tab.
Click Manage access.
Click Add role, and assign the Service Account User role to the principal who will reference the service account while creating the API config.
Click Save.

Google Cloud CLI

The role and permission can be added to the service account for the user with the following command:

gcloud iam service-accounts add-iam-policy-binding SERVICE_ACCOUNT_EMAIL \
--member user:USER_EMAIL \
--role roles/iam.serviceAccountUser

where:

SERVICE_ACCOUNT_EMAIL is the email of the service account, in the format SA_NAME@PROJECT_ID.iam.gserviceaccount.com.
USER_EMAIL is the email address of the user.

For example:

gcloud iam service-accounts add-iam-policy-binding my-service-account@my-project.iam.gserviceaccount.com \
--member user:myemail@email.com \
--role roles/iam.serviceAccountUser

In addition, the gateway service account requires the permissions necessary to access your backend service. For example:

For a Cloud Function backend, the service account must be assigned the role of Cloud Functions Invoker.
For a Cloud Run backend, the service account must be assigned the role of Cloud Run Invoker.
For an App Engine backend, you must follow the steps in Set up IAP access to grant the service account associated with your gateway the IAP-secured Web App User role.

By limiting the permissions associated with the API config, you can better secure your backend systems. For more information, see the Identity and Access Management (IAM) documentation.

After you create the service account, use the --backend-auth-service-account option to specify the email address of that service account when creating an API config:

gcloud api-gateway api-configs create CONFIG_ID \
--api=API_ID --openapi-spec=API_DEFINITION \
--backend-auth-service-account=SERVICE_ACCOUNT_EMAIL

See Create an API config for more on creating API configs.

Use a default service account

Some Google Cloud products define a default service account. For example, if you are using Compute Engine and have enabled the Compute Engine API for your project, a default Compute Engine service account is created for you. The default service account is identifiable by its email address:

PROJECT_NUMBER-compute@developer.gserviceaccount.com

If you assign the necessary permissions to the default service account, you can omit the --backend-auth-service-account option when creating an API config:

gcloud api-gateway api-configs create CONFIG_ID \
  --api=API_ID --openapi-spec=API_DEFINITION

See Compute Engine default service account for more.

Use OpenID Connect

Requests from API Gateway to backend services may use authentication. These requests are secured using OpenID Connect (OIDC) tokens signed by the gateway's service account. You should confirm that your backend service is correctly configured to accept OIDC tokens for authentication and authorization. Cloud Run functions, Cloud Run, and the Identity Aware Proxy (IAP) provide this option.

What's next

Create an API