Configure Shared VPC networking

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This page describes the Shared VPC network and host project requirements for Cloud Composer.

Shared VPC enables organizations to establish budgeting and access control boundaries at the project level while allowing for secure and efficient communication using private IPs across those boundaries. In the Shared VPC configuration, Cloud Composer can invoke services hosted in other Google Cloud projects in the same organization without exposing services to the public internet.

Guidelines for Shared VPC

Figure 1. Service and host projects for Cloud Composer

• Shared VPC requires that you designate a host project to which networks and subnetworks belong and a service project, which is attached to the host project. When Cloud Composer participates in a Shared VPC, the Cloud Composer environment is in the service project.

• To set up Shared VPC, select the following IP ranges in the host project:

  • Primary IP Range of the subnet used by GKE nodes that Cloud Composer uses as its Compute Engine layer.
  • Secondary IP Range for GKE services.
  • Secondary IP Range for GKE pods.

• Secondary IP Ranges cannot overlap with any other secondary ranges in this VPC.

• Ensure that secondary ranges are large enough to accommodate the cluster's size and your environment scaling.

  See Creating a VPC-native cluster for guidelines on configuring secondary ranges for pods and services.

  Caution: You can create user-managed secondary ranges with mask values that are up to /28. This gives you a range with only 16 IP addresses, which is not enough for pods of your environment's cluster. For a Cloud Composer environment, the minimum recommended range for Pods is /23. This range can support only a single small environment with a single scheduler and three workers. The minimum range does not allow you to scale the environment up later or use the same range for more than one environment. Consider using a broader range (less than /23). You must also use at least a /27 range for services. The 172.17.0.0/16 range is reserved in Cloud SQL.

• The primary address range of the subnet should accommodate anticipated growth and account for the unusable IP addresses.

• If you use the IP Masquerate Agent and the Private IP configuration for your environments, then add the IP ranges of Nodes and Pods to the nonMasqueradeCIDRs section of the ip-masq-agent ConfigMap. For more information, see Configuring an IP masquerade agent.

Preparation

1. Find the following project IDs and project numbers:

   • Host project: The project that contains the Shared VPC network.
   • Service project: The project that contains the Cloud Composer environment.

2. Prepare your organization.

3. Enable the GKE API in your host and service projects.

4. If you create an environment in the service project using Google Cloud console, then your account must have the compute.subnetworks.use permission in the host project. Otherwise, the list of available subnetworks does not contain subnetworks from the host project. If you create an environment using gcloud, API, or Terraform, then your account does not need this additional permission.

Configure the service project

If Cloud Composer environments were never created in the service project, then provision the Composer Service Agent Account in the service project:

gcloud beta services identity create --service=composer.googleapis.com`

Configure the host project

Configure the host project as described further.

Caution: Do all of the described actions in the host project. For example, if you add roles to a service account from the service project, assign them in the host project's IAM configuration.

(Private IP) Enable Private Google Access

If you plan to use Private IP environments, then enable Private Google Access for the subnet in the host project. You can do so on the next step, when you configure networking resources for a new or an already existing subnet.

If you plan to use Public IP environments, we still recommend enabling Private Google Access for the subnet in the host project. If you choose not to use Private Google Access, then make sure you are not blocking traffic that otherwise the Implied IPv4 allow egress Firewall rule would allow. This is required to reach *.googleapis.com endpoints successfully.

Configure networking resources

Choose one of the following options to allocate and configure networking resources. For each option, you must name the secondary IP ranges for pods and services.

• Option 1. Create a new VPC network, subnet, and two secondary IP ranges.

  • When creating the subnet, use the Primary IP Range following the guidelines.

  • When defining the subnet, define two secondary IP ranges for pods and services.

• Option 2. Create a subnet and two secondary IP ranges in an existing VPC.

  • When creating the subnet, use the Primary IP Range following the guidelines.

  • When defining the subnet, define two secondary IP ranges for pods and services.

• Option 3. Create two secondary IP ranges in an existing subnet and VPC network.

  • Define two secondary IP ranges for Pods and Services following the guidelines. Avoid name and IP range conflicts with existing secondary ranges.

Set up Shared VPC and attach the service project

1. If not already done, Set up Shared VPC. If you already have set up Shared VPC, skip to the next step.

2. Attach the service project, which you use to host Cloud Composer environments.

   When attaching a project, leave the default VPC Network permissions in place.

Grant permissions to the Composer Service Agent account

Warning: On this and next steps, when editing permissions, keep the existing account roles. Add another role to an account instead of replacing an existing role.

In the host project:

1. Edit permissions for the Composer Service Agent account, [e-mail])

2. For this account, add another role on the project level:

   • For Private IP environments, add the Composer Shared VPC Agent role.

   • For Public IP environments, add the Compute Network User role.

Grant permissions to the Google API Service Agent account

In the host project:

1. Edit permissions for the Google API Service Agent account, [e-mail].

2. Add another role, Compute Network User (compute.networkUser) at the project level. This is a requirement for managed instance groups used with Shared VPC because this type of service account performs tasks such as instance creation.

Edit permissions for GKE service accounts

In the host project, edit permissions for the GKE service accounts, [e-mail].

For each service account, add another role, compute.networkUser using one of the following options:

• Grant this role at the subnet level to allow a service account to set up the VPC peerings required by Cloud Composer. In this case, explicitly specify the subnetwork to be used by the environment, because the environment's cluster might lack permissions to find the subnetwork within the network.

• Grant this role at the project level for the whole host project. In this case, the service project's GKE service account has permissions to use any subnet in the host project.

Edit permissions for the GKE Service Account of the service project

In the host project, edit permissions for the GKE Service Account of the service project.

For this account, add another role on the project level, Kubernetes Engine Host Service Agent User (roles/container.hostServiceAgentUser).

This allows the GKE Service Account of the service project to use the GKE Service Account of the host project to configure shared network resources.

(Private IP, optional) Configure firewall rules and connectivity to Google domains

In a Shared VPC configuration with Private IP environments, as an option, you might want to route all traffic to Google APIs and services through several IP addresses that belong to the private.googleapis.com domain and configure corresponding firewall rules. In this configuration, your environment accesses Google APIs and services through IP addresses only routable from within Google Cloud. If your Shared VPC configuration uses VPC Service Controls, then route traffic through restricted.googleapis.com instead.

Caution: In a Shared VPC configuration, configure connectivity and firewall rules in the host project, not in the service project where your environments are located.

If your Shared VPC configuration uses Private IP environments:

1. (Optional) Configure connectivity to Google APIs and services.
2. (Optional) Configure firewall rules.

If your Shared VPC configuration uses VPC Service Controls, use instructions for environments with VPC Service Controls instead:

1. Configure connectivity to Google APIs and services.
2. Configure firewall rules

Conclusion

You've completed the Shared VPC network configuration for both service and host projects.

Now you can create new environments in the service project that use the host project's VPC network.

What's next

• Create a Cloud Composer environment and provide the host project's network and subnetwork as configuration parameters.