Connecting to a VPC network

This page shows how to use Serverless VPC Access to connect your App Engine standard environment app directly to your VPC network, allowing access to Compute Engine VM instances, Memorystore instances, and any other resources with an internal IP address.

Before you begin

Create a Serverless VPC Access connector

To send requests to your VPC network and receive the corresponding responses without using the public internet, you can use a Serverless VPC Access connector.

If your connector is located in the same project as its VPC network, you can either create a connector using an existing subnet or create a connector and a new subnet.

If your connector is located in a service project and uses a Shared VPC network, the connector and its associated VPC network are in different projects. When a connector and its VPC network are in different projects, a Shared VPC network administrator must create the connector's subnet in the Shared VPC network before you can create the connector, and you must create the connector using an existing subnet.

To learn more about subnet requirements, see connector subnet requirements.

To learn about connector throughput, including machine type and scaling, see Throughput and scaling.

You can create a connector by using the Google Cloud console, Google Cloud CLI, or Terraform.

Console

  1. Go to the Serverless VPC Access overview page.

    Go to Serverless VPC Access

  2. Click Create connector.

  3. In the Name field, enter a name for your connector, matching Compute Engine naming conventions, with the additional requirements that the name must be less than 21 characters long, and that hyphens (-) count as two characters.

  4. In the Region field, select a region for your connector. This must match the region of your serverless service.

    If your service or job is in the region us-central or europe-west, use us-central1 or europe-west1.

  5. In the Network field, select the VPC network to attach your connector to.

  6. In the Subnet field, select one of the following options:

    • Create a connector using an existing subnet: Select the existing subnet in the Subnet field.

    • Create a connector and a new subnet: Select Custom IP range in the Subnet field. Then, enter the first address in an unused /28 CIDR (for example 10.8.0.0/28) to use as the primary IPv4 address range of a new subnet that Google Cloud creates in the connector's VPC network. Ensure that the IP range does not conflict with any existing routes in the connector's VPC network. The name of the new subnet begins with the "aet-" prefix.

  7. (Optional) To set scaling options for additional control over the connector, click Show Scaling Settings to display the scaling form.

    1. Set the minimum and maximum number of instances for your connector, or use the defaults, which are 2 (min) and 10 (max). The connector scales up to the maximum specified if traffic usage requires it, but the connector does not scale back down when traffic decreases. You must use values between 2 and 10.
    2. In the Instance Type menu, choose the machine type to be used for the connector, or use the default e2-micro. Notice the cost sidebar on the right when you choose the instance type, which displays bandwidth and cost estimations.

  8. Click Create.

  9. A green check mark will appear next to the connector's name when it is ready to use.

gcloud

  1. In the Google Cloud console, activate Cloud Shell.

    Activate Cloud Shell

    At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

  2. Update gcloud components to the latest version:

    gcloud components update

  3. Ensure that the Serverless VPC Access API is enabled for your project:

    gcloud services enable vpcaccess.googleapis.com

  4. Create the connector using one of the following options:

    For more details and optional arguments, see the gcloud reference.

    • Create a connector using an existing subnet:

      gcloud compute networks vpc-access connectors create CONNECTOR_NAME \
 --region REGION \
 --subnet SUBNET_NAME \
 --subnet-project HOST_PROJECT_ID \
 --min-instances MIN \
 --max-instances MAX \
 --machine-type MACHINE_TYPE

      Replace the following:

      • CONNECTOR_NAME: a name for your connector, matching Compute Engine naming conventions, with the additional requirements that the name must be less than 21 characters long, and that hyphens (-) count as two characters.
      • REGION: a region for your connector, matching the region of your serverless service or job. If your service or job is in us-central or europe-west, use us-central1 or europe-west1.
      • SUBNET_NAME: the name of the existing subnet.
      • HOST_PROJECT_ID: the Shared VPC host project ID. If the connector and existing subnet are located the same project, omit the --subnet-project flag.
      • MIN: the minimum number of instances to use for the connector. Use an integer between 2(the default) and 9.
      • MAX: the maximum number of instances to use for the connector. Use an integer between 3 and 10 (the default). If the connector scales up to the maximum number of instances, it does not scale back down.
      • MACHINE_TYPE: must be one of the following: f1-micro, e2-micro, or e2-standard-4.

    • Create a connector and a new subnet:

      gcloud compute networks vpc-access connectors create CONNECTOR_NAME \
 --region REGION \
 --network VPC_NETWORK \
 --range IP_RANGE
 --min-instances MIN \
 --max-instances MAX \
 --machine-type MACHINE_TYPE

      Replace the following:

      • CONNECTOR_NAME: a name for your connector, matching Compute Engine naming conventions, with the additional requirements that the name must be less than 21 characters long, and that hyphens (-) count as two characters.
      • REGION: a region for your connector, matching the region of your serverless service or job. If your service or job is in us-central or europe-west, use us-central1 or europe-west1.
      • VPC_NETWORK: the name of the VPC network to attach your connector to. The connector and VPC network must be located in the same project.
      • IP_RANGE: provide an unused /28 CIDR (for example 10.8.0.0/28) to use as the primary IPv4 address range of a new subnet that Google Cloud creates in the connector's VPC network. Ensure that the IP range does not conflict with any existing routes in the connector's VPC network. The name of the new subnet begins with the "aet-" prefix.
      • MIN: the minimum number of instances to use for the connector. Use an integer between 2(the default) and 9.
      • MAX: the maximum number of instances to use for the connector. Use an integer between 3 and 10 (the default). If the connector scales up to the maximum number of instances, it does not scale back down.
      • MACHINE_TYPE: must be one of the following: f1-micro, e2-micro, or e2-standard-4.

  5. Verify that your connector is in the READY state before using it:

    gcloud compute networks vpc-access connectors describe CONNECTOR_NAME \
--region REGION

    Replace the following:

    • CONNECTOR_NAME: the name of your connector; this is the name that you specified in the previous step.
    • REGION: the region of your connector; this is the region that you specified in the previous step.

    The output should contain the line state: READY.

Terraform

You can use a Terraform resource to enable the vpcaccess.googleapis.com API.

resource "google_project_service" "vpcaccess-api" {
  project = var.project_id # Replace this with your project ID in quotes
  service = "vpcaccess.googleapis.com"
}

You can use Terraform modules to create a VPC network and subnet and then create the connector.

module "test-vpc-module" {
  source       = "terraform-google-modules/network/google"
  version      = "~> 10.0"
  project_id   = var.project_id # Replace this with your project ID in quotes
  network_name = "my-serverless-network"
  mtu          = 1460

  subnets = [
    {
      subnet_name   = "serverless-subnet"
      subnet_ip     = "10.10.10.0/28"
      subnet_region = "us-central1"
    }
  ]
}

module "serverless-connector" {
  source     = "terraform-google-modules/network/google//modules/vpc-serverless-connector-beta"
  version    = "~> 10.0"
  project_id = var.project_id
  vpc_connectors = [{
    name        = "central-serverless"
    region      = "us-central1"
    subnet_name = module.test-vpc-module.subnets["us-central1/serverless-subnet"].name
    # host_project_id = var.host_project_id # Specify a host_project_id for shared VPC
    machine_type  = "e2-standard-4"
    min_instances = 2
    max_instances = 7
    }
    # Uncomment to specify an ip_cidr_range
    #   , {
    #     name          = "central-serverless2"
    #     region        = "us-central1"
    #     network       = module.test-vpc-module.network_name
    #     ip_cidr_range = "10.10.11.0/28"
    #     subnet_name   = null
    #     machine_type  = "e2-standard-4"
    #     min_instances = 2
    #   max_instances = 7 }
  ]
  depends_on = [
    google_project_service.vpcaccess-api
  ]
}

Configure your service to use a connector

After you have created a Serverless VPC Access connector, you must configure each service in your App Engine app that you want to connect to your VPC network.

To specify a connector for a service in your app:

  1. Discontinue use of the App Engine URL Fetch service URLFetchService.

  2. Add the <vpc-access-connector> element to your service's appengine-web.xml file:

    <vpc-access-connector>
  <name>projects/PROJECT_ID/locations/REGION/connectors/CONNECTOR_NAME</name>
</vpc-access-connector>

    Where PROJECT_ID is your Google Cloud project ID, REGION is the region your connector is in, and CONNECTOR_NAME is the name of your connector.

  3. Deploy the service:

    gcloud app deploy WEB-INF/appengine-web.xml

After you deploy your service, it is able to send requests to internal IP addresses in order to access resources in your VPC network.

Restrict access to VPC resources

Required firewall rules for connectors in service projects

If you create a connector in a standalone VPC network or in the host project of a Shared VPC network, Google Cloud creates all necessary firewall rules for the connector's operation. For more information, see Firewall rules for connectors in standalone VPC networks or Shared VPC host projects.

However, if you create a connector in a service project and the connector targets a Shared VPC network in the host project, you must add firewall rules to allow necessary traffic for the connector's operation from the following ranges:

These ranges are used by the Google infrastructure underlying Cloud Run, Cloud Run functions, and App Engine standard environment. All requests from these IP addresses originate from Google infrastructure to make sure that each serverless resource only communicates with the connector that it's connected to.

You must also allow traffic from the connector's subnet to resources in your VPC network.

To perform these steps, you must have one of the following roles on the host project:

For a basic configuration, apply the rules to allow serverless resources in any service project connected to the Shared VPC network to send requests to any resource in the network.

To apply these rules, run the following commands in the host project:

  1. Create firewall rules that allow requests from Google's serverless infrastructure and health check probes to reach all connectors in the network. In these commands, UDP and TCP ports are used as proxies and for HTTP health checks, respectively. Don't change the specified ports.

    gcloud compute firewall-rules create serverless-to-vpc-connector \
    --allow tcp:667,udp:665-666,icmp \
    --source-ranges=35.199.224.0/19 \
    --direction=INGRESS \
    --target-tags vpc-connector \
    --network=VPC_NETWORK
     
    gcloud compute firewall-rules create vpc-connector-to-serverless \
    --allow tcp:667,udp:665-666,icmp \
    --destination-ranges=35.199.224.0/19 \
    --direction=EGRESS \
    --target-tags vpc-connector \
    --network=VPC_NETWORK
     
    gcloud compute firewall-rules create vpc-connector-health-checks \
    --allow tcp:667 \
    --source-ranges=35.191.0.0/16,35.191.192.0/18,130.211.0.0/22 \
    --direction=INGRESS \
    --target-tags vpc-connector \
    --network=VPC_NETWORK

    Replace VPC_NETWORK with the name of the VPC network to attach your connector to.

  2. Create an ingress firewall rule on your VPC network to allow requests from connectors that target this network:

    gcloud compute firewall-rules create vpc-connector-requests \
    --allow tcp,udp,icmp \
    --direction=INGRESS \
    --source-tags vpc-connector \
    --network=VPC_NETWORK

    This rule gives the connector access to every resource in the network. To limit the resources that your serverless environment can reach by using Serverless VPC Access, see Restrict connector VM access to VPC network resources.

Create firewall rules for specific connectors

Following the procedure in Required firewall rules for connectors in service projects results in firewall rules that apply to all connectors, both current ones and ones created in the future. If you don't want this, but instead want to create rules for specific connectors only, you can scope the rules so that they apply only to those connectors.

To limit the scope of the rules to specific connectors, you can use one of the following mechanisms:

  • Network tags: Every connector has two network tags: vpc-connector and vpc-connector-REGION-CONNECTOR_NAME. Use the latter format to limit the scope of your firewall rules to a specific connector.
  • IP ranges: Use this for the egress rules only, because it doesn't work for ingress rules. You can use the IP range of the connector subnet to limit the scope of your firewall rules to a single VPC connector.

Restrict connector VM access to VPC network resources

You can restrict your connector's access to resources in its target VPC network by using VPC firewall rules or rules in firewall policies. You can accomplish these restrictions using one of the following strategies:

  • Create ingress rules whose targets represent the resources that you want to limit connector VM access to and whose sources represent the connector VMs.
  • Create egress rules whose targets represent the connector VMs and whose destinations represent the resources that you want to limit connector VM access to.

The following examples illustrate each strategy.

Restrict access using ingress rules

Choose either network tags or CIDR ranges to control the incoming traffic to your VPC network.

Network tags

The following steps show how to create ingress rules that restrict a connector's access to your VPC network based on the connector network tags.

  1. Ensure that you have the required permissions to insert firewall rules. You must have one of the following Identity and Access Management (IAM) roles:

  2. Deny connector traffic across your VPC network.

    Create an ingress firewall rule with priority lower than 1000 on your VPC network to deny ingress from the connector network tag. This overrides the implicit firewall rule that Serverless VPC Access creates on your VPC network by default.

    gcloud compute firewall-rules create RULE_NAME \
--action=DENY \
--rules=PROTOCOL \
--source-tags=VPC_CONNECTOR_NETWORK_TAG \
--direction=INGRESS \
--network=VPC_NETWORK \
--priority=PRIORITY

    Replace the following:

    • RULE_NAME: the name of your new firewall rule. For example, deny-vpc-connector.

    • PROTOCOL: one or more protocols that you want to allow from your VPC connector. Supported protocols are tcp or udp. For example, tcp:80,udp allows TCP traffic through port 80 and UDP traffic. For more information, see the documentation for the allow flag.

      For security and validation purposes, you can also configure deny rules to block traffic for the following unsupported protocols: ah, all, esp, icmp, ipip, and sctp.

    • VPC_CONNECTOR_NETWORK_TAG: the universal connector network tag if you want to restrict access for all connectors (including any connectors made in the future), or the unique network tag if you want to restrict access for a specific connector.

      • Universal network tag: vpc-connector

      • Unique network tag: vpc-connector-REGION-CONNECTOR_NAME

        Replace:

        • REGION: the region of the connector that you want to restrict
        • CONNECTOR_NAME: the name of the connector that you want to restrict

      To learn more about connector network tags, see Network tags.

    • VPC_NETWORK: the name of your VPC network

    • PRIORITY: an integer between 0-65535. For example, 0 sets the highest priority.

  3. Allow connector traffic to the resource that should receive connector traffic.

    Use the allow and target-tags flags to create an ingress firewall rule targeting the resource in your VPC network that you want the VPC connector to access. Set the priority for this rule to be a lower value than the priority of the rule you made in the previous step.

    gcloud compute firewall-rules create RULE_NAME \
--allow=PROTOCOL \
--source-tags=VPC_CONNECTOR_NETWORK_TAG \
--direction=INGRESS \
--network=VPC_NETWORK \
--target-tags=RESOURCE_TAG \
--priority=PRIORITY

    Replace the following:

    • RULE_NAME: the name of your new firewall rule. For example, allow-vpc-connector-for-select-resources.

    • PROTOCOL: one or more protocols that you want to allow from your VPC connector. Supported protocols are tcp or udp. For example, tcp:80,udp allows TCP traffic through port 80 and UDP traffic. For more information, see the documentation for the allow flag.

    • VPC_CONNECTOR_NETWORK_TAG: the universal connector network tag if you want to restrict access for all connectors (including any connectors made in the future), or the unique network tag if you want to restrict access for a specific connector. This must match the network tag that you specified in the previous step.

      • Universal network tag: vpc-connector

      • Unique network tag: vpc-connector-REGION-CONNECTOR_NAME

        Replace:

        • REGION: the region of the connector that you want to restrict
        • CONNECTOR_NAME: the name of the connector that you want to restrict

      To learn more about connector network tags, see Network tags.

    • VPC_NETWORK: the name of your VPC network

    • RESOURCE_TAG: the network tag for the VPC resource that you want your VPC connector to access

    • PRIORITY: an integer less than the priority you set in the previous step. For example, if you set the priority for the rule you created in the previous step to 990, try 980.

For more information about the required and optional flags for creating firewall rules, refer to the documentation for gcloud compute firewall-rules create.

CIDR range

The following steps show how to create ingress rules that restrict a connector's access to your VPC network based on the connector's CIDR range.

  1. Ensure that you have the required permissions to insert firewall rules. You must have one of the following Identity and Access Management (IAM) roles:

  2. Deny connector traffic across your VPC network.

    Create an ingress firewall rule with priority lower than 1000 on your VPC network to deny ingress from the connector's CIDR range. This overrides the implicit firewall rule that Serverless VPC Access creates on your VPC network by default.

    gcloud compute firewall-rules create RULE_NAME \
--action=DENY \
--rules=PROTOCOL \
--source-ranges=VPC_CONNECTOR_CIDR_RANGE \
--direction=INGRESS \
--network=VPC_NETWORK \
--priority=PRIORITY

    Replace the following:

    • RULE_NAME: the name of your new firewall rule. For example, deny-vpc-connector.

    • PROTOCOL: one or more protocols that you want to allow from your VPC connector. Supported protocols are tcp or udp. For example, tcp:80,udp allows TCP traffic through port 80 and UDP traffic. For more information, see the documentation for the allow flag.

      For security and validation purposes, you can also configure deny rules to block traffic for the following unsupported protocols: ah, all, esp, icmp, ipip, and sctp.

    • VPC_CONNECTOR_CIDR_RANGE: the CIDR range for the connector whose access you are restricting

    • VPC_NETWORK: the name of your VPC network

    • PRIORITY: an integer between 0-65535. For example, 0 sets the highest priority.

  3. Allow connector traffic to the resource that should receive connector traffic.

    Use the allow and target-tags flags to create an ingress firewall rule targeting the resource in your VPC network that you want the VPC connector to access. Set the priority for this rule to be a lower value than the priority of the rule you made in the previous step.

    gcloud compute firewall-rules create RULE_NAME \
--allow=PROTOCOL \
--source-ranges=VPC_CONNECTOR_CIDR_RANGE \
--direction=INGRESS \
--network=VPC_NETWORK \
--target-tags=RESOURCE_TAG \
--priority=PRIORITY

    Replace the following:

    • RULE_NAME: the name of your new firewall rule. For example, allow-vpc-connector-for-select-resources.

    • PROTOCOL: one or more protocols that you want to allow from your VPC connector. Supported protocols are tcp or udp. For example, tcp:80,udp allows TCP traffic through port 80 and UDP traffic. For more information, see the documentation for the allow flag.

    • VPC_CONNECTOR_CIDR_RANGE: the CIDR range for the connector you whose access you are restricting

    • VPC_NETWORK: the name of your VPC network

    • RESOURCE_TAG: the network tag for the VPC resource that you want your VPC connector to access

    • PRIORITY: an integer less than the priority you set in the previous step. For example, if you set the priority for the rule you created in the previous step to 990, try 980.

For more information about the required and optional flags for creating firewall rules, see the documentation for gcloud compute firewall-rules create.

Restrict access using egress rules

The following steps show how to create egress rules to restrict connector access.

  1. Ensure that you have the required permissions to insert firewall rules. You must have one of the following Identity and Access Management (IAM) roles:

  2. Deny egress traffic from your connector.

    Create an egress firewall rule on your Serverless VPC Access connector to prevent it from sending outgoing traffic, with the exception of established responses, to any destination.

    gcloud compute firewall-rules create RULE_NAME \
--action=DENY \
--rules=PROTOCOL \
--direction=EGRESS \
--target-tags=VPC_CONNECTOR_NETWORK_TAG \
--network=VPC_NETWORK \
--priority=PRIORITY

    Replace the following:

    • RULE_NAME: the name of your new firewall rule. For example, deny-vpc-connector.

    • PROTOCOL: one or more protocols that you want to allow from your VPC connector. Supported protocols are tcp or udp. For example, tcp:80,udp allows TCP traffic through port 80 and UDP traffic. For more information, see the documentation for the allow flag.

      For security and validation purposes, you can also configure deny rules to block traffic for the following unsupported protocols: ah, all, esp, icmp, ipip, and sctp.

    • VPC_CONNECTOR_NETWORK_TAG: the universal VPC connector network tag if you want the rule to apply to all existing VPC connectors and any VPC connectors made in the future. Or, the unique VPC connector network tag if you want to control a specific connector.

    • VPC_NETWORK: the name of your VPC network

    • PRIORITY: an integer between 0-65535. For example, 0 sets the highest priority.

  3. Allow egress traffic when the destination is in the CIDR range that you want your connector to access.

    Use the allow and destination-ranges flags to create a firewall rule allowing egress traffic from your connector for a specific destination range. Set the destination range to the CIDR range of the resource in your VPC network that you want your connector to be able to access. Set the priority for this rule to be a lower value than the priority of the rule you made in the previous step.

    gcloud compute firewall-rules create RULE_NAME \
--allow=PROTOCOL \
--destination-ranges=RESOURCE_CIDR_RANGE \
--direction=EGRESS \
--network=VPC_NETWORK \
--target-tags=VPC_CONNECTOR_NETWORK_TAG \
--priority=PRIORITY

    Replace the following:

    • RULE_NAME: the name of your new firewall rule. For example, allow-vpc-connector-for-select-resources.

    • PROTOCOL: one or more protocols that you want to allow from your VPC connector. Supported protocols are tcp or udp. For example, tcp:80,udp allows TCP traffic through port 80 and UDP traffic. For more information, see the documentation for the allow flag.

    • RESOURCE_CIDR_RANGE: the CIDR range for the connector whose access you are restricting

    • VPC_NETWORK: the name of your VPC network

    • VPC_CONNECTOR_NETWORK_TAG: the universal VPC connector network tag if you want the rule to apply to all existing VPC connectors and any VPC connectors made in the future. Or, the unique VPC connector network tag if you want to control a specific connector. If you used the unique network tag in the previous step, use the unique network tag.

    • PRIORITY: an integer less than the priority you set in the previous step. For example, if you set the priority for the rule you created in the previous step to 990, try 980.

For more information about the required and optional flags for creating firewall rules, refer to the documentation for gcloud compute firewall-rules create.

Manage your connector

Controlling egress traffic from a service

By default, only requests to internal IP addresses and internal DNS names are routed through a Serverless VPC Access connector. You can specify the egress setting for your service in your appengine-web.xml file.

Egress settings are not compatible with the URL Fetch service. If you have not already done so, discontinue any use of URLFetchService. Using the urlfetch library ignores egress settings, and requests will not route through a Serverless VPC Access connector.

To configure the egress behavior of your App Engine service:

  1. Add the <egress-setting> element to the <vpc-access-connector> element in your service's appengine-web.xml file:

    <vpc-access-connector>
 <name>projects/PROJECT_ID/locations/REGION/connectors/CONNECTOR_NAME</name>
 <egress-setting>EGRESS_SETTING</egress-setting>
</vpc-access-connector>

    Replace:

    • PROJECT_ID with your Google Cloud project ID
    • REGION with the region your connector is in
    • CONNECTOR_NAME with the name of your connector
    • EGRESS_SETTING with one of the following:
      • private-ranges-only Default. Only requests to RFC 1918 and RFC 6598 IP address ranges or internal DNS names are routed to your VPC network. All other requests are routed directly to the internet.
      • all-traffic All outbound requests from your service are routed to your VPC network. Requests are then subject to the firewall, DNS, and routing rules of your VPC network. Note that routing all outbound requests to your VPC network increases the amount of egress handled by the Serverless VPC Access connector and can incur charges.

  2. Deploy the service:

    gcloud app deploy WEB-INF/appengine-web.xml

Disconnect a service from a VPC network

To disconnect a service from a VPC network, remove the <vpc-access-connector> element from the appengine-web.xml file and re-deploy the service.

Connectors continue to incur charges even if they have no traffic and are disconnected. For details, see pricing. If you no longer need your connector, be sure to delete it to avoid continued billing.

Update a connector

You can update and monitor the following attributes of your connector by using the Google Cloud console, Google Cloud CLI, or the API:

  • Machine (instance) type
  • Minimum and maximum number of instances
  • Recent throughput, number of instances, and CPU utilization

Update machine type

Console

  1. Go to the Serverless VPC Access overview page.

    Go to Serverless VPC Access

  2. Select the connector you want to edit and click Edit.

  3. In the Instance type list, select your preferred machine (instance) type. To learn about available machine types, see the documentation on Throughput and scaling.

gcloud

  1. In the Google Cloud console, activate Cloud Shell.

    Activate Cloud Shell

    At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

  2. To update the connector machine type, run the following command in your terminal: 

    gcloud beta compute networks vpc-access connectors update CONNECTOR_NAME --region=REGION --machine-type=MACHINE_TYPE
     Replace the following:

    • CONNECTOR_NAME: the name of your connector
    • REGION: the name of your connector's region
    • MACHINE_TYPE: your preferred machine type. To learn about available machine types, see the documentation on Throughput and scaling.

Decrease minimum and maximum number of instances

To decrease the number of minimum and maximum number of instances, you must do the following:

  1. Create a new connector with your preferred values.
  2. Update your service or function to use the new connector.
  3. Delete the old connector when you've moved its traffic.

See Create Serverless VPC Access connector for more information.

Increase minimum and maximum number of instances

Console

  1. Go to the Serverless VPC Access overview page.

    Go to Serverless VPC Access

  2. Select the connector you want to edit and click Edit.

  3. In the Minimum instances field, select your preferred minimum number of instances.

    The smallest possible value for this field is the current value. The largest possible value for this field is the current value in the Maximum instances field minus 1. For example, if the value in the Maximum instances field is 8, then the largest possible value for the Minimum instances field is 7.

  4. In the Maximum instances field, select your preferred maximum number of instances.

    The smallest possible value for this field is the current value. The largest possible value for this field is 10.

gcloud

  1. In the Google Cloud console, activate Cloud Shell.

    Activate Cloud Shell

    At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

  2. To increase the minimum or maximum number of instances for the connector, run the following command in your terminal: 

    gcloud beta compute networks vpc-access connectors update CONNECTOR_NAME --region=REGION --min-instances=MIN_INSTANCES --max-instances=MAX_INSTANCES
     Replace the following:

  • CONNECTOR_NAME: the name of your connector
  • REGION: the name of your connector's region
  • MIN_INSTANCES: your preferred minimum number of instances.
    • Smallest possible value for this field is the current value of min_instances. To find the current value, see Find the current attribute values.
    • Largest possible value for this field is the current max_instances value minus 1, because min_instances must be less than max_instances. For example, if max_instances is 8, the largest possible value for this field is 7. If your connector uses the default max-instances value of 10, the largest possible value of this field is 9. To find the value of max-instances, see Find the current attribute values.

  • MAX_INSTANCES:

    • Smallest possible value for this field is the current value of max_instances. To find the current value, see Find the current attribute values.
    • Largest possible value for this field is 10.

    If you only want to increase the minimum number of instances but not the maximum, you must still specify the maximum number of instances. Conversely, if you only want to update the maximum number of instances but not the minimum, you must still specify the minimum number of instances. To keep either the minimum or maximum number of instances at their current value, specify their current value. To find their current value, see Find the current attribute values.

Find the current attribute values

To find the current attribute values for your connector, run the following in your terminal: 

gcloud compute networks vpc-access connectors describe CONNECTOR_NAME --region=REGION --project=PROJECT
 Replace the following:

  • CONNECTOR_NAME: the name of your connector
  • REGION: the name of your connector's region
  • PROJECT: the name of your Google Cloud project

Monitor connector usage

Monitoring usage over time can help you determine when to adjust a connector's settings. For example, if CPU utilization spikes, you might try increasing the maximum number of instances for better results. Or if you are maxing out throughput, you might decide to switch to a larger machine type.

To display charts for the connector's throughput, number of instances, and CPU utilization metrics over time by using the Google Cloud console:

  1. Go to the Serverless VPC Access overview page.

    Go to Serverless VPC Access

  2. Click on the name of the connector you want to monitor.

  3. Select the number of days you want to display between 1 and 90 days.

  4. In the Throughput chart, hover over the chart to view the connector's recent throughput.

  5. In the Number of instances chart, hover over the chart to view the number of instances recently used by the connector.

  6. In the CPU Utilization chart, hover over the chart to view the connector's recent CPU usage. The chart displays the CPU usage distributed across instances for the 50th, 95th, and 99th percentiles.

Delete a connector

Before you delete a connector, ensure that no services or jobs are still connected to it.

For Shared VPC users who set up connectors in the Shared VPC host project, you can use the command gcloud compute networks vpc-access connectors describe to list the projects in which there are services or jobs that use a given connector.

To delete a connector, use the Google Cloud console or the Google Cloud CLI:

Console

  1. Go to the Serverless VPC Access overview page in the Google Cloud console:

    Go to Serverless VPC Access

  2. Select the connector you want to delete.

  3. Click Delete.

gcloud

  1. In the Google Cloud console, activate Cloud Shell.

    Activate Cloud Shell

    At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

  2. Use the following gcloud command to delete a connector:

    gcloud compute networks vpc-access connectors delete CONNECTOR_NAME --region=REGION

    Replace the following:

    • CONNECTOR_NAME with the name of the connector you want to delete
    • REGION with the region where the connector is located

Troubleshooting

Service account permissions

To perform operations in your Google Cloud project, Serverless VPC Access uses the Serverless VPC Access Service Agent service account. This service account's email address has the following form:

service-PROJECT_NUMBER@gcp-sa-vpcaccess.iam.gserviceaccount.com

By default, this service account has the Serverless VPC Access Service Agent role (roles/vpcaccess.serviceAgent). Serverless VPC Access operations may fail if you change this account's permissions.

Poor network performance or high idle CPU utilization

Using a single connector for thousands of instances can cause performance degradation and elevated idle CPU utilization. To fix this, shard your services between multiple connectors.

Errors

Service account needs Service Agent role error

If you use the Restrict Resource Service Usage organization policy constraint to block Cloud Deployment Manager (deploymentmanager.googleapis.com), you might see the following error message:

Serverless VPC Access service account (service-<PROJECT_NUMBER>@gcp-sa-vpcaccess.iam.gserviceaccount.com) needs Serverless VPC Access Service Agent role in the project.

Set the organization policy to either remove Deployment Manager from the denylist or add it to the allowlist.

Connector creation error

If creating a connector results in an error, try the following:

  • Specify an RFC 1918 internal IP range that does not overlap with any existing IP address reservations in the VPC network.
  • Grant your project permission to use Compute Engine VM images from the project with ID serverless-vpc-access-images. For more information about how to update your organization policy accordingly, see Set image access constraints.

Unable to access resources

If you specified a connector but still cannot access resources in your VPC network, make sure that there are no firewall rules on your VPC network with a priority lower than 1000 that deny ingress from your connector's IP address range.

If you configure a connector in a Shared VPC service project, make sure that your firewall rules allow ingress from your serverless infrastructure to the connector.

Connection refused error

If you receive connection refused or connection timeout errors that degrade network performance, your connections could be growing without limit across invocations of your serverless application. To limit the maximum number of connections used per instance, use a client library that supports connection pools. For detailed examples of how to use connection pools, see Manage database connections.

Resource not found error

When deleting a VPC network or a firewall rule, you might see a message that is similar to the following: The resource "aet-uscentral1-subnet--1-egrfw" was not found.

For information about this error and its solution, see Resource not found error in the VPC firewall rules documentation.

Next steps