Use an HTTP proxy

This document shows you how to route traffic from the GKE on Azure through an HTTP/HTTPS proxy. You specify proxy configuration when you create a cluster.

Overview

GKE on Azure can route outbound internet traffic through a proxy for the following reasons:

  • To register clusters with Google Cloud through Connect
  • To run the Connect Agent
  • To download images from Container Registry

Limitations

  • The httpProxy and httpsProxy fields do not support URLs beginning with https://. You must use http://. Requests to port 443 use HTTPS.
  • You must set values for httpProxy, httpsProxy, and noProxy.
  • A cluster's proxy configuration— the resource group ID and secret ID— is immutable. You must create a new cluster and node pool to update these values.
  • You might need to add additional domains, IPs, or CIDRs to the noProxy field. We recommend adding your cluster's control planes subnet CIDRs (Pod address CIDR and Service address CIDR are added by default).

Prerequisites

This section describes the prerequisites you must apply before using a proxy.

Azure Key Vault configuration

GKE on Azure stores proxy configuration information in Azure Key Vault. To configure a proxy with GKE on Azure, you need to have permissions to create a secret in a Key Vault. The Key Vault must be accessible from your cluster's VNet.

Proxy Allowlist

For GKE on Azure to connect to Google Cloud services, the proxy server must allow traffic to specific Google and Microsoft domains.

.azure.com
.gcr.io
cloudresourcemanager.googleapis.com
container.googleapis.com
gkeconnect.googleapis.com
gkehub.googleapis.com
oauth2.googleapis.com
securetoken.googleapis.com
storage.googleapis.com
sts.googleapis.com
www.googleapis.com
servicecontrol.googleapis.com
logging.googleapis.com
monitoring.googleapis.com
opsconfigmonitoring.googleapis.com
GCP_LOCATION-gkemulticloud.googleapis.com

Replace GCP_LOCATION with the Google Cloud region in which your cluster resides. Specify us-west1 or another supported region.

Subnet Network Security Group requirement

If you're using Network Security Groups (NSGs) to manage traffic to your subnets, your NSG rules must allow outgoing TCP traffic to following destinations:

  • AzureCloud: TCP, port 80 and 443

See Azure service tags for more information about using service tags with NSGs.

Create a proxy configuration file

The proxy configuration is stored in an Azure Key Vault secret as a JSON string. You can pass this configuration to the az command-line tool as a file. This section describes how to create that file.

The following table describes the contents of this file.

Field Description Examples Required
httpProxy A proxy server URL. The value should include a hostname/IP address and optionally a port, username, and password. "http://user:password@10.184.37.42:80"
"10.184.37.42"		 Yes
httpsProxy A proxy URL for encrypted, HTTPS traffic. The httpProxy URL will be used if httpsProxy has an empty value. "http://10.101.16.31:80" Yes
noProxy A comma-separated list of URLs to exclude from proxying. Each value can be an IP address, a CIDR range, a domain name, or the asterix character (*). Domains specified with a leading dot (for example, `.google.com`) indicate that a subdomain is required. A single asterix * ignores all proxy configuration. "1.2.3.4,10.0.0.0/16,example.com,.site.com" Yes

  1. To create the configuration file, create a JSON file that contains values for httpProxy, noProxy, and optional httpsProxy keys.

    {
  "httpProxy": "AUTHENTICATION_URL",
  "httpsProxy": "AUTHENTICATION_URL",
  "noProxy": "NO_PROXY_ADDRESSES"
}

    Replace the following:

    • AUTHENTICATION_URL: Encoded URL containing the proxy username and the password
    • NO_PROXY_ADDRESSES: Comma-separated list of CIDR blocks and URLs— for example 10.0.0.0/16,http://example.com

    Save the file to use in the following section.

  2. Create a secret with this JSON data as a secret in Azure Key Vault using the az command-line tool.

    az keyvault secret set --name SECRET_NAME \
--vault-name KEY_VAULT_NAME \
--file PROXY_CONFIGURATION_FILE

    Replace the following:

    • SECRET_NAME: the name of the new secret
    • KEY_VAULT_NAME: the name of your Key Vault

    • PROXY_CONFIGURATION_FILE: the path to your proxy configuration file.

      The output includes the secret's name and contents. You can now reference this secret when you create a cluster.

Create a cluster that uses a proxy

To configure GKE on Azure to use an HTTP proxy for outbound connectivity, perform the following steps:

Follow the steps in Create a cluster and node pool and pass the --proxy-resource-group-id and --proxy-secret-id flags.

gcloud container azure clusters create CLUSTER_NAME \
  --proxy-resource-group-id=PROXY_RESOURCE_GROUP_ID \
  --proxy-secret-id=PROXY_SECRET_ID
    ...

Replace the following:

  • CLUSTER_NAME: your cluster's name
  • PROXY_RESOURCE_GROUP_ID: the resource group that hosts your cluster
  • PROXY_SECRET_ID: the ID of the secret that contains your proxy configuration— for example, https://VAULT_NAME.vault.azure.net/secrets/SECRET_NAME/SECRET_VERSION

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