Configuring Multiple Ingresses to Use the Same Load Balancer

Multiple Ingresses Accessing the Same External ELB Port

In a cluster, you can configure multiple ingresses to use the same ELB listener, allowing them to use the same port on a single load balancer. If two ingresses have different listener configurations, the listener configuration of the earlier ingress (known as the first route) will be used. For details about how to confirm the first route, see How Can I Determine Which Ingress the Listener Settings Have Been Applied To?

Figure 1 Diagram for multiple ingresses to use the same external ELB port
Click to enlarge

The following table lists listener parameters.

Listener	Annotation	Helpful Links
Configuring ELB Certificates	kubernetes.io/elb.tls-certificate-ids kubernetes.io/elb.tls-ciphers-policy	Configuring an HTTPS Certificate for a LoadBalancer Ingress
Using HTTP/2	kubernetes.io/elb.http2-enable	Configuring HTTP/2 for a LoadBalancer Ingress
Configuring Timeout for an Ingress	kubernetes.io/elb.keepalive_timeout kubernetes.io/elb.client_timeout kubernetes.io/elb.member_timeout	Configuring Timeout for a LoadBalancer Ingress
Configuring a Blocklist/Trustlist	kubernetes.io/elb.acl-id kubernetes.io/elb.acl-status kubernetes.io/elb.acl-type	Configuring a Blocklist/Trustlist Access Policy for a LoadBalancer Ingress
Configuring an HTTP/HTTPS Header	kubernetes.io/elb.x-forwarded-port kubernetes.io/elb.x-forwarded-for-port kubernetes.io/elb.x-forwarded-host kubernetes.io/elb.x-real-ip	Configuring an HTTP/HTTPS Header for a LoadBalancer Ingress
Enabling GZIP	kubernetes.io/elb.gzip-enabled	Configuring GZIP Data Compression for a LoadBalancer Ingress

Ensure that the configurations of different listeners for various ingresses are synchronized. To do so, perform the following operations:

Log in to the CCE console and click the cluster name to access the cluster console.
In the navigation pane, choose Services & Ingresses. Then, click the Ingresses tab, and choose More > Update in the Operation column.
Synchronize Configuration is available if the listener configuration of the ingress differs from that of the ELB. Click Synchronize Configuration. Then, the listener configuration will be automatically synchronized.

Multiple Ingresses Associated with the Same Service Accessing the Same ELB Port

When you create an ingress, CCE automatically adds a backend server group on the ELB based on the associated Service.

In a cluster, if multiple ingresses access the same ELB port and are associated with the same Service and port, only one backend server group will be created on the ELB. The configuration applied to this backend server group will be that of the first ingress created (referred to as the first route). If ingresses use multiple load balancers to access the same Service, multiple backend server groups will be created. In this case, the sequence of ingress configurations does not matter. For details about how to confirm the first route, see How Can I Determine Which Ingress the Listener Settings Have Been Applied To?

Figure 2 Diagram for multiple ingresses associated with the same Service to access the same ELB port
Click to enlarge