F5SPKIngressGTP

Overview

This overview discusses the F5SPKIngressGTP Custom Resource (CR). For the full list of CRs, refer to the SPK CRs overview. The F5SPKIngressGTP CR configures the Service Proxy Traffic Management Microkernel (TMM) to proxy and load balance low-latency GPRS Tunnelling Protocol (GTP) traffic between networks using a virtual server and load balancing pool.

This document guides you through understanding, configuring and installing a simple F5SPKIngressGTP CR.

CR integration

SPK CRs should be integrated into the cluster after the Kubernetes application Deployment and application Service object have been installed. The SPK Controller uses the CR service.name to discover the application Endpoints, and use them to create TMM’s load balancing pool. The recommended method for installing SPK CRs is to include them in the application’s Helm release. Refer to the Helm CR Integration guide for more information.

CR parameters

The table below describes the CR parameters.

service

The table below describes the CR service parameters.

Parameter Description
name Selects the Service object name for the internal applications (Pods), and creates a round-robin load balancing pool using the Service Endpoints.
port Selects the Service object port value.

spec

The table below describes the CR spec parameters.

Parameter Description
destinationAddress The IPv4 address receiving ingress GTP connections.
v6destinationAddress The IPv6 address receiving ingress GTP connections.
destinationPort The service port receiving ingress TCP connections. When the Kubernetes service being load balanced has multiple ports, install one CR per service, or use port 0 for all ports.
persistenceMethod Specifies the persistence method: NONE (default), TEID, TEID_PLUS_ULI, TEID_PLUS_ULI. The dSSM Database is required to store persistence entries.
persistenceTimeout The persistence timeout for the GTP session in seconds. The default is 180.
idleTimeout The idle timeout for the UDP connnections in seconds. The default is 300.
enableInboundSnat If true, source address translation will be enabled
snatIP The IPv4 address used as the source for packets egressing the TMM Pod.
v6snatIP The IPv6 address used as the source for packets egressing the TMM Pod.
spec.ipfamilies Should match the Service object ipFamilies parameter, ensuring SNAT Automap is applied correctly: IPv4 (default), IPv6, and IPv4andIPv6.
vlans.vlanList Option to explicitly specify list of vlans to pass traffic on
vlans.disableListedVlans Whether to use all vlans except the listed ones (true) or only the ones in the list (false)

CR example

apiVersion: "k8s.f5net.com/v1"
kind: F5SPKIngressGTP
metadata:
  name: "spk-gtp-app"
  namespace: "spk-apps"
service:
  name: "gtp-apps"
  port: 2123
spec:
  destinationAddress: "192.168.10.100"
  destinationPort: 2123
  idleTimeout: 301
  enableInboundSnat: true
  snatIP: "10.10.10.100"
  enableTeidPersistence: false
  persistenceMethod: "TEID_PLUS_ULI"
  persistenceTimeout: 180

Application Project

The SPK Controller and Service Proxy TMM Pods install to a different Project than the GTP application (Pods). When installing the SPK Controller, set the controller.watchNamespace parameter to the GTP Pod Project(s) in the Helm values file. For example:

Note: The watchNamespace parameter accepts multiple namespaces.

controller:
  watchNamespace: 
    - "spk-apps"
    - "spk-apps2"

Dual-Stack environments

Service Proxy TMM’s load balancing pool is created by discovering the Kubernetes Service Endpoints in the Project. In IPv4/IPv6 dual-stack environments, to populate the load balancing pool with IPv6 members, set the Service PreferDualStack parameter to IPv6. For example:

kind: Service
metadata:
  name: gtp-app
  namespace: spk-apps
  labels:
    app: gtp-app
spec:
  ipFamilyPolicy: PreferDualStack
  ipFamilies:
  - IPv6
  - IPv4

_images/spk_warn.png Important: When enabling PreferDualStack, ensure TMM’s internal F5SPKVlan interface configuration includes both IPv4 and IPv6 addresses.

Ingress traffic

To enable ingress network traffic, the Service Proxy Pod must be configured to advertise virtual server IP addresses to remote networks using the Border Gateway Protocol (BGP). Alternatively, you can configure appropriate routes on upstream devices. For BGP configuration assistance, refer to the BGP Overview.

Requirements

Ensure you have:

  • Installed a K8S Service object and application.
  • Installed the dSSM Database when enabling persistence.
  • Installed the SPK Controller Pods.
  • Have a Linux based workstation.

Installation

Use the following steps to verify the application’s Service object configuration, and install the example F5SPKIngressGTP CR.

  1. Switch to the application Project:

    oc project <project>

    In this example, the application is in the spk-apps Project:

    oc project spk-apps

  2. Verify the K8S Service object NAME and PORT are set using the CR service.name and service.port parameters:

    oc get service

    In this example, the Service object NAME gtp-app and PORT 3868 are set in the example CR:

    NAME      TYPE       CLUSTER-IP    EXTERNAL-IP   PORT(S)         
gtp-app   NodePort   10.99.99.99   <none>        2123:2123/UDP

  3. Copy the example CR into a YAML file:

    apiVersion: "k8s.f5net.com/v1"
kind: F5SPKIngressGTP
metadata:
  name: "spk-gtp-app"
  namespace: "spk-apps"
service:
  name: "spk-gtp-app"
  port: 2123
spec:
  destinationAddress: "192.168.10.100"
  destinationPort: 2123
  idleTimeout: 301
  enableInboundSnat: true
  snatIP: "10.10.10.100"
  enableTeidPersistence: false
  persistenceMethod: "TEID_PLUS_ULI"
  persistenceTimeout: 180

  4. Install the the F5SPKIngressGTP CR:

    oc apply -f spk-ingress-gtp.yaml

  5. GTP clients should now be able to connect to the application through the Service Proxy TMM.

Verify Connectivity

If you installed the SPK Controller with the Debug Sidecar enabled, connect to the sidecar to view virtual server and pool member connecitivy statistics.

  1. Log in to the TMM Debug container:

    oc exec -it deploy/f5-tmm -c debug -n <project> -- bash

    In this example, the TMM Pod is in the spk-ingress Project:

    oc exec -it deploy/f5-tmm -c debug -n spk-ingress -- bash

  2. View the virtual server connection statistics:

    tmctl -f /var/tmstat/blade/tmm0 virtual_server_stat -s name,serverside.tot_conns

    For example:

    name                                      serverside.tot_conns
---------------------------------         --------------------
gtp-apps-gtp-app-int-vs                           19 
gtp-apps-gtp-app-ext-vs                           31

  3. View the load balancing pool connection statistics:

    tmctl -f /var/tmstat/blade/tmm0 pool_member_stat -s pool_name,serverside.tot_conns

    For example:

    gtp-apps-gtp-app-pool                           15
gtp-apps-gtp-app-pool                           16

Feedback

Provide feedback to improve this document by emailing spkdocs@f5.com.

Supplemental