Module for searching nodes with running hostport services (shturval-coreha)

About the service

ParameterDescription
GUI nameModule for searching nodes with running hostport services
System name (identifier)shturval-coreha
Cluster AssignmentDynamically adding backends to HAProxy: tracking Ingress pods from hostPort and generating DNS records for the balancer.
CriticalNo
Public repository— (component in the delivery of the Shturval platform)
Dependenciesshturval-ingress-controller
Namespacekube-system

Purpose

shturval-coreha is designed for dynamically adding backends to an external balancer (HAProxy). The service is needed if you use an external balancer for Ingress. By default it is installed in the cluster in the disabled state. To enable: Services and repositories → Installed services → find the service by name above and change the mode. If the service is not in the list, install it from the Available charts page (chart shturval-coreha), selecting the namespace kube-system.

Note: when setting up the search for Ingress Controller pods, you will also need to make changes to the External connection control module (shturval-ingress-controller).

Where to configure

Services and repositories → Installed services → find Module for searching nodes with running hostport services (shturval-coreha) → Manage. If you need to redefine chart parameters, apply the changes via ShturvalServicePatch.

Configuration parameters (customvalues)

ParameterDescriptionExample / default
config.zoneNameDNS zone name for recordscluster-prod01-dc1.shturval
config.labelKeyLabel key by which pods are tracked; the key value is involved in the formation of the DNS nameingress.cluster/name
config.dns_portModule DNS server port1053
config_nameCoreDNS configuration file nameshturval-coreha-config
strictHostPortStrict selection of pods with hostPortfalse
Example customvalues for shturval-coreha
config:
  zoneName: cluster-prod01-dc1.shturval

When shturval-coreha is running in the cluster and you need to configure the search for Ingress Controller pods:

  1. ShturvalServicePatch for shturval-ingress-controller - set the label ingress.cluster/name and, if necessary, enable hostPort, NodePort (for example, 30080/30443).
Example ShturvalServicePatch for ingress-controller
apiVersion: ops.shturval.tech/v1beta2
kind: ShturvalServicePatch
metadata:
  name: <resource name>
spec:
  shturvalServiceConfigName: shturval-ingress-controller
  customvalues:
    controller:
      labels:
        ingress.cluster/name: <your parameter value>
      hostPort:
        enabled: true # When enabled, the ingress controller pods will also use ports 80 and 443 on cluster nodes
      service:
        nodePorts:
          http: "<your parameter value>"
          https: "<your parameter value>"
        type: NodePort

The DNS record is formed as <label_value>.<namespace>.<config.zoneName> (for example, default-nginx.ingress.cluster-prod01-dc1.shturval).

  1. Upload ShturvalServicePatch to the cluster (import manifests or kubectl).
Screenshot of ShturvalServicePatch for ingress-controller

ShturvalServicePatch for shturval-coreha and Ingress Controller

  1. Configure HAProxy - use a resolver pointing to the cluster API server and DNS port (for example, 1053), backend with server-template by DNS name.
Example of HAProxy configuration snippet
resolvers coredns-cluster
    nameserver ns1 <api-server-vip>:1053
    accepted_payload_size 8192

backend cluster-prod01-dc1-ingress-http
    balance source
    mode tcp
    server-template daemonset 2 default-nginx.ingress.cluster-prod01-dc1.shturval:80 check resolvers coredns-cluster init-addr none
  1. Check - from a node with access to the cluster API server: dig @<api-server-vip> -p 1053 default-nginx.ingress.cluster-prod01-dc1.shturval (IP of Ingress pods should be returned).

How to deploy this service - How to deploy a new service.

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