Available in editions:  CE, BE, SE, SE+, EE

The module lifecycle stage: General Availability

The module has 1 alert.

The module is enabled by default in the Default bundle. The module is disabled by default in the following bundles: Managed, Minimal.

How to explicitly enable the module…

You may explicitly enable or disable the module in one of the following ways:

  • Via Deckhouse web UI. In the “System” → “System Management” → “Deckhouse” → “Modules” section, open the kube-dns module and enable (or disable) the “Module enabled” toggle. Save changes.

    Example:

    Module enable/disable interface

  • Via Deckhouse CLI (d8).

    Use the d8 system module enable command for enabling, or d8 system module disable command for disabling the module (you need Deckhouse CLI (d8), configured to work with the cluster).

    Example of enabling the module:

    d8 system module enable kube-dns

  • Using ModuleConfig kube-dns.

    Set spec.enabled to true or false in ModuleConfig kube-dns (create it if necessary);

    Example of a manifest to enable module kube-dns:

    apiVersion: deckhouse.io/v1alpha1
kind: ModuleConfig
metadata:
  name: kube-dns
spec:
  enabled: true

How to configure the module…

You can configure the module in one of the following ways:

  • Via Deckhouse web UI.

    In the “System” → “System Management” → “Deckhouse” → “Modules” section, open the kube-dns module and enable the “Advanced Settings” switch. Fill in the required fields in the “Configuration” tab or specify the module settings in YAML format on the “YAML” tab, excluding the settings section. Save the changes.

    Example:

    Module Setup Interface

    You can also edit the ModuleConfig object kube-dns on the “YAML” tab in the module settings window (“System” → “System Management” → “Deckhouse” → “Modules”, open the module kube-dns) by specifying the schema version in the spec.version parameter and the necessary module parameters in the spec.settings section.

  • Via Deckhouse CLI (d8) (requires Deckhouse CLI (d8) configured to work with the cluster).

    Edit the existing ModuleConfig kube-dns (for more details on configuring Deckhouse, see the documentation) by executing the following command:

    d8 k edit mc kube-dns

    Make the necessary changes in the spec.settings section. If necessary, specify the schema version in the spec.version parameter. Save the changes.

    You can also create a file with manifest for ModuleConfig kube-dns using the example below. Fill in the spec.settings section with the required module parameters. If necessary, specify the schema version in the spec.version parameter.

    Apply the manifest using the following command (indicate the manifest file name):

    d8 k apply -f <FILENAME>

    Example of a manifest for ModuleConfig kube-dns:

    apiVersion: deckhouse.io/v1alpha1
kind: ModuleConfig
metadata:
  name: kube-dns
spec:
  version: 1
  enabled: true
  settings: # Module parameters from the "Parameters" section below.

Parameters

Schema version: 1

  • settings
    object
    • settings.clusterDomainAliases
      array of strings

      A list of cluster domain aliases; these are resolved on par with global.discovery.clusterDomain.

      Please note: the domain alias must not match the domain used in the DNS name template in the publicDomainTemplate parameter.

      • Element of the array
        string

        Pattern: ^[0-9a-zA-Z\.-]+$

    • settings.enableLogs
      boolean

      Enable CoreDNS logging.

      Default: false

    • settings.hosts
      array of objects

      Not required value.

      A static list of hosts similar to that of /etc/hosts.

      • settings.hosts.domain
        string

        Pattern: ^[0-9a-zA-Z\.-]+$

      • settings.hosts.ip
        string

        Pattern: ^[0-9]{1,}\.[0-9]{1,}\.[0-9]{1,}\.[0-9]{1,}$

    • settings.stubZones
      array of objects

      A list of additional zones CoreDNS should be authoritative for.

      Default: []

      Example:

      stubZones:
- zone: example.com
  upstreamNameservers:
  - 8.8.8.8
  cacheTTLSeconds: 3600
  transportProtocolMode: PreferUDP
      • settings.stubZones.cacheTTLSeconds
        integer

        Max TTL in seconds for NOERROR responses.

        Default: 30

        Allowed values: 1 <= X <= 3600

      • settings.stubZones.transportProtocolMode
        string

        The mode of the transport protocol for communicating with the upstream DNS server:

        • PreferUDP — UDP is used, even if the original request came over TCP. Note that if the DNS response from the upstream DNS server exceeds 512 bytes and has been truncated and marked with the TC bit (RFC 1035), then it will be resent over TCP (RFC 5966). The request will not be resent over TCP if there are other UDP issues.
        • ForceTCP — Always uses TCP, even if the original request is over UDP.
        • KeepOriginal — Uses the same protocol (TCP or UDP) as the original request.

        Default: PreferUDP

        Allowed values: PreferUDP, ForceTCP, KeepOriginal

      • settings.stubZones.upstreamNameservers
        array of strings

        Required value

        A list of IP addresses of recursive DNS servers that CoreDNS will use to resolve domains in this zone.

        • Element of the array
          string

          Pattern: ^[0-9]{1,}\.[0-9]{1,}\.[0-9]{1,}\.[0-9]{1,}(:[0-9]{1,})?$

      • settings.stubZones.zone
        string

        Required value

        The CoreDNS zone.

        Pattern: ^[0-9a-zA-Z\.\-_]+$

        Example:

        zone: consul.local
    • settings.transportProtocolMode
      string

      The mode of the transport protocol for communicating with the upstream DNS server:

      • PreferUDP — UDP is used, even if the original request came over TCP. Note that if the DNS response from the upstream DNS server exceeds 512 bytes and has been truncated and marked with the TC bit (RFC 1035), then it will be resent over TCP (RFC 5966). The request will not be resent over TCP if there are other UDP issues.
      • ForceTCP — Always uses TCP, even if the original request is over UDP.
      • KeepOriginal — Uses the same protocol (TCP or UDP) as the original request.

      Default: PreferUDP

      Allowed values: PreferUDP, ForceTCP, KeepOriginal

    • settings.upstreamNameservers
      array of strings

      A list of IP addresses of recursive DNS servers that CoreDNS will use to resolve external domains.

      By default, the /etc/resolv.conf list is used.

      • Element of the array
        string

        Pattern: ^[0-9]{1,}\.[0-9]{1,}\.[0-9]{1,}\.[0-9]{1,}(:[0-9]{1,})?$