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  1. Configurable Parameters in Kubespray
  2. ================================
  3. #### Generic Ansible variables
  4. You can view facts gathered by Ansible automatically
  5. [here](http://docs.ansible.com/ansible/playbooks_variables.html#information-discovered-from-systems-facts).
  6. Some variables of note include:
  7. * *ansible_user*: user to connect to via SSH
  8. * *ansible_default_ipv4.address*: IP address Ansible automatically chooses.
  9. Generated based on the output from the command ``ip -4 route get 8.8.8.8``
  10. #### Common vars that are used in Kubespray
  11. * *calico_version* - Specify version of Calico to use
  12. * *calico_cni_version* - Specify version of Calico CNI plugin to use
  13. * *docker_version* - Specify version of Docker to used (should be quoted
  14. string). Must match one of the keys defined for *docker_versioned_pkg*
  15. in `roles/container-engine/docker/vars/*.yml`.
  16. * *etcd_version* - Specify version of ETCD to use
  17. * *ipip* - Enables Calico ipip encapsulation by default
  18. * *kube_network_plugin* - Sets k8s network plugin (default Calico)
  19. * *kube_proxy_mode* - Changes k8s proxy mode to iptables mode
  20. * *kube_version* - Specify a given Kubernetes hyperkube version
  21. * *searchdomains* - Array of DNS domains to search when looking up hostnames
  22. * *nameservers* - Array of nameservers to use for DNS lookup
  23. * *preinstall_selinux_state* - Set selinux state, permitted values are permissive and disabled.
  24. #### Addressing variables
  25. * *ip* - IP to use for binding services (host var)
  26. * *access_ip* - IP for other hosts to use to connect to. Often required when
  27. deploying from a cloud, such as OpenStack or GCE and you have separate
  28. public/floating and private IPs.
  29. * *ansible_default_ipv4.address* - Not Kubespray-specific, but it is used if ip
  30. and access_ip are undefined
  31. * *loadbalancer_apiserver* - If defined, all hosts will connect to this
  32. address instead of localhost for kube-masters and kube-master[0] for
  33. kube-nodes. See more details in the
  34. [HA guide](https://github.com/kubernetes-sigs/kubespray/blob/master/docs/ha-mode.md).
  35. * *loadbalancer_apiserver_localhost* - makes all hosts to connect to
  36. the apiserver internally load balanced endpoint. Mutual exclusive to the
  37. `loadbalancer_apiserver`. See more details in the
  38. [HA guide](https://github.com/kubernetes-sigs/kubespray/blob/master/docs/ha-mode.md).
  39. #### Cluster variables
  40. Kubernetes needs some parameters in order to get deployed. These are the
  41. following default cluster parameters:
  42. * *cluster_name* - Name of cluster (default is cluster.local)
  43. * *dns_domain* - Name of cluster DNS domain (default is cluster.local)
  44. * *kube_network_plugin* - Plugin to use for container networking
  45. * *kube_service_addresses* - Subnet for cluster IPs (default is
  46. 10.233.0.0/18). Must not overlap with kube_pods_subnet
  47. * *kube_pods_subnet* - Subnet for Pod IPs (default is 10.233.64.0/18). Must not
  48. overlap with kube_service_addresses.
  49. * *kube_network_node_prefix* - Subnet allocated per-node for pod IPs. Remaining
  50. bits in kube_pods_subnet dictates how many kube-nodes can be in cluster.
  51. * *skydns_server* - Cluster IP for DNS (default is 10.233.0.3)
  52. * *skydns_server_secondary* - Secondary Cluster IP for CoreDNS used with coredns_dual deployment (default is 10.233.0.4)
  53. * *enable_coredns_k8s_external* - If enabled, it configures the [k8s_external plugin](https://coredns.io/plugins/k8s_external/)
  54. on the CoreDNS service.
  55. * *coredns_k8s_external_zone* - Zone that will be used when CoreDNS k8s_external plugin is enabled
  56. (default is k8s_external.local)
  57. * *enable_coredns_k8s_endpoint_pod_names* - If enabled, it configures endpoint_pod_names option for kubernetes plugin.
  58. on the CoreDNS service.
  59. * *cloud_provider* - Enable extra Kubelet option if operating inside GCE or
  60. OpenStack (default is unset)
  61. * *kube_hostpath_dynamic_provisioner* - Required for use of PetSets type in
  62. Kubernetes
  63. * *kube_feature_gates* - A list of key=value pairs that describe feature gates for
  64. alpha/experimental Kubernetes features. (defaults is `[]`)
  65. * *authorization_modes* - A list of [authorization mode](
  66. https://kubernetes.io/docs/admin/authorization/#using-flags-for-your-authorization-module)
  67. that the cluster should be configured for. Defaults to `['Node', 'RBAC']`
  68. (Node and RBAC authorizers).
  69. Note: `Node` and `RBAC` are enabled by default. Previously deployed clusters can be
  70. converted to RBAC mode. However, your apps which rely on Kubernetes API will
  71. require a service account and cluster role bindings. You can override this
  72. setting by setting authorization_modes to `[]`.
  73. Note, if cloud providers have any use of the ``10.233.0.0/16``, like instances'
  74. private addresses, make sure to pick another values for ``kube_service_addresses``
  75. and ``kube_pods_subnet``, for example from the ``172.18.0.0/16``.
  76. #### DNS variables
  77. By default, hosts are set up with 8.8.8.8 as an upstream DNS server and all
  78. other settings from your existing /etc/resolv.conf are lost. Set the following
  79. variables to match your requirements.
  80. * *upstream_dns_servers* - Array of upstream DNS servers configured on host in
  81. addition to Kubespray deployed DNS
  82. * *nameservers* - Array of DNS servers configured for use by hosts
  83. * *searchdomains* - Array of up to 4 search domains
  84. For more information, see [DNS
  85. Stack](https://github.com/kubernetes-sigs/kubespray/blob/master/docs/dns-stack.md).
  86. #### Other service variables
  87. * *docker_options* - Commonly used to set
  88. ``--insecure-registry=myregistry.mydomain:5000``
  89. * *docker_plugins* - This list can be used to define [Docker plugins](https://docs.docker.com/engine/extend/) to install.
  90. * *http_proxy/https_proxy/no_proxy* - Proxy variables for deploying behind a
  91. proxy. Note that no_proxy defaults to all internal cluster IPs and hostnames
  92. that correspond to each node.
  93. * *kubelet_deployment_type* - Controls which platform to deploy kubelet on.
  94. Available options are ``host`` and ``docker``. ``docker`` mode
  95. is unlikely to work on newer releases. Starting with Kubernetes v1.7
  96. series, this now defaults to ``host``. Before v1.7, the default was Docker.
  97. This is because of cgroup [issues](https://github.com/kubernetes/kubernetes/issues/43704).
  98. * *kubelet_load_modules* - For some things, kubelet needs to load kernel modules. For example,
  99. dynamic kernel services are needed for mounting persistent volumes into containers. These may not be
  100. loaded by preinstall kubernetes processes. For example, ceph and rbd backed volumes. Set this variable to
  101. true to let kubelet load kernel modules.
  102. * *kubelet_cgroup_driver* - Allows manual override of the
  103. cgroup-driver option for Kubelet. By default autodetection is used
  104. to match Docker configuration.
  105. * *kubelet_rotate_certificates* - Auto rotate the kubelet client certificates by requesting new certificates
  106. from the kube-apiserver when the certificate expiration approaches.
  107. * *node_labels* - Labels applied to nodes via kubelet --node-labels parameter.
  108. For example, labels can be set in the inventory as variables or more widely in group_vars.
  109. *node_labels* can be defined either as a dict or a comma-separated labels string:
  110. ```
  111. node_labels:
  112. label1_name: label1_value
  113. label2_name: label2_value
  114. node_labels: "label1_name=label1_value,label2_name=label2_value"
  115. ```
  116. * *node_taints* - Taints applied to nodes via kubelet --register-with-taints parameter.
  117. For example, taints can be set in the inventory as variables or more widely in group_vars.
  118. *node_taints* has to be defined as a list of strings in format `key=value:effect`, e.g.:
  119. ```
  120. node_taints:
  121. - "node.example.com/external=true:NoSchedule"
  122. ```
  123. * *podsecuritypolicy_enabled* - When set to `true`, enables the PodSecurityPolicy admission controller and defines two policies `privileged` (applying to all resources in `kube-system` namespace and kubelet) and `restricted` (applying all other namespaces).
  124. Addons deployed in kube-system namespaces are handled.
  125. * *kubernetes_audit* - When set to `true`, enables Auditing.
  126. The auditing parameters can be tuned via the following variables (which default values are shown below):
  127. * `audit_log_path`: /var/log/audit/kube-apiserver-audit.log
  128. * `audit_log_maxage`: 30
  129. * `audit_log_maxbackups`: 1
  130. * `audit_log_maxsize`: 100
  131. * `audit_policy_file`: "{{ kube_config_dir }}/audit-policy/apiserver-audit-policy.yaml"
  132. By default, the `audit_policy_file` contains [default rules](https://github.com/kubernetes-sigs/kubespray/blob/master/roles/kubernetes/master/templates/apiserver-audit-policy.yaml.j2) that can be overridden with the `audit_policy_custom_rules` variable.
  133. ##### Custom flags for Kube Components
  134. For all kube components, custom flags can be passed in. This allows for edge cases where users need changes to the default deployment that may not be applicable to all deployments. This can be done by providing a list of flags. The `kubelet_node_custom_flags` apply kubelet settings only to nodes and not masters. Example:
  135. ```
  136. kubelet_custom_flags:
  137. - "--eviction-hard=memory.available<100Mi"
  138. - "--eviction-soft-grace-period=memory.available=30s"
  139. - "--eviction-soft=memory.available<300Mi"
  140. ```
  141. The possible vars are:
  142. * *kubelet_custom_flags*
  143. * *kubelet_node_custom_flags*
  144. Extra flags for the API server, controller, and scheduler components can be specified using these variables,
  145. in the form of dicts of key-value pairs of configuration parameters that will be inserted into the kubeadm YAML config file:
  146. * *kube_kubeadm_apiserver_extra_args*
  147. * *kube_kubeadm_controller_extra_args*
  148. * *kube_kubeadm_scheduler_extra_args*
  149. #### User accounts
  150. By default, a user with admin rights is created, named `kube`.
  151. The password can be viewed after deployment by looking at the file
  152. `{{ credentials_dir }}/kube_user.creds` (`credentials_dir` is set to `{{ inventory_dir }}/credentials` by default). This contains a randomly generated
  153. password. If you wish to set your own password, just precreate/modify this
  154. file yourself or change `kube_api_pwd` var.