» Kubernetes Provider

The Kubernetes (K8S) provider is used to interact with the resources supported by Kubernetes. The provider needs to be configured with the proper credentials before it can be used.

Use the navigation to the left to read about the available resources.

» Example Usage

provider "kubernetes" {
  config_context_auth_info = "ops"
  config_context_cluster   = "mycluster"
}

resource "kubernetes_namespace" "example" {
  metadata {
    name = "my-first-namespace"
  }
}

» Kubernetes versions

Both backward and forward compatibility with Kubernetes API is mostly defined by the official K8S Go library (prior to 1.1 release) and client Go library which we ship with Terraform. Below are versions of the library bundled with given versions of Terraform.

  • Terraform <= 0.9.6 (prior to provider split) - Kubernetes 1.5.4
  • Terraform 0.9.7 (prior to provider split) < 1.1 (provider version) - Kubernetes 1.6.1
  • 1.1+ - Kubernetes 1.7

» Stacking with managed Kubernetes cluster resources

Terraform providers for various cloud providers feature resources to spin up managed Kubernetes clusters on services such as EKS, AKS and GKE. Such resources (or data-sources) will have attributes that expose the credentials needed for the Kubernetes provider to connect to these clusters.

To use these credentials with the Kubernetes provider, they can be interpolated into the respective attributes of the Kubernetes provider configuration block.

IMPORTANT WARNING When using interpolation to pass credentials to the Kubernetes provider from other resources, these resources SHOULD NOT be created in the same apply operation where Kubernetes provider resources are also used. This will lead to intermittent and unpredictable errors which are hard to debug and diagnose. The root issue lies with the order in which Terraform itself evaluates the provider blocks vs. actual resources. Please refer to this section of Terraform docs for further explanation.

The best-practice in this case is to ensure that the cluster itself and the Kubernetes provider resources are managed with separate apply operations. Data-sources can be used to convey values between the two stages as needed.

» Authentication

There are generally two ways to configure the Kubernetes provider.

» File config

The provider always first tries to load a config file from a given (or default) location. Depending on whether you have current context set this may require config_context_auth_info and/or config_context_cluster and/or config_context.

» Setting default config context

Here's an example for how to set default context and avoid all provider configuration:

kubectl config set-context default-system \
  --cluster=chosen-cluster \
  --user=chosen-user

kubectl config use-context default-system

Read more about kubectl in the official docs.

» In-cluster service account token

If no other configuration is specified, and when it detects it is running in a kubernetes pod, the provider will try to use the service account token from the /var/run/secrets/kubernetes.io/serviceaccount/token path. Detection of in-cluster execution is based on the sole availability both of the KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT environment variables, with non empty values.

provider "kubernetes" {
  load_config_file = "false"
}

If you have any other static configuration setting specifiedin a config file or static configuration, in-cluster service account token will not be tried.

» Statically defined credentials

An other way is statically define TLS certificate credentials:

provider "kubernetes" {
  load_config_file = "false"

  host = "https://104.196.242.174"

  client_certificate     = "${file("~/.kube/client-cert.pem")}"
  client_key             = "${file("~/.kube/client-key.pem")}"
  cluster_ca_certificate = "${file("~/.kube/cluster-ca-cert.pem")}"
}

or username and password (HTTP Basic Authorization):

provider "kubernetes" {
  load_config_file = "false"

  host = "https://104.196.242.174"

  username = "username"
  password = "password"
}

If you have both valid configuration in a config file and static configuration, the static one is used as override. i.e. any static field will override its counterpart loaded from the config.

» Argument Reference

The following arguments are supported:

  • host - (Optional) The hostname (in form of URI) of Kubernetes master. Can be sourced from KUBE_HOST.
  • username - (Optional) The username to use for HTTP basic authentication when accessing the Kubernetes master endpoint. Can be sourced from KUBE_USER.
  • password - (Optional) The password to use for HTTP basic authentication when accessing the Kubernetes master endpoint. Can be sourced from KUBE_PASSWORD.
  • insecure - (Optional) Whether server should be accessed without verifying the TLS certificate. Can be sourced from KUBE_INSECURE. Defaults to false.
  • client_certificate - (Optional) PEM-encoded client certificate for TLS authentication. Can be sourced from KUBE_CLIENT_CERT_DATA.
  • client_key - (Optional) PEM-encoded client certificate key for TLS authentication. Can be sourced from KUBE_CLIENT_KEY_DATA.
  • cluster_ca_certificate - (Optional) PEM-encoded root certificates bundle for TLS authentication. Can be sourced from KUBE_CLUSTER_CA_CERT_DATA.
  • config_path - (Optional) Path to the kube config file. Can be sourced from KUBE_CONFIG or KUBECONFIG. Defaults to ~/.kube/config.
  • config_context - (Optional) Context to choose from the config file. Can be sourced from KUBE_CTX.
  • config_context_auth_info - (Optional) Authentication info context of the kube config (name of the kubeconfig user, --user flag in kubectl). Can be sourced from KUBE_CTX_AUTH_INFO.
  • config_context_cluster - (Optional) Cluster context of the kube config (name of the kubeconfig cluster, --cluster flag in kubectl). Can be sourced from KUBE_CTX_CLUSTER.
  • token - (Optional) Token of your service account. Can be sourced from KUBE_TOKEN.
  • load_config_file - (Optional) By default the local config (~/.kube/config) is loaded when you use this provider. This option at false disables this behaviour which is desired when statically specifying the configuration or relying on in-cluster config. Can be sourced from KUBE_LOAD_CONFIG_FILE.
  • exec - (Optional) Configuration block to use an exec-based credential plugin, e.g. call an external command to receive user credentials.
    • api_version - (Required) API version to use when decoding the ExecCredentials resource, e.g. client.authentication.k8s.io/v1beta1.
    • command - (Required) Command to execute.
    • args - (Optional) List of arguments to pass when executing the plugin.
    • env - (Optional) Map of environment variables to set when executing the plugin.