Use TF-Controller to Set Variables for Terraform Resources

~> BREAKING CHANGE: This is a breaking change of the v1alpha1 API.

Users who are upgrading from TF-Controller <= 0.7.0 must update varsFrom from a single object to become an array of objects:

  varsFrom:
    kind: ConfigMap
    name: cluster-config

changes to

  varsFrom:
  - kind: ConfigMap
    name: cluster-config

vars and varsFrom

You can pass variables to Terraform using the vars and varsFrom fields.

Inline variables can be set using vars. The varsFrom field accepts a list of ConfigMaps / Secrets. You may use the varsKeys property of varsFrom to select specific keys from the input or omit this field to select all keys from the input source.

Note that in the case of the same variable key being passed multiple times, the controller will use the lattermost instance of the key passed to varsFrom.

apiVersion: infra.contrib.fluxcd.io/v1alpha2
kind: Terraform
metadata:
  name: helloworld
  namespace: flux-system
spec:
  approvePlan: auto
  interval: 1m
  path: ./
  sourceRef:
    kind: GitRepository
    name: helloworld
    namespace: flux-system
  vars:
  - name: region
    value: us-east-1
  - name: env
    value: dev
  - name: instanceType
    value: t3-small
  varsFrom:
  - kind: ConfigMap
    name: cluster-config
    varsKeys:
    - nodeCount
    - instanceType
  - kind: Secret
    name: cluster-creds

Variable Value as HCL

The vars field supports HCL string, number, bool, object and list types. For example, the following variable can be populated using the accompanying Terraform spec:

variable "cluster_spec" {
  type = object({
      region     = string
      env        = string
      node_count = number
      public     = bool
  })
}

apiVersion: infra.contrib.fluxcd.io/v1alpha2
kind: Terraform
metadata:
  name: helloworld
  namespace: flux-system
spec:
  approvePlan: auto
  interval: 1m
  path: ./
  sourceRef:
    kind: GitRepository
    name: helloworld
    namespace: flux-system
  vars:
  - name: cluster_spec
    value:
      region: us-east-1
      env: dev
      node_count: 10
      public: false

Rename Variables in varsFrom

To rename a variable, you can use the varsKeys key within the varsFrom field. Here's the basic structure:

spec:
  varsFrom:
  - kind: Secret
    name: <secret_name>
    varsKeys:
    - <original_variable_name>:<new_variable_name>

original_variable_name corresponds to the initial name of the variable in the referenced secret, while new_variable_name represents the alias you want to use within the Terraform code.

Consider this example below, where we rename nodeCount to node_count and instanceType to instance_type:

apiVersion: infra.contrib.fluxcd.io/v1alpha2
kind: Terraform
metadata:
  name: helloworld
  namespace: flux-system
spec:
  approvePlan: auto
  interval: 1m
  path: ./
  sourceRef:
    kind: GitRepository
    name: helloworld
    namespace: flux-system
  varsFrom:
  - kind: Secret
    name: cluster-config
    varsKeys:
    - nodeCount:node_count
    - instanceType:instance_type

Rename output variables

See Rename outputs for more details.

Rename Input Secrets

See Rename input secrets for more details.