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Connectors and Variables

Connectors and Variables define the full set of inputs and integrations your workspace uses when running Plan, Apply, or Drift detection pipelines. This combined configuration is known as a variable set, and it includes:

  • Connectors for authenticating with cloud providers or Git
  • Environment variables and OpenTofu/Terraform variables
  • Variable files stored in version control

Connectors​

A connector is required to authenticate with cloud providers or external systems. Most workspace operations, like fetching modules or variable files, depend on a connector.

add connectors

Connectors can be added via Account Settings or directly from your workspaces Connectors and Variables tab.

Add a connector​

  1. From your workspace Connectors and Variables tab, click + Connector.
  2. Select an existing connector from your account or project scope (e.g., aws-oidc).

Or, you can add a new connector by clicking + New Connector.

interactive guide

Also, see Add Connectors for an interactive guide.

Connectors from templates​

If your workspace is created from a workspace template, it may include connectors defined in the template.

  • These appear in the Connectors and Variables tab.
  • Currently, these connectors cannot be modified in the workspace.

Environment variables​

Environment variables provide runtime configuration for your infrastructure. These behave like standard shell variables and can be used by your provisioning logic, module behavior, or CLI tooling.

  • Key: The name of the variable (e.g., TF_LOG, ENVIRONMENT).
  • Value: You can set a static value, insert a pipeline variable (FQN), or use <+input> for runtime input.

Add an environment variable​

  1. Click + New Environment Variable.
  2. Define the Type (usually string).
  3. Provide a Key and a Value.
# Example: Static and runtime-injected environment variables
environmentVariables:
  - key: TF_LOG
    value: INFO
    type: String
    source: CUSTOM
  - key: ENVIRONMENT
    value: <+input>
    type: String
    source: CUSTOM

OpenTofu/Terraform variables​

OpenTofu/Terraform variables (variable {} blocks in your code) must be declared by name and value. These are injected into Terraform runs and used in your *.tf files.

  1. Click + Add Variable under the OpenTofu/Terraform Variables section.
  2. Define the Key to match your Terraform variable name.
  3. Set the Value, or use <+input> for runtime prompts.

Each variable declared in your OpenTofu/Terraform code must be supplied with a value from one of the following input sources. If a variable is defined in multiple places, the order of precedence determines which value is used:

Order of precedence:

  1. Pipeline-level variable (highest)
  2. Workspace configuration
  3. HCL default value in your code (lowest)

Option 1: Define default values in HCL​

You can assign a default value directly in your OpenTofu/Terraform code. This acts as a fallback if no value is provided from the workspace or pipeline.

# main.tf
variable "instance_type" {
  type    = string
  default = "t3.micro"
}

Option 2: Provide values in the Workspace​

Configure variables in the OpenTofu/Terraform Variables section of your workspace. These values override any defaults in your code.

# Workspace configuration
terraformVariables:
  - key: instance_type
    value: <+input> # or a static value like "t3.large"
    type: String
    source: CUSTOM
runtime input

Use <+input> to prompt users for values at runtime.

Option 3: Override with Pipeline Variables​

If your workspace is triggered by a reusable pipeline, you can pass in values from pipeline-level variables. These take precedence over workspace or HCL values.

# Pipeline YAML
variables:
  - name: aws_region
    type: String
    value: us-west-2
tip

You can use Harness pipeline variables by referencing their Fully-Qualified Name (FQN) in the value field.

Variable files​

Variable files allow you to inject multiple variables via .tfvars, .json, or .yaml files stored in Git.

Add a variable file​

  1. Click + New Variable File.
  2. Select the Connector to access your Git repo.
  3. Choose a repository, branch, and file path (e.g., main, envs/dev.tfvars).
note

Harness will retrieve and use this file during your pipeline execution. You can include multiple files if needed.

# Workspace variable file definition
variableFiles:
  - type: Git
    spec:
      connectorRef: account.git_connector
      repoName: terraform-configs
      branch: main
      paths:
        - envs/dev.tfvars
variable file source

Your variable files and HCL can come from the same Git repository or different repositories.

Input Sources and Runtime Behavior​

Each variable shows its source, such as:

  • TEMPLATE: inherited from the selected Template.
  • CUSTOM: defined directly in the workspace.

You can use <+input> to prompt users to supply values at runtime.

Next Steps​