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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. These inputs can come from multiple sources and are resolved based on a clear order of precedence.

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.

Multiple Connectors​

You can attach more than one connector to a workspace. This allows your IaCM runs to access multiple cloud providers or external systems from a single workspace (for example, both AWS and Azure). However, a workspace can only have one connector per provider type (for example, one AWS, one GCP, one Azure).

  • Connectors appear in the Connectors and Variables tab.
  • If a workspace is created from a template, template-defined connectors are included automatically (read-only).
  • You can add more connectors inline or select from account/project scope.

Variable sources​

set variables

You can provide variables in the following ways:

  • Variable Sets: Reusable collections of variables and secrets defined at the account level and applied to multiple workspaces.
  • Workspace Templates: Predefined templates that inject connectors and variables into workspaces.
  • Workspace-level variables: Environment variables and OpenTofu/Terraform variables defined directly in the workspace.
  • Variable files: .tfvars, .json, or .yaml files stored in Git and linked to the workspace.
  • Connectors: Authentication references for cloud providers, Git, and external systems (used for fetching modules, variable files, or credentials).
  • HCL defaults: Default values defined directly in your OpenTofu/Terraform code.
  • Pipeline-level variables: Values passed at runtime from pipelines.

Order of precedence​

Variables can be defined in multiple places. The order of precedence determines which value is used if the same variable appears more than once.

PrioritySource
1 (highest)Workspace Template variables
2Workspace-level variables (Environment or OpenTofu/Terraform variables)
3Variable Sets (in their assigned priority order)
4 (lowest)HCL default values in your code

If a variable is defined in multiple places, Harness resolves conflicts using this order of precedence.

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:

The following options are available in order of precedence, go to Order of Precedence for the full list of variable options in order of precedence:

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.

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.

Variable Sets​

A Variable Set is a reusable collection of environment variables, OpenTofu/Terraform variables, and secrets. They allow you to standardize configuration across multiple workspaces.

Variable Sets are supported at the account, org, and project level:

  • Navigate to Account Settings > IaCM Settings > Variable Sets.
  • Create: Click Create a new Variable Set.
  • Update: Click an existing Variable Set tile.
  • Delete: Use the ellipsis menu on a Variable Set tile and select Delete.

When applied to a workspace, Variable Sets can be prioritized. Variables from a higher-priority set will override those from lower-priority sets.

Variable set priority

In the Connectors and Variables tab of a workspace, drag Variable Sets to set their priority. Priority 1 > Priority 2 > Priority 3.

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​