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Tofu/Terraform plugin commands

Incorporate an OpenTofu or Terraform Plugin step in your pipeline to execute specific IaC commands at designated stages. This topic provides a detailed look at the available commands within the Infrastructure as Code Management (IaCM) module. For instance, incorporating a Provision operation automatically configures your pipeline with the init, plan, and apply commands by default.

IaCM Supported Commands​

The supported commands include:

Command Descriptions​

Initialize​

The init command prepares a working directory containing IaC configuration files, performing key functions like:

  • Backend Initialization: Sets up the backend for state management. Visit OpenTofu backend documentation for more information on infrastructure initialization.
  • Provider Installation: Downloads and installs necessary provider plugins to interact with service provider APIs.
  • Module Installation: Downloads and sets up modules included in the configuration within the .terraform directory.

Plan​

The plan command creates an execution plan to preview the actions OpenTofu/Terraform will take to align the infrastructure with the specified configuration. This includes:

  • State Refresh: Updates the state file with the latest data from the managed infrastructure.
  • Configuration Comparison: Analyzes current versus desired states to identify necessary changes.
  • Change Proposal: Lists the actions that apply will execute to reach the desired state.

Harness IaCM supports resource targeting and replacement, allowing you to specify which resources to focus on during a plan operation. You can use environment variable prefixes to define these targets or replacements:

  • PLUGIN_PLAN_TARGET_
  • PLUGIN_PLAN_REPLACE_

For example, set PLUGIN_PLAN_TARGET_1=tfcode.bucket1 to target a specific resource.

Apply​

The apply command executes the proposed plan to modify the infrastructure state:

  • Executing Plan: Implements the changes outlined in the plan to modify resource states.
  • State Update: Updates the state file to reflect the new status of the infrastructure.

Destroy​

The destroy command removes all resources managed by OpenTofu/Terraform:

  • Resource Removal: Identifies and eliminates all managed resources, respecting their interdependencies.

Plan & Destroy​

The plan-destroy command prepares a plan for dismantling infrastructure, outlining:

  • Destruction Overview: Highlights which resources will be removed if the plan is executed.

Plan - Refresh Only​

The plan-refresh-only command focuses on updating the state file to mirror real-time data without altering the infrastructure:

  • State Refresh: Updates the state file with the current infrastructure status.
use case

In scenarios where drift is detected, but there are unreviewed changes pending in your configuration code, the plan-refresh-only step is ideal. It refreshes the state to reconcile drift without applying any pending code updates, ensuring only the manual changes are addressed. Go to Drift Detection to see a specific example.

Apply - Refresh Only​

The apply-refresh-only applies a state update without changing the infrastructure:

  • Immediate State Update: Refreshes the state file to ensure it accurately reflects the current infrastructure conditions.

Detect Drift​

Although not an official command, detect-drift is typically executed using plan with specific flags to:

  • Drift Detection: Identifies discrepancies between the configured and actual states of the infrastructure.

Validate​

The validate command checks the configuration for errors:

  • Syntax Checks: Ensures all configuration files are syntactically correct.
  • Consistency Checks: Confirms all configurations are internally consistent with no unresolved references or missing mandatory arguments.

Import​

The import command allows you to bring existing infrastructure under IaC control. This feature is now supported in Harness pipelines, similar to the init or plan commands. Key benefits include:

  • Seamless Integration: Supports the import command, so users don't need to execute it manually outside of Harness.
  • Infrastructure Management: Allows you to bring existing infrastructure under the control of IaC.

Example Usage:​

Suppose you have an existing AWS S3 bucket that you want to manage using IaC. You can use the import command as follows:

import aws_s3_bucket.my_bucket my-existing-bucket

In this example, aws_s3_bucket.my_bucket is the resource name in your IaC configuration, and my-existing-bucket is the identifier of the existing S3 bucket in AWS. The import command associates the existing bucket with your IaC configuration, allowing you to manage it as part of your infrastructure code. This process effectively transitions the resource under IaC management without altering its current state.