Terraform Visualization: Rover, tf-summarize, terraform-docs

Rover: interactive UI

Rover (im2nguyen) is a Go application that starts a web UI on :9000 and renders state and plan as an interactive graph. You can zoom, filter by resource type, and click any node to see its details.

rover -tfPath /home/student/myproject -planPath plan.tfplan

# browser: http://localhost:9000

Rover is useful when:

• The plan is large and the text output does not fit on screen.
• You want to see cross-module dependencies.
• You are presenting the architecture to management or a new engineer.

The alternative is terraform graph | dot -Tpng > graph.png. Rover is dynamic and easier to navigate; the built-in terraform graph command is static but requires no external binary.

tf-summarize: plan diff in one table

terraform plan -out=plan.tfplan

tf-summarize plan.tfplan

Output:

┌────────────────────────────────────────┬──────────┐

│ CHANGE                                 │ COUNT    │

├────────────────────────────────────────┼──────────┤

│ add                                    │ 12       │

│ change                                 │ 3        │

│ destroy                                │ 1        │

│ replace                                │ 2        │

├────────────────────────────────────────┼──────────┤

│ aws_s3_bucket                          │ 3 add    │

│ aws_iam_role                           │ 2 add    │

│ aws_lambda_function                    │ 1 change │

│ ...                                    │          │

└────────────────────────────────────────┴──────────┘

Useful for:

• A PR comment with a short summary. Instead of a 5000-line plan output, you post one table.
• CI logs: the full scope of a plan is visible on one screen.

tf-summarize -md plan.tfplan > summary.md

# Markdown format for a PR comment

terraform-docs: auto-generated README

Designed for modules. It parses variables.tf and outputs.tf and generates a Markdown file with inputs and outputs tables.

cd modules/audited-bucket

terraform-docs markdown table --output-file README.md .

Output in README.md:

## Requirements

| Name | Version |

|------|---------|

| terraform | >= 1.6 |

| aws | ~> 5.0 |

## Inputs

| Name | Description | Type | Default | Required |

|------|-------------|------|---------|----------|

| name | Bucket name | string | n/a | yes |

| tags | Resource tags | map(string) | {} | no |

## Outputs

| Name | Description |

|------|-------------|

| id | Bucket id |

Use it in pre-commit (see tf-fmt-validate-ci) or CI. Every time variables or outputs change, the README is updated automatically.

Comparison

All four tools complement each other rather than replace one another.

CI integration

In pre-commit config:

- repo: https://github.com/terraform-docs/terraform-docs

  rev: v0.19.0

  hooks:

    - id: terraform-docs-go

      args:

        - markdown

        - table

        - --output-file

        - README.md

        - ./modules/

In a GitHub Action for tf-summarize:

- run: |

    terraform plan -out=plan.tfplan

    go install github.com/dineshba/tf-summarize@latest

    tf-summarize -md plan.tfplan > summary.md

- uses: actions/github-script@v7

  with:

    script: |

      const fs = require('fs');

      const summary = fs.readFileSync('summary.md', 'utf8');

      github.rest.issues.createComment({

        issue_number: context.issue.number,

        owner: context.repo.owner,

        repo: context.repo.repo,

        body: summary,

      });

Pitfalls

• Rover requires a plan file for interactive mode. Without one, it renders only state. For a pre-apply view, you need plan.tfplan.

• terraform-docs depends on accurate variable descriptions. If a description field is empty, the README shows "n/a". The tool cannot fix that; the author must.

• tf-summarize shows counts, not the actual diff. To inspect the change details, use terraform show plan.tfplan or terraform-plan-md.

• Rover does not work with a remote backend unless you have local state. Pull state before running: terraform state pull > state.json.

• terraform-docs hooks in pre-commit may regenerate README on every commit. When variables have not changed, the regeneration is a no-op, but it adds commit noise. The fix: configure terraform-docs-go to run only when .tf files are modified.