> ## Documentation Index
> Fetch the complete documentation index at: https://www.ravion.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Module deploys

> A deploy is a single release of application code to a Ravion module instance, with statuses, instance-level events, and one-command rollback.

A **deploy** (deployment) is a single release of application code to one module instance. Where the [stack](/modules/stack) tracks a module's infrastructure changes, deploys track its code releases. The two are separate: a deploy never runs Terraform, and a stack change never redeploys your code.

Each deploy records:

* A **description** and the **artifact inputs** it was given, such as a digest-pinned image URI.
* A **status**: `PENDING` → `IN_PROGRESS` → `SUCCESS`, `ERROR`, or `CANCELLED` (plus `ROLLING_BACK` and `ROLLED_BACK`).
* A **timeline of deployment events** and instance-level resource status.
* A **snapshot of what was released** — for ECS, the full task definition — which is what rollback replays.

## Deployment types

The module's definition determines how a deploy rolls out:

| Type           | What a deploy does                                                                                                                                                                  |
| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **ECS**        | Creates a new task definition revision and rolls the service. Strategies: `rolling` (default), `blue_green`, `canary`, and `linear`, with configurable bake times and pause stages. |
| **Kubernetes** | *Coming soon*                                                                                                                                                                       |
| **EC2**        | *Coming soon*                                                                                                                                                                       |
| **Lambda**     | Updates the function code and config, publishes a new version, and flips the alias to it.                                                                                           |
| **Static**     | Promotes a new S3 directory of assets and optionally invalidates the CloudFront cache.                                                                                              |

ECS deploys also support `pre_deploy` and `post_deploy` hooks — one-off tasks like database migrations that run before or after the rollout. A failed pre-deploy hook aborts the deploy.

Deploys are locked per module instance, so concurrent triggers queue instead of colliding.

## How deploys are triggered

<Steps>
  <Step title="From a Ravion pipeline">
    A `deploy` step passes a preceding build step's output to the module's deploy manager:

    ```yaml theme={null}
    - id: deploy_web_app
      type: deploy
      module_instance: << pipeline.variant.id >>.web-app
      input:
        image_ref: << steps.build_web_app.output.image_digest >>
    ```

    The deploy records which pipeline run and step created it. See [step types](/pipelines/step-types).
  </Step>

  <Step title="From the API or CLI">
    External CI systems like GitHub Actions build the artifact themselves, then trigger the deploy:

    ```bash theme={null}
    ravion deploy create --module-instance-id <mi-id> \
      --description "Release v1.4.2" \
      --inputs '{"image_ref": "<digest-pinned-image-uri>"}'
    ```
  </Step>

  <Step title="From the dashboard">
    Trigger a deploy manually from the module instance page.
  </Step>
</Steps>

## Watching a deploy

Ravion surfaces every low-level event during a rollout — far more than a CI log line:

* **Deploy phases**: provision, snapshot, pre-deploy hook, update, wait-for-healthy, post-deploy hook, activate, complete — with traffic-shift, bake, and pause sub-phases for blue-green style strategies.
* **Resource-level status**: each ECS task's status ladder (provisioning → pending → running) and target-group health.
* **AWS infrastructure events**: task state changes, service actions, and deployment state changes ingested from EventBridge.

All of this streams live to the dashboard and is available via the API and `ravion deploy get`.

## Rollback, redeploy, cancel

* **Rollback** starts a *new* deploy that replays a previous successful deploy's snapshot. List valid targets (previous successes whose images still exist in the registry), then roll back:

  ```bash theme={null}
  ravion deploy rollback-candidates <deployment-id>
  ravion deploy rollback <deployment-id-to-roll-back-to>
  ```

* **Redeploy** (`ravion deploy redeploy <id>`) starts a new deploy with the same definition as a previous one.

* **Cancel** (`ravion deploy cancel <id>`) stops an in-progress deploy; ECS traffic-shift deploys still in their rollback window are rolled back natively by ECS.

* **Continue** (`ravion deploy continue <id>`) resumes a deploy paused on a pause-stage hook.

See the [`ravion deploy`](/cli/reference/deploy) CLI reference.