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

# Migrate to Airflow 3 from Airflow 2 in Astro Private Cloud

This guide describes the steps required to migrate your Airflow deployments from Airflow 2 to Airflow 3 in Astro Private Cloud.

## 1. Enable Airflow 3 on the cluster

1. Navigate to the **Cluster Configuration Override** page in the Astro Private Cloud UI.
2. Enable the **Airflow 3 flag**:

```yaml wrap theme={null}
astronomer:
    houston:
        deployments:
            airflowV3:
                enabled: true
```

3. Enable the mandatory Dag processor component for Airflow 3:

```yaml wrap theme={null}
astronomer:
    houston:
        deployments:
            dagProcessorEnabled: true
```

<Warning> Airflow 3 requires the Dag processor to be enabled. Deployments without this component will fail. </Warning>

4. Enable **Sidecar Logging** for Airflow tasks:

```yaml wrap theme={null}
global:
    loggingSidecar:
        enabled: true
```

<Warning> Airflow 3 requires sidecar logging. Deployments without this component won't be able to view task logs. </Warning>

## 2. Configure registry access

1. Allowlist the Azure Container Registry (`azurecr`) repository and URL for pulling Airflow 3 images.
2. If using third-party registries, configure mirroring to ensure reliable image pulls.

<Note> Airflow 3 images are hosted at `astrocrpublic.azurecr.io`. </Note>

## 3. Check Dag compatibility before migration

Before upgrading, follow the [Airflow 2 → 3 upgrade guide](/docs/learn/airflow-upgrade-2-3) to verify that your Dags are compatible with Airflow 3.

## 4. Update Deployment Dockerfile

1. Modify your Dockerfile to use the Airflow 3 image and updated registry URL:

```dockerfile wrap theme={null}
FROM astrocrpublic.azurecr.io/runtime:3.1-2
```

2. Build and push your updated Docker image.
   <Note> Airflow 2 images are available on Quay (`quay.io/astronomer/airflow`), while Airflow 3 images are hosted on `astrocr` (`astrocrpublic.azurecr.io`). </Note>

## 5. Update Deployment

Perform the Deployment update using one of the following methods:

1. UI: Navigate to your Deployment and trigger an update with the new Airflow 3 image.
2. API: Use the UpsertDeployment API to update the Deployment image.
3. CLI: Use the Astro CLI to deploy the updated image.

Ensure the updated Deployment reflects the Airflow 3 runtime version.

## 6. Validate after migration

* Confirm that Dags are running as expected in Airflow 3.
* Monitor logs and metrics to ensure stability.
* Verify that the Dag processor component is active and functioning.

<Note>
  This guide provides a **safe and supported path** to migrate from Airflow 2 to Airflow 3 in Astro Private Cloud.
</Note>