asset-bundles

# Databricks Asset Bundle (DABs) Writer

## Overview
Create DABs for multi-environment deployment (dev/staging/prod).

## Reference Files

- **[SDP_guidance.md](SDP_guidance.md)** - Spark Declarative Pipeline configurations
- **[alerts_guidance.md](alerts_guidance.md)** - SQL Alert schemas (critical - API differs)

## Bundle Structure

```
project/
├── databricks.yml           # Main config + targets
├── resources/*.yml          # Resource definitions
└── src/                     # Code/dashboard files
```

### Main Configuration (databricks.yml)

```yaml
bundle:
  name: project-name

include:
  - resources/*.yml

variables:
  catalog:
    default: "default_catalog"
  schema:
    default: "default_schema"
  warehouse_id:
    lookup:
      warehouse: "Shared SQL Warehouse"

targets:
  dev:
    default: true
    mode: development
    workspace:
      profile: dev-profile
    variables:
      catalog: "dev_catalog"
      schema: "dev_schema"

  prod:
    mode: production
    workspace:
      profile: prod-profile
    variables:
      catalog: "prod_catalog"
      schema: "prod_schema"
```

### Dashboard Resources

```yaml
resources:
  dashboards:
    dashboard_name:
      display_name: "[${bundle.target}] Dashboard Title"
      file_path: ../src/dashboards/dashboard.lvdash.json  # Relative to resources/
      warehouse_id: ${var.warehouse_id}
      permissions:
        - level: CAN_RUN
          group_name: "users"
```

**Permission levels**: `CAN_READ`, `CAN_RUN`, `CAN_EDIT`, `CAN_MANAGE`

### Pipelines

**See [SDP_guidance.md](SDP_guidance.md)** for pipeline configuration

### SQL Alerts

**See [alerts_guidance.md](alerts_guidance.md)** - Alert schema differs significantly from other resources

### Jobs Resources

```yaml
resources:
  jobs:
    job_name:
      name: "[${bundle.target}] Job Name"
      tasks:
        - task_key: "main_task"
          notebook_task:
            notebook_path: ../src/notebooks/main.py  # Relative to resources/
          new_cluster:
            spark_version: "13.3.x-scala2.12"
            node_type_id: "i3.xlarge"
            num_workers: 2
      schedule:
        quartz_cron_expression: "0 0 9 * * ?"
        timezone_id: "America/Los_Angeles"
      permissions:
        - level: CAN_VIEW
          group_name: "users"
```

**Permission levels**: `CAN_VIEW`, `CAN_MANAGE_RUN`, `CAN_MANAGE`

⚠️ **Cannot modify "admins" group permissions** on jobs - verify custom groups exist before use

### Path Resolution

⚠️ **Critical**: Paths depend on file location:

| File Location | Path Format | Example |
|--------------|-------------|---------|
| `resources/*.yml` | `../src/...` | `../src/dashboards/file.json` |
| `databricks.yml` targets | `./src/...` | `./src/dashboards/file.json` |

**Why**: `resources/` files are one level deep, so use `../` to reach bundle root. `databricks.yml` is at root, so use `./`

### Volume Resources

```yaml
resources:
  volumes:
    my_volume:
      catalog_name: ${var.catalog}
      schema_name: ${var.schema}
      name: "volume_name"
      volume_type: "MANAGED"
```

⚠️ **Volumes use `grants` not `permissions`** - different format from other resources

### Apps Resources

**Apps resource support added in Databricks CLI 0.239.0 (January 2025)**

Apps in DABs have a minimal configuration - environment variables are defined in `app.yaml` in the source directory, NOT in databricks.yml.

#### Generate from Existing App (Recommended)

```bash
# Generate bundle config from existing CLI-deployed app
databricks bundle generate app --existing-app-name my-app --key my_app --profile DEFAULT

# This creates:
# - resources/my_app.app.yml (minimal resource definition)
# - src/app/ (downloaded source files including app.yaml)
```

#### Manual Configuration

**resources/my_app.app.yml:**
```yaml
resources:
  apps:
    my_app:
      name: my-app-${bundle.target}        # Environment-specific naming
      description: "My application"
      source_code_path: ../src/app         # Relative to resources/ dir
```

**src/app/app.yaml:** (Environment variables go here)
```yaml
command:
  - "python"
  - "dash_app.py"

env:
  - name: USE_MOCK_BACKEND
    value: "false"
  - name: DATABRICKS_WAREHOUSE_ID
    value: "your-warehouse-id"
  - name: DATABRICKS_CATALOG
    value: "main"
  - name: DATABRICKS_SCHEMA
    value: "my_schema"
```

**databricks.yml:**
```yaml
bundle:
  name: my-bundle

include:
  - resources/*.yml

variables:
  warehouse_id:
    default: "default-warehouse-id"

targets:
  dev:
    default: true
    mode: development
    workspace:
      profile: dev-profile
    variables:
      warehouse_id: "dev-warehouse-id"
```

#### Key Differences from Other Resources

| Aspect | Apps | Other Resources |
|--------|------|-----------------|
| **Environment vars** | In `app.yaml` (source dir) | In databricks.yml or resource file |
| **Configuration** | Minimal (name, description, path) | Extensive (tasks, clusters, etc.) |
| **Source path** | Points to app directory | Points to specific files |

⚠️ **Important**: When source code is in project root (not src/app), use `source_code_path: ..` in the resource file

### Other Resources

DABs supports schemas, models, experiments, clusters, warehouses, etc. Use `databricks bundle schema` to inspect schemas.

**Reference**: [DABs Resource Types](https://docs.databricks.com/dev-tools/bundles/resources)

## Common Commands

### Validation
```bash
databricks bundle validate                    # Validate default target
databricks bundle validate -t prod           # Validate specific target
```

### Deployment
```bash
databricks bundle deploy                      # Deploy to default target
databricks bundle deploy -t prod             # Deploy to specific target
databricks bundle deploy --auto-approve      # Skip confirmation prompts
databricks bundle deploy --force             # Force overwrite remote changes
```

### Running Resources
```bash
databricks bundle run resource_name          # Run a pipeline or job
databricks bundle run pipeline_name -t prod  # Run in specific environment

# Apps require bundle run to start after deployment
databricks bundle run app_resource_key -t dev    # Start/deploy the app
```

### Monitoring & Logs

**View application logs (for Apps resources):**
```bash
# View logs for deployed apps
databricks apps logs <app-name> --profile <profile-name>

# Examples:
databricks apps logs my-dash-app-dev -p DEFAULT
databricks apps logs my-streamlit-app-prod -p DEFAULT
```

**What logs show:**
- `[SYSTEM]` - Deployment progress, file updates, dependency installation
- `[APP]` - Application output (print statements, errors)
- Backend connection status
- Deployment IDs and timestamps
- Stack traces for errors

**Key log patterns to look for:**
- ✅ `Deployment successful` - Confirms deployment completed
- ✅ `App started successfully` - App is running
- ✅ `Initialized real backend` - Backend connected to Unity Catalog
- ❌ `Error:` - Look for error messages and stack traces
- 📝 `Requirements installed` - Dependencies loaded correctly

### Cleanup
```bash
databricks bundle destroy -t dev
databricks bundle destroy -t prod --auto-approve
```

---

## Common Issues

| Issue | Solution |
|-------|----------|
| **App deployment fails** | Check logs: `databricks apps logs <app-name>` for error details |
| **App not connecting to Unity Catalog** | Check logs for backend connection errors; verify warehouse ID and permissions |
| **Wrong permission level** | Dashboards: CAN_READ/RUN/EDIT/MANAGE; Jobs: CAN_VIEW/MANAGE_RUN/MANAGE |
| **Path resolution fails** | Use `../src/` in resources/*.yml, `./src/` in databricks.yml |
| **Catalog doesn't exist** | Create catalog first or update variable |
| **"admins" group error on jobs** | Cannot modify admins permissions on jobs |
| **Volume permissions** | Use `grants` not `permissions` for volumes |
| **Hardcoded catalog in dashboard** | Create environment-specific files or parameterize JSON |
| **App not starting after deploy** | Apps require `databricks bundle run <resource_key>` to start |
| **App env vars not working** | Environment variables go in `app.yaml` (source dir), not databricks.yml |
| **Wrong app source path** | Use `../` from resources/ dir if source is in project root |
| **Debugging any app issue** | First step: `databricks apps logs <app-name>` to see what went wrong |

## Key Principles

1. **Path resolution**: `../src/` in resources/*.yml, `./src/` in databricks.yml
2. **Variables**: Parameterize catalog, schema, warehouse
3. **Mode**: `development` for dev/staging, `production` for prod
4. **Groups**: Use `"users"` for all workspace users
5. **Job permissions**: Verify custom groups exist; can't modify "admins"

## Resources

- [Databricks Asset Bundles Documentation](https://docs.databricks.com/dev-tools/bundles/)
- [Bundle Resources Reference](https://docs.databricks.com/dev-tools/bundles/resources)
- [Bundle Configuration Reference](https://docs.databricks.com/dev-tools/bundles/settings)
- [Supported Resource Types](https://docs.databricks.com/aws/en/dev-tools/bundles/resources#resource-types)
- [Examples Repository 1](https://github.com/databricks-solutions/databricks-dab-examples)
- [Example Repository 2](https://github.com/databricks/bundle-examples)