# Setup OSV offline DB Action

A reusable Gitea Action that restores or populates the [OSV-Scanner local vulnerability cache](https://google.github.io/osv-scanner/usage/offline-mode/) used with `--offline-vulnerabilities`.

Databases are fetched with **curl** from `https://osv-vulnerabilities.storage.googleapis.com/` as described under [Manual database download](https://google.github.io/osv-scanner/usage/offline-mode/#manual-database-download): for each requested ecosystem, download `…/<ecosystem>/all.zip` into `osv-scanner/<ecosystem>/all.zip`. **OSV-Scanner is not invoked** for downloads.

**Requires:** `curl`, `bash` 4+ (associative arrays), `python3` (URL-encoding paths).

**Note:** This action only prepares the local DB directory. Install the scanner separately.

## Ecosystems input

Use **`ecosystems`**: a comma-separated list (spaces around commas are trimmed). Each token is matched to an entry from [ecosystems.txt](https://osv-vulnerabilities.storage.googleapis.com/ecosystems.txt) by:

- **Slug match:** lowercased, spaces → `-`, brackets removed (e.g. `GitHub Actions` and `github-actions` both match).
- **Special case:** `docker` is not an OSV ecosystem; it is treated as **`Linux`** (useful as a default when scanning image-related data). Override with `Alpine`, `Debian`, etc. if you prefer.

The **`actions/cache` key includes** the sorted, slugified list of resolved ecosystems (e.g. `github-actions,go,linux,npm`) plus the hour bucket settings, so different ecosystem sets never share a cache entry.

## Usage

```yaml
uses: https://gitea.example/your-user/osv-scanner-actions/setup-osv-db@0.0.1
with:
  ecosystems: PyPI,npm,Go
```

## Example workflow

```yaml
jobs:
  scan:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Setup offline DB
        id: setup-db
        uses: https://gitea.example/your-user/osv-scanner-actions/setup-osv-db@0.0.1
        with:
          cache-bucket-hours: 6
          ecosystems: github-actions,npm,go,Alpine
      - name: Scan (offline vulnerabilities only)
        env:
          OSV_SCANNER_LOCAL_DB_CACHE_DIRECTORY: ${{ steps.setup-db.outputs.cache-dir }}
        run: osv-scanner scan source --offline-vulnerabilities -r .
```

## Inputs

| Name                 | Description                                                               | Required | Default                          |
| -------------------- | ------------------------------------------------------------------------- | -------- | -------------------------------- |
| `cache-dir`          | Directory for `OSV_SCANNER_LOCAL_DB_CACHE_DIRECTORY`                      | No       | `${{ runner.temp }}/osv-scanner` |
| `cache-bucket-hours` | `actions/cache` primary key includes `floor(UTC unix time / (3600 × N))`. | No       | `24`                             |
| `ecosystems`         | Comma-separated tokens (names/slugs; `docker` → `Linux`).                 | No       | `github-actions,npm,go,docker`   |

## Outputs

| Name        | Description        |
| ----------- | ------------------ |
| `cache-dir` | Same as input path |

## Behavior

- **Cache:** Key pattern `osv-scanner-db-{hours}h-eco-{sorted-slugs}-{bucket}`. `restore-keys` reuse the newest cache for the same hours + ecosystem set when the current time bucket misses.
- **Populate:** On cache miss, `${cache-dir}/osv-scanner` is recreated and only the requested ecosystems are downloaded.