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1 Commits

Author SHA1 Message Date
Achilleas Athanasiou Fragkoulis cb95b1cf92 fix: Add LITELLM_UI_PATH and LITELLM_ASSETS_PATH for read-only filesystem support (#20492)
Fixes #19578

---

When deploying the LiteLLM proxy with `readOnlyRootFilesystem: true` in Kubernetes, UI routes returned `404` because:

- Hardcoded paths:
  - `/var/lib/litellm/ui`
  - `/var/lib/litellm/assets`
- Runtime copy/restructure operations failed on read-only filesystems
- No detection mechanism for pre-restructured UI

---

Add configurable environment variables with intelligent detection, graceful fallbacks, and code quality improvements.

---

- **`LITELLM_UI_PATH`** — Custom UI directory location
  - Default: `/var/lib/litellm/ui` (when `LITELLM_NON_ROOT=true`)
  - Default: packaged UI path (otherwise)
  - Example: `/app/var/litellm/ui` for `emptyDir` volumes

- **`LITELLM_ASSETS_PATH`** — Custom assets directory location
  - Default: `/var/lib/litellm/assets` (when `LITELLM_NON_ROOT=true`)
  - Default: current working directory (otherwise)
  - Example: `/app/var/litellm/assets`

---

UI is detected as **pre-restructured and ready** if any of the following apply:

1. **Primary**: `.litellm_ui_ready` marker file exists (created by Dockerfile)
2. **Fallback**: Pattern-based detection — finds *any* subdirectory containing `index.html`
   (resilient to UI structure changes; no hardcoded route names)
3. **Safety**: Filesystem writability check before operations

---

**`litellm/proxy/proxy_server.py`**

- `_validate_ui_directory()` — Verifies UI has required structure (`index.html`, `_next/`)
- `_is_ui_pre_restructured()` — Pattern-based detection (not hardcoded routes)
- `_try_populate_ui_directory()` — Helper for clean error handling
- Refactored UI path decision tree with numbered cases (1, 2, 3, 4a, 4b)
- Updated UI path logic to use `LITELLM_UI_PATH`
- Added writability checks before copy/restructure operations
- Graceful fallback to packaged UI if operations fail
- Updated `server_root_path` replacement with read-only check
- Simplified assets directory creation (try/except instead of complex parent checks)
- Updated `get_image()` endpoint to use `LITELLM_ASSETS_PATH`
- Added validation for packaged and final UI paths

**`docker/Dockerfile.non_root`**

- Added `touch .litellm_ui_ready` marker after UI restructuring
- Enables automatic detection of pre-built UI in Docker images

**`tests/proxy_unit_tests/test_ui_path_detection.py`**

- Added comprehensive unit tests for new functionality
- Tests env var handling, detection logic, and writability checks

---

**`docs/my-website/docs/proxy/config_settings.md`**

- Added `LITELLM_UI_PATH` and `LITELLM_ASSETS_PATH` to env vars table
- Documented defaults and use cases

**`docs/my-website/docs/proxy/prod.md`**

- Added comprehensive "Read-Only Root Filesystem" section
- Quick fixes for permission errors
- Full Kubernetes setup with `initContainer` + `emptyDir` volumes
- API-only deployment option
- Environment variables reference table
- Notes on migrations, caching, and `server_root_path`

**`docker/README.md`**

- Updated hardened setup notes to mention pre-built UI
- Added details about UI serving from read-only paths

---

- No breaking changes
- Existing deployments continue working without modifications
- New env vars are optional with sensible defaults
- Detection logic supports both old and new builds
- Graceful fallbacks throughout

---

```yaml
apiVersion: apps/v1
kind: Deployment
spec:
  template:
    spec:
      initContainers:
        - name: setup-ui
          image: ghcr.io/berriai/litellm:main-stable
          command: ["sh", "-c", "cp -r /var/lib/litellm/ui/* /app/var/litellm/ui/"]
          volumeMounts:
            - name: ui-volume
              mountPath: /app/var/litellm/ui
      containers:
        - name: litellm
          env:
            - name: LITELLM_UI_PATH
              value: "/app/var/litellm/ui"
            - name: LITELLM_ASSETS_PATH
              value: "/app/var/litellm/assets"
          securityContext:
            readOnlyRootFilesystem: true
          volumeMounts:
            - name: ui-volume
              mountPath: /app/var/litellm/ui
      volumes:
        - name: ui-volume
          emptyDir:
            sizeLimit: 100Mi
2026-02-12 19:39:04 +05:30