Add GitHub Actions workflow to build custom router image

Signed-off-by: llm-net <[email protected]>

Author: llm-net

.github/workflows/build-custom-router.yml

@@ -0,0 +1,44 @@
+name: Build Custom Router Image
+
+on:
+  push:
+    branches:
+      - fix-max-model-len
+      - main
+  workflow_dispatch:
+
+jobs:
+  build:
+    permissions:
+      contents: read
+      packages: write
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      # Login to GitHub Container Registry (GHCR)
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: docker/Dockerfile
+          push: true
+          tags: |
+            ghcr.io/${{ github.repository }}/router:latest
+            ghcr.io/${{ github.repository }}/router:max-model-len-fix
+            ghcr.io/${{ github.repository }}/router:${{ github.sha }}
+          cache-from: type=registry,ref=ghcr.io/${{ github.repository }}/router:buildcache
+          cache-to: type=registry,ref=ghcr.io/${{ github.repository }}/router:buildcache,mode=max