ci: add nightly eval (#1291)

.github/workflows/nightly-eval.yml

+name: Nightly Evaluation
+
+on:
+  schedule:
+    - cron: '0 0 * * *'
+  push:
+    branches:
+      - main
+    paths:
+      - "python/sglang/version.py"
+  workflow_dispatch:
+
+concurrency:
+  group: nightly-eval-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  meta-llama-31-8b-instruct:
+    if: github.repository == 'sgl-project/sglang' || github.event_name == 'pull_request'
+    runs-on: 1-gpu-runner
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Install dependencies
+        run: |
+          pip install --upgrade pip
+          pip install -e "python[dev]"
+          pip install flashinfer -i https://flashinfer.ai/whl/cu121/torch2.4/ --force-reinstall
+          git clone https://github.com/EleutherAI/lm-evaluation-harness
+          pushd lm-evaluation-harness
+          pip install -e .
+          pip install lm_eval[api]
+          popd
+
+      - name: Run eval
+        timeout-minutes: 20
+        run: |
+            python3 -m sglang.launch_server --model meta-llama/Meta-Llama-3.1-8B-Instruct --disable-radix-cache &
+
+            echo "Waiting for server to start..."
+            for i in {1..120}; do
+              if curl -s http://127.0.0.1:30000/health; then
+                echo "Server is up!"
+                break
+              fi
+              if [ $i -eq 120 ]; then
+                echo "Server failed to start within 120 seconds"
+                exit 1
+              fi
+              sleep 1
+            done
+
+            lm_eval --model local-completions --tasks gsm8k --model_args model=meta-llama/Meta-Llama-3.1-8B-Instruct,base_url=http://127.0.0.1:30000/v1/completions,num_concurrent=128,max_retries=3,tokenized_requests=False
+
+            echo "Stopping server..."
+            kill -9 $(ps aux | grep sglang | grep Meta-Llama-3.1-8B-Instruct | grep -v grep | awk '{print $2}')
+
+  finish:
+    needs: [
+      meta-llama-31-8b-instruct
+    ]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Finish
+        run: echo "This is an empty step to ensure that all jobs are completed."