[CI/Build] Replace vllm.entrypoints.openai.api_server entrypoint with vllm serve command (#25967)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

docs/deployment/frameworks/skypilot.md

@@ -32,6 +32,7 @@ See the vLLM SkyPilot YAML for serving, [serving.yaml](https://github.com/skypil
       ports: 8081  # Expose to internet traffic.
 
     envs:
+      PYTHONUNBUFFERED: 1
       MODEL_NAME: meta-llama/Meta-Llama-3-8B-Instruct
       HF_TOKEN: <your-huggingface-token>  # Change to your own huggingface token, or use --env to pass.
 
@@ -47,9 +48,8 @@ See the vLLM SkyPilot YAML for serving, [serving.yaml](https://github.com/skypil
     run: |
       conda activate vllm
       echo 'Starting vllm api server...'
-      python -u -m vllm.entrypoints.openai.api_server \
+      vllm serve $MODEL_NAME \
         --port 8081 \
-        --model $MODEL_NAME \
         --trust-remote-code \
         --tensor-parallel-size $SKYPILOT_NUM_GPUS_PER_NODE \
         2>&1 | tee api_server.log &
@@ -131,6 +131,7 @@ SkyPilot can scale up the service to multiple service replicas with built-in aut
       ports: 8081  # Expose to internet traffic.
 
     envs:
+      PYTHONUNBUFFERED: 1
       MODEL_NAME: meta-llama/Meta-Llama-3-8B-Instruct
       HF_TOKEN: <your-huggingface-token>  # Change to your own huggingface token, or use --env to pass.
 
@@ -146,9 +147,8 @@ SkyPilot can scale up the service to multiple service replicas with built-in aut
     run: |
       conda activate vllm
       echo 'Starting vllm api server...'
-      python -u -m vllm.entrypoints.openai.api_server \
+      vllm serve $MODEL_NAME \
         --port 8081 \
-        --model $MODEL_NAME \
         --trust-remote-code \
         --tensor-parallel-size $SKYPILOT_NUM_GPUS_PER_NODE \
         2>&1 | tee api_server.log
@@ -243,6 +243,7 @@ This will scale the service up to when the QPS exceeds 2 for each replica.
       ports: 8081  # Expose to internet traffic.
 
     envs:
+      PYTHONUNBUFFERED: 1
       MODEL_NAME: meta-llama/Meta-Llama-3-8B-Instruct
       HF_TOKEN: <your-huggingface-token>  # Change to your own huggingface token, or use --env to pass.
 
@@ -258,9 +259,8 @@ This will scale the service up to when the QPS exceeds 2 for each replica.
     run: |
       conda activate vllm
       echo 'Starting vllm api server...'
-      python -u -m vllm.entrypoints.openai.api_server \
+      vllm serve $MODEL_NAME \
         --port 8081 \
-        --model $MODEL_NAME \
         --trust-remote-code \
         --tensor-parallel-size $SKYPILOT_NUM_GPUS_PER_NODE \
         2>&1 | tee api_server.log