api: add health and server_time

Signed-off-by: Lu Ken <[email protected]>

requirements.txt

@@ -1,2 +1,6 @@
 fastapi[standard]
-uvicorn
+uvicorn
+pydantic
+pydantic-settings
+ntplib
+python-dateutil

src/gentrade_server/config.py

@@ -0,0 +1,12 @@
+"""
+Configure
+"""
+from pydantic_settings import BaseSettings
+
+class Settings(BaseSettings):
+    """
+    Settings
+    """
+    ntp_server: str = "ntp.ntsc.ac.cn"
+
+settings = Settings()

src/gentrade_server/main.py

@@ -1,13 +1,39 @@
 """
 The main entry
 """
-import uvicorn
+import logging
+from contextlib import asynccontextmanager
 
+import uvicorn
 from fastapi import FastAPI, Depends
+from fastapi.middleware.cors import CORSMiddleware
+
 from .routers import secure, public
 from .auth import get_user
+from .util import sync_ntp_server
+
+logging.basicConfig(level=logging.INFO, format='%(asctime)s %(message)s')
+LOG = logging.getLogger(__name__)
+
+@asynccontextmanager
+async def lifespan(_:FastAPI):
+    """
+    App lifecycle
+    """
+    LOG.info("Starting Up...")
+    sync_ntp_server()
+    yield
+    LOG.info("Shutting Down...")
 
 app = FastAPI()
+app = FastAPI(lifespan=lifespan)
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
 
 app.include_router(
     public.router,

src/gentrade_server/routers/public.py

@@ -1,7 +1,19 @@
 """
 Public result API interfaces
 """
+import logging
+
+import time
+import datetime
+from dateutil.tz import tzlocal
+
 from fastapi import APIRouter
+from pydantic import BaseModel
+
+from ..util import sync_ntp_server
+from ..config import settings
+
+LOG = logging.getLogger(__name__)
 
 router = APIRouter()
 
@@ -11,3 +23,43 @@ async def get_testroute():
     Test public interface
     """
     return "OK"
+
+class HealthCheck(BaseModel):
+    """
+    Response model to validate and return when performing a health check.
+    """
+
+    status: str = "OK"
+
+@router.get("/health")
+async def get_health() -> HealthCheck:
+    """
+    Check health
+    """
+    return HealthCheck(status="OK")
+
+@router.get("/settings")
+async def get_settings():
+    """
+    Get server settings
+    """
+    return {
+        'ntp_server': settings.ntp_server
+    }
+
+@router.get("/server_time")
+async def get_server_time():
+    """
+    Get server time
+    """
+    curr_ts = time.time()
+    now_utc   = datetime.datetime.fromtimestamp(curr_ts, datetime.UTC)
+    tl = tzlocal()
+    ntp_offset = sync_ntp_server()
+
+    return {
+        'ntp_offset': ntp_offset,
+        'timezone_name': tl.tzname(now_utc),
+        'timezone_offset': tl.utcoffset(now_utc).total_seconds(),
+        'timestamp_server': int(curr_ts)
+    }

src/gentrade_server/util.py

@@ -0,0 +1,32 @@
+"""
+Utils
+"""
+import logging
+import ntplib
+
+LOG = logging.getLogger(__name__)
+
+def sync_ntp_server() -> float:
+    """
+    Sync with NTP server
+
+    :return : offset in seconds
+    """
+    ntp_servers = ['ntp.ntsc.ac.cn', 'ntp.sjtu.edu.cn', 'cn.ntp.org.cn',
+                   'cn.pool.ntp.org', 'ntp.aliyun.com']
+    retry = len(ntp_servers) - 1
+    client = ntplib.NTPClient()
+    while retry > 0:
+        LOG.info("Try to get time from NTP: %s", ntp_servers[retry])
+
+        try:
+            ret = client.request(ntp_servers[retry], version=3)
+            offset = (ret.recv_time - ret.orig_time +
+                    ret.dest_time - ret.tx_time) / 2
+            LOG.info("NTP offset: %.2f", offset)
+            return offset
+        except ntplib.NTPException:
+            LOG.error("Fail to get time, try another")
+            retry -= 1
+            continue
+    return None