fix: apisix restart failed (#10495)

apisix/cli/ops.lua

@@ -806,6 +806,7 @@ local function start(env, ...)
         local ok, err, err_no = signal.kill(pid, signone)
         if ok then
             print("APISIX is running...")
+            print("the old process is still running, the new one won't be started!")
             return
         -- no such process
         elseif err_no ~= errno.ESRCH then
@@ -916,10 +917,32 @@ local function stop(env)
 end
 
 
+local function sleep(n)
+  execute("sleep " .. tonumber(n))
+end
+
+
+local function wait_stop_finish(env, n)
+    for i = 1, n do
+         -- check running
+        local pid_path = env.apisix_home .. "/logs/nginx.pid"
+        local pid = util.read_file(pid_path)
+        pid = tonumber(pid)
+        if not pid then
+            print("old apisix process has stopped")
+            return
+        else
+            sleep(1)
+        end
+    end
+end
+
+
 local function restart(env)
   -- test configuration
   test(env)
   stop(env)
+  wait_stop_finish(env, 3)
   start(env)
 end