需求描述
项目需求测试过程中，需要向Nginx服务器发送一些用例请求，然后查看对应的Nginx日志，判断是否存在特征内容，来判断任务是否执行成功。为了提升效率，需要将这一过程实现自动化。
实践环境
Python 3.6.5
代码设计与实现
#!/usr/bin/env python
# -*- coding:utf-8 -*-
"""
@CreateTime: 2021/06/26 9:05
@Author : shouke
"""
import time
import threading
import subprocess
from collections import deque
def collect_nginx_log():
global nginx_log_queue
global is_tasks_compete
global task_status
args = "tail -0f /usr/local/openresty/nginx/logs/access.log"
while task_status != "req_log_got":
with subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True, universal_newlines = True) as proc:
log_for_req = ""
outs, errs = "", ""
try:
outs, errs = proc.communicate(timeout=2)
except subprocess.TimeoutExpired:
print("获取nginx日志超时，正在重试")
proc.kill()
try:
outs, errs = proc.communicate(timeout=5)
except subprocess.TimeoutExpired:
print("获取nginx日志超时，再次超时，停止重试")
break
finally:
for line in outs.split("
"):
flag = ""client_ip":"10.118.0.77"" # 特征
if flag in line: # 查找包含特征内容的日志
log_for_req += line
if task_status == "req_finished":
nginx_log_queue.append(log_for_req)
task_status = "req_log_got"
def run_tasks(task_list):
"""
运行任务
:param task_list 任务列表
"""
global nginx_log_queue
global is_tasks_compete
global task_status
for task in task_list:
thread = threading.Thread(target=collect_nginx_log,
name="collect_nginx_log")
thread.start()
time.sleep(1) # 执行任务前，让收集日志线程先做好准备
print("正在执行任务：%s" % task.get("name"))
# 执行Nginx任务请求
# ...
task_status = "req_finished"
time_to_wait = 0.1
while task_status != "req_log_got": # 请求触发的nginx日志收集未完成
time.sleep(time_to_wait)
time_to_wait += 0.01
else:# 获取到用例请求触发的nginx日志
if nginx_log_queue:
nginx_log = nginx_log_queue.popleft()
task_status = "req_ready"
# 解析日志
# do something here
# ...
else:
print("存储请求日志的队列为空")
# do something here
# ...
if __name__ == "__main__":
nginx_log_queue = deque()
is_tasks_compete = False # 所有任务是否执行完成
task_status = "req_ready" # req_ready，req_finished，req_log_got # 存放执行次任务任务的一些状态
print("###########################任务开始###########################")
tast_list = [{"name":"test_task", "other":"..."}]
run_tasks(tast_list)
is_tasks_compete = True
current_active_thread_num = len(threading.enumerate())
while current_active_thread_num != 1:
time.sleep(2)
current_active_thread_num = len(threading.enumerate())
print("###########################任务完成###########################")注意：
1、上述代码为啥不一步到位，直接 tail -0f /usr/local/openresty/nginx/logs/access.log | grep "特征内容"呢？这是因为这样做无法获取到Nginx的日志
2、实践时发现，第一次执行proc.communicate(timeout=2)获取日志时，总是无法获取，会超时，需要二次获取，并且timeout设置太小时(实践时尝试过设置为1秒)，也会导致第二次执行时无法获取Nginx日志。
