How can I get a python program to check linux services?

Question

I want to make a simple python script that I can run cron to work. I just want to see if these services are started or stopped

Httpd mysql 

How can I test them using python.

Do I need to parse the output of netstat -tlnp

Answer 1

If you use a subprocess module, you can do this without creating a shell that the command module will execute. (You probably do not need a separate shell for this, and perhaps this may be due to security).

Please note that this also gives you the opportunity to deal with errors (see err variable below), for example, you can try restarting services that are not available, etc.

 import subprocess p = subprocess.Popen(["ps", "-a"], stdout=subprocess.PIPE) out, err = p.communicate() if ('Httpd' in str(out)): print('Httpd running') if ('mysql' in str(out)): print('mysql running') 

http://docs.python.org/2/library/subprocess.html

Answer 2

You can use the command module to run the ps shell argument:

 import commands output = commands.getoutput('ps -A') if 'Httpd' in output: print("Httpd is up an running!") 

[edit] I just read the command module, and although it works fine, it seems deprecated since Python 2.6 and is even removed in Python 3.x. Therefore, if you are on Python 3 or want to be prepared for future porting to Python 3, you can use the subprocess module:

 import subprocess output = subprocess.check_output(['ps', '-A']) if 'Httpd' in output: print("Httpd is up an running!") 

Answer 3

Use the psutils class. Its fantastic and cross platform .. The following is the functional use.

 import psutil >>> psutil.get_pid_list() [1, 2, 3, 4, 5, 6, 7, 46, 48, 50, 51, 178, 182, 222, 223, 224, 268, 1215, 1216, 1220, 1221, 1243, 1244, 1301, 1601, 2237, 2355, 2637, 2774, 3932, 4176, 4177, 4185, 4187, 4189, 4225, 4243, 4245, 4263, 4282, 4306, 4311, 4312, 4313, 4314, 4337, 4339, 4357, 4358, 4363, 4383, 4395, 4408, 4433, 4443, 4445, 4446, 5167, 5234, 5235, 5252, 5318, 5424, 5644, 6987, 7054, 7055, 7071] >>> >>> p = psutil.Process(7055) >>> p.name 'python' >>> p.exe '/usr/bin/python' >>> p.getcwd() '/home/giampaolo' >>> p.cmdline ['/usr/bin/python', 'main.py'] >>> >>> str(p.status) 'running' >>> p.username 'giampaolo' >>> p.create_time 1267551141.5019531 >>> p.terminal '/dev/pts/0' >>> >>> p.uids user(real=1000, effective=1000, saved=1000) >>> p.gids group(real=1000, effective=1000, saved=1000) >>> >>> p.get_cpu_times() cputimes(user=1.02, system=0.31) >>> p.get_cpu_percent(interval=1.0) 12.1 >>> p.get_cpu_affinity() [0, 1, 2, 3] >>> p.set_cpu_affinity([0]) >>> >>> p.get_memory_percent() 0.63423 >>> p.get_memory_info() meminfo(rss=7471104, vms=68513792) >>> p.get_ext_memory_info() meminfo(rss=9662464, vms=49192960, shared=3612672, text=2564096, lib=0, data=5754880,dirty=0) >>> p.get_memory_maps() [mmap(path='/lib/x86_64-linux-gnu/libutil-2.15.so', rss=16384, anonymous=8192, swap=0), mmap(path='/lib/x86_64-linux-gnu/libc-2.15.so', rss=6384, anonymous=15, swap=0), mmap(path='/lib/x86_64-linux-gnu/libcrypto.so.1.0.0', rss=34124, anonymous=1245, swap=0), mmap(path='[heap]', rss=54653, anonymous=8192, swap=0), mmap(path='[stack]', rss=1542, anonymous=166, swap=0), ...] >>> >>> p.get_io_counters() io(read_count=478001, write_count=59371, read_bytes=700416, write_bytes=69632) >>> >>> p.get_open_files() [openfile(path='/home/giampaolo/svn/psutil/somefile', fd=3)] >>> >>> p.get_connections() [connection(fd=115, family=2, type=1, local_address=('10.0.0.1', 48776), remote_address=('93.186.135.91', 80), status='ESTABLISHED'), connection(fd=117, family=2, type=1, local_address=('10.0.0.1', 43761), remote_address=('72.14.234.100', 80), status='CLOSING'), connection(fd=119, family=2, type=1, local_address=('10.0.0.1', 60759), remote_address=('72.14.234.104', 80), status='ESTABLISHED'), connection(fd=123, family=2, type=1, local_address=('10.0.0.1', 51314), remote_address=('72.14.234.83', 443), status='SYN_SENT')] >>> >>> p.get_num_threads() 4 >>> p.get_num_fds() 8 >>> p.get_num_ctx_switches() amount(voluntary=78, involuntary=19) >>> >>> p.get_threads() [thread(id=5234, user_time=22.5, system_time=9.2891), thread(id=5235, user_time=0.0, system_time=0.0), thread(id=5236, user_time=0.0, system_time=0.0), thread(id=5237, user_time=0.0707, system_time=1.1)] >>> >>> p.get_nice() 0 >>> p.set_nice(10) >>> >>> p.suspend() >>> p.resume() >>> >>> p.terminate() >>> p.wait(timeout=3) 0 >>> >>> psutil.test() USER PID %CPU %MEM VSZ RSS TTY START TIME COMMAND root 1 0.0 0.0 24584 2240 ? Jun17 00:00 init root 2 0.0 0.0 0 0 ? Jun17 00:00 kthreadd root 3 0.0 0.0 0 0 ? Jun17 00:05 ksoftirqd/0 ... giampaolo 31475 0.0 0.0 20760 3024 /dev/pts/0 Jun19 00:00 python2.4 giampaolo 31721 0.0 2.2 773060 181896 ? 00:04 10:30 chrome root 31763 0.0 0.0 0 0 ? 00:05 00:00 kworker/0:1 >>> 

Answer 4

If your services are correctly registered and support the status report (init script or pop up), use the linux command

 service <name> status 

If the service is running, the command will return exit code 0

 import os import subprocess def is_service_running(name): with open(os.devnull, 'wb') as hide_output: exit_code = subprocess.Popen(['service', name, 'status'], stdout=hide_output, stderr=hide_output).wait() return exit_code == 0 if not is_service_running('mysql'): print 'mysql is not running' 

• os.devnull is a bonus to hide the output of a child process.