supervisor进程管理工具
26 July 2017
Supervisor是一款基于客户端、服务端模式的进程管理工具。当然，通过nohup、screen等命令也可以实现Linux程序的后台运行，但是如果服务因为内存泄露等原因导致程序异常退出，上述方案就无能为力了。Supervisor就是这样由Python开发的通用进程管理工具，能够将一个普通进程变为守护进程，并且监控进程状态，异常退出时能够自动重启。
安装
Supervisor的安装和其他python程序一样，可通过pip install supervisor命令直接安装。对于没有网络，或者防火墙比较厚的机器需要下载以下两个依赖包：
解压并在目录下分别执行python setup.py install，最后到supervisor目录，执行python setup.py install完成安装。
配置
Supervisor默认配置文件在/etc/supervisord.conf，格式及其含义如下：
; Sample supervisor config file.
[unix_http_server]
file=/run/supervisor.sock ; (the path to the socket file)
;chmod=0700 ; socked file mode (default 0700)
;chown=nobody:nogroup ; socket file uid:gid owner
;username=user ; (default is no username (open server))
;password=123 ; (default is no password (open server))
[inet_http_server] ; inet (TCP) server disabled by default
port=127.0.0.1:9001 ; (ip_address:port specifier, *:port for all iface)
;username=user ; (default is no username (open server))
;password=123 ; (default is no password (open server))
[supervisord]
logfile=/var/log/supervisord.log ; (main log file;default $CWD/supervisord.log)
;logfile_maxbytes=50MB ; (max main logfile bytes b4 rotation;default 50MB)
;logfile_backups=10 ; (num of main logfile rotation backups;default 10)
loglevel=info ; (log level;default info; others: debug,warn,trace)
pidfile=/run/supervisord.pid ; (supervisord pidfile;default supervisord.pid)
nodaemon=false ; (start in foreground if true;default false)
;minfds=1024 ; (min. avail startup file descriptors;default 1024)
;minprocs=200 ; (min. avail process descriptors;default 200)
;umask=022 ; (process file creation umask;default 022)
;user=chrism ; (default is current user, required if root)
;identifier=supervisor ; (supervisord identifier, default is 'supervisor')
;directory=/tmp ; (default is not to cd during start)
;nocleanup=true ; (don't clean up tempfiles at start;default false)
childlogdir=/var/log/supervisor ; ('AUTO' child log dir, default $TEMP)
;environment=KEY=value ; (key value pairs to add to environment)
;strip_ansi=false ; (strip ansi escape codes in logs; def. false)
; the below section must remain in the config file for RPC
; (supervisorctl/web interface) to work, additional interfaces may be
; added by defining them in separate rpcinterface: sections
[rpcinterface:supervisor]
supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface
[supervisorctl]
serverurl=unix:///run/supervisor.sock ; use a unix:// URL for a unix socket
;serverurl=http://127.0.0.1:9001 ; use an http:// url to specify an inet socket
;username=chris ; should be same as http_username if set
;password=123 ; should be same as http_password if set
;prompt=mysupervisor ; cmd line prompt (default "supervisor")
;history_file=~/.sc_history ; use readline history if available
; The below sample program section shows all possible program subsection values,
; create one or more 'real' program: sections to be able to control them under
; supervisor.
;[program:theprogramname]
;command=/bin/cat ; the program (relative uses PATH, can take args)
;process_name=%(program_name)s ; process_name expr (default %(program_name)s)
;numprocs=1 ; number of processes copies to start (def 1)
;directory=/tmp ; directory to cwd to before exec (def no cwd)
;umask=022 ; umask for process (default None)
;priority=999 ; the relative start priority (default 999)
;autostart=true ; start at supervisord start (default: true)
;autorestart=unexpected ; whether/when to restart (default: unexpected)
;startsecs=1 ; number of secs prog must stay running (def. 1)
;startretries=3 ; max # of serial start failures (default 3)
;exitcodes=0,2 ; 'expected' exit codes for process (default 0,2)
;stopsignal=QUIT ; signal used to kill process (default TERM)
;stopwaitsecs=10 ; max num secs to wait b4 SIGKILL (default 10)
;killasgroup=false ; SIGKILL the UNIX process group (def false)
;user=chrism ; setuid to this UNIX account to run the program
;redirect_stderr=true ; redirect proc stderr to stdout (default false)
;stdout_logfile=/a/path ; stdout log path, NONE for none; default AUTO
;stdout_logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB)
;stdout_logfile_backups=10 ; # of stdout logfile backups (default 10)
;stdout_capture_maxbytes=1MB ; number of bytes in 'capturemode' (default 0)
;stdout_events_enabled=false ; emit events on stdout writes (default false)
;stderr_logfile=/a/path ; stderr log path, NONE for none; default AUTO
;stderr_logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB)
;stderr_logfile_backups=10 ; # of stderr logfile backups (default 10)
;stderr_capture_maxbytes=1MB ; number of bytes in 'capturemode' (default 0)
;stderr_events_enabled=false ; emit events on stderr writes (default false)
;environment=A=1,B=2 ; process environment additions (def no adds)
;serverurl=AUTO ; override serverurl computation (childutils)
; The below sample eventlistener section shows all possible
; eventlistener subsection values, create one or more 'real'
; eventlistener: sections to be able to handle event notifications
; sent by supervisor.
;[eventlistener:theeventlistenername]
;command=/bin/eventlistener ; the program (relative uses PATH, can take args)
;process_name=%(program_name)s ; process_name expr (default %(program_name)s)
;numprocs=1 ; number of processes copies to start (def 1)
;events=EVENT ; event notif. types to subscribe to (req'd)
;buffer_size=10 ; event buffer queue size (default 10)
;directory=/tmp ; directory to cwd to before exec (def no cwd)
;umask=022 ; umask for process (default None)
;priority=-1 ; the relative start priority (default -1)
;autostart=true ; start at supervisord start (default: true)
;autorestart=unexpected ; whether/when to restart (default: unexpected)
;startsecs=1 ; number of secs prog must stay running (def. 1)
;startretries=3 ; max # of serial start failures (default 3)
;exitcodes=0,2 ; 'expected' exit codes for process (default 0,2)
;stopsignal=QUIT ; signal used to kill process (default TERM)
;stopwaitsecs=10 ; max num secs to wait b4 SIGKILL (default 10)
;killasgroup=false ; SIGKILL the UNIX process group (def false)
;user=chrism ; setuid to this UNIX account to run the program
;redirect_stderr=true ; redirect proc stderr to stdout (default false)
;stdout_logfile=/a/path ; stdout log path, NONE for none; default AUTO
;stdout_logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB)
;stdout_logfile_backups=10 ; # of stdout logfile backups (default 10)
;stdout_events_enabled=false ; emit events on stdout writes (default false)
;stderr_logfile=/a/path ; stderr log path, NONE for none; default AUTO
;stderr_logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB)
;stderr_logfile_backups ; # of stderr logfile backups (default 10)
;stderr_events_enabled=false ; emit events on stderr writes (default false)
;environment=A=1,B=2 ; process environment additions
;serverurl=AUTO ; override serverurl computation (childutils)
; The below sample group section shows all possible group values,
; create one or more 'real' group: sections to create "heterogeneous"
; process groups.
;[group:thegroupname]
;programs=progname1,progname2 ; each refers to 'x' in [program:x] definitions
;priority=999 ; the relative start priority (default 999)
; The [include] section can just contain the "files" setting. This
; setting can list multiple files (separated by whitespace or
; newlines). It can also contain wildcards. The filenames are
; interpreted as relative to this file. Included files *cannot*
; include files themselves.
[include]
files = /etc/supervisor.d/*.ini
各配置项的含义其实已经很明显了。进程管理的配置可以直接写在配置文件supervisord.conf中，也可以分进程保存在指定目录下，在include中导入，推荐后者。配置格式如下：
[program:mydeamon]
directory = /usr/local/mydeamon/ ; 程序的启动目录
command = /usr/local/mydeamon/bin/mydeamon ; 启动命令，与手动在命令行启动的命令是一样的
autostart = true ; 在 supervisord 启动的时候是否自动启动
startsecs = 10 ; 启动10秒后没有异常退出，就当作已经正常启动了
autorestart = unexpected ; 程序异常退出后自动重启
exitcodes = 0 ; 返回码为0时，正常退出，否则自动重启
startretries = 3 ; 启动失败自动重试次数，默认是 3
user = root ; 用哪个用户启动
redirect_stderr = true ; 把 stderr 重定向到 stdout，默认 false
stdout_logfile_maxbytes = 20MB ; stdout 日志文件大小，默认 50MB
stdout_logfile_backups = 20 ; stdout 日志文件备份数
; stdout 日志文件，需要注意当指定目录不存在时无法正常启动，所以需要手动创建目录（supervisord 会自动创建日志文件）
stdout_logfile = /var/log/mydeamon_stdout.log
将上述文件命名为mydeamon.init保存在/etc/supervisor.d目录下即可。
管理命令
supervisord # 初始启动Supervisord，启动、管理配置中设置的进程。
supervisorctl stop xxx # 停止某一个进程(xxx)，xxx为[program:mydeamon]里配置的值，这个示例就是mydeamon。
supervisorctl start xxx # 启动某个进程
supervisorctl restart xxx # 重启某个进程
supervisorctl stop all # 停止全部进程，注：start、restart、stop都不会载入最新的配置文件。
supervisorctl reload # 载入最新的配置文件，并按新的配置启动、管理所有进程。