Metadata-Version: 1.1
Name: ordered-startup-supervisord
Version: 1.0.3
Summary: An event listener for supervisord that will start up items in order upon certain states.
Home-page: http://github.com/jasoncorbett/ordered-startup-supervisord
Author: Jason Corbett
Author-email: UNKNOWN
License: Apache Software License v2
Description: =======================================
         Priority Order Startup for Supervisor
        =======================================
        
        The Problem
        ===========
        The problem can be seen in `supervisor bug 122`_.  The priority order in supervisor does determine startup order, but
        when **autostart=true** supervisor doesn't wait for the previous process to be RUNNING in order to continue.  What is
        even harder is having initialization scripts that need to exit before continuing.  This software is meant to make
        this one use case easier.
        
        .. _supervisor bug 122: https://github.com/Supervisor/supervisor/issues/122
        
        How it works
        ============
        
        This is an event listener for supervisor.  This means it is run by supervisor on startup and supervisor will send it
        messages whenever a program reaches a particular process state.  When configured it will wait till a supervisor
        subprocess get's to the configured state, then starts the next process.  The next process is determined by priority.
        
        Caveats
        =======
        
        This does not solve every situation.  If what you need is everything starting up one by one, then this will likely solve
        your issue.  If you need to mix and match which starts in parallel and which in serial (dependencies) this is probably
        not what you want.
        
        This does not start groups.  It can start programs that are part of a group, but it won't directly start a group.
        
        Configuration
        =============
        
        Configuration requires several things.  First you need to configure this software as a event listener::
        
            [eventlistener:inorder]
            command=/path/to/ordered-startup-listener
            autostart=true
            events=PROCESS_STATE
        
        This is probably the only thing you want to autostart.  It needs xml rpc api, so don't forget to configure that.  A
        full example is shown later.
        
        There are 2 additional configurations that can be put in a *[program:* section.  These are:
        
            **startinorder**
              This must be set to *true* in order to have the next process in the line to be started after this one.
            **startnextafter**
              This is optional and is defaulted to *RUNNING*.  If you want the process to exit before continuing then set
              this to *EXITED* (this is useful for initialization scripts that have to finish before something else starts).
              This is case insensitive.
        
        Example
        =======
        
        The following is an example of a supervisor configuration that starts one item after the next in priority order.
        The order will be ping, sleep, ping2, and ping3.  The ping jobs are configured to wait till they have exited before
        the next job is started (this is commonly used for initialization scripts that need to complete before continuing).
        
        First **supervisord.conf**::
        
            [supervisord]
            nodaemon=true
        
            [inet_http_server]
            port=127.0.0.1:9001
        
            [supervisorctl]
            serverurl=http://127.0.0.1:9001
        
            [rpcinterface:supervisor]
            supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface
        
            [eventlistener:inorder]
            command=/path/to/ordered-startup-listener
            autostart=true
            events=PROCESS_STATE
        
            [include]
            files=supervisord.d/*.conf
        
        Next we will look at the jobs in the **supervisord.d** directory like **supervisord.d/ping.conf**::
        
            [program:ping]
            command=/sbin/ping -c1 www.google.com
            priority=100
            startsecs=0
            autorestart=false
            autostart=false
            startinorder=true
            startnextafter=exited
        
        **supervisord.d/ping2.conf**::
        
            [program:ping2]
            command=/sbin/ping -c1 www.google.com
            priority=200
            startsecs=0
            autorestart=false
            autostart=false
            startinorder=true
            startnextafter=exited
        
        **supervisord.d/ping3.conf**::
        
            [program:ping3]
            command=/sbin/ping -c1 www.google.com
            priority=400
            startsecs=0
            autorestart=false
            autostart=false
            startinorder=true
            startnextafter=exited
        
        **supervisord.d/sleep.conf**::
        
            [program:sleep]
            command=/bin/sleep 60
            priority=101
            startsecs=5
            autorestart=true
            autostart=false
            startinorder=true
        
        Notice how all of the *program:* sections have autostart=false.  Finally let's look at the output of running
        supervisord::
        
            2016-10-08 12:15:22,014 INFO Increased RLIMIT_NOFILE limit to 1024
            2016-10-08 12:15:22,015 INFO Included extra file "/Users/jason.corbett/tmp/supervisor/supervisord.d/ping.conf" during parsing
            2016-10-08 12:15:22,015 INFO Included extra file "/Users/jason.corbett/tmp/supervisor/supervisord.d/ping2.conf" during parsing
            2016-10-08 12:15:22,015 INFO Included extra file "/Users/jason.corbett/tmp/supervisor/supervisord.d/ping3.conf" during parsing
            2016-10-08 12:15:22,015 INFO Included extra file "/Users/jason.corbett/tmp/supervisor/supervisord.d/sleep.conf" during parsing
            2016-10-08 12:15:22,044 INFO RPC interface 'supervisor' initialized
            2016-10-08 12:15:22,044 CRIT Server 'inet_http_server' running without any HTTP authentication checking
            2016-10-08 12:15:22,045 INFO supervisord started with pid 39396
            2016-10-08 12:15:23,050 INFO spawned: 'inorder' with pid 39402
            2016-10-08 12:15:23,325 INFO spawned: 'ping' with pid 39403
            2016-10-08 12:15:23,325 INFO success: ping entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
            2016-10-08 12:15:23,359 INFO exited: ping (exit status 0; expected)
            2016-10-08 12:15:24,048 INFO success: inorder entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
            2016-10-08 12:15:24,052 INFO spawned: 'sleep' with pid 39404
            2016-10-08 12:15:29,051 INFO success: sleep entered RUNNING state, process has stayed up for > than 5 seconds (startsecs)
            2016-10-08 12:15:29,055 INFO spawned: 'ping2' with pid 39410
            2016-10-08 12:15:29,056 INFO success: ping2 entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
            2016-10-08 12:15:29,069 INFO exited: ping2 (exit status 0; expected)
            2016-10-08 12:15:29,072 INFO spawned: 'ping3' with pid 39411
            2016-10-08 12:15:29,072 INFO success: ping3 entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
            2016-10-08 12:15:29,084 INFO exited: ping3 (exit status 0; expected)
            2016-10-08 12:16:24,059 INFO exited: sleep (exit status 0; expected)
            2016-10-08 12:16:24,061 INFO spawned: 'sleep' with pid 39452
            2016-10-08 12:16:29,059 INFO success: sleep entered RUNNING state, process has stayed up for > than 5 seconds (startsecs)
        
        All of the processes started in order.  **ping2** started after sleep was *RUNNING* (influenced by startsecs).  When
        sleep respawned it didn't restart the chain, it only goes through it once.
        
Platform: UNKNOWN
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Programming Language :: Python :: 2.7
Classifier: Topic :: System :: Boot :: Init
Classifier: Environment :: Plugins
