Superfsmon

Supervisor plugin to watch a directory and restart programs on changes

Overview

Superfsmon is especially useful during development to restart applications when the code changes. It can monitor a directory for changes, filter the file paths by glob patterns or regular expressions and restart Supervisor programs individually or by group.

Superfsmon uses Supervisor's XML-RPC API. Your supervisord.conf file must have a valid [unix_http_server] or [inet_http_server] section and a [rpcinterface:supervisor] section. If you are able to control your Supervisor instance with supervisorctl, you have already met these requirements.

To restart your celery workers on changes in the /app/devops directory your supervisord.conf could look like this.

[program:celery]
command=celery -A devops.celery worker --loglevel=INFO --concurrency=10

[program:superfsmon]
command=superfsmon /app/devops celery

You can use multiple instances of Superfsmon to control different programs.

Installation

pip install superfsmon

Python 3

This script requires Supervisor >= 4.0.0, released on April 26, 2019. That, in turn, requires python >= 3.4.

Command Line Arguments

usage: superfsmon [-h] [-e FLAG] [--disable [FLAG]] [-r PATTERN] [-i PATTERN]
                  [--recognize-regex REGEX] [--ignore-regex REGEX] [-f] [-c]
                  [-d] [--no-recursion] [-g GROUP] [-a]
                  PATH [PROG [PROG ...]]

Supervisor plugin to watch a directory and restart programs on changes

optional arguments:
  -h, --help            show this help message and exit
  -e FLAG, --enable FLAG
                        disable functionality if flag is not set
  --disable [FLAG]      disable functionality if flag is set

directory monitoring:
  PATH                  directory path to watch for changes
  -r PATTERN, --recognize PATTERN
                        recognize changes to file paths matching the pattern
  -i PATTERN, --ignore PATTERN
                        ignore changes to file paths matching the pattern
  --recognize-regex REGEX
                        recognize changes to file paths matching the regular
                        expression
  --ignore-regex REGEX  ignore changes to file paths matching the regular
                        expression
  -f, --hidden-files    recognize changes to hidden files
  -c, --case-insensitive
                        case insensitive file path matching
  -d, --directories     recognize changes to directories
  --no-recursion        don't watch for changes in subdirectories

programs:
  PROG                  supervisor program name to restart
  -g GROUP, --group GROUP
                        supervisor group name to restart
  -a, --any             restart any child of this supervisor

Examples

Only recognize changes to .py files:

command=superfsmon /app/devops celery -r *.py

Restart all Supervisor programs in the workers group:

command=superfsmon /app/devops -g workers

Disable functionality using an environment variable (useful for production):

command=superfsmon /app/devops celery -e %(ENV_CELERY_AUTORELOAD)s

Known Issues

• The --ignore option is case insensitive. When using --case-insensitive it is case sensitive. This is caused by a bug in Watchdog.