Sentry

Watch Linux processes and notify when they complete. Should also work with MacOS*.

Only needs the /proc pseudo-filesystem to check and gather information about processes. Does not need to create/own the process, if you want a daemon manager, see the Alternatives section below.

Currently written for Python3, but shouldn't be difficult to make python2 compatible.

*If you run process-watcher on MacOS and it works, let me know so I can update the documentation.

Supported notification methods:

Console (STDOUT)
Email
Desktop Notification

Example output message

Sent in body of messages. Other information from /proc/PID/status can easily be added by modifying the code.

PID 18851: /usr/lib/libreoffice/program/soffice.bin --writer --splash-pipe=5
 Started: Thu, Mar 10 18:33:37  Ended: Thu, Mar 10 18:34:26  (duration 0:00:49)
 Memory (current/peak) - Resident: 155,280 / 155,304 kB   Virtual: 1,166,968 / 1,188,216 kB

Help

Access script help with -h, --help, or no arguments at all.

usage: process_watcher [-h] [-p PID] [-c COMMAND_PATTERN] [-crx COMMAND_REGEX]
                       [-w] [--to EMAIL_ADDRESS] [--channel CHANNEL] [-n]
                       [-i SECONDS] [-q] [--log] [--tag LABEL] [-l LOGIN]
                       [--password PASSWORD] [--smtp SMTP]

Watch a process and notify when it completes via various communication protocols.
(See README.md for help installing dependencies)

A simple invocation:

$ (prog)s -p 123 --to me@email.com

A more complex invocation:
 ([+] indicates the argument may be specified multiple times)

$ process_watcher -p 1234 -p 4258 -c myapp* -crx "exec\d+" --to person1@domain.com --to person2@someplace.com

optional arguments:
  -h, --help            show this help message and exit
  -p PID, --pid PID     process ID(s) to watch [+].
  -c COMMAND_PATTERN, --command COMMAND_PATTERN
                        watch all processes matching the command name pattern. (shell-style wildcards) [+].
  -crx COMMAND_REGEX, --command-regex COMMAND_REGEX
                        watch all processes matching the command name regular expression. [+].
  -w, --watch-new       watch for all new processes that match -c|--command.
  --to EMAIL_ADDRESS    email address to send to [+].
  --channel CHANNEL     Slack channel to send to [+].)
  -n, --notify          send DBUS Desktop notification
  -i SECONDS, --interval SECONDS
                        how often to check on processes. (default: 15.0 seconds).
  -q, --quiet           don't print anything to stdout except warnings and errors
  --log                 log style output (timestamps and log level)
  --tag LABEL           label for process [+]
  -l LOGIN, --login LOGIN
                        Originating Mail account (default GMAIL env variable).
  --password PASSWORD   Password for the account specified in -l|-login. Defaults to env variable GPASSWORD.
  --smtp SMTP           SMTP server address for email service. (default Gmail: smtp.gmail.com:587)

Installation

Just create a symbolic link to sentry.py

For example: ln -s /path/to/sentry/sentry.py /usr/local/bin/sentry or for a local install ln -s /path/to/sentry/sentry.py /home/username/bin/sentry

Running

The program just runs until all processes end or forever if --watch-new is specified.

In Unix environments you can run a program in the background and disconnect from the terminal like this:

$ nohup sentry -p 1234 [options] &

This can also be done neatly in a one-liner, with the bash variable $! which captures the previous commands PID:

$ somecommand & nohup sentry -p $! &

Note, since somecommand is not disowned, this is best used inside screen or tmux where a hangup isnt sent.

Examples

Send an email when process 1234 exits.

process_watcher --pid 1234 --to me@gmail.com

Watch all myapp processes and continue to watch for new ones. Send desktop notifications.

process_watcher --command myapp --notify --watch-new

Watch 2 PIDs, continue to watch for multiple command name patterns, email two people.

process_watcher -p 4242 -p 5655 -c myapp -c anotherapp -c "kworker/[24]" -w --to bob@gmail.com --to alice@gmail.com

Optional Dependencies

Desktop Notifications

Requires notify2

python3 -m pip install notify2

Requires python-dbus, which is easiest to install with your package manager:

sudo apt-get install python3-dbus

Email

Uses Python's built-in email module, however email configuration will be required. By default, you can give the script a Gmail account and password (directly, or stored as the environment variables $GMAIL and $GPASSWORD. It's up to you how you elect to secure this.

If you want to use a different email client, you will need to alter the parameters: --smtp, -l|--login, and --password, to suit.

Ideas & Bugs

Record other proc stats
Rare race condition where a PID is found but ends before /proc/PID is read.
Package up, so installable easily with pip
Alert on high-memory and high-CPU usage
Add --command-args option
Refactor to support wrapping a command? e.g. sentry command [args] &
RegEx flags

jrjhealey/sentry