connmonitor 3.0.4

Uses the connvitals library to continuously poll and record network connectivity statistics.

Persistently monitors network conditions with respect to a set of specific hosts.

Dependencies

The executable for the connvitals-monitor package (connmonitor) runs on python3 (tested CPython 3.6.3) and requires a python3 interpreter. It also requires `connvitals <https://github.com/comcast/connvitals>`__ to exist as a subdirectory in its directory (or your import path) as it uses that as a library.

Note: Because this package is not in a standard repository (nor is its dependency), dependencies cannot be automatically resolved; you must first install connvitals for this package to work.

Installation

Note: Versions 1.2+ **only* support Linux systems that run systemd. It’s possible that it may install on your system even if you do not run systemd, but it will attempt to install the Unit File under /usr/lib/systemd/system.*

Via pip (Standard)

By far the easiest way to install connvitals-monitor is to simply use pip like so:

pip install connmonitor

Note that you’ll probably need to run this command with sudo or the --user flag.

Via pip (From This Repository)

The easiest way to install is to simply use pip. You can install directly from this repository without needing to manually download it by running

user@hostname ~ $ pip install git+https://github.com/comcast/connvitals-monitor.git#egg=connmonitor

Note that you may need to run this command as root/with sudo or with --user, depending on your pip installation. Also ensure that pip is installing packages for Python 3.x. Typically, if both Python2 and Python3 exist on a system with pip installed for both, the pip to use for Python3 packages is accessible as pip3.

Manually

To install manually, first download or clone this repository. Then, in the directory you downloaded/cloned it into, run the command

user@hostname ~/connvitals-monitor $ python setup.py install

Note that it’s highly likely that you will need to run this command as root/with sudo. Also ensure that the python command points to a valid Python3 interpreter (you can check with python --version). On many systems, it is common for python to point to a Python2 interpreter. If you have both Python3 and Python2 installed, it’s common that they be accessible as python3 and python2, respectively.

Finally, if you are choosing this option because you do not have a Python3 pip installation, you may not have setuptools installed. On most ‘nix distros, this can be installed without installing pip by running sudo apt-get install python3-setuptools (Debian/Ubuntu), sudo pacman -S python3-setuptools (Arch), sudo yum install python3-setuptools (RedHat/Fedora/CentOS), or brew install python3-setuptools (macOS with brew installed).

Usage

$ connmonitor [input file]
$ connmonitor [ -v --version ]

input file is a file containing a set of options and hosts to check. If not specified, connmonitor will read input of the same format from stdin. If instead -v or --version is passed as the first argument, the program’s version is printed to stdout, and the program exits successfully.

Upon receiving SIGHUP (e.g. when the terminal used to run it is closed), connmonitor will attempt to re-read its configuration file, then continue execution. If the configuration file cannot be read, the program will log an error, clean up its resources and exit with error code 1. If input was given on stdin, the program will log an error and resume execution.

connmonitor handles SIGTERM by neatly cleaning up resources (finishing any running tasks and printing their output to stdout, still logging any errors) and exiting.

As a systemd daemon

Starting with version 1.2.1, connvitals-monitor (unfortunately) comes packaged with a systemd Unit File, and will attempt to install it. To run the daemon, simply run systemctl start connmonitor (as root), and to stop it run systemctl stop connmonitor (also as root). By default, the monitor will log its stdout in JSON format to /var/log/connmonitor.log, and its stderr to /var/log/connmonitor.err. Whenever the monitor is started, it looks for a configuration file at /var/run/connmonitor.conf, and creates it if it does not exist with the following default contents (see ‘Input Format’):

1 1 1 10 41 40 1 500
localhost

The monitor service does not check for filesystem updates to that config file; if you wish to edit it you may safely do so, but should run systemctl reload connmonitor to read in the new configuration.

Input Format

connmonitor expects input formatted like this:

DOPINGS DOTRACE DOPSCAN NUMPINGS PAYLOAD HOPS JSON SLEEP
host1
host2
host3
...

where the fields have the following meanings

• DOPINGS is either 0 to indicate that pings should not be sent, or any other integer (typically 1) to indicate that they should be sent.

• DOTRACE is either 0 to indicate that route tracing should not be done, or any other integer (typically 1) to indicate they should be done.

• DOPSCAN is either 0 to indicate that port scanning should not be done, or any other integer (typically 1) to indicate they should be done.

• NUMPINGS is a positive integer indicating the number of pings to be sent. If DOPINGS is 0, this is not used, but must still be specified. Note that - in general - setting NUMPINGS to 0 is less efficient than setting DOPINGS to 0.

• PAYLOAD is a positive integer indicating the size of each ping payload. If DOPINGS is 0, this is not used, but must still be specified. It is recommended that this be at least 14.

• HOPS is a positive integer that sets the maximum number of network hops to be considered in route tracing. If DOTRACE is 0, this is not used, but must still be specified. It is recommended that this be at least 15 for testing hosts that are not on LAN. Note that - in general - setting HOPS to 0 is less efficient than setting DOTRACE to 0.

• JSON is either 0 to indicate that output should not be formatted as JSON, or any other integer (typically 1) to indicate that output should be formatted as JSON.

• SLEEP is the amount of time for the process to “sleep” between queries of its hosts (in milliseconds).

Output Format

connmonitor outputs results to stdout and logs errors to stderr. Output (including JSON output) takes the same form as connvitals, and you can read about that format on that project’s README.

Starting with version 3.0, connmonitor will no longer output traces if they are determined to be the same as the most recent route previously recorded for a given host. This is as a result of changes made to connvitals (but only the Python version) which are discussed in greater detail on that project’s page.

Example

Here’s an example of a configuration file that will gather port scans and ping statistics for 10 pings per run each having a payload of 1337B - but not route traces - from google.com, github.com and the address 127.0.0.1 (localhost) every half-second and outputs in connvitals’s standard, plain-text format:

1 0 1 10 1337 100 0 500
google.com
github.com
127.0.0.1