===================================
OpenWISP Monitoring OpenWrt package
===================================

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------------

The `OpenWISP Monitoring <https://github.com/openwisp/openwisp-monitoring>`_ agent
for `OpenWRT <https://openwrt.org/>`_.

**Want to help OpenWISP?** `Find out how to help us grow here
<http://openwisp.io/docs/general/help-us.html>`_.

.. image:: http://netjsonconfig.openwisp.org/en/latest/_images/openwisp.org.svg
  :target: http://openwisp.org

.. contents:: **Table of Contents**:
 :backlinks: none
 :depth: 3

Install pre-compiled packages
-----------------------------

First run:

.. code-block:: shell

    opkg update

Then install ``openwisp-monitoring`` and ``netjson-monitoring`` packages from the
`latest builds <https://downloads.openwisp.io/?prefix=openwisp-monitoring/latest/>`_:

.. code-block:: shell

    opkg install <URL>

Where ``<URL>`` is the URL of the pre-compiled package.

For a list of the latest built images, take a look at `downloads.openwisp.io/?prefix=openwisp-monitoring/
<https://downloads.openwisp.io/?prefix=openwisp-monitoring/>`_.

**If you need to compile the package yourself**, see
`Compiling openwisp-monitoring <#compiling-openwrt-openwisp-monitoring>`_.

Once installed *openwisp-monitoring* needs to be configured (see `Configuration options <#configuration-options>`_)
and then started with:

.. code-block:: shell

    /etc/init.d/openwisp-monitoring restart

To ensure the agent is working correctly find out how to perform debugging in
the `Debugging <#debugging>`_ section.

Configuration options
---------------------

UCI configuration options must go in ``/etc/config/openwisp-monitoring``.

- ``monitored_interfaces``: interfaces that needs to be monitored, defaults to ``*`` for all interfaces.
- ``interval``: time after which device data should be sent to server, defaults to ``300``.
- ``verbose_mode``: can be enabled (set to ``1``) to ease `debugging <#debugging>`__ in case of issues, defaults to ``0`` (disabled).
- ``required_memory``: available memory required to save data temporarily, defaults to ``0.05`` (5 percent).
- ``max_retries``: maximum number of retries in case of failures to send data to server in case of failure, defaults to ``5`` retries.

In case, `maximum retries are reached <#send-mode>`_, agent will try sending data again in next cycle.

Collecting vs Sending
---------------------

We use two procd services in `monitoring agent <https://github.com/openwisp/openwrt-openwisp-monitoring/blob/master/openwrt-openwisp-monitoring/files/monitoring.agent>`_, one for collecting the data and other for sending the data.

This helps handle failure in sending the data in more flexible way. Old data saved during network connectivity issues can be sent while new data is being collected. If old data has piled up and takes several minutes to be uploaded, new data will be collected without waiting for the sending to complete.

Monitoring agent uses two different modes to handle this, ``send`` and ``collect``.

Collect Mode
~~~~~~~~~~~~

If openwisp-monitoring agent is called with this mode, then the agent will keep charge of collecting and saving data.

Agent will periodically check if enough memory is available. If true, data will be collected and saved in temporary storage with the timestamp (in UTC timezone).

Once the data is saved, a signal will be sent to the other agent to ensure data is sent as soon as it is collected.

**Note:** Date and time on device should be set correctly. Otherwise, data will be saved with wrong timestamp in timeseries database.

Send Mode
~~~~~~~~~

If openwisp-monitoring agent is called with this mode, then the agent will keep charge of sending data.

Agent will check if any data file is available in temporary storage.

If there is no data file, the agent will sleep for the time interval and check for the data file again. This will be continued until a data file is found.
If a signal is received from the other agent, then the sleep will be interrupted and agent will start sending data.

If agent fails to send data to the server, an exponential backoff will be used to retry until `max_retries` is reached.
If all attempts of sending data failed, the agent will try to send data in the next cycle.

If data is sent successfully, then the data file will be deleted and agent will look for another file.

**SIGUSR1** signals are used to instantly send the data when collected. However, the service will keep trying
to send data periodically.

Compiling openwisp-monitoring
-----------------------------

This repository ships 2 OpenWrt packages:

- **netjson-monitoring**: provides
  `NetJSON DeviceMonitoring
  <https://netjson.org/docs/what.html#devicemonitoring>`_ output
- **openwisp-monitoring**: daemon which collects and sends
  `NetJSON DeviceMonitoring
  <https://netjson.org/docs/what.html#devicemonitoring>`_ data to
  `OpenWISP Monitoring
  <https://github.com/openwisp/openwisp-monitoring>`_
  depends on **netjson-monitoring** and
  `openwisp-config
  <https://github.com/openwisp/openwisp-config>`_

The following procedure illustrates how to compile *openwisp-monitoring*, *netjson-monitoring* and their dependencies:

.. code-block:: shell

    git clone https://git.openwrt.org/openwrt/openwrt.git
    cd openwrt
    git checkout <openwrt-branch>

    # configure feeds
    echo "src-git openwisp_config https://github.com/openwisp/openwisp-config.git^1.0.0" >feeds.conf
    echo "src-git openwisp_monitoring https://github.com/openwisp/openwrt-openwisp-monitoring.git" >> feeds.conf
    cat feeds.conf.default >> feeds.conf
    ./scripts/feeds update -a
    ./scripts/feeds install -a
    echo "CONFIG_PACKAGE_netjson-monitoring=y" >> .config
    echo "CONFIG_PACKAGE_openwisp-monitoring=y" >> .config
    make defconfig
    make tools/install
    make toolchain/install
    make package/openwisp-monitoring/compile

The compiled packages will go in ``bin/packages/*/openwisp``.

Alternatively, you can configure your build interactively with ``make menuconfig``, in this case
you will need to select the *openwisp-monitoring* and *netjson-monitoring* by going to ``Administration > admin > openwisp``:

.. code-block:: shell

    git clone https://git.openwrt.org/openwrt/openwrt.git
    cd openwrt
    git checkout <openwrt-branch>

    # configure feeds
    echo "src-git openwisp_config https://github.com/openwisp/openwisp-config.git^1.0.0" >feeds.conf
    echo "src-git openwisp_monitoring https://github.com/openwisp/openwrt-openwisp-monitoring.git" >> feeds.conf
    cat feeds.conf.default >> feeds.conf
    ./scripts/feeds update -a
    ./scripts/feeds install -a
    make menuconfig
    # go to Administration > admin > openwisp and select the packages you need interactively
    make tools/install
    make toolchain/install
    make package/openwisp-monitoring/compile

Debugging
---------

Debugging the *openwisp-monitoring package* can be easily done by using
the ``logread`` command::

    logread | grep openwisp-monitoring

In case of any issue, you can enable `verbose_mode <#configuration-options>`__.

If you are in that doubt openwisp-monitoring is running at all or not, you can check with::

    ps | grep openwisp-monitoring

You should see something like::

    2712 root      1224 S    /bin/sh /usr/sbin/openwisp-monitoring --interval 300 --monitored_interfaces ...
    2713 root      1224 S    /bin/sh /usr/sbin/openwisp-monitoring --url http://192.168.1.195:8000 ...

You can inspect the version of openwisp-monitoring currently installed with::

    openwisp-monitoring --version

Quality Assurance Checks
------------------------

We use `LuaFormatter <https://luarocks.org/modules/tammela/luaformatter>`_
and `shfmt <https://github.com/mvdan/sh#shfmt>`_ to format lua files and
shell scripts respectively.

Once they are installed, you can format all files by::

    ./qa-format

Run quality assurance tests with::

    #install openwisp-utils QA tools first
    pip install openwisp-utils[qa]

    #run QA checks before committing code
    ./run-qa-checks

Run tests
---------

To run the unit tests, you must install the required dependencies first;
to do this, you can take
a look at the
`install-dev.sh
<https://github.com/openwisp/openwisp-config/blob/master/install-dev.sh>`_
script.

Install test requirements::

    sudo ./install-dev.sh

You can run all unit tests by launching the dedicated script::

    ./runtests

Alternatively, you can run specific tests, e.g.::

    cd openwrt-openwisp-monitoring/tests/
    lua test_utils.lua -v

Contributing
------------

Please read the `OpenWISP contributing guidelines
<http://openwisp.io/docs/developer/contributing.html>`_.

Changelog
---------

See `CHANGELOG <https://github.com/openwisp/openwrt-openwisp-monitoring/blob/master/CHANGELOG.rst>`_.

License
-------

See `LICENSE <https://github.com/openwisp/openwrt-openwisp-monitoring/blob/master/LICENSE>`_.

Support
-------

See `OpenWISP Support Channels <http://openwisp.org/support.html>`_.