Demos
=====

Elos comes with a set of demo applications to show certain aspects of elos.

elosMon – publish events as mails
---------------------------------

.. program-output:: elosMon -h

elosc – simple commandline client
---------------------------------

.. program-output:: elosc -h

To verify the elos version use :

.. command-output:: elosc -v

To subscribe on any event :

.. command-output:: elosc -s "1 1 EQ"
   :returncode: 1

To subscribe on coredump events :

.. command-output:: elosc -s ".event.messageCode 5005 EQ"
   :returncode: 1

To list all events logged :

.. command-output:: elosc -f "1 1 EQ"
   :returncode: 1

To list all logged events that are critical :

.. command-output:: elosc -f "event.severity 1 EQ"
   :returncode: 1

To publish an event :

.. command-output:: elosc -p '{"messageCode": 1001, "severity": 4, "payload": "a custom event with severity INFO (4)"}'
   :returncode: 1

To publish 100 events as fast as possible :

.. command-output:: elosc -c 100 -p '{"messageCode": 1001, "severity": 4, "payload": "publish 100 events as fast as possible"}'
   :returncode: 1

To publish 100 events with 50Hz :

.. command-output:: elosc -c 100 -r 50 -p '{"messageCode": 1001, "severity": 4, "payload": "publish 100 events at 50Hz"}'
   :returncode: 1

To set host ip :

.. command-output:: elosc -H 127.0.0.1 -f "1 1 Q"
   :returncode: 1

To set host connection port :

.. command-output:: elosc -H 127.0.0.10 -P 9876 -f "1 1 Q"
   :returncode: 1

demo_libelos_v2 – publish subscrie demo using libelos
-----------------------------------------------------

To verify the elos version use :

.. command-output:: demo_libelos_v2 -v

demo_libeloslite
----------------

This demo is a simple demonstration of libelos-lite.
It Connects to elosd, publishes a simple event
than publishes a very long event than a simple event again
and finally disconnects from elosd again.


demo_scanner_shmem - publish random messages into shared memory ringbuffer
--------------------------------------------------------------------------

This demo is a simple demonstrator that writes into an ebRingBuffer
located in a shared memory region. Writes 1-8 messages with random content
every 0.5 seconds until the demo is stopped with ctrl+c.

The name of the shared memory region comes first, followed by the offset:

.. command-output:: demo_scanner_shmem scanner_shmem 0
   :returncode: 1

The name of the semaphore will be autogenerated from the first parameter
if you call the demo with 2 parameters (by appending "_sem" to the name).
You can also call the demo with an explicitely specified semaphore name:

.. command-output:: demo_scanner_shmem scanner_shmem 0 scanner_shmem_sem
   :returncode: 1

Note: The size is detected automatically by reading out the number of
ringbuffer entries in the shmem area. Calling the demo on a shmem area that is
not big enough the contain the ringbuffer struct itself is undefined behaviour
and must be avoided.

demo_eventbuffer – test performance of event buffer
-----------------------------------------------------

This demo was manly developed to test and verify the `EventBuffer` component.

.. program-output:: demo_eventbuffer -h

To benchmark the event buffers on a target with default value run:

.. command-output:: demo_eventbuffer

To benchmark the event buffers on a target to find optimal configuration :

.. command-output:: demo_eventbuffer --publisher 100 --consumer 10 --messageCount 1000 --eventLimit 300

syslog_example – demonstrate and test the syslog scanner
------------------------------------------------------------

With the `syslog_example` demo it is possible to verify if the syslog scanner
is configured correctly. It can also be used to develop the mapping rules for
the syslog scanner.

To verify that the syslog scanner is working:

.. command-output:: syslog_example "Syslog scanner test"; elosc -f ".event.payload 'Syslog scanner test' STRCMP"
   :returncode: 1

Simulate syslog lines and test a filter if it can be used as mapping rule for the syslog-scanner:

.. command-output:: syslog_example "Jun 15 19:56:23 hostnameXY wpa_supplicant[420]: wlp0s20f3: WPA: Group rekeying completed with 00:00:00:00:00:00 [GTK=TKIP]"
   :caption: simulate the syslog line
   :returncode: 1

.. command-output:: elosc -f ".event.payload r'WPA: Group rekeying' REGEX"
   :caption: check if rule mtches the syslog line
   :returncode: 1

tinyElosc – minimized elos client to send raw payload
-----------------------------------------------------

This demo was developed to send raw formatted payload. The payload is not
preprocessed and validated by any JSON parser. This can be used to send
malformed or any arbitrary encoded payload.

.. program-output:: tinyElosc -h

To verify the elos version use :

.. command-output:: tinyElosc -v
   :returncode: 1


Test elos for arbitrary not valid encoded payload:

.. command-output:: tinyElosc -p "<wrong>this is not a JSON string</wrong>"
   :caption: try to publish an XML string instead of a JSON string
   :returncode: 1

elos_log4c_demo - a demo program to show log4c logging in elos
--------------------------------------------------------------

This demo was developed to demonstrate the usage of log4c logging framework
with elos. The configuration for log4c can be set with the help of a log4crc
configuration file.

In order to log with a log4c framework, a category, a priority
and an appender for the logged message should be set in the config file.

.. literalinclude:: /src/demos/elos_log4c_demo/log4crc
   :language: xml

More information about how to use log4c framework can be found here :
https://log4c.sourceforge.net/


For the elos_log4c_demo application a separate category ``log4c.elos.demo.log4cdemo`` with an appender ``elos`` is created in the config file ``log4crc`` as shown above. The category is the log message destination. The appender outputs the log message to the specified output. An example of an log4c appender can be found here : https://sourceforge.net/p/log4c/log4c/ci/master/tree/examples/example_appenders.c. The output can be an output stream, file, syslog etc. The ``elos_appender`` has a layout ``elos_layout`` which formats the log message using the formatter ``elos_formatter``. An example ofa log4c formatter can be found here : https://sourceforge.net/p/log4c/log4c/ci/master/tree/examples/example_formatters.c. The ``elos_formatter`` formats the log message using pattern strings and sends the formatted string back to the appender to be released out.

.. command-output:: elos_log4c_demo


elosDlt - a demo program to show useage of libelosdlt
-----------------------------------------------------

Elos provides a basic implementation of the DLT protocol to publish elos events
to a DLT daemon. To observer the workings of libelosdlt and DLT, a dlt-daemon
is required to be installed and running. Information about dlt-daemon
installation and setup can be found here: https://github.com/COVESA/dlt-daemon.

.. command-output:: elosDlt
   :returncode: 1