knot-virtualthing

KNoT VirtualThing is part of the KNoT project. It aims to provide an abstraction to allow certain protocols to interact with a cloud service using the KNoT AMQP Protocol, by virtualizing a KNoT Device.

Dependencies

Build:

• build-essential
• autoconf v2.69
• libtool v2.4.6-11
• automake v1.16.1
• pkg-config v0.29.1
• ell v0.18
• json-c v0.14-20200419
• rabbitmq-c v0.10.0
• knot-protocol 891d01d
• libmodbus v3.1.4

Test:

• check v0.10.0

Other versions might work, but aren't officially supported

How to install dependencies:

$ sudo apt-get install automake libtool libssl-dev valgrind

Install libell

The Embedded Linux Library (ELL) provides core, low-level functionality for system daemons. To install libell, you have to follow the instructions below:

1. git clone git://git.kernel.org/pub/scm/libs/ell/ell.git
2. git checkout 0.18 to checkout to version 0.18
3. Follow instructions on INSTALL file

Install KNoT Cloud SDK in C

KNoT Cloud SDK in C is a client-side library that provides an AMQP abstraction to the KNoT Cloud for C applications.

1. git clone git@github.com:CESARBR/knot-cloud-sdk-c.git
2. git checkout 1bdb2dd to checkout to a hash
3. Follow instructions on README.md file

Install KNoT Protocol

KNOT Application layer protocol library provides the application layer messages definition for exchanging messages between KNoT Nodes (KNoT Thing Devices), KNoT Gateway and KNoT Apps. To install KNoT Protocol, you have to follow the instructions below:

1. git clone git@github.com:CESARBR/knot-protocol-source.git
2. git checkout ead9e66 to checkout to a hash on devel branch.
3. Follow instructions on README file

Install libmodbus

libmodbus is a free software library to send/receive data according to the Modbus protocol. To install libmodbus, you must follow the instructions:

1. Grab the release package for version 3.1.4 from libmodus website https://libmodbus.org/releases/libmodbus-3.1.4.tar.gz
2. Extract it with tar -xzvf libmodbus-3.1.4.tar.gz
3. Change into the extracted folder with cd libmodbus-3.1.4
4. Finally, build and install libmodbus with ./configure && make && sudo make install

Building

Run ./bootstrap-configure and then make

Running the VirtualThing

Start the daemon:

./src/thingd

To see the daemon options:

./src/thingd --help

How to test locally

Start the daemon with the options to indicate the configuration files path:

./src/thingd -n -c confs/credentials.conf -d confs/device.conf -p confs/cloud.conf

How to check for memory leaks and open file descriptors

valgrind --leak-check=full --track-fds=yes ./src/thingd -n -c confs/credentials.conf -d confs/device.conf -p confs/cloud.conf

Automated Testing

Run ./bootstrap-configure --with-check, make and then make check

How to run on Docker

You can run the KNoT Virtual Thing on Docker using the configuration files located under the confs/ folder.

Building

To build:

docker build -t thingd .

You can also use the options --build-arg ENV=value to install other dependencies versions.

The build arguments available are:

• LIBELL_VERSION (Default: v0.18)
• JSONC_VERSION (Default: 0.14-20200419)
• RABBITMQC_VERSION (Default: v0.10.0)
• KNOT_PROTOCOL_VERSION (Default: 891d01d)
• LIBMODBUS_VERSION (Default: v3.1.4)

Running

To run the container:

docker run --network=host -it thingd

Warning

The docker environment has it own set of configuration files.

To edit them you first need to identify the thingd container id:

docker ps --filter "ancestor=thingd"

Then you need to open its bash and navigate to the configuration files path:

docker exec -it <CONTAINER_ID> /bin/sh cd /etc/knot

Now you can open and edit using vi:

vi <file>

License

All KNoT VirtualThing files are under LGPL v2.1 license, you can check COPYING file for details.

The checkpatch.pl and spelling.txt files, on hooks folder, are under the Linux Kernel's GPL v2 license.