uCentralGW

What is this?

The uCentralGW is an added service for the TIP controller that allows integration with the uCentral protocol. It supports a complete OpenAPI definition and uses the ucentral communication protocol. To use the uCentralGW, you either need to build it or use the Docker version.

Building

In order to build the uCentralGW, you will need to install its dependencies, which includes the following:

• cmake
• boost
• POCO 1.10.1 or later
• a C++17 compiler
• libyaml
• openssl
• libpq-dev (PortgreSQL development libraries)
• mysql-client (MySQL client)

The build is done in 2 parts. The first part is to build a local copy of the framework tailored to your environment. This framework is called Poco. The version used in this project has a couple of fixes from the master copy needed for cmake. Please use the version of this Poco fix. Building Poco may take several minutes depending on the platform you are building on.

Ubuntu

These instructions have proven to work on Ubuntu 20.4.

sudo apt install git cmake g++ libssl-dev libmysqlclient-dev unixodbc-dev postgesql-client-dev 
sudo apt install libpq-dev libaprutil1-dev apache2-dev libboost-all-dev libyaml-cpp-dev

git clone https://github.com/stephb9959/poco
cd poco
mkdir cmake-build
cd cmake-build
cmake ..
cmake --build . --config Release
sudo cmake --build . --target install

cd ~
git clone https://github.com/Telecominfraproject/wlan-cloud-ucentralgw
cd wlan-cloud-ucentralgw
mkdir cmake-build
cd cmake-build
cmake ..
make

Fedora

The following instructions have proven to work on Fedora 33

sudo yum install cmake g++ openssl-devel unixODBC-devel mysql-devel mysql apr-util-devel boost boost-devel
sudo yum install yaml-cpp-devel lua-devel
sudo dnf install postgresql.x86_64
sudo dnf install postgresql-devel

git clone https://github.com/stephb9959/poco
cd poco
mkdir cmake-build
cd cmake-build
cmake ..
cmake --build . --config Release
sudo cmake --build . --target install

cd ~
git clone https://github.com/Telecominfraproject/wlan-cloud-ucentralgw
cd wlan-cloud-ucentralgw
mkdir cmake-build
cd cmake-build
cmake ..
make

OSX Build

The following instructions have proven to work on OSX Big Sur. You need to install Homebrew. You must also have installed XCode for OS X.

brew install openssl
brew install cmake
brew install libpq
brew install mysql-client
brew install apr
brew install apr-util
brew install boost
brew install yaml-cpp
brew install postgresql
brew install unixodbc

git clone https://github.com/stephb9959/poco
cd poco
mkdir cmake-build 
cd cmake-build
cmake ..
cmake --build . --config Release -j
sudo cmake --build . --target install

cd ~
git clone https://github.com/Telecominfraproject/wlan-cloud-ucentralgw
cd wlan-cloud-ucentralgw
mkdir cmake-build
cd cmake-build
cmake ..
make -j

Raspberry

The build on a rPI takes a while. You can shorten that build time and requirements by disabling all the larger database support. You can build with only SQLite support by not installing the packages for ODBC, PostgreSQL, and MySQL by adding -DSMALL_BUILD=1 on the cmake build line.

sudo apt install git cmake g++ libssl-dev libaprutil1-dev apache2-dev libboost-all-dev libyaml-cpp-dev
git clone https://github.com/stephb9959/poco
cd poco
mkdir cmake-build
cd cmake-build
cmake ..
cmake --build . --config Release
sudo cmake --build . --target install

cd ~
git clone https://github.com/Telecominfraproject/wlan-cloud-ucentralgw
cd wlan-cloud-ucentralgw
mkdir cmake-build
cd cmake-build
cmake -DSMALL_BUILD=1 ..
make

After the build step is completed

Once your build is done. You can remove the Poco source as it is no longer needed.

Expected directory layout

From the directory where your cloned source is, you will need to create the certs, logs, and uploads directories.

mkdir certs
mkdir logs
mkdir uploads

You should now have the following:

-- cert_scripts
  |
  +-- certs
  |
  +-- cmake
  |
  +-- cmake-build
  |
  +-- logs (dir)
  |
  +-- src
  |
  +-- test_scripts
  |
  +-- openapi
  |
  +-- uploads
  |
  +-- ucentral.properties

Certificates for your gateway

If you have not been provided with certificates, you need to generate your own certificates using the procedure in this document. When done, copy the server-cert.pem and server-key.pem files in the certs directory. If you generate your own, you must remember to copy the generated devices certificates on the devices. You should now have:

-- cert_scripts
  |
  +-- certs
  |     +---- server-key.pem
  |     +---- server-cert.pem
  |
  +-- cmake
  |
  +-- cmake-build
  |
  +-- logs (dir)
  |
  +-- src
  |
  +-- test_scripts
  |
  +-- openapi
  |
  +-- uploads
  |
  +-- ucentral.properties

Configuration

The configuration for this service is kept in a properties file. This file is called ucentral.properties and you can see the latest version here. The file will be loaded from the directory set by the environment variable UCENTRAL_CONFIG. To use environment variables in the configuration, you must use $<varname>. Only path names support the use of environment variables. The sample configuration requires very little changes if you keep the suggested directory structure. For the sample configuration to work, you need to define 2 environment variables.

export UCENTRAL_ROOT=`pwd`
export UCENTRAL_CONFIG=`pwd`

If you current working directory is the root of the project, this will set the variables properly. Otherwise, you can set the variables to point to wherever is necessary.

Important config entries

This is the logging directory

logging.channels.c2.path = $UCENTRAL_ROOT/logs/sample.log

This is the type of storage in use

storage.type = sqlite

Autoprovisioning settings

ucentral.autoprovisioning = true
ucentral.autoprovisioning.type.0 = AP:ea8300,edge
ucentral.autoprovisioning.type.1 = IOT:ea8301,edge2
ucentral.autoprovisioning.type.2 = AP:ea8302,edge6

This is the RESTAPI endpoint

ucentral.restapi.host.0.address = *
ucentral.restapi.host.0.port = 16001
ucentral.restapi.host.0.cert = $UCENTRAL_ROOT/certs/server-cert.pem
ucentral.restapi.host.0.key = $UCENTRAL_ROOT/certs/server-key.pem

This is the end point for the devices to connect with

ucentral.websocket.host.0.address = *
ucentral.websocket.host.0.port = 15002
ucentral.websocket.host.0.cert = $UCENTRAL_ROOT/certs/server-cert.pem
ucentral.websocket.host.0.key = $UCENTRAL_ROOT/certs/server-key.pem

This is the end point for the devices when uploading files

ucentral.fileuploader.host.0.address = *
ucentral.fileuploader.host.0.name = 192.168.1.176       <<<<<<< Replace this IP with the IP of your gateway or its FQDN
ucentral.fileuploader.host.0.port = 16003
ucentral.fileuploader.host.0.cert = $UCENTRAL_ROOT/certs/server-cert.pem
ucentral.fileuploader.host.0.key = $UCENTRAL_ROOT/certs/server-key.pem
ucentral.fileuploader.host.0.key.password = mypassword
ucentral.fileuploader.path = $UCENTRAL_ROOT/uploads

host.0.address entries

If you want to limit traffic to a specific interface, you should specify the IP address of that interface instead of the *. Using the * means all interfaces will be able to accept connections. You can add multiple interfaces by changing the 0 to another index. You need to repeat the whole configuration block for each index. Indexes must be sequential start at 0.

ucentral.fileuploader.host.0.name

This must point to the IP or FQDN of your uCentralGW.

Running the gateway

Tu run the gateway, you must run the executable ucentralgw. You can use several command line options to run as a daemon or specify the configuration file location.

Command line options

The current implementation supports the following. If you use the built-in configuration file, you do not need to use any command-line options. However, you may decide to use the --daemon or umask options.

./ucentralgw --help
usage: ucentralgw OPTIONS
A uCentral gateway implementation for TIP.

--daemon        Run application as a daemon.
--umask=mask    Set the daemon's umask (octal, e.g. 027).
--pidfile=path  Write the process ID of the application to given file.
--help          display help information on command line arguments
--file=file     specify the configuration file
--debug         to run in debug, set to true
--logs=dir      specify the log directory and file (i.e. dir/file.log)

file

This allows you to point to another file without specifying the UCENTRAL_CONFIG variable. The file name must end in .properties.

daemon

Run this as a UNIX service

pidfile

When running as a daemon, the pid of the running service will be set in the speficied file

debug

Run the service in debug mode.

logs

Speficy where logs should be kept. You must include an existing directory and a file name. For example /var/ucentral/logs/log.0.

umask

Seet the umask for the running service.

Docker

So building this thing from scratch is not your thing? I can't blame you. It takes some patience and in the end, there's still more work. Here comes docker to the rescue. You can run a docker version following these instructions. The following is the content of the docker_run.sh script you can find here:

#!/bin/sh

HUBNAME=tip-tip-wlan-cloud-ucentral.jfrog.io
IMAGE_NAME=ucentralgw
DOCKER_NAME=$HUBNAME/$IMAGE_NAME

CONTAINER_NAME=ucentralgw

#stop previously running images
docker container stop $CONTAINER_NAME
docker container rm $CONTAINER_NAME --force

if [[ ! -d logs ]]
then
    mkdir logs
fi

if [[ ! -d certs ]]
then
  echo "certs directory does not exist. Please create and add the proper certificates."
  exit 1
fi

if [[ ! -f ucentral.properties ]]
then
  echo "Configuration file ucentral.properties is missing in the current directory"
  exit 2
fi

docker run -d -p 15002:15002 \
              -p 16001:16001 \
              -p 16003:16003 \
              --init \
              --volume="$PWD:/ucentral-data" \
              -e UCENTRAL_ROOT="/ucentral-data" \
              -e UCENTRAL_CONFIG="/ucentral-data" \
              --name="ucentralgw" $DOCKER_NAME

Create yourself a directory and copy that script which you can also get from here. You must have the basic configuration file copied in the directory. This file must be called ucentral.properties. You can bring your own or copy it from here. Please look at this to have the right certificates. You need to make sure that the names match the content of the ucentral.properties file. Once all this is done, you can simply run docker_run.sh.

Docker installation directory layout

Here is the layout expected for your Docker installation

Run-time root
    |
    |
    ----- certs (dir)
    |        |
    |        +-- server-key.pem
    |        --- server-cert.pem
    +---- logs  (dir)
    +---- uploads  (dir)
    +---- ucentral.properties (file)

ucentral.properties for Docker

If you use the pre-made configuration file, and you follow the directory layout, the only line you must change is the following line:

ucentral.fileuploader.host.0.name = 192.168.1.176

This line should reflect the IP of your gateway or its FQDN. You must make sure that this name or IP is accessible from your devices. This is used during file uploads from the devices.

Certificates with Docker

If you have not been provided with certificates, you should generate some using the procedure in this section. When done, copy the server-cert.pem and server-key.pem files in the certs directory. If you generate your own certificates, you must remember to copy the generated devices certificates on the devices.

Configuration with Docker

The configuration for this service is kept in a properties file. Currently, this configuration file must be kept in the current directory of uCentral or one level up. This file is called ucentral.properties and you can see the latest version here. The file will be loaded from the directory set by the environment variable UCENTRAL_CONFIG. To use environment variables in the configuration, you must use $<varname>. The path for the logs for the service must exist prior to starting the service. The path is defined under logging.channels.c2.path. Only path names support the use of environment variables. Here is a sample configuration:

Certificates

Love'em of hate'em, we gotta use'em. So we tried to make this as easy as possible for you. Under the cert_scripts you can run a single command (create_sertificates.sh) that will generate all the files you need. By default, this will generate the server side of the certificates as well as certificates for 10 devices. You can change the variable howmany in the script to change that number.

cd cert_scripts
./create_certificates.sh
ls
clean.sh                dev-1-cert.pem          dev-2-cert.pem          dev-4-cert.pem          dev-6-cert.pem          dev-8-cert.pem          more_devices.sh         server-key.pem
create_certificates.sh  dev-10-cert.pem         dev-3-cert.pem          dev-5-cert.pem          dev-7-cert.pem          dev-9-cert.pem          server-cert.pem         server.csr

You have now created:

• server-key.pem: this file is the server key and should be used in the ucentral.properties file.
• server-cert.pem: this is the certificate to be used with the generated key. This should also be used in ucentral.properties.
• dev-1-cert.pem .. dev-10-cert.pem : certificates to be used on the actual devices in the /etc/config directories of the devices. These files must be renamed cert.pem on the devices.

The script more_devices can be used to generate more devices without regenerating the original key. Just change the finish variable to the number you need. The script clean.sh let's you start from scratch again.

uCentral communication protocol

The communication protocol between the device and the controller is detailed in this document.

OpenAPI

The service supports an OpenAPI REST based interface for management. You can find the definition here. And here is how to use it

Using the API

In the test_scripts directory, you will find a series of scripts that will show you how to use the API with curl or Python3. More scripts will be added in the future.

Firewall Considerations

• The protocol uses TCP port 15002 between the devices and the gateway. This port must be opened.
• Devices use the TCP port 16003 to upload files. This port is configurable in the ucentral.properties file. Look for ucentral.fileuploader.host.0.port.
• The RESTAPI is accessed through TCP port 16001 by default. This port is configurable in the ucentral.properties file. Look for the entry ucentral.restapi.host.0.port.