Here are my notes on how to retrieve, compile and configure Mosquitto with Websockets on Centos 7. Installing websockets on Centos required to compile the library and it was a longer process than with Mint but doable nevertheless.
yum install wget mercurial cmake openssl-devel c-ares-devel libuuid-devel
yum install git gcc gcc-c++
git clone https://github.com/warmcat/libwebsockets.git
cd libwebsockets
mkdir build
cd build
cmake .. -DLIB_SUFFIX=64
make
make install
Get the version that you prefer by changing the tar.gz file name below
wget http://mosquitto.org/files/source/mosquitto-1.4.10.tar.gz
tar xvzf mosquitto-1.4.10.tar.gz
cd mosquitto-1.4.10/
vi config.mk
# Build with websockets support on the broker.
WITH_WEBSOCKETS:=yes
make
sudo make install
adduser mosquitto
mosquitto_passwd -c /etc/mosquitto/pwfile mosquitto
vi /etc/mosquitto/mosquitto.conf
# =================================================================
user mosquitto
# =================================================================
listener 1883
protocol mqtt
listener 9001
protocol websockets
# =================================================================
persistence true
persistence_location /var/lib/mosquitto/
# =================================================================
log_dest syslog
log_type error
log_type warning
log_type notice
log_type information
Two commands, different style. Fix some paths for the libraries
echo “/usr/local/lib64” | sudo tee -a /etc/ld.so.conf.d/libwebsockets.conf
echo /usr/local/lib > /etc/ld.so.conf.d/local.conf
ldconfig
Test the setup by using two additional shells one for each of the two commands below
mosquitto_sub -h localhost -t “greetings” -v
mosquitto_pub -h localhost -t “greetings” -m “hello”
NB The commands about do not test the websockets on port 9001 for which you would need to develop a Javascript test program or similar
{Smiles}