Net::MQTT::Simple::SSL - Minimal MQTT version 3 interface with SSL support

       Juerd Waalboer <juerd@tnx.nl>

       A subclass of Net::MQTT::Simple that adds SSL/TLS.

       Like its base class, a server can be given on the "use" line, in which case "publish" and "retain" are
       exported so that they can be used as simple functions. This interface supports configuration via
       environment variables, but not via explicit options in code.

       The object oriented interface does support explicit SSL configuration. See IO::Socket::SSL for a
       comprehensive overview of all the options that can be supplied to the constructor, "new".

   Environmentvariables
       Instead of explicitly specifying the SSL options in the constructor, they can be set with environment
       variables. These are overridden by options given to "new".

       MQTT_SIMPLE_SSL_INSECURE  Set to something other than 0 to disable SSL validation.

       MQTT_SIMPLE_SSL_CA        Path  to the CA certificate or a directory of certificates. IO::Socket::SSL can
                                 find the CA path automatically on some systems.

       MQTT_SIMPLE_SSL_CERT
       MQTT_SIMPLE_SSL_KEY       Path to the client certificate file and its key file.

       Pick your favourite OSI approved license :)

       http://www.opensource.org/licenses/alphabetical

       Net::MQTT::Simple::SSL - Minimal MQTT version 3 interface with SSL support

       Net::MQTT::Simple

perl v5.36.0                                       2023-10-30                        Net::MQTT::Simple::SSL(3pm)

           # Specifying SSL parameters in environment variables

           export MQTT_SIMPLE_SSL_CA=/etc/ssl/ca.crt
           export MQTT_SIMPLE_SSL_CERT=/etc/ssl/mqtt.crt
           export MQTT_SIMPLE_SSL_KEY=/etc/ssl/mqtt.key

           perl -MNet::MQTT::Simple::SSL=mosquitto.example.org \
                -nle'retain "topic/here" => $_'

           # Specifying explicit SSL parameters

           use Net::MQTT::Simple::SSL;

           my $mqtt = Net::MQTT::Simple::SSL->new("mosquitto.example.org", {
               SSL_ca_file   => '/etc/ssl/ca.crt',
               SSL_cert_file => '/etc/ssl/mqtt.crt',
               SSL_key_file  => '/etc/ssl/mqtt.key',
           });

           $mqtt->publish("topic/here" => "Message here");
           $mqtt->retain( "topic/here" => "Message here");