messagehub079.md

copyright	lastupdated
years 2015, 2017	2017-02-13

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How to connect and authenticate

{: #mql_connect}

To connect an app to the service, the app must use the user, password, and mqlight_lookup_url details from the VCAP_SERVICES environment variable. Use the following guidance for your chosen language:

For Java

If you specify ‘null’ as the endpointService parameter of the create() call, this instructs the client to read the user, password and, mqlight_lookup_url details from VCAP_SERVICES:

NonBlockingClient.create(null, new NonBlockingClientAdapter() {
    public void onStarted(NonBlockingClient client, Void context) {
        client.send("my/topic", "Hello World!", null);
    }
}, null);

{:codeblock}

For Node.js

Retrieve the user, password, and mqlight_lookup_url details from VCAP_SERVICES and use them to create the client as follows:

var services = JSON.parse(process.env.VCAP_SERVICES);
mqlightService = services['messagehub'][0];
opts.service = mqlightService.credentials.mqlight_lookup_url;
opts.user = mqlightService.credentials.user;
opts.password = mqlightService.credentials.password;
var mqlightClient = mqlight.createClient(opts, function(err) {
...

{:codeblock}

For Ruby

Retrieve the user, password, and mqlight_lookup_url details from VCAP_SERVICES and use them to create the client as follows:

vcap_services = JSON.parse(ENV['VCAP_SERVICES'])
conn_details = vcap_services['messagehub']
credentials = conn_details.first['credentials']
service = credentials['mqlight_lookup_url']
opts[:user] = credentials['user']
opts[:password] = credentials['password']
set :client, Mqlight::BlockingClient.new(service, opts)
...

{:codeblock}

For Python

Retrieve the user, password, and mqlight_lookup_url details from VCAP_SERVICES and use them to create the client as follows:

vcap_services = json.loads(os.environ.get('VCAP_SERVICES'))
conn_details = vcap_services['messagehub'][0]
service = str(conn_details['credentials']['mqlight_lookup_url'])
security_options = {
      'user': str(conn_details['credentials']['user']),
      'password': str(conn_details['credentials']['password'])
}
client = mqlight.Client(service=service, 
                        security_options=security_options,
                        on_started=on_started)

{:codeblock}

For more information about the {{site.data.keyword.mql}} APIs, see: {{site.data.keyword.mql}} developerWorks® site {:new_window}.