public void connectSensors()

in software/webapp/src/main/java/org/apache/brooklyn/entity/proxy/nginx/NginxControllerImpl.java [106:164]
41 lines of code
5 McCabe index (conditional complexity)

    public void connectSensors() {
        super.connectSensors();

        ConfigToAttributes.apply(this);

        // "up" is defined as returning a valid HTTP response from nginx (including a 404 etc)
        httpFeed = addFeed(HttpFeed.builder()
                .uniqueTag("nginx-poll")
                .entity(this)
                .period(getConfig(HTTP_POLL_PERIOD))
                .baseUri(new UrlInferencer(null))
                .poll(new HttpPollConfig<Boolean>(NGINX_URL_ANSWERS_NICELY)
                        // Any response from Nginx is good.
                        .checkSuccess(Predicates.alwaysTrue())
                        // Accept any nginx response (don't assert specific version), so that sub-classing
                        // for a custom nginx build is not strict about custom version numbers in headers
                        .onResult(HttpValueFunctions.containsHeader("Server"))
                        .setOnException(false)
                        .suppressDuplicates(true))
                .build());
        
        // TODO PERSISTENCE WORKAROUND kept anonymous function in case referenced in persisted state
        new Function<HttpToolResponse, Boolean>() {
            @Override
            public Boolean apply(HttpToolResponse input) {
                // Accept any nginx response (don't assert specific version), so that sub-classing
                // for a custom nginx build is not strict about custom version numbers in headers
                List<String> actual = input.getHeaderLists().get("Server");
                return actual != null && actual.size() == 1;
            }
        };
        
        if (!Lifecycle.RUNNING.equals(getAttribute(SERVICE_STATE_ACTUAL))) {
            // TODO when updating the map, if it would change from empty to empty on a successful run
            // gate with the above check to prevent flashing on ON_FIRE during rebind (this is invoked on rebind as well as during start)
            ServiceNotUpLogic.updateNotUpIndicator(this, NGINX_URL_ANSWERS_NICELY, "No response from nginx yet");
        }
        enrichers().add(Enrichers.builder().updatingMap(Attributes.SERVICE_NOT_UP_INDICATORS)
            .uniqueTag("not-up-unless-url-answers")
            .from(NGINX_URL_ANSWERS_NICELY)
            .computing(Functionals.ifNotEquals(true).value("URL where nginx listens is not answering correctly (with expected header)") )
            .build());
        connectServiceUpIsRunning();

        // Can guarantee that parent/managementContext has been set
        Group urlMappings = getConfig(URL_MAPPINGS);
        if (urlMappings!=null && urlMappingsMemberTrackerPolicy==null) {
            // Listen to the targets of each url-mapping changing
            targetAddressesHandler = subscriptions().subscribeToMembers(urlMappings, UrlMapping.TARGET_ADDRESSES, new SensorEventListener<Collection<String>>() {
                    @Override public void onEvent(SensorEvent<Collection<String>> event) {
                        updateNeeded();
                    }
                });

            // Listen to url-mappings being added and removed
            urlMappingsMemberTrackerPolicy = policies().add(PolicySpec.create(UrlMappingsMemberTrackerPolicy.class)
                    .configure("group", urlMappings));
        }
    }