Expand mod_cluster manager console to output JSON data about worker nodes

mod_proxy_cluster needs a module that would provide a comprehensive command & control visualization of events going on within the balancer and with worker nodes. The visualization would also serve as a demonstration for presentation purposes (to replace current SWING app from ~2009-ish).

The new module would most likely work with https://d3js.org/ and generate an SVG/JS page on a new added httpd handler. For this new module to work, we need JSON data from mod_cluster manager (currently spits out only HTML/text/XML).

Task one: mod_cluster manager JSON data

bsikora researched suitable JavaScript libraries and he would like to have the JSON output resemble the following:

I find the Wildfly style of Undertow mod_cluster proxy filter CLI output the most suitable:

"balancer" => {"mycluster" => {
            "max-attempts" => 1,
            "sticky-session" => true,
            "sticky-session-cookie" => "JSESSIONID",
            "sticky-session-force" => false,
            "sticky-session-path" => undefined,
            "sticky-session-remove" => false,
            "wait-worker" => 0,
            "load-balancing-group" => undefined,
            "node" => {
                "jboss-eap-7.1-1" => {
                    "aliases" => [
                        "default-host",
                        "localhost"
                    ],
                    "cache-connections" => 40,
                    "elected" => 0,
                    "flush-packets" => false,
                    "load" => 0,
                    "load-balancing-group" => undefined,
                    "max-connections" => 40,
                    "open-connections" => 0,
                    "ping" => 10,
                    "queue-new-requests" => true,
                    "read" => 0L,
                    "request-queue-size" => 1000,
                    "status" => "NODE_HOT_STANDBY",
                    "timeout" => 0,
                    "ttl" => 60L,
                    "uri" => "ajp://192.168.122.88:8009/?#",
                    "written" => 0L,
                    "context" => {"/clusterbench" => {
                        "requests" => 0,
                        "status" => "enabled"
                    }}
                },

So, the JSON for my JavaScript renderer could look like:

{
    "balancers": [{
        "name": "mycluster",
        "max-attempts": 1,
        "sticky-session": true,
        "sticky-session-cookie": "JSESSIONID",
        "sticky-session-force": false,
        "sticky-session-remove": false,
        "wait-worker": 0,
        "workers": [
            {
                "name": "jboss-eap-7.1-1",
                "aliases": ["default-host", "localhost"],
                "cache-connections": 40,
                "elected": 0,
                "flush-packets": false,
                "load": 0,
                "requests": 350
            }, {
                "name": "jboss-eap-7.1-2",
                "aliases": ["default-host", "localhost"],
                "cache-connections": 40,
                "elected": 0,
                "flush-packets": false,
                "load": 0,
                "requests": 350
            }
        ]
    }]
}

Task two: mod_cluster gui console

Write a separate module that could be optionally loaded alongside with mod_manager to provide the gui JavaScript/SVG gui console and/or consider deploying the console as a web page into the httpd's web serving directory.