Add additional external connectivity Checks to kconmon

[MaxRink]

We have the Use-Case of also monitoring some of our external connections as some of our Networks are a bit flaky sometimes and we want be able to detect that.
This PR impliments external ICMP and HTTP connection checks to for example monitor your rough network latency (routing changes e.g.) and status of connection to for example your registry,

[Stono]

Hey,
Sorry for the delay in reviewing this, had a busy few days. Firstly, thanks a lot for the contribution, I think the custom http checks is a great addition.

I'm on the fence about the ping implementation however.

The module you're importing, ping simply shells out to the os ping, rather than natively crafting an ICMP packets such as node-net-ping. I'm against this for a couple of reasons:

1. We bring into play a dependency on the native OS implementation of ping (in this case provided by iputils), as the module is simply parsing stdout. That feels very flakey and something that could bite us later.
2. I'm concerned about the cpu and memory overhead of frequently shelling out, it's quite an expensive operation when compared to crafting an icmp packet natively.

[MaxRink]

Ok, ill see if i can restructure it

[MaxRink]

Hi @Stono
we've did some reworking but are now running into the issue that crafting raw ICMP packets requires root rights.

{"timestamp":"2020-07-21T14:25:21.121Z","level":"error","module":"tester","message":"icmp test for 8.8.8.8 failed","error":{"name":"Error","message":"Operation not permitted","stack":"at new Socket (/app/node_modules/raw-socket/index.js:47:14)"}}
{"timestamp":"2020-07-21T14:25:21.121Z","level":"error","module":"tester","message":"icmp test for 8.8.4.4 failed","error":{"name":"Error","message":"Operation not permitted","stack":"at new Socket (/app/node_modules/raw-socket/index.js:47:14)"}}

Imo it would be a bad idea to run tasks as root, so im not sure how to proceed here. Tbh, im propably just lacking unterstanding for Node.js and how to accomplish this root-less with node.

[Stono]

Interesting, if you share your branch with me I can try and take a look tomorrow.

You might not need root, just a certain netcap

[MaxRink]

sure https://github.com/MaxRink/kconmon/tree/npm-ping