randomports: give user ability to init ipfs using random port for swarm.

[tarekbadrsh]

Issue : ipfs/kubo#5176

It's still under development, just to make sure that the code is going to
do as we expected.

[Stebalien]

Preliminary review: LGTM.

[tarekbadrsh]

Hi @Stebalien,

• I change the description.
• I don't know how do we test this repo, I can't find any test pkg.
• I have another idea about random port, we can generate random number and check if it's available, ex.

	src := rand.NewSource(time.Now().UnixNano())
	rnd := rand.New(src)
	portRange := 10000
	port := rnd.Intn(portRange)
	for !isAvailablePort(port) {
		port = rnd.Intn(portRange)
	}

please feel free to ask about more update.

[djdv]

@tarekbadrshalaan

I don't know how do we test this repo, I can't find any test pkg.

There are tests in go-ipfs at the moment that check the output of the config command.
https://github.com/ipfs/go-ipfs/blob/master/test/sharness/t0021-config.sh
It may be best to add your cases there.

I have another idea about random port, we can generate random number and check if it's available, ex.

Is there benefit to this over the randomness inherited from net.Listen("tcp", "[::]:0")?

[tarekbadrsh]

Hello @djdv
as you can see here I updated the discretion as you said.

again sorry be late and please feel free to ask about more update.

[tarekbadrsh]

Is there benefit to this over the randomness inherited from net.Listen("tcp", "[::]:0")?

• no it was just an idea i thought it might help.

[djdv]

This seems fine to me. 👍
The considerations that came up during review where:

• Should net.Listen("tcp", "[::]:0") try net.Listen("tcp", "127.0.0.1:") instead of, or in addition to, the ipv6 port?
  But I doubt it's necessary, so I think not.
• Lack of type assertion check in port = ln.Addr().(*net.TCPAddr).Port
  But it's pretty clear that we'd always have a *net.TCPAddr from Listen here.

[djdv]

@tarekbadrshalaan
Sorry for my absence, something unexpected came up.
The delay is on me this time ;^)

Patch seems good to me, handing off to @Stebalien