check bridge's port state

[hongli-my]

fix #463
link host veth pair to bridge, the Initial state
of port is BR_STATE_DISABLED and change to
BR_STATE_FORWARDING async.

[squeed]

"wait for bridge port state to be Up"

[mars1024]

nit: should we make this section into to a utility function?

[squeed]

It would be nice if this had some backoff - sleeping 50, then, 500, then 1000 ms.

A more idiomatic way of writing this might be

retries := []int{50, 500, 1000, 1000}
for idx, sleep := range retries {
  (check host)
  if idx == len(retries) - 1) {
    fail
  }
  time.Sleep(sleep + time.Millisecond)
}

[hongli-my]

@squeed have been modified.

[squeed]

lgtm

[mars1024]

If we try to escape from here, we only try 4 times and need 3 intervals, so I think we should sleep in the beginning of the loop and let retries := []int{0,50,500,1000,1000} , so we will make full use of retries.

[hongli-my]

@mars1024 add it.

[mars1024]

Sorry, I think sleep should be the first step of the loop... just like

retries := []int{0, 50, 500, 1000, 1000}
for idx, sleep := range retries {
  time.Sleep(sleep * time.Millisecond)

  (check host)

  if idx == (len(retries) - 1) {
    fail
  }
}

[hongli-my]

sleep 0 before do something ?

[mars1024]

yes, 0 means no sleep in the first time, then we will have 5 tries and 4 non-zero intervals as expectation.

[hongli-my]

@mars1024 , have changed.

[mars1024]

nit: should we make this section into to a utility function?

[mars1024]

/lgtm, thanks!

[dcbw]

lgtm