Ohara: the length of container host name is too long

[saivirtue]

container.name format : {prefixKey}-{group}-{clusterName}-{service}-{index}
which is guarantee < 255 length

container hostname required the length <= 63, we should random a string for it (since it is used internally) instead of using container.name.

for docker

using random string for command: docker -h {RANDOM_STRING}

for k8s

using random string for json:

"spce": {
  "hostname": "{RANDOM_STRING}"
}

[saivirtue]

/cc @chia7712 @jackyoh

[chia7712]

@saivirtue Let me take over this one :)

[chia7712]

I remove the 0.8 from fixed version since this is not a critical bug. Also, the changes is too big to be a hot fix :(