This fix tries to fix issues encountered when running a container with a hostname
that is longer than HOST_NAME_MAX(64).
Previously, `could not synchronise with container process` was generated as the
length of the regex check was missing.
This fix covers the length check so that a hostname that is longer than
HOST_NAME_MAX(64) will be given a correct error message.
Several unit tests cases and additional integration test cases are added as well.
This fix closes#21445.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Upstream-commit: fa44b4e81ee87f1c2b39ad335a22795415c8cdf2
Component: engine