Fixes#1563
This implements dmesg reading via `/dev/kmsg`, with message parsing and
formatting. Kernel log facility and severity are parsed, timestamp is
calculated relative to boot time (it's accurate unless time jumps a
lot during node lifetime).
New flags to follow dmesg was added, tail flag allows to stream only new
message (ignoring old messages). We could try to implement tailing last
N messages, just a bit more work, open to suggestions (for symmetry with
regular logs).
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>
Now default is not to follow the logs (which is similar to `kubectl logs`).
Integration test was added for `Logs()` API and `osctl logs` command.
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>
This starts with a very simple test for `osctl version` using regexps as
output of the command depends a lot on current version.
We might use more of 'gold' matches for other commands potentially.
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>