**What**
- Instead of sleeping to ensure the msg channel is populated, use an
unbuffered channel. This seems to work just as well in all the manual
tests cases
Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>
**What**
- Remove the `output-fields` flag because not all journalctl versions
support it
- Add a short sleep to the start of the log stream to avoid some kind of
race/buffering condition with the Handler
Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>
**What**
- journald log provider using exec to journalctl
```
journalctl -t <namespace>:<name> --output=json --since=<timestamp> <--follow> --output-fields=SYSLOG_IDENTIFIER,MESSAGE,_PID,_SOURCE_REALTIME_TIMESTAMP
```
- This can be tested manually using `faas-cli logs` as normal, e.g.
`faas-cli logs nodeinfo` should tail the last 5 mins of logs.
- Very basic tests ensuring that the `journalctl` comamand is correctly
construction and that the json log entrys are parsed correctly.
- Add simple e2e test to grep the function logs
Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>
