jeffchao

The full scale (which is explained) is:

10 - Wrote the book on it (there must be a book)
9 - Could have written the book, but didn't.
8 - Deep understanding of corner cases and esoteric features.
7 - Understanding and (appropriate) usage of most lesser known features.
6 - Can develop large programs and deploy new systems from scratch.
5 - Can develop/deploy larger programs/systems using all basic (w/o book) and more esoteric features (some w/ book, some without)
4 - Can develop/deploy medium programs/systems using all basic (w/o book) and a few esoteric features (w/ book). Understands enough about internals to do nontrivial troubleshooting.
3 - Can utilize basic features without much help, manage a small installation competently.

jeffchao

docker-machine start
eval $(docker-machine env default)
docker ps

jeffchao

ssh -t bastion -L localhost:port:remotehost:port
use jconsole, visualvm, zmc, etc.

-L [bind_address:]port:host:hostport
     -L [bind_address:]port:remote_socket
     -L local_socket:host:hostport
     -L local_socket:remote_socket
             Specifies that connections to the given TCP port or Unix socket on the local (client) host are to be forwarded to the given host and port, or Unix
             socket, on the remote side.  This works by allocating a socket to listen to either a TCP port on the local side, optionally bound to the specified
             bind_address, or to a Unix socket.  Whenever a connection is made to the local port or socket, the connection is forwarded over the secure channel,