a small fix suggestion

[hetzbh]

Instead of:
docker run --name goodbye echo "Goodbye"

it should be IMHO:
docker run --name goodbye minimal /bin/echo "Goodbye"

[karamcnair]

I was here for the same reason! I didn't need the full path for 'echo' though - mine worked with this:
docker run --name goodbye minimal echo "Goodbye"

But the image parameter seems to be mandatory now