Make -x (execute) the default behaviour

[philmcmahon]

What does this change?

This PR modifies ssm-scala so that you no longer need to pass -x or --execute in order to get it to execute the ssh command.

In 7 years of using SSM, I don't think I have ever wanted to run a command without -x. The only use case has been for scripts which have made use of --raw to build a more complex ssh command. With that in mind, I have modified the --raw setting so that it now disables execution.

This PR introduces a new 'dryrun' command line option as a way of getting the old behaviour back (printing out the ssh command rather than executing).

As this affects the default behaviour of SSM I this will need to be at least a minor version bump and I'll send out some comms as well after releasing.

What is the value of this?

Two characters less typing every time anyone uses SSM. Only 2 characters! So best not to think about this PR too much or it will take another year to pay off!

Any additional notes?

[mchv]

👍 from me

[tjsilver]

Great work! 👍

[johnduffell]

I just updated and this PR seems to break ssm --help output

% ssm --help                
bash: Usage:: command not found
bash: repl: command not found
bash: args: No such file or directory
usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface] [-b bind_address]
           [-c cipher_spec] [-D [bind_address:]port] [-E log_file]
           [-e escape_char] [-F configfile] [-I pkcs11] [-i identity_file]
           [-J destination] [-L address] [-l login_name] [-m mac_spec]
           [-O ctl_cmd] [-o option] [-P tag] [-p port] [-R address]
           [-S ctl_path] [-W host:port] [-w local_tun[:remote_tun]]
           destination [command [argument ...]]
       ssh [-Q query_option]
bash: line 2: --help: command not found
bash: line 3: value: No such file or directory
bash: -c: line 4: syntax error near unexpected token `('
bash: -c: line 4: `  -i, --instances <value>  Specify the instance ID(s) on which the specified command(s) should execute'

however if I do ssm --raw --help it seems ok

% ssm --raw --help
Error: Unknown option --raw
Usage: ssm [cmd|repl|ssh|scp] [options] <args>...

  --help                   prints this usage text
..........etc............