suggestion: add bpsh/bpshd for ssh-like interactive remote shell

[zebastian]

server side on target node:

• bpshd daemon listens on a local ipn endpoint with bp_receive
• command payload is forked into actual program invocation
• program output / exit code is relayed back to requestor with bp_send
• multiple commands may run in parallel

client side on user node:

• bpsh: opens a local ipn service / permanently listen on inbound data with bp_receive
• exposes REPL terminal to user (behaves serial: after each command initiated waits for the result and exit from server)
• on key ENTER send current line with bp_send
• inbound data handled analogue to ssh (print data received / re-show prompt on exit signal)
• if no local ipn service is given a ephemeral service id is used
• nice to have: implement shell detection and stdin forwarding for non-TTY invocation, eg:
  cat /stream-this-local-file | bpsh -h ipn:1,5 -c "tee /to-this-file-on-remote"

multiple local bpsh instances can be started and be run in parallel against the same server, if all bpsh have a differing service number.
server and client: mark bundles with an order id for bundle ordering on receiver side

config:

• server:
  • mandatory: ipn listen endpoint
  • optional: whitelist requestor ipn, whitelist commands, bpsec requirement, command timeout, command max output
• client:
  • options given as cli arguments
  • mandatory: remote ipn
  • optional: local ipn, show progress bar based on expected response time

[zebastian]

i wrote proof of concept code for this.
Let me know, if you are interested in this.