nixops-mosh-adaptor.sh

#!/usr/bin/env bash

SEP=
for ((i = 3 ; i <= $# ; i++)); do
    if [ "${!i}" != "--" ]; then continue; fi
    SEP="$i"
    break
done
FLAGs=$((SEP - 2 - 2))
MACHINE=$((SEP - 1))

exec nixops ssh "${@:1:2}" "${!MACHINE}" "${@:3:$FLAGs}" "${@:$SEP}"

nixops-mosh.nix

# Requires mosh/mosh-client in PATH

let 
    nixops-mosh = pkgs.writeScriptBin "nixops-mosh" ''
      #!${pkgs.stdenv.shell}
      exec ${mosh}/bin/mosh --experimental-remote-ip=remote --ssh="${nixops-mosh-adaptor}/bin/nixops-mosh-adaptor -d $1" $2
    '';
    nixops-mosh-adaptor = pkgs.writeScriptBin "nixops-mosh-adaptor" ''
      #!${pkgs.stdenv.shell}
      SEP=
      for ((i = 3 ; i <= $# ; i++)); do
          if [ "''${!i}" != "--" ]; then continue; fi
          SEP="$i"
          break
      done
      FLAGs=$((SEP - 2 - 2))
      MACHINE=$((SEP - 1))

      exec ${nixops}/bin/nixops ssh "''${@:1:2}" "''${!MACHINE}" "''${@:3:$FLAGs}" "''${@:$SEP}"
    '';
in nixops-mosh
    

USAGE.sh

mosh --experimental-remote-ip=remote --ssh='./nixops-mosh-adaptor.sh -d deployment' machine

nixops-mosh deployment machine