tutorial/mtu: add duoexec to utility

Add duoexec utility to display side by side two executions.

Author: msune

tutorials/net/mtu/.bashrc

@@ -24,6 +24,7 @@ alias rm='rm -i'
 
 alias _exec='exec'
 alias help="/bp/help.sh"
+alias duoexec="/bp/duoexec.sh"
 alias describe="/bp/describe.sh"
 
 exec(){

tutorials/net/mtu/docker/Dockerfile

@@ -10,6 +10,7 @@ LABEL org.opencontainers.image.source="https://github.com/bitpuff-io/code/"
 LABEL org.opencontainers.image.licenses="BSD"
 
 RUN apt update && apt install -y --no-install-recommends \
+	byobu          \
 	curl           \
 	iproute2       \
 	iputils-ping   \

tutorials/net/mtu/duoexec.sh

@@ -0,0 +1,56 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source /bp/common.sh
+
+# multi-exec on multiple namespaces
+# $1 namespace1
+# $2 command1
+# $3 namespace2
+# $4 command2
+# $5 [optional, split: vertical or horizontal ]
+
+if [ $# -lt 4 ] || [ $# -gt 5 ]; then
+	log_err "Invalid number of parameters"
+	log_err "Usage: ${0} ns1 cmd1 ns2 cmd2 [horizontal | vertical]"
+	exit 1
+fi
+
+MODE="${5:-horizontal}"
+
+#_check_ns ${1}
+NS1=${1}
+CMD1=${2}
+
+#_check_ns ${3}
+NS2=${3}
+CMD2=${4}
+
+# Disable welcome messages for clean view
+export BYOBU_NO_WELCOME=1
+export BYOBU_DISABLE_STATUS=1
+#export BYOBU_BACKEND=tmux
+
+if [ "${MODE}" != "vertical" ]; then
+	SPLIT_OP="-h"
+	LAYOUT="even-horizontal"
+else
+	SPLIT_OP="-v"
+	LAYOUT="even-vertical"
+fi
+
+
+SESSION="duoexec$$"
+
+LABEL1="${CMD1}"
+LABEL2="${CMD2}"
+CMD1="${SUDO} ip netns exec ${NS1} bash -c \"${CMD1}\""
+CMD2="${SUDO} ip netns exec ${NS2} bash -c \"${CMD2}\""
+
+byobu new-session -A -d -s "${SESSION}" "echo ${CMD1}; ${CMD1}"
+byobu split-window ${SPLIT_OP} -t "${SESSION}" "echo ${CMD2}; ${CMD2}"
+
+byobu select-layout -t "${SESSION}" ${LAYOUT}
+byobu rename-window -t "${SESSION}" "${NS1}$ ${LABEL1} | ${NS2}$ ${LABEL2}"
+byobu attach-session -t "${SESSION}"