From f3c83317eb614e50bade5c13617eafec151b72ea Mon Sep 17 00:00:00 2001
From: Flo <flo@fino.fr>
Date: Sun, 28 Mar 2021 19:05:03 +0200
Subject: [PATCH] Remove user, add dryRun

* Remove user option, shoud be defined in config or SSH will use default
* Improve usage()
* Add dryRun option
* Some syntax enhancement
---
 README.md | 31 +++++++++++++-----
 csc       | 97 ++++++++++++++++++++++++++++++++++++-------------------
 2 files changed, 86 insertions(+), 42 deletions(-)

diff --git a/README.md b/README.md
index d26f357..c1dd674 100644
--- a/README.md
+++ b/README.md
@@ -1,13 +1,28 @@
-# csc : cluster ssh command
+# csc : Cluster SSH Command
 
-simple script to execute command over ssh on remote hosts with "dialog" DEBIAN_FRONTEND
+Launch command over SSH on cluster hosts with "dialog" DEBIAN_FRONTEND.
+
+## Tree
+
+```bash
+$ tree
+.
+├── csc
+└── README.md
+
+0 directories, 2 files
+```
 
 ## Usage
 
+```bash
+$ csc -h
 Usage: csc [OPTION]... [COMMAND]
-    -v  enable verbose mode
-    -c  specify config dir, default is /$HOME/.config/csc
-    -u  specify user, default is $USER
-    -g  specify hosts group
-    
-Host group file must exists under config dir, one host per line
+  -h  show help
+  -v  enable verbose mode
+  -c  specify config dir, default is /home/flo/.config/csc
+  -g  specify group
+  -d  enable dry run mode
+```
+
+Host group file must exists under config dir, one host per line.
diff --git a/csc b/csc
index 848ac75..972bd1a 100755
--- a/csc
+++ b/csc
@@ -1,35 +1,43 @@
 #!/bin/bash
 
-# csc : cluster ssh command
-# launch command over ssh on cluster hosts with "dialog" DEBIAN_FRONTEND
+#
+# csc : Cluster SSH Command
+# Launch command over SSH on cluster hosts with "dialog" DEBIAN_FRONTEND.
+#
 
-# Usage : csc [OPTION]... [COMMAND]
-# options :
-# -v    enable verbose mode
-# -c    specify config dir, default is $HOME/.config/csc
-# -u    specify user, default is $USER
-# -g    specify hosts group
+usage () {
+    echo "Usage: csc [OPTION]... [COMMAND]"
+    echo "  -h  show help"
+    echo "  -v  enable verbose mode"
+    echo "  -c  specify config dir, default is $HOME/.config/csc"
+    echo "  -g  specify group"
+	echo "  -d  enable dry run mode"
+}
 
-# defaults
+# variable defaults
+usage=false
 verbose=false
 confdir="$HOME/.config/csc"
-user=$USER
+dryRun=false
 
 # get options
-while getopts ":vc:u:g:" opt; do
+while getopts "hvc:g:d" opt; do
     case $opt in
+        h)
+            usage=true
+            ;;
         v)
             verbose=true
             ;;
         c)
             confdir=$OPTARG
             ;;
-        u)
-            user=$OPTARG
-            ;;
         g)
             group=$OPTARG
             ;;
+		d)
+			dryRun=true
+			;;
         \?)
             echo "Invalid option: -$OPTARG" >&2
             exit 1
@@ -44,28 +52,38 @@ done
 # clean $@ of options
 shift $((OPTIND-1))
 
-cmd=$@
+cmd=$*
+
+if [ "$usage" = true ]
+then
+    usage
+    exit 0
+fi
+
+if [ "$verbose" = true ]
+then
+	echo "> starting csc"
+	echo "> options :"
+	echo "  - help: $usage"
+	echo "  - verbose: $verbose"
+	echo "  - confdir: $confdir"
+	echo "  - group: $group"
+	echo "  - dryRun: $dryRun"
+fi
 
 if [ -z "$cmd" ]
 then
     echo "Error : command is missing"
-    echo "Usage: csc [OPTION]... [COMMAND]"
-    echo "  -v  enable verbose mode"
-    echo "  -c  specify config dir, default is $HOME/.config/csc"
-    echo "  -u  specify user, default is $USER"
-    echo "  -g  specify group"
+    echo
+    usage
     exit 1
 fi
 
-if [ -z "$user" ]
-then
-    echo "Error: user is not defined !"
-    exit
-fi
-
 if [ -z "$group" ]
 then
     echo "Error: group is not defined !"
+    echo
+    usage
     exit
 fi
 
@@ -74,6 +92,8 @@ hosts="$confdir/$group"
 if [ -z "$hosts" ]
 then
     echo "Error: hosts file $confdir/$group do not exists !"
+    echo
+    usage
     exit
 fi
 
@@ -84,16 +104,25 @@ FRONTEND="TERM=$TERM DEBIAN_FRONTEND=dialog"
 
 if [ "$verbose" = true ]
 then
-    echo "will do :"
-    echo "for i in `cat $hosts | grep -v '^#'`; do ssh -t $user@\$i "$FRONTEND $cmd"; done"
+    echo "> will do :"
+    echo "  grep -v '^ *#' < \"$hosts\" | while IFS= read -r line; do ssh -n -t \"\$line\" \"$FRONTEND $cmd\"; done"
 fi
 
-for i in `cat $hosts | grep -v '^#'`
+if [ "$dryRun" = false ]
+then
+    for line in $(grep -v '^#' "$hosts")
     do
-    echo -e "\e[34m---------------\e[0m"
-    echo -e "\e[34m$i\e[0m"
-    echo -e "\e[34m---------------\e[0m"
-    ssh -t $user@$i "$FRONTEND $cmd"
-done
+		echo -e "\e[34m------------------------------------------------------------\e[0m"
+		echo -e "\e[34m> \e[32m\"$cmd\" \e[34mon \e[32m$line\e[0m"
+		echo -e "\e[34m> \e[33mssh -t \"$line\" \"$FRONTEND $cmd\"\e[0m"
+		echo -e "\e[34m------------------------------------------------------------\e[0m"
+		ssh -t "$line" "$FRONTEND $cmd"
+    done
+fi
+
+if [ "$verbose" = true ]
+then
+	echo "> All done, bye."
+fi
 
 exit