From 2b47bb65d2aba2175fd9062fc65cefa9b57f581b Mon Sep 17 00:00:00 2001
From: Matteo Cypriani <mcy@lm7.fr>
Date: Mon, 21 Oct 2019 16:09:35 +0200
Subject: [PATCH] [ssh_tools] multicopy: don't require pscp

Fallback to plain SCP if parallel-scp is not available.
---
 ssh_tools/multicopy.sh | 61 +++++++++++++++++++++++++++++-------------
 1 file changed, 43 insertions(+), 18 deletions(-)

diff --git a/ssh_tools/multicopy.sh b/ssh_tools/multicopy.sh
index fb8860c..081074e 100755
--- a/ssh_tools/multicopy.sh
+++ b/ssh_tools/multicopy.sh
@@ -53,12 +53,24 @@ bad_usage()
 
 err()
 {
-  printf 'Error! %s\n' "$@" >&2
+  printf 'Error! ' >&2
+  printf '%s\n' "$@" >&2
 }
 
 warn()
 {
-  printf 'Warning! %s\n' "$@" >&2
+  printf 'Warning! ' >&2
+  printf '%s\n' "$@" >&2
+}
+
+# Copy file $FILE to the remote hosts using plain old SCP
+scp_copy()
+{
+  grep -v '^#' "$HOSTS" | while read -r host ; do
+    [ -z "$host" ] && continue
+    echo "Deploying '$FILE' to '$host'..."
+    scp -r "$FILE" "${SSH_LOGIN}${host}:${DEST_DIR}"
+  done
 }
 
 # Parse CLI options
@@ -84,30 +96,38 @@ shift $((OPTIND - 1))
 [ $# -lt 2 ] && bad_usage "Wrong number of arguments."
 
 # Check the usage of -r and -R
-if [ "$DELETE" = "1" ] ; then
-  [ "$RSYNC" = "1" ] && bad_usage "Use either -r or -R, but not both."
+if [ "$DELETE" = 1 ] ; then
+  [ "$RSYNC" = 1 ] && bad_usage "Use either -r or -R, but not both."
   RSYNC=1
   DELETE="-X --delete"
 fi
 
 # Ignore -P if rsync is going to be used
-if [ "$RSYNC" = "1" ] && [ "$PARALLEL" = "1" ] ; then
+if [ "$RSYNC" = 1 ] && [ "$PARALLEL" = 1 ] ; then
   warn "Cannot transfer in parallel when using rsync: ignoring -P."
   PARALLEL=
 fi
 
 # Check dependencies
-PSCP=$(command -v parallel-scp || command -v pscp.pssh || command -v pscp)
-PRSYNC=$(command -v parallel-rsync || command -v prsync)
+if [ "$RSYNC" = 1 ] ; then
+  PRSYNC=$(command -v parallel-rsync || command -v prsync)
+  if [ -z "$PRSYNC" ] ; then
+    err "Parallel rsync (prsync) is required for this script to work with -r or -R."
+    exit $EXIT_DEPENDENCY
+  fi
+
+else # $RSYNC != 1
+  PSCP=$(command -v parallel-scp || command -v pscp.pssh || command -v pscp)
+  if [ -z "$PSCP" ] ; then
+    warn "Parallel SSH (pssh) is not installed. Install it for best results."
+    if [ "$PARALLEL" = 1 ] ; then
+      warn "Parallel copy will not work without Parallel SSH. Ignoring -P."
+      PARALLEL=
+    fi
+  fi
+fi
+
 MULTIPING=$(command -v multiping)
-if [ -z "$RSYNC" ] && [ -z "$PSCP" ] ; then
-  err "Parallel SSH (pssh) is required for this script to work."
-  exit $EXIT_DEPENDENCY
-fi
-if [ -z "$PRSYNC" ] ; then
-  err "Parallel rsync (prsync) is required for this script to work."
-  exit $EXIT_DEPENDENCY
-fi
 if [ -z "$MULTIPING" ] ; then
   err "multiping (which should have been provided along with this" \
       "script) is required for this script to work."
@@ -150,7 +170,7 @@ fi
 echo "Destination directory: $DEST_DIR"
 
 # Transfer the files in parallel...
-if [ "$PARALLEL" = "1" ] ; then
+if [ "$PARALLEL" = 1 ] ; then
   # shellcheck disable=SC2086
   exec $PSCP -r $LOGIN -h "$HOSTS" -- "$@" "$DEST_DIR"
 fi
@@ -162,11 +182,16 @@ for FILE in "$@" ; do
     warn "This file doesn't exist, skipping."
     continue
   fi
-  if [ "$RSYNC" = "1" ] ; then
+  if [ "$RSYNC" = 1 ] ; then
     # shellcheck disable=SC2086
     $PRSYNC -a $DELETE $LOGIN -h "$HOSTS" -- "$FILE" "$DEST_DIR"
-  else
+    continue
+  fi
+  if [ -n "$PSCP" ] ; then
     # shellcheck disable=SC2086
     $PSCP -r $LOGIN -h "$HOSTS" -- "$FILE" "$DEST_DIR"
+    continue
   fi
+  # If we're still here, that means we'll have to copy with plain SCP
+  scp_copy
 done