F #5773: Add retry options to downloader.sh (#1857)

(cherry picked from commit 99ae8d3cdc111b6e9a2acb348874ce5d272c156c)

src/datastore_mad/remotes/downloader.sh

@@ -295,7 +295,30 @@ function get_rbd_cmd
     echo "ssh '$(esc_sq "$DST_HOST")' \"$RBD export '$(esc_sq "$SOURCE")' -\""
 }
 
-TEMP=`getopt -o m:s:l:c:n -l md5:,sha1:,limit:,max-size:,nodecomp -- "$@"`
+# Compare 2 version strings using sort -V
+# Usage:
+#   verlte "3.2.9" "3.4.0"
+function verlte() {
+    [  "$1" = "`echo -e "$1\n$2" | sort -V | head -n1`" ]
+}
+
+# Returns curl retry options based on its version
+function curl_retry_args {
+    [ "$NO_RETRY" = "yes" ] && return
+
+    RETRY_ARGS="--retry 3 --retry-delay 3"
+
+    CURL_VER=`curl --version | grep -o 'curl [0-9\.]*' | awk '{print $2}'`
+
+    # To retry also on conn-reset-by-peer fresh curl is needed
+    if verlte "7.71.0" "$CURL_VER"; then
+        RETRY_ARGS+=" --retry-all-errors"
+    fi
+
+    echo $RETRY_ARGS
+}
+
+TEMP=`getopt -o m:s:l:c:n:o -l md5:,sha1:,limit:,max-size:,nodecomp,noretry -- "$@"`
 
 if [ $? != 0 ] ; then
     echo "Arguments error" >&2
@@ -328,6 +351,10 @@ while true; do
             export MAX_SIZE="$2"
             shift 2
             ;;
+        -o|--noretry)
+            export NO_RETRY="yes"
+            shift
+            ;;
         --)
             shift
             break
@@ -349,7 +376,7 @@ else
     export HASH_FILE="/tmp/downloader.hash.$$"
 fi
 
-GLOBAL_CURL_ARGS="--fail -sS -k -L"
+GLOBAL_CURL_ARGS="--fail -sS -k -L $(curl_retry_args)"
 
 case "$FROM" in
 http://*|https://*)