Retry get docker image digest (#4364)

---------

Signed-off-by: Oriol Muñoz <oriol.munoz@digitalasset.com>

Author: OriolMunoz-da

build-tools/get-docker-image-digests.sh

@@ -17,7 +17,31 @@ echo "imageDigests:"
 for dir in "${SPLICE_ROOT}"/cluster/images/*; do
   app=$(basename "$dir");
   if [ ! -f "$dir" ] && [ "$app" != "common" ]; then
-    digest=$(get_digest "$app")
+    n=0
+    MAX_RETRIES=5
+    # Client.Timeout from ghcr are not fun
+    until [ $n -ge $MAX_RETRIES ]; do
+      if ! digest=$(get_digest "$app"); then
+        digest=""
+      fi
+
+      if [ -n "$digest" ]; then
+        break
+      fi
+
+      n=$((n+1))
+      if [ $n -ge $MAX_RETRIES ]; then
+        break
+      fi
+      echo "Failed to get digest for $app, attempt $n/$MAX_RETRIES. Retrying in 5 seconds..." >&2
+      sleep 5
+    done
+
+    if [ -z "$digest" ]; then
+      echo "Failed to get digest for $app after $MAX_RETRIES attempts" >&2
+      exit 1
+    fi
+
     a=${app//-/_}
     echo "  $a: \"@$digest\""
   fi