From b8cd8f3d00dd700175adb56812fd034ce1f6e5b1 Mon Sep 17 00:00:00 2001
From: Vaibhav Hemant Dixit <vaibhav.hemant@gmail.com>
Date: Thu, 6 Jul 2023 17:34:35 -0700
Subject: [PATCH] Revert "Revert "Fix for fast/cold-boot: call db_migrator only
 after old config is loaded (#14933)" (#15464)" (#15684)

This reverts commit 9649a44470151f62cae4ce79eff68a5782fa27ea.
---
 files/build_templates/docker_image_ctl.j2    | 16 ++++++++++++----
 files/image_config/config-setup/config-setup | 13 +++++++++++++
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/files/build_templates/docker_image_ctl.j2 b/files/build_templates/docker_image_ctl.j2
index ba260dbfb648..01a52fb7a0d3 100644
--- a/files/build_templates/docker_image_ctl.j2
+++ b/files/build_templates/docker_image_ctl.j2
@@ -257,10 +257,18 @@ function postStartAction()
             $SONIC_DB_CLI CONFIG_DB SET "CONFIG_DB_INITIALIZED" "1"
         fi
 
-        if [[ -x /usr/local/bin/db_migrator.py ]]; then
-            # Migrate the DB to the latest schema version if needed
-            if [ -z "$DEV" ]; then
-                /usr/local/bin/db_migrator.py -o migrate
+        if [ -e /tmp/pending_config_migration ]; then
+            # this is first boot to a new image, config-setup execution is pending.
+            # For fast/cold reboot case, DB contains nothing at this point
+            # Call db_migrator after config-setup loads the config (from old config or minigraph)
+            echo "Delaying db_migrator until config migration is over"
+        else
+            # this is not a first time boot to a new image. Datbase container starts w/ old pre-existing config
+            if [[ -x /usr/local/bin/db_migrator.py ]]; then
+                # Migrate the DB to the latest schema version if needed
+                if [ -z "$DEV" ]; then
+                    /usr/local/bin/db_migrator.py -o migrate
+                fi
             fi
         fi
         # Add redis UDS to the redis group and give read/write access to the group
diff --git a/files/image_config/config-setup/config-setup b/files/image_config/config-setup/config-setup
index 0f5a248b05f8..28a3a4373a42 100755
--- a/files/image_config/config-setup/config-setup
+++ b/files/image_config/config-setup/config-setup
@@ -304,6 +304,16 @@ check_all_config_db_present()
     return 0   
 }
 
+# DB schema is subject to change between two images
+# Perform DB schema migration after loading backup config from previous image
+do_db_migration()
+{
+    if [[ -x /usr/local/bin/db_migrator.py ]]; then
+        # Migrate the DB to the latest schema version if needed
+        /usr/local/bin/db_migrator.py -o migrate
+    fi
+}
+
 # Perform configuration migration from backup copy.
 #  - This step is performed when a new image is installed and SONiC switch boots into it
 do_config_migration()
@@ -326,16 +336,19 @@ do_config_migration()
     if [ x"${WARM_BOOT}" == x"true" ]; then
         echo "Warm reboot detected..."
         disable_updategraph
+        do_db_migration
         rm -f /tmp/pending_config_migration
         exit 0
     elif check_all_config_db_present; then
         echo "Use config_db.json from old system..."
         reload_configdb
+        do_db_migration
         # Disable updategraph
         disable_updategraph
     elif [ -r ${MINGRAPH_FILE} ]; then
         echo "Use minigraph.xml from old system..."
         reload_minigraph
+        do_db_migration
         # Disable updategraph
         disable_updategraph
     else