diff --git a/.docker-mongo/Dockerfile b/.docker-mongo/Dockerfile
index ca963c16aad..5294e94f7d3 100644
--- a/.docker-mongo/Dockerfile
+++ b/.docker-mongo/Dockerfile
@@ -1,24 +1,24 @@
 FROM rocketchat/base:12.14.0
 
-ADD . /app
-ADD entrypoint.sh /app/bundle/
-
-MAINTAINER buildmaster@rocket.chat
+LABEL maintainer="buildmaster@rocket.chat"
 
 RUN set -x \
- && apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4 \
+ && apt-get update \
+ && apt-get install -y wget \
+ && wget -qO - https://www.mongodb.org/static/pgp/server-4.0.asc | apt-key add - \
  && echo "deb http://repo.mongodb.org/apt/debian stretch/mongodb-org/4.0 main" | tee /etc/apt/sources.list.d/mongodb-org-4.0.list \
  && apt-get update \
- && apt-get install -y --force-yes pwgen mongodb-org \
- && echo "mongodb-org hold" | dpkg --set-selections \
- && echo "mongodb-org-server hold" | dpkg --set-selections \
- && echo "mongodb-org-shell hold" | dpkg --set-selections \
- && echo "mongodb-org-mongos hold" | dpkg --set-selections \
- && echo "mongodb-org-tools hold" | dpkg --set-selections \
+ && apt-get install -y pwgen mongodb-org \
+ && apt-get clean my room
+
+ADD . /app
+ADD entrypoint.sh /app/bundle/
+
+RUN set -x \
  && cd /app/bundle/programs/server \
  && npm install \
  && npm cache clear --force \
- && rm -rf /var/lib/apt/lists/*
+ && chown -R rocketchat:rocketchat /app
 
 VOLUME /app/uploads
 
@@ -28,6 +28,7 @@ WORKDIR /app/bundle
 ENV DEPLOY_METHOD=docker-preview \
     NODE_ENV=production \
     MONGO_URL=mongodb://localhost:27017/rocketchat \
+    MONGO_OPLOG_URL=mongodb://localhost:27017/local \
     HOME=/tmp \
     PORT=3000 \
     ROOT_URL=http://localhost:3000 \
diff --git a/.docker-mongo/entrypoint.sh b/.docker-mongo/entrypoint.sh
index f86035acba5..15d0c0f76e6 100644
--- a/.docker-mongo/entrypoint.sh
+++ b/.docker-mongo/entrypoint.sh
@@ -39,11 +39,32 @@ echo """
 ╚═╝  ╚═╝ ╚═════╝  ╚═════╝╚═╝  ╚═╝╚══════╝   ╚═╝╚═╝ ╚═════╝╚═╝  ╚═╝╚═╝  ╚═╝   ╚═╝       ╚═╝     ╚═╝  ╚═╝╚══════╝  ╚═══╝  ╚═╝╚══════╝ ╚══╝╚══╝
 """
 
-mongod --smallfiles --storageEngine=mmapv1 --fork --config /etc/mongod.conf
+mongod --smallfiles --storageEngine=mmapv1 --fork --replSet rs0 --config /etc/mongod.conf
 
 until mongo --eval "db" &> /dev/null; do
 	echo "MongoDB still not ready, sleeping"
 	sleep 1
 done
 
-node main.js
+sleep 2
+
+# initiate mongo replica set
+for i in `seq 1 30`; do
+	mongo rocketchat --eval "
+	rs.initiate({
+		_id: 'rs0',
+		members: [ { _id: 0, host: 'localhost:27017' } ]})" &&
+	s=$? && break || s=$?;
+	echo "Tried $i times. Waiting 5 secs...";
+	sleep 5;
+done;
+
+sleep 2
+
+# try multiple times until replica set is ready
+for i in `seq 1 30`; do
+	node main.js &&
+	s=$? && break || s=$?;
+	echo "Tried $i times. Waiting 5 secs...";
+	sleep 5;
+done;
diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
index 9a9f943d9e0..f379dfe98aa 100644
--- a/.github/workflows/build_and_test.yml
+++ b/.github/workflows/build_and_test.yml
@@ -419,7 +419,6 @@ jobs:
 
         export DOCKER_PATH="${GITHUB_WORKSPACE}/.docker"
         if [[ '${{ matrix.release }}' = 'preview' ]]; then
-          export IMAGE="${IMAGE}.preview"
           export DOCKER_PATH="${DOCKER_PATH}-mongo"
         fi;
 
@@ -437,6 +436,10 @@ jobs:
         cd /tmp/build
         export CIRCLE_TAG="${GITHUB_REF#*tags/}"
 
+        if [[ '${{ matrix.release }}' = 'preview' ]]; then
+          export IMAGE="${IMAGE}.preview"
+        fi;
+
         docker build -t ${IMAGE}:$CIRCLE_TAG .
         docker push ${IMAGE}:$CIRCLE_TAG
 
@@ -453,5 +456,10 @@ jobs:
       if: github.ref == 'refs/heads/develop'
       run: |
         cd /tmp/build
+
+        if [[ '${{ matrix.release }}' = 'preview' ]]; then
+          export IMAGE="${IMAGE}.preview"
+        fi;
+
         docker build -t ${IMAGE}:develop .
         docker push ${IMAGE}:develop