first

.gitlab-ci.yml

+stages:
+  - build
+  - deploy
+
+variables:
+  GIT_DEPTH: "1"
+  CONTAINER_TEST_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
+  CONTAINER_RELEASE_IMAGE: $CI_REGISTRY_IMAGE:latest
+
+before_script:
+  - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+
+build:
+  stage: build
+  tags: 
+    - docker
+  script:
+    - docker build --pull -t $CONTAINER_TEST_IMAGE .
+    - docker push $CONTAINER_TEST_IMAGE
+
+deploy_latest:
+  stage: deploy
+  tags: 
+    - docker
+  script:
+    - docker pull $CONTAINER_TEST_IMAGE
+    - docker tag $CONTAINER_TEST_IMAGE $CONTAINER_RELEASE_IMAGE
+    - docker push $CONTAINER_RELEASE_IMAGE
+  only:
+    - master
+
+deploy_tag:
+  stage: deploy
+  tags: 
+    - docker
+  variables:
+    CONTAINER_TAG_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
+  script:
+    - docker pull $CONTAINER_TEST_IMAGE
+    - docker tag $CONTAINER_TEST_IMAGE $CONTAINER_TAG_IMAGE
+    - docker push $CONTAINER_TAG_IMAGE
+  only:
+    - tags

Dockerfile

+FROM debian:buster-slim
+
+RUN apt update && apt -y install subnetcalc iproute2 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+WORKDIR /usr/src/app
+COPY ddns-route.sh .
+
+CMD ["/usr/src/app/ddns-route.sh"]

tr069-daemon.sh

+#!/bin/bash
+#TRO69_INTERFACE
+#TABLE
+
+while :
+do
+
+	LOCAL_IP=$(ip addr show dev brtr069 | grep 'inet ' | awk '{print $2}')
+	GATEWAY=$(subnetcalc $LOCAL_IP -n | grep "Host Range" | awk '{print $5}')
+	ROUTE_TXT="default via $GATEWAY dev $TRO69_INTERFACE table $TABLE" 
+	echo "$ROUTE_TXT"
+
+	bash -c "ip route replace $ROUTE_TXT || ip route add $ROUTE_TXT"
+
+	sleep 60
+
+done