Unable to implement WatchTower in Docker

Question

I am trying to implement Watchtower which auto-build a container if any updates are found in Docker image.

These are commands I used for implementing watchtower:

git clone https://github.com/linuxacademy/content-express-demo-app.git watchtower

cd watchtower/

git checkout dockerfile

docker login -u "MYDOCKERREPO"

docker image build -t MYDOCKERREPO/my-express .

docker image push MYDOCKERREPO/my-express

docker container run -d --name watched-app -p 80:3000 --restart always MYDOCKERREPO/my-express

docker container run -d --name watchtower --restart always -v /var/run/docker.sock:/var/run/docker.sock
v2tec/watchtower -i 15

vi .dockerignore

Dockerfile
 .git
 .gitignore

#Added comment in app.js

created a sample.js file

docker image build -t MYDOCKERREPO/my-express --no-cache .

docker image push MYDOCKERREPO/my-express

I waited for many hours but no changes came. Also while pushing updated docker image it didn't show a single Pushed. All were saying 'Layers already exists"

Please if someone can help

EDIT:

Dockerfile:

FROM node 
RUN mkdir -p /var/node 
ADD . /var/node/ 
WORKDIR /var/node 
RUN npm install 
CMD ./bin/www

FROM node RUN mkdir -p /var/node ADD . /var/node/ WORKDIR /var/node RUN npm install CMD ./bin/www — Hetul Sheth, Sep 10 '20 at 09:31
It's a bit confusing that you've named your app folder `watchtower` as well. Took me a while to wrap my head around! — simme, Sep 21 '20 at 15:01

score 0 · Answer 1 · answered Sep 21 '20 at 15:05

I waited for many hours but no changes came. Also while pushing updated docker image it didn't show a single Pushed. All were saying 'Layers already exists"

This means that none of the layers (changesets) you pushed differed from the ones already pushed, and as such, no new hashes were produced. Watchtower will only detect and update when the image has actual changes.

docker container run -d --name watchtower --restart always \
   -v /var/run/docker.sock:/var/run/docker.sock v2tec/watchtower -i 15

The image you're using is more than a year old at this point. It might (likely won't) be compatible with current docker versions. The latest release of the watchtower image is available at containrrr/watchtower:latest.

Unable to implement WatchTower in Docker

1 Answers1