Dockerfile:
FROM ruby:2.6
RUN apt-get update -yqq
RUN apt-get install -yqq --no-install-recommends nodejs
COPY . /usr/src/app/
WORKDIR /usr/src/app/
RUN bundle install
The Dockerfile instructs us to copy the current directory into /usr/src/app/. Placing our directory myapp into /usr/src/app/.
Then the WORKDIR is defined as /usr/src/app/
And RUN bundle install.
This fails as bundle install should be run in the app directory. We’re in /usr/src/app/ but we should be in /usr/src/app/myapp.
The Dockerfile is corrected with
FROM ruby:2.6
RUN apt-get update -yqq
RUN apt-get install -yqq --no-install-recommends nodejs
COPY . /usr/src/app/
WORKDIR /usr/src/app/myapp
RUN bundle install