Automatic build of docker container (java backend, angular frontend) - docker

Question

I would like to say that this is my first container and actually my first JAVA app so maybe I will have basic questions so be lenient, please.
I wrote spring boot app and my colleague has written the frontend part for it in angular. What I would like to achieve is to have "one button/one command" in IntelliJ to create a container containing whole app backend and front end.
What I need to do is:
Clone FE from company repository (I am using ssh key now)
Clone BE from GitHub
Build FE
Copy built FE to static folder in java app
Build BE
Create a container running this app
My current solution is to create "builder" container and there build FE and BE and then copy it to "production" container like this:
#BUILDER
FROM alpine AS builder
WORKDIR /src
# add credentials on build
ARG SSH_PRIVATE_KEY
RUN mkdir /root/.ssh/ \
&& echo "${SSH_PRIVATE_KEY}" > /root/.ssh/id_rsa \
&& echo "github.com,140.82.121.3 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==" >> /root/.ssh/known_hosts \
&& chmod 600 /root/.ssh/id_rsa
# installing dependencies
RUN apk update && apk upgrade && apk add --update nodejs nodejs-npm \
&& npm install -g #angular/cli \
&& apk add openjdk11 \
&& apk add maven \
&& apk add --no-cache openssh \
&& apk add --no-cache git
#cloning repositories
RUN git clone git#code.siemens.com:apcprague/edge/metal-forming-fe.git
RUN git clone git#github.com:bzumik1/metalForming.git
# builds front end
WORKDIR /src/metal-forming-fe
RUN npm install && ng build
# builds whole java app with front end
WORKDIR /src/metalForming
RUN cp -a /src/metal-forming-fe/dist/metal-forming/. /src/metalForming/src/main/resources/static \
&& mvn install -DskipTests=true
#PRODUCTION CONTAINER
FROM adoptopenjdk/openjdk11:debian-slim
LABEL maintainer jakub.znamenacek#siemens.com
RUN mkdir app
RUN ["chmod", "+rwx", "/app"]
WORKDIR /app
COPY --from=builder /src/metalForming/target/metal_forming-0.0.1-SNAPSHOT.jar .
EXPOSE 4200
RUN java -version
CMD java -jar metal_forming-0.0.1-SNAPSHOT.jar
This works but I takes very long time so I guess this is not correct way how to do it. Could anyone point me in correct direction? I was thinking if there is a way how to make maven to all these steps for me but maybe this is totally off.
Also if you will find any problem in my Dockerfile please let me know as I said this is my first Dockerfile so I could overlook something.
EDITED:
BTW does anyone know how can I get rid of this part:
echo "github.com,140.82.121.3 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==" >> /root/.ssh/known_hosts \
it adds GitHub to known_hosts (I also need to add a company repository there). It is because when I run git clone it will ask me if I trust this ... and I have to write yes but I don't know how to do it if it is automatically running in docker and I have no option to write there yes. I have tried yes | git clone ... but this is also not working

Answer 1

a few things:
1, if this runs "slow" on the machine than it will run slow inside a container too.
2, remove --no-cache,* you want to cache everything that is static, because next time when you build those commands will not run where there is no change. Once there is change in one command than that command will rerun instead using the builder cache and also all subsequent commands will have to rerun too.
*UPDATE: I have mistaken "apk update --no-cache" with "docker build --no-cache". I stated wrong that "apk add --no-cache" would mean that command is not cached, because this command is cached on docker builder level. However with this parameter you wouldn't need to delete in a later step the /var/cache/apk/ directory to make you image smaller, but that you wouldn't need to do here, because you are already using multi stage build, so this would not affect your final image size.
One more thing to clarify, all statements in Dockerfile are checked if they changed, if they did not than docker builder uses the cached layer for it and won't run that statement. Exception is ADD and COPY commands, here builder also checks the copied, added files if they changed with checksum. Also if a statement is changed or ADD-ed COPY-ed file(s) changed than that statement is re-run and all subsequent statements re-run too, so you want to put your source code copy statemant as much at the end as it is possible
If you want to disable this cache, do "docker build --no-cache ..." this way all the steps will be re-run that is in the Dockerfile.
3, specify WORKDIR at the top once, if you need to switch directory later use this:
RUN cd /someotherdir && mycommand
Also specifying a Subsequent WORKDIR will be relativ to the previous WORKDIR so it will mess up readibilty what is the (probably) sole purpose of WORKDIR statement.
4, Enable BuildKit:
Either declare environment variable
DOCKER_BUILDKIT=1
or add this to /etc/docker/daemon.json
{ "features": { "buildkit": true } }
BuildKit might not help in this case, but if you do more complex Dockerfiles with more stages Buildkit can run those parallel so overall build will be faster.
5, Do not skip tests with DskipTests=true :)
6, as stated in a comment, do not clone the repo inside the image build, you do not need to do that at all. Just put the Dockerfile in the / of the repo, and COPY the repo files with a Dockerfile command:
COPY . .
First dot is the source that is your current directory on your machine, second dot is the target, the working dir inside the image, /src with your Dockerfile. You build the image and publish it, push it to a docker registry so others can pull it and start using it. If you want more complex stuff building and publishing with a help of a server, look up CI/CD techniques.