#The first line of a dockerfile sets the base image. The image we build will have everything that is already on the base image. If there is already an existing image that has what you need, you could use that as well
#Because this is a linux based image we are building (We usually suggest Alpine linux based on it's size), the next thing we need to do is update all of the packages
RUN apk update && apk upgrade
#Now that the OS is up to date, let's create a directory to keep all of our work and dependencies in. This following command set's the directory we will be working out of. If it doesn't exist, it is created here.
#This is not really needed for this particular example, but we'll add the contents of the directory we're working in
ADD . /app
#Now, I'll install git so we can clone the repos you're using.
RUN apk --update add git
#Cloning the needed repos
RUN git clone https://github.com/mtdowling/cron-expression.git
RUN git clone https://github.com/iron-io/iron_worker_php.git
RUN git clone https://github.com/dnovikov/ironio-oauth.git
#Last but not least, clear out the cache to keep the image slim
RUN rm -rf /var/cache/apk/*