Create docker configuration for the counter system

Author: zucchinidev

counter/.dockerignore

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+.git
+counter

counter/Dockerfile

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+FROM golang
+
+# if left blank app will run with dev settings
+# to build production image run:
+# $ docker build ./api --build-args app_env=production
+ARG app_env
+ENV APP_ENV $app_env
+
+
+COPY . /go/src/github.com/zucchinidev/building-distributed-system-golang/counter
+WORKDIR /go/src/github.com/zucchinidev/building-distributed-system-golang/counter
+
+RUN go get ./
+RUN go build
+
+# if dev setting will use pilu/fresh for code reloading via docker-compose volume sharing with local machine
+# if production setting will build binary
+CMD if [ ${APP_ENV} = production ]; \
+	then \
+	counter; \
+	else \
+	go get github.com/pilu/fresh && \
+	fresh; \
+	fi