Rollback dockerfile (image too big) and add docker run command to docs. (#488)

Dockerfile

@@ -1,24 +1,12 @@
-FROM fnproject/dind
-RUN apk add --no-cache ca-certificates build-base go git bzr mercurial gcc
-
-ENV GOPATH=/go
-RUN env
-ENV PATH=$PATH:/go/bin
-RUN env
+# build stage
+FROM golang:alpine AS build-env
+RUN apk --no-cache add build-base git bzr mercurial gcc
 ENV D=/go/src/github.com/fnproject/fn
-
 ADD . $D
-RUN cd $D && go build -o /app/functions
+RUN cd $D && go build -o fn-alpine && cp fn-alpine /tmp/
 
+# final stage
+FROM fnproject/dind
 WORKDIR /app
+COPY --from=build-env /tmp/fn-alpine /app/functions
 CMD ["./functions"]
-
-# For building extensions
-ONBUILD ENV REPOPATH=$GOPATH/src/github.com/x/y
-ONBUILD ADD . $REPOPATH
-# note: It might be a good idea to move interfaces and models to a new repo with minimal dependencies, then doing a dep ensure/install might work nice
-# ONBUILD RUN go get -u github.com/golang/dep/cmd/dep
-# ONBUILD RUN cd $REPOPATH && dep init && dep ensure
-# Try doing regular go get:
-ONBUILD RUN cd $REPOPATH && go get
-ONBUILD RUN cd $REPOPATH && go build -o /app/functions

docs/operating/options.md

@@ -1,5 +1,15 @@
 # Fn Runtime Options
 
+## Default run command for production
+
+This will run with docker in docker. 
+
+```sh
+docker run --privileged --rm --name fns -it -v $PWD/data:/app/data -p 80:8080 fnproject/functions
+```
+
+See below for starting without docker in docker.
+
 ## Configuration
 
 When starting Fn, you can pass in the following configuration variables as environment variables. Use `-e VAR_NAME=VALUE` in