Refit Docker build to match our current demands

Dockerfile

@@ -1,11 +1,15 @@
-# This file is a template, and might need editing before it works on your project.
-FROM golang:1.8-alpine AS builder
-# We'll likely need to add SSL root certificates
-RUN apk --no-cache add ca-certificates
-# Missing part for compiling the application by it self because it requires a sock
+#
+# NB! This file is a template and might need editing before it works on your project!
+#
+FROM golang:1.8 AS builder
+WORKDIR /go/src/github.com/ivanilves/lstags
+COPY . ./
+RUN ln -nfs /bin/bash /bin/sh && make assemble
 FROM scratch
-# Since we started from scratch, we'll copy the SSL root certificates from the builder
+# Since we started from scratch, we'll copy following files from the builder:
+# * SSL root certificates bundle
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
-COPY lstags /usr/local/bin/lstags
-ENTRYPOINT [ "/usr/local/bin/lstags" ]
+# * compiled lstags binary
+COPY --from=builder /go/src/github.com/ivanilves/lstags/lstags /lstags
+ENTRYPOINT [ "/lstags" ]
 CMD ["--help"]

Makefile

@@ -4,6 +4,8 @@ all: prepare dep test lint vet build
 
 offline: unit-test lint vet build
 
+assemble: prepare dep lint vet build
+
 prepare:
 	go get -u -v \
 		github.com/golang/dep/cmd/dep \
@@ -69,10 +71,10 @@ shell-test-push-local:
 	./lstags localhost:${REGISTRY_PORT}/qa/library/alpine
 	${MAKE} --no-print-directory stop-local-registry
 
-lint: ERRORS:=$(shell find . -name "*.go" ! -path "./vendor/*" | xargs -i golint {} | tr '`' '|')
+lint: ERRORS=$(shell find . -name "*.go" ! -path "./vendor/*" | xargs -i golint {} | tr '`' '|')
 lint: fail-on-errors
 
-vet: ERRORS:=$(shell find . -name "*.go" ! -path "./vendor/*" | xargs -i go tool vet {} | tr '`' '|')
+vet: ERRORS=$(shell find . -name "*.go" ! -path "./vendor/*" | xargs -i go tool vet {} | tr '`' '|')
 vet: fail-on-errors
 
 fail-on-errors:
@@ -121,6 +123,7 @@ deploy:
 	GITHUB_TOKEN=${GITHUB_TOKEN} ./scripts/github-create-release.sh ./dist/release
 	GITHUB_TOKEN=${GITHUB_TOKEN} ./scripts/github-upload-assets.sh ${TAG} ./dist/assets
 
+docker: DOCKER_REPO:=ivanilves/lstags
+docker: RELEASE_TAG:=latest
 docker:
-	@docker container run -v $(shell pwd):/go/src/github.com/ivanilves/lstags -w /go/src/github.com/ivanilves/lstags -v /var/run/docker.sock:/var/run/docker.sock golang:1.8 scripts/prepare-docker-build.sh
-	@docker image build -t ivanilves/lstags .
+	@docker image build -t ${DOCKER_REPO}:${RELEASE_TAG} .

README.md

@@ -31,11 +31,11 @@ You could use `lstags`, if you ...
 * ... compare local images with registry ones (e.g. know, if image tagged "latest" was re-pushed).
 
 ... pull Ubuntu 14.04 & 16.04, all the Alpine images and Debian "stretch" to have latest software to play with:
-```
+```sh
 lstags --pull ubuntu~/^1[46]\\.04$/ alpine debian~/stretch/
 ```
 ... pull and re-push CoreOS-related images from `quay.io` to your own registry (in case these hipsters will break everything):
-```
+```sh
 lstags -P /quay -r registry.company.io quay.io/coreos/hyperkube quay.io/coreos/flannel
 ```
 **NB!** In case you use private registry with authentication, make sure your Docker client knows how to authenticate against it!
@@ -59,7 +59,7 @@ You can either:
 https://github.com/ivanilves/lstags/releases
 
 ## Install: From source
-```
+```sh
 git clone git@github.com:ivanilves/lstags.git
 cd lstags
 dep ensure
@@ -68,9 +68,9 @@ go build
 ```
 **NB!** I assume you have current versions of Go & [dep](https://github.com/golang/dep) installed and also have set up [GOPATH](https://github.com/golang/go/wiki/GOPATH) correctly.
 
-## Using it with docker
+## Using it with Docker
 
-```sh
+```
 docker run --rm -it -v /var/run/docker.sock:/var/run/docker.sock ivanilves/lstags
 Usage:
   lstags [OPTIONS] REPO1 REPO2 REPOn...
@@ -108,17 +108,17 @@ Arguments:
 
 ### Analyze an image
 
-```sh
-docker run --rm -it  -v /var/run/docker.sock:/var/run/docker.sock ivanilves/lstags alpine~/^3\\./
+```
+docker run --rm -it -v /var/run/docker.sock:/var/run/docker.sock ivanilves/lstags alpine~/^3\\./
 ANALYZE alpine
 FETCHED alpine
 -
-<STATE>      <DIGEST>                                      <(local) ID>    <Created At>              <TAG>
-CHANGED      sha256:b40e202395eaec699f2d0c5e01e6d6cb8      76da55c8019d    2017-10-25T23:19:51Z      alpine:3.6
-ABSENT       sha256:d95da16498d5d6fb4b907cbe013f95032      n/a             2017-10-25T23:20:18Z      alpine:3.1
-ABSENT       sha256:cb275b62f789b211114f28b391fca3cc2      n/a             2017-10-25T23:20:32Z      alpine:3.2
-ABSENT       sha256:27af7da847283a947c008592f2b2cd6d2      n/a             2017-10-25T23:20:45Z      alpine:3.3
-CHANGED      sha256:246bbbaa81b28837b64cb9dfc574de958      1a19a71e5d38    2017-10-25T23:20:59Z      alpine:3.4
-CHANGED      sha256:aa96c8dc3815c44d4aceaf1ee7903ce58      37c7be7a096b    2017-10-25T23:21:13Z      alpine:3.5
+<STATE>   <DIGEST>                                  <(local) ID>    <Created At>            <TAG>
+CHANGED   sha256:b40e202395eaec699f2d0c5e01e6d6cb8  76da55c8019d    2017-10-25T23:19:51Z    alpine:3.6
+ABSENT    sha256:d95da16498d5d6fb4b907cbe013f95032  n/a             2017-10-25T23:20:18Z    alpine:3.1
+ABSENT    sha256:cb275b62f789b211114f28b391fca3cc2  n/a             2017-10-25T23:20:32Z    alpine:3.2
+ABSENT    sha256:27af7da847283a947c008592f2b2cd6d2  n/a             2017-10-25T23:20:45Z    alpine:3.3
+CHANGED   sha256:246bbbaa81b28837b64cb9dfc574de958  1a19a71e5d38    2017-10-25T23:20:59Z    alpine:3.4
+CHANGED   sha256:aa96c8dc3815c44d4aceaf1ee7903ce58  37c7be7a096b    2017-10-25T23:21:13Z    alpine:3.5
 -
 ```