Merge pull request #45 from rog-golang-buddies/dockerfile-fix

fix(Dockerfile): Go image update

What does this commit do?
=========================
* Use alpine Go base image to reduce size
* Reuse make command to build binary

Why are we doing this?
======================
* Shrink image size to increase build times
* Reuse make to provide a single place add binary build updates

Author: haani-niyaz

.github/dependabot.yml

@@ -5,3 +5,7 @@ updates:
   schedule:
     interval: weekly
   open-pull-requests-limit: 5
+- package-ecosystem: "docker"
+  directory: "/"
+  schedule:
+    interval: "weekly"

.gitignore

@@ -15,5 +15,9 @@ bin/
 # Dependency directories (remove the comment below to include it)
 # vendor/
 
+# Code editor personal settings
+.vscode/
+.idea/
+
 # Other
 .DS_Store

Dockerfile

@@ -1,13 +1,22 @@
-FROM golang:1.18 as build
-WORKDIR /go/src/app
+FROM golang:1.18-alpine as builder
+
+RUN apk update && apk upgrade && \
+    apk add --no-cache make bash
+
+WORKDIR /src
 COPY . .
-# Static build requires CGO_ENABLED=0
-RUN mkdir -p /go/bin && CGO_ENABLED=0 go build -ldflags="-w -s" -o /go/bin/app ./...
+
+# Build executable
+RUN make build
 
 # Using a distroless image from https://github.com/GoogleContainerTools/distroless
-# Image sourced from https://console.cloud.google.com/gcr/images/distroless/global/static
 FROM gcr.io/distroless/static:nonroot
-COPY --from=build /go/bin/app /
-# numeric version of user nonroot:nonroot provided in image
+
+# Copy executable from builder image
+COPY --from=builder /src/bin/app /
+
+# Numeric version of user nonroot:nonroot provided in image
 USER 65532:65532
+
+# Run the executable
 CMD ["/app"]

Makefile

@@ -1,5 +1,7 @@
 SHELL=/bin/bash -e -o pipefail
 PWD = $(shell pwd)
+GO_BUILD= go build
+GOFLAGS= CGO_ENABLED=0
 
 ## help: Print this help message
 .PHONY: help
@@ -37,4 +39,4 @@ fmt:
 ## build: Build binary into bin/ directory
 .PHONY: build
 build:
-	go build -ldflags="-w -s" -o bin/app ./...
+	$(GOFLAGS) $(GO_BUILD) -a -v -ldflags="-w -s" -o bin/app cmd/main.go

sonar-project.properties

@@ -10,3 +10,6 @@ sonar.organization=rog-golang-buddies
 
 # Encoding of the source code. Default is default system encoding
 #sonar.sourceEncoding=UTF-8
+
+# ensure that test files are identified and not used to check coverage
+sonar.test.inclusions=**/*_test.go