Build improvements

- ensure CGO is always off and netgo is always on
- add musl-dev (somehow cgo still gets dragged in)
- add .dockerignore files

.dockerignore

@@ -0,0 +1,5 @@
+Dockerfile
+build
+*.md
+DCO
+LICENSE*

.goreleaser.yml

@@ -4,8 +4,7 @@ builds:
   - main: ./cmd/eksctl
     binary: eksctl
     flags:
-      - -tags
-      - release
+      - -tags=netgo,release
     env:
       - CGO_ENABLED=0
     ldflags:

Makefile

@@ -22,7 +22,7 @@ install-build-deps: ## Install dependencies (packages and tools)
 
 .PHONY: build
 build: ## Build eksctl
-	@go build -ldflags "-X $(version_pkg).gitCommit=$(git_commit) -X $(version_pkg).builtAt=$(built_at)" ./cmd/eksctl
+	@CGO_ENABLED=0 go build -v -tags netgo -ldflags "-X $(version_pkg).gitCommit=$(git_commit) -X $(version_pkg).builtAt=$(built_at)" ./cmd/eksctl
 
 ##@ Testing & CI
 

build/.dockerignore

@@ -0,0 +1,2 @@
+Dockerfile
+vendor

build/Dockerfile

@@ -5,6 +5,7 @@ RUN apk add --no-cache \
       git \
       make \
       gcc \
+      musl-dev \
       && true
 
 ENV DEP_VERSION v0.5.0
@@ -24,6 +25,6 @@ RUN dep ensure
 RUN ./install.sh
 
 WORKDIR $EKSCTL_BUILD/vendor/github.com/goreleaser/goreleaser
-RUN CGO_ENABLED=0 make build && go install
+RUN make build && go install
 
 WORKDIR $GOPATH