Add some env-variables for the go build of the controller executable.

- Standardize for Linux
- Disable cgo.

Dockerfile

@@ -7,7 +7,7 @@ RUN go get -d -v github.com/slimhazard/gogitversion && \
     cd /go/src/code.uplex.de/uplex-varnish/k8s-ingress && \
     go get -v $PACKAGES && \
     go generate && \
-    go build -o k8-ingress *.go
+    CGO_ENABLED=0 GOOS=linux go build -o k8-ingress *.go
 
 FROM centos:centos7
 COPY varnishcache_varnish60.repo /etc/yum.repos.d/

Makefile

@@ -53,7 +53,7 @@ k8s-ingress:
 	go get ${PACKAGES}
 	go generate
 	go fmt ./...
-	GOOS=linux go build -o k8s-ingress *.go
+	CGO_ENABLED=0 GOOS=linux go build -o k8s-ingress *.go
 
 check: k8s-ingress
 	go vet ./...