does linting on docker build/ci now

Dockerfile

@@ -1,12 +1,22 @@
+## lint image
+FROM golangci/golangci-lint@sha256:9ae3767101cd3468cdaea5b6573dadb358013e05ac38abe37d53646680fd386c AS linter
+
+RUN mkdir -p /go/src/git.eeqj.de/sneak/historyposter
+WORKDIR /go/src/git.eeqj.de/sneak/historyposter
+COPY ./ ./
+RUN golangci-lint run
+
 ## build image:
-ARG GO_VERSION=1.15
-FROM golang:${GO_VERSION}-alpine AS builder
+#ARG GO_VERSION=1.15
+FROM golang:1.15-alpine AS builder
 
 RUN mkdir /user && \
     echo 'nobody:x:65534:65534:nobody:/:' > /user/passwd && \
     echo 'nobody:x:65534:' > /user/group
 RUN apk add --no-cache ca-certificates git bzip2 make gcc libc-dev
 
+#RUN GO111MODULE=on go get github.com/golangci/golangci-lint/cmd/golangci-lint@v1.31.0
+
 RUN mkdir -p /go/src/git.eeqj.de/sneak/historyposter
 WORKDIR /go/src/git.eeqj.de/sneak/historyposter
 
@@ -15,11 +25,12 @@ COPY go.sum .
 RUN go mod download
 
 COPY ./ ./
+#RUN make lint
 RUN make build
 RUN tar -c /go | bzip2 > /go.tbz2
 
 ## output image:
-FROM scratch as final
+FROM scratch AS final
 COPY --from=builder /user/group /user/passwd /etc/
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 COPY --from=builder /go/src/git.eeqj.de/sneak/historyposter/historyposter /app/historyposter