Switch runtime to alpine base image

Dockerfile

@@ -5,23 +5,10 @@ RUN apk add --no-cache git mercurial \
     && go get github.com/kardianos/govendor \
     && govendor sync \
     && apk del git mercurial
-# Static build required so that we can safely copy the binary over.
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o /go/bin/konturtransferbot github.com/beevee/konturtransferbot/cmd/konturtransferbot
 
-FROM alpine:latest as alpine
-RUN apk --no-cache add tzdata zip ca-certificates
-WORKDIR /usr/share/zoneinfo
-# -0 means no compression.  Needed because go's
-# tz loader doesn't handle compressed data.
-RUN zip -r -0 /zoneinfo.zip .
-
-FROM scratch
-# the program:
+FROM alpine
+RUN apk add --no-cache ca-certificates && update-ca-certificates
 COPY cmd/konturtransferbot/schedule.yml /schedule.yml
 COPY --from=golang /go/bin/konturtransferbot /konturtransferbot
-# the timezone data:
-ENV ZONEINFO /zoneinfo.zip
-COPY --from=alpine /zoneinfo.zip /
-# the tls certificates:
-COPY --from=alpine /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 ENTRYPOINT ["/konturtransferbot"]