fix: update broken alpine dep in dockerfile (#61)

* fix: update broken alpine dep in dockerfile

* chore: remove librdkafka-dev from final image

Author: jpfe-tid

Dockerfile

@@ -1,22 +1,17 @@
-FROM golang:1.14.4-alpine3.11 as build
+FROM golang:1.14.4-alpine3.12 as build
 
 # Get prebuilt libkafka.
-# XXX stop using the edgecommunity channel once librdkafka 1.3.0+ is officially published
-RUN echo "@edge http://dl-cdn.alpinelinux.org/alpine/edge/main" >> /etc/apk/repositories && \
-    echo "@edgecommunity http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories && \
-    apk add --no-cache alpine-sdk 'librdkafka@edgecommunity>=1.3.0' 'librdkafka-dev@edgecommunity>=1.3.0'
+RUN apk add --no-cache alpine-sdk 'librdkafka>=1.3.0' 'librdkafka-dev>=1.3.0'
 
 WORKDIR /src/prometheus-kafka-adapter
 ADD . /src/prometheus-kafka-adapter
 
 RUN go test
 RUN go build -tags static -o /prometheus-kafka-adapter
 
-FROM alpine:3.11
+FROM alpine:3.12
 
-RUN echo "@edge http://dl-cdn.alpinelinux.org/alpine/edge/main" >> /etc/apk/repositories && \
-    echo "@edgecommunity http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories && \
-    apk add --no-cache 'librdkafka@edgecommunity>=1.3.0'
+RUN apk add --no-cache alpine-sdk 'librdkafka>=1.3.0'
 
 COPY --from=build /src/prometheus-kafka-adapter/schemas/metric.avsc /schemas/metric.avsc
 COPY --from=build /prometheus-kafka-adapter /