Replace alpine base docker image with ubuntu (#12)

Author: sethfowler

Dockerfile

@@ -1,16 +1,21 @@
-
-FROM golang:1.18-alpine3.16 AS builder
+FROM ubuntu:22.04 AS builder
+RUN apt-get update && \
+    apt-get install -y \
+      build-essential \
+      ca-certificates \
+      golang \
+      golang-1.18
 ADD ./catcher ./catcher
 ADD ./relay ./relay
 ADD ./go.mod .
 ADD ./go.sum .
 ADD ./Makefile .
-RUN apk add --update make build-base git binutils-gold
 RUN set -ex && \
-    unset GOPATH && \
 	make
 
-FROM alpine
-RUN apk add --update ca-certificates
-COPY --from=builder /go/dist /dist
+FROM ubuntu:22.04
+RUN apt-get update && \
+    apt-get install -y \
+      ca-certificates
+COPY --from=builder /dist /dist
 ENTRYPOINT [ "/dist/relay" ]