fix: docker/Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE317-OPENSSL-8235199
- https://snyk.io/vuln/SNYK-ALPINE317-OPENSSL-8235199

docker/Dockerfile

@@ -0,0 +1,40 @@
+#                                                                         __
+# .-----.-----.______.-----.----.-----.--.--.--.--.______.----.---.-.----|  |--.-----.
+# |  _  |  _  |______|  _  |   _|  _  |_   _|  |  |______|  __|  _  |  __|     |  -__|
+# |___  |_____|      |   __|__| |_____|__.__|___  |      |____|___._|____|__|__|_____|
+# |_____|            |__|                   |_____|
+#
+# Copyright (c) 2023 Fabio Cicerchia. https://fabiocicerchia.it. MIT License
+# Repo: https://github.com/fabiocicerchia/go-proxy-cache
+
+FROM golang:1.20.1-alpine3.17 AS builder
+
+ARG BUILD_CMD=build
+
+WORKDIR /go/src/github.com/fabiocicerchia/go-proxy-cache
+
+ENV CGO_CFLAGS -march=native -O3
+
+RUN apk update \
+    && apk add --no-cache \
+      gcc \
+      libc-dev \
+      make
+
+COPY . ./
+
+RUN make $BUILD_CMD
+
+FROM alpine:3.21.0
+
+WORKDIR /app
+
+COPY --from=builder /go/src/github.com/fabiocicerchia/go-proxy-cache/go-proxy-cache /usr/local/bin/
+COPY --from=builder /go/src/github.com/fabiocicerchia/go-proxy-cache/config.yml.dist /app/config.yml
+
+RUN apk upgrade
+
+RUN go-proxy-cache --version \
+    && go-proxy-cache --test
+
+CMD ["go-proxy-cache"]