Improve Dockerfiles

- Specify Docker registry explicitly (e.g., Podman does not use
  `docker.io` by default)
- Use `make miniflux` instead of duplicating `go build` arguments (this
  leverages Go's PIE build mode)
- Enable cgo to fix ARM containers (we need to make sure to use the same
  OS version for both container stages to avoid libc issues)

packaging/docker/alpine/Dockerfile

@@ -1,14 +1,10 @@
-FROM golang:alpine AS build
+FROM docker.io/library/golang:alpine3.19 AS build
-ENV CGO_ENABLED=0
+RUN apk add --no-cache build-base git make
-RUN apk add --no-cache --update git
 ADD . /go/src/app
 WORKDIR /go/src/app
-RUN go build \
+RUN make miniflux
-    -o miniflux \
-    -ldflags="-s -w -X 'miniflux.app/v2/internal/version.Version=`git describe --tags --abbrev=0`' -X 'miniflux.app/v2/internal/version.Commit=`git rev-parse --short HEAD`' -X 'miniflux.app/v2/internal/version.BuildDate=`date +%FT%T%z`'" \
-    main.go
 
-FROM alpine:latest
+FROM docker.io/library/alpine:3.19
 
 LABEL org.opencontainers.image.title=Miniflux
 LABEL org.opencontainers.image.description="Miniflux is a minimalist and opinionated feed reader"

packaging/docker/distroless/Dockerfile

@@ -1,13 +1,9 @@
-FROM golang:latest AS build
+FROM docker.io/library/golang:bookworm AS build
-ENV CGO_ENABLED=0
 ADD . /go/src/app
 WORKDIR /go/src/app
-RUN go build \
+RUN make miniflux
-    -o miniflux \
-    -ldflags="-s -w -X 'miniflux.app/v2/internal/version.Version=`git describe --tags --abbrev=0`' -X 'miniflux.app/v2/internal/version.Commit=`git rev-parse --short HEAD`' -X 'miniflux.app/v2/internal/version.BuildDate=`date +%FT%T%z`'" \
-    main.go
 
-FROM gcr.io/distroless/base:nonroot
+FROM gcr.io/distroless/base-debian12:nonroot
 
 LABEL org.opencontainers.image.title=Miniflux
 LABEL org.opencontainers.image.description="Miniflux is a minimalist and opinionated feed reader"