feat: Use distroless/static as base image

Author: mdomke

CHANGELOG.md

@@ -5,7 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [6.4.0] - 2022-03-10
+## [6.5.0] - 2022-06-24
+### Changed
+* Use [distroless/static:nonroot](https://github.com/GoogleContainerTools/distroless/tree/main/base) as 
+  base image for the dockerized version of `git-semver` and build with Golang 1.18.
+
+## [6.4.0] - 2022-06-24
 ### Changed
 * If two annotated tags point to the same commit `git-semver` will now select the one that
   was created last. E.g.
@@ -106,6 +111,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 
 [1]: https://semver.org/#spec-item-11
+[6.5.0]: https://github.com/mdomke/git-semver/compare/v6.4.0...v6.5.0
 [6.4.0]: https://github.com/mdomke/git-semver/compare/v6.3.0...v6.4.0
 [6.3.0]: https://github.com/mdomke/git-semver/compare/v6.2.0...v6.3.0
 [6.2.0]: https://github.com/mdomke/git-semver/compare/v6.1.1...v6.2.0

Dockerfile

@@ -1,22 +1,9 @@
-FROM golang:1.16-buster as builder
-ENV USER=semver
-ENV UID=10001
-RUN adduser \
- --disabled-password \
- --gecos "" \
- --home "/nonexistent" \
- --shell "/sbin/nologin" \
- --no-create-home \
- --uid "${UID}" \
- "${USER}"
+FROM golang:1.18-bullseye as builder
 WORKDIR /go/src/github.com/mdomke/git-semver
 COPY . .
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags='-w -s -extldflags="-static"' -a -o /go/bin/git-semver
 
-FROM scratch
-COPY --from=builder /etc/passwd /etc/passwd
-COPY --from=builder /etc/group /etc/group
+FROM gcr.io/distroless/static:nonroot
 COPY --from=builder /go/bin/git-semver /bin/git-semver
-USER semver:semver
 WORKDIR /git-semver
 ENTRYPOINT ["/bin/git-semver"]