contributed container build definition (#350)

as discussed with @noerw on Discord

Co-authored-by: Tamás Gérczei <tamas@gerczei.eu>
Reviewed-on: https://gitea.com/gitea/tea/pulls/350
Reviewed-by: 6543 <6543@obermui.de>
Reviewed-by: Norwin <noerw@noreply.gitea.io>
Reviewed-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Tamás Gérczei <tgerczei@noreply.gitea.io>
Co-committed-by: Tamás Gérczei <tgerczei@noreply.gitea.io>

Dockerfile

@@ -0,0 +1,25 @@
+ARG GOVERSION="1.16.2"
+
+FROM golang:${GOVERSION}-alpine AS buildenv
+
+ARG CGO_ENABLED="0"
+ARG GOOS="linux"
+
+COPY . $GOPATH/src/
+WORKDIR $GOPATH/src
+
+RUN	apk add --quiet --no-cache \
+		make \
+		git && \
+	make build
+
+FROM scratch
+ARG VERSION="0.7.0"
+LABEL org.opencontainers.image.title="tea - CLI for Gitea - git with a cup of tea"
+LABEL org.opencontainers.image.description="A command line tool to interact with Gitea servers"
+LABEL org.opencontainers.image.version="${VERSION}"
+LABEL org.opencontainers.image.authors="Tamás Gérczei <tamas@gerczei.eu>"
+LABEL org.opencontainers.image.vendor="The Gitea Authors"
+COPY --from=buildenv /go/src/tea /
+ENV HOME="/app"
+ENTRYPOINT ["/tea"]

Makefile

@@ -38,6 +38,8 @@ else
 	TEA_VERSION ?= $(shell git describe --tags --always | sed 's/-/+/' | sed 's/^v//')
 endif
 
+TEA_VERSION_TAG ?= $(shell sed 's/+/_/' <<< $(TEA_VERSION))
+
 LDFLAGS := -X "main.Version=$(TEA_VERSION)" -X "main.Tags=$(TAGS)"
 
 PACKAGES ?= $(shell $(GO) list ./... | grep -v /vendor/)
@@ -139,6 +141,10 @@ build: $(EXECUTABLE)
 $(EXECUTABLE): $(SOURCES)
 	$(GO) build -mod=vendor $(GOFLAGS) $(EXTRA_GOFLAGS) -tags '$(TAGS)' -ldflags '-s -w $(LDFLAGS)' -o $@
 
+.PHONY: build-image
+build-image:
+	docker build --build-arg VERSION=$(TEA_VERSION) -t gitea/tea:$(TEA_VERSION_TAG) .
+
 .PHONY: release
 release: release-dirs release-os release-compress release-check