Merge 19869d0 into c2bb7c3

Dockerfile

@@ -0,0 +1,40 @@
+# This is a Docker image of Kagome on Alpine Linux.
+# =================================================
+# Aimed to check the functionality of version command but the built image will
+# work as a single 'kagome' binary.
+# - USAGE:
+#   - To build the image, run:
+#     $ docker build --tag kagome:latest ./Dockerfile && docker image prune -f
+#   - To run the container, run:
+#     $ # This is equivalent to "kagome version"
+#     $ docker run --rm kagome:latest version
+
+# 1st stage: Build binary.
+# ------------------------
+FROM golang:alpine AS build-app
+
+# Copy the current dir including .git dir for versioning.
+COPY . /go/src/github.com/ikawaha/kagome
+WORKDIR /go/src/github.com/ikawaha/kagome
+
+# Shell script to build the image (with the tag as version).
+RUN apk --no-cache add git && \
+    version_app=$(git describe --tag) && \
+    echo "- Current git tag: ${version_app}" && \
+    go version && \
+    CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \
+      -a \
+      -installsuffix cgo \
+      --ldflags "-w -s -extldflags \"-static\" -X 'main.version=${version_app}'" \
+      -o /go/bin/kagome \
+      ./cmd/kagome && \
+    echo '- Running tests ...' && \
+    /go/bin/kagome version
+
+# 2nd stage: Copy only the built binary to shrink the image size.
+# ---------------------------------------------------------------
+FROM alpine:latest
+
+COPY --from=build-app /go/bin/kagome /usr/local/bin/kagome
+
+ENTRYPOINT [ "kagome" ]