Merge pull request #35 from johejo/optimize_docker_image_size

Optimize docker image size

.github/workflows/go.yml

@@ -1,28 +1,36 @@
 name: Go
-on: [push]
+on: [push, pull_request]
 jobs:
 
  build:
  name: Build
  runs-on: ubuntu-latest
  steps:
 
- - name: Set up Go 1.12
- uses: actions/setup-go@v1
+ - name: Set up Go 1.15
+ uses: actions/setup-go@v2
  with:
- go-version: 1.12
+ go-version: 1.15
  id: go
 
  - name: Check out code into the Go module directory
- uses: actions/checkout@v1
-
- - name: Get dependencies
- run: |
- go get -v -t -d ./...
- if [ -f Gopkg.toml ]; then
- curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
- dep ensure
- fi
+ uses: actions/checkout@v2
 
  - name: Build
  run: go build -v .
+
+ docker:
+ name: Docker
+ runs-on: ubuntu-latest
+ steps:
+
+ - uses: actions/checkout@v2
+
+ - name: docker build
+ run: docker build -t mattn/longcat .
+
+ - name: check image size
+ run: docker images | grep longcat
+
+ - name: check run
+ run: docker run --rm mattn/longcat

Dockerfile

@@ -3,9 +3,12 @@ FROM golang:alpine AS build-env
 WORKDIR /app
 COPY go.mod .
 COPY go.sum .
-RUN go mod download
+RUN apk add --no-cache upx && \
+ go version && \
+ go mod download
 COPY . .
-RUN CGO_ENABLED=0 go build -o /go/bin/longcat
+RUN CGO_ENABLED=0 go build -trimpath -ldflags '-w -s' -o /go/bin/longcat && \
+ upx /go/bin/longcat
 FROM scratch
 COPY --from=build-env /go/bin/longcat /go/bin/longcat
 ENTRYPOINT ["/go/bin/longcat"]