Cloud Runをたった3ステップでデプロイしてみた (golang)

gcloud components update
gcloud components install beta
gcloud config set run/region us-central1

mkdir helloworld-go && cd helloworld-go
touch helloworld.go Dockerfile

package main
 
import (
        "fmt"
        "log"
        "net/http"
        "os"
)
 
func handler(w http.ResponseWriter, r *http.Request) {
        log.Print("Hello world received a request.")
        target := os.Getenv("TARGET")
        if target == "" {
                target = "World"
        }
        fmt.Fprintf(w, "Hello %s!\n", target)
}
 
func main() {
        log.Print("Hello world sample started.")
 
        http.HandleFunc("/", handler)
 
        port := os.Getenv("PORT")
        if port == "" {
                port = "8080"
        }
 
        log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
}

## Use the offical Golang image to create a build artifact.
## This is based on Debian and sets the GOPATH to /go.
## https://hub.docker.com/_/golang
FROM golang:1.12 as builder
 
## Copy local code to the container image.
WORKDIR /go/src/github.com/knative/docs/helloworld
COPY . .
 
## Build the command inside the container.
## (You may fetch or manage dependencies here,
## either manually or with a tool like "godep".)
RUN CGO_ENABLED=0 GOOS=linux go build -v -o helloworld
 
## Use a Docker multi-stage build to create a lean production image.
## https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
FROM alpine
 
## Copy the binary to the production image from the builder stage.
COPY --from=builder /go/src/github.com/knative/docs/helloworld/helloworld /helloworld
 
## Run the web service on container startup.
CMD ["/helloworld"]

gcloud builds submit --tag gcr.io/[PROJECT-ID]/helloworld
gcloud beta run deploy --image gcr.io/[PROJECT-ID]/helloworld