How to deploy a container to Google Cloud Run

Google Cloud Run runs containers serverlessly. You provide an image that listens on a port; Cloud Run handles scaling, TLS, and request routing, billing only while requests are being served. It suits any language as long as it ships in a container.

This tutorial deploys a small Go web server to Cloud Run.

Prerequisites

• A Google Cloud project with billing enabled.
• The gcloud CLI authenticated (gcloud auth login).
• Docker installed locally.

Steps

1. Write the app

Create main.go that reads the PORT env var Cloud Run injects:

package main

import (
  "fmt"; "net/http"; "os"
)

func main() {
  http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintln(w, "hello from cloud run")
  })
  http.ListenAndServe(":"+os.Getenv("PORT"), nil)
}

2. Add a Dockerfile

FROM golang:1.22 AS build
WORKDIR /src
COPY . .
RUN CGO_ENABLED=0 go build -o /app

FROM gcr.io/distroless/static
COPY --from=build /app /app
ENTRYPOINT ["/app"]

3. Enable APIs

gcloud services enable run.googleapis.com artifactregistry.googleapis.com

4. Build and push

Let Cloud Build do the work, no local Docker push required:

gcloud builds submit --tag <region>-docker.pkg.dev/<project>/apps/hello

5. Deploy the service

gcloud run deploy hello \
  --image <region>-docker.pkg.dev/<project>/apps/hello \
  --region <region> --allow-unauthenticated

The command returns a public HTTPS URL.

6. Tune scaling

Set concurrency (requests per instance) and instance bounds:

gcloud run services update hello \
  --concurrency 80 --min-instances 0 --max-instances 10

Minimum instances above zero reduces cold starts at a small idle cost.

Verification

curl $(gcloud run services describe hello --region <region> --format 'value(status.url)')

You should see the greeting. Check Cloud Run metrics for request count and instance utilization.

Next Steps

Lock down the service with IAM instead of --allow-unauthenticated, add a Cloud SQL connection, and wire continuous deployment from a Git repository.