Deploy a static Sapper app with Deno on Cloud Run

Yesterday, Deno 1.0 was released. If Deno does not sound familiar, don’t worry this is fine at this point. Please head over to and once you’ve read that, come back here to learn how we can use this to deploy a static Sapper / Svelte application to Cloud Run.

Code review

Let’s review what changes are necessary and how you can apply it to your project, if you use Sapper to deploy a static web application. It does not work if you use Sapper for server-side rendering.

First, add a .dockerignore file with the following content:


It ignores everything, except the files and directories listed. To learn more about that, please review my previous blog post.

Next, here’s the Dockerfile that does the following:

  • Install NPM dependencies
  • Export the Sapper web application as a static site
  • Create a runtime Docker stage based on hayd/alpine-deno
  • Use the file_server.ts to serve the static web app
# This stage exports the sapper application.
FROM mhart/alpine-node:12 AS export-app
COPY . .
RUN npm install --no-audit --unsafe-perm
RUN npm run export

# This stage runs Deno and serves the static site
FROM hayd/alpine-deno:1.0.0
COPY --from=export-app /app/__sapper__/export .
CMD ["run", "--allow-read", "--allow-net", ""]

I had to get a tiny PR merged into Deno and within minutes, the team merged it. No need to wait for a new Deno release since the change is immediately available in the latest version of Deno’s Standard Library at

Lastly, to make deployment a bit more seamless, we let’s use a file:

GCP_PROJECT=$(gcloud config list --format 'value(core.project)')

gcloud builds submit --tag$GCP_PROJECT/$IMAGE
gcloud run deploy $IMAGE --image$GCP_PROJECT/$IMAGE --port 4507 --platform managed --allow-unauthenticated --region $REGION

Make sure you’re satisfied with the environment variables before you run the script. Also, you need gcloud installed and configured with a default project to make this work.

When you deploy for the first time, you will be asked to enable a few GCP APIs.

Once the service is deployed, you will see a message similar to the following:

Service [deno-sapper-cloud-run] revision [deno-sapper-cloud-run-00002-zob] has been deployed and is serving 100 percent of traffic at

Your static Sapper app now runs on Cloud Run, served by Deno at


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