**Tags:** "Hello World" Examples · Ruby # Ruby Hello World A minimal [Ruby](https://www.ruby-lang.org/) web application built with [Sinatra](https://sinatrarb.com/) and [Puma](https://puma.io/), connected to [PostgreSQL](https://www.postgresql.org/) on [Zerops](https://zerops.io). Includes a database migration demo, a health-check endpoint, and ready-made infrastructure configurations for the entire development lifecycle. ### Available Environments - [AI Agent](https://app.zerops.io/recipes/ruby-hello-world.md?environment=ai-agent) - [Remote (CDE)](https://app.zerops.io/recipes/ruby-hello-world.md?environment=remote-cde) - [Local](https://app.zerops.io/recipes/ruby-hello-world.md?environment=local) - [Stage](https://app.zerops.io/recipes/ruby-hello-world.md?environment=stage) - **Small Production** ← current - [Highly-available Production](https://app.zerops.io/recipes/ruby-hello-world.md?environment=highly-available-production) ### Services in this Environment **Services:** - **core** (core@1) - Containers: 1 × Shared Core, 0.00 GB RAM, 0 GB Disk - **app** (ruby@3.4) :8080 - Containers: 2 × Shared Core, 0.75 GB RAM, 1 GB Disk - Repository: [zerops-recipe-apps/ruby-hello-world-app](https://github.com/zerops-recipe-apps/ruby-hello-world-app) - **db** (postgresql@18) :5432, :6432 - Containers: 1 × Shared Core, 0.38 GB RAM, 1 GB Disk **Total Resources:** 4 containers, 1.88 GB RAM, 3 GB Disk ### One-Click Deploy (Import YAML) Use this YAML with `zcli project import` to deploy this environment: ```yaml # Small production environment offers a production-ready # setup optimized for moderate throughput. project: name: ruby-hello-world-small-prod services: # Production app — Zerops builds from the # 'buildFromGit' repo using the 'prod' zeropsSetup. # enableSubdomainAccess provides a public HTTPS URL; # map your custom domain in the Zerops dashboard. # # minContainers: 2 keeps two runtime containers # running at all times — requests are distributed # across both, eliminating single-container downtime. # Zerops scales up automatically under load. - hostname: app type: ruby@3.4 zeropsSetup: prod buildFromGit: https://github.com/zerops-recipe-apps/ruby-hello-world-app enableSubdomainAccess: true minContainers: 2 verticalAutoscaling: # minFreeRamGB reserves headroom above minRam — # Zerops scales up before the container hits its # limit, preventing OOM kills under traffic spikes. minRam: 0.5 minFreeRamGB: 0.25 # PostgreSQL single-node with automatic encrypted # backups enabled by default. For higher-traffic # workloads, consider HA mode (Environment 5) or # your own backup export strategy. # Priority 10 starts the database before app containers. - hostname: db type: postgresql@18 mode: NON_HA priority: 10 ``` --- ## Next Steps After deploying one of the environments and getting to know Zerops, you have two paths to choose from: 1. **Template Flow** — Clone our GitHub repositories and use the whole recipe as a template 2. **Integrate Flow** — If you already have an existing application on a similar stack, integrate the recipe setup with your application Select a flow: [Template Flow](https://app.zerops.io/recipes/ruby-hello-world.md?environment=small-production&guideFlow=template) or [Integrate Flow](https://app.zerops.io/recipes/ruby-hello-world.md?environment=small-production&guideFlow=integrate) Both flows are shown below: ## How to take over the Small Production environment ### 📦 Clone the template repositories Fork or clone the following repositories to your local machine or GitHub account: - [zerops-recipe-apps/ruby-hello-world-app](https://github.com/zerops-recipe-apps/ruby-hello-world-app) ### 1. Find your service name Many commands and configurations need the exact name of your service. You can find it in the Zerops Dashboard. - Open your project in the Zerops Dashboard. - In the project overview, find the service you want to manage. - Use this exact name whenever a command or pipeline configuration asks for ``. Zerops GUI: Locating the Service Name ### 2. Configure deployment pipeline Go to Service Settings > Pipelines & CI/CD Settings in the Zerops Dashboard and connect your repository. For production, use a trigger on new tags. This keeps deployments intentional and tied to a specific version. You can also add a regex filter, such as `^v[0-9]+\.[0-9]+\.[0-9]+$`, if you want to allow only semantic version tags. Zerops GUI: Triggers Alternatively, add `zcli push` to your existing CI/CD pipeline if you want full control over when deployments happen. Learn more about pipeline triggers: https://docs.zerops.io/features/pipeline ### 3. Deploy to production Create and push a new Git tag to deploy a specific version of your app: ```bash git tag -a v1.0.0 -m "Release version 1.0.0" git push origin v1.0.0 ``` > [!TIP] > Open the pipeline detail in the Zerops Dashboard to check the build progress and verify that all steps finish successfully. ### 4. Configure autoscaling Review the autoscaling settings for your runtime services and databases in Service Settings > Automatic Scaling Configuration in the Zerops Dashboard. Zerops GUI: Autoscaling configuration The most important settings are: ```yaml verticalAutoscaling: minRam: 1 minFreeRamGB: 0.5 minFreeRamPercent: 20 ``` > [!CAUTION] > Pay attention to `minFreeRamGB`. This value tells Zerops when to scale RAM vertically. Adjust it based on your app’s real memory needs. RAM scales up immediately, while CPU scales after two consecutive measurements below the threshold. > [!TIP] > Run a quick stress test with a tool like hey before real users arrive. This helps you see how your app behaves under load and tune the autoscaling settings. ### 5. Set up your domain To send real traffic to your app, configure public HTTP access in Service Settings > Public Access & Internal Ports in the Zerops Dashboard. Add your custom domain and point your DNS records to the Zerops IPs shown in the dashboard: Zerops GUI: Public access and custom domain ```text Type Name Content TTL A example.com Auto AAAA example.com Auto ``` For wildcard domains, add a CNAME record for SSL validation. Check the public access documentation: https://docs.zerops.io/features/access > [!TIP] > When changing DNS records for production, start with a low TTL value. Make sure SSL certificates are active before you disable the fallback Zerops subdomain. Once everything works, you can disable the Zerops subdomain so all traffic goes through your custom domain. --- ### 🎉 You are good to go! Your application is live in production and the core setup is complete. The following sections are optional. They cover extra production features such as log forwarding, backups, and diagnostic access. You can stop here and come back later when you need them. --- ### 6. Set up log forwarding (Optional) To send logs to an external service, go to Project Settings > Log Forwarding & Logs Overview in the Zerops Dashboard. You can forward logs to services like Better Stack, Papertrail, or your own self-hosted solution. Learn more about log forwarding: https://docs.zerops.io/references/logging ### 7. Configure database backups (Optional) Manage automated encrypted backups in Service Settings > Backups in the Zerops Dashboard. By default, backups run daily between 00:00 and 01:00 UTC. Before a major deployment, create a manual protected backup: ```bash zcli backup create --tags pre-deploy,protected ``` Read the backup documentation for more options: https://docs.zerops.io/features/backup ### 8. Set up diagnostic access (Optional) Use zCLI and VPN access when you need to inspect or maintain services directly. For runtime services: ```bash zcli vpn up ssh .zerops ``` For databases, connect through the VPN to reach the project’s private network, or set up secure direct IP access for your database admin tools. Check the VPN documentation: https://docs.zerops.io/references/cli/commands#vpn-up ## How to integrate app with Zerops ### 1. Adding `zerops.yaml` The main application configuration file you place at the root of your repository, it tells Zerops how to build, deploy and run your application. ```yaml zerops: # Production setup — bundle only runtime gems, deploy minimal # artifacts. Used for stage and all production environments. - setup: prod build: base: ruby@3.4 # BUNDLE_DEPLOYMENT=1 requires Gemfile.lock (reproducible), # installs gems to vendor/bundle, and skips development gems # — so only production dependencies are bundled and deployed. envVariables: BUNDLE_PATH: vendor/bundle BUNDLE_DEPLOYMENT: "1" BUNDLE_WITHOUT: development buildCommands: - bundle install # Deploy the bundled gems alongside source and the migration # script. Gemfile + lock must be present so 'bundle exec' # resolves gems at runtime without re-installing them. deployFiles: - ./vendor - ./Gemfile - ./Gemfile.lock - ./config.ru - ./src - ./migrate.rb # Restore vendor/bundle from the previous build — bundle # install then only fetches gems that changed in Gemfile.lock. cache: - vendor # Readiness check: Zerops polls GET / before routing traffic to # a new runtime container, ensuring zero-downtime deployments. deploy: readinessCheck: httpGet: port: 8080 path: / run: base: ruby@3.4 # Run the migration once per deploy across all containers. # initCommands execute before 'start' — the database schema # is ready when the app boots. zsc execOnce prevents parallel # containers from racing to run the same migration. # --retryUntilSuccessful handles transient DB startup delays. initCommands: - zsc execOnce ${appVersionId} --retryUntilSuccessful -- bundle exec ruby migrate.rb ports: - port: 8080 httpSupport: true envVariables: RACK_ENV: production # Tell bundle exec where the vendored gems are and that # the development group was excluded at build time — # prevents Bundler from failing on missing dev gems. BUNDLE_PATH: vendor/bundle BUNDLE_WITHOUT: development DB_NAME: db # Referencing variables: ${db_hostname} resolves to the # 'db' service's internal hostname — Zerops injects these # at runtime from the database service's generated vars. DB_HOST: ${db_hostname} DB_PORT: ${db_port} DB_USER: ${db_user} DB_PASS: ${db_password} # Puma is the production Rack server. -b tcp://0.0.0.0 # ensures it binds to all interfaces, not just localhost. start: bundle exec puma -p 8080 -b tcp://0.0.0.0 # Development setup — deploy full source for live SSH # development. The container stays idle ('zsc noop'); the # developer SSHs in and starts the app manually after Zerops # runs the migration and prepares the workspace. - setup: dev build: base: ruby@3.4 # Install all gems (including dev group) into vendor/bundle # so they are available when the developer SSHs in — no # 'bundle install' needed after connecting. envVariables: BUNDLE_PATH: vendor/bundle buildCommands: - bundle install # Deploy the entire working directory — source, vendor, and # zerops.yaml — so the developer can edit and push to other # services directly from the SSH session. deployFiles: ./ cache: - vendor run: base: ruby@3.4 # Migration runs once per deploy — database schema and seed # data are ready when the developer SSHs in. initCommands: - zsc execOnce ${appVersionId} --retryUntilSuccessful -- bundle exec ruby migrate.rb ports: - port: 8080 httpSupport: true envVariables: RACK_ENV: development BUNDLE_PATH: vendor/bundle DB_NAME: db DB_HOST: ${db_hostname} DB_PORT: ${db_port} DB_USER: ${db_user} DB_PASS: ${db_password} # Container stays idle — start the app from SSH: # bundle exec puma -p 8080 -b tcp://0.0.0.0 # For auto-reload during development: # bundle exec rerun -- puma -p 8080 -b tcp://0.0.0.0 start: zsc noop --silent ``` ### 🎯 What's next? **Deploy other environments** — Ready to scale? Deploy additional environments for different stages of your workflow: - [AI Agent](https://app.zerops.io/recipes/ruby-hello-world.md?environment=ai-agent) - [Remote (CDE)](https://app.zerops.io/recipes/ruby-hello-world.md?environment=remote-cde) - [Local](https://app.zerops.io/recipes/ruby-hello-world.md?environment=local) - [Stage](https://app.zerops.io/recipes/ruby-hello-world.md?environment=stage) - [Highly-available Production](https://app.zerops.io/recipes/ruby-hello-world.md?environment=highly-available-production) ## Knowledge Base ### Platform Reference - [Routing & Domains](https://docs.zerops.io/features/access) - [Scaling](https://docs.zerops.io/features/scaling) - [Environment Variables](https://docs.zerops.io/features/env-variables) - [CLI (zcli)](https://docs.zerops.io/references/cli) ### Service Type Reference **Ruby** - [Getting Started](https://docs.zerops.io/ruby/getting-started) - [Build & Deploy](https://docs.zerops.io/ruby/how-to/build-pipeline) - [Environment Variables](https://docs.zerops.io/ruby/how-to/env-variables) - [Logs](https://docs.zerops.io/ruby/how-to/logs) **PostgreSQL** - [Connect](https://docs.zerops.io/postgresql/how-to/connect) - [Backup & Restore](https://docs.zerops.io/postgresql/how-to/backup) - [Manage](https://docs.zerops.io/postgresql/how-to/manage) - [Scale](https://docs.zerops.io/postgresql/how-to/scale) --- ## Related Recipes - [Bun Hello World](https://app.zerops.io/recipes/bun-hello-world.md) - [Go Hello World](https://app.zerops.io/recipes/go-hello-world.md) - [Zerops showcase](https://app.zerops.io/recipes/zerops-showcase.md) - [Java Hello World](https://app.zerops.io/recipes/java-hello-world.md)