Preview & ephemeral environments

What are ephemeral environments on SeaGit?

An ephemeral environment is a temporary, isolated deployment of your application built from a specific commit or pull request and served on its own URL, so you can validate changes against real infrastructure without touching production. On SeaGit these are ephemeral deployments — true dark releases that run in the same environment as your main deployment, each as its own Helm release with its own DNS subdomain (dep-name.domain.com). Because they run on managed Kubernetes in your own AWS, Azure or GCP account, a preview is a production-like slice, not a mock: same environment, real add-ons, no infrastructure markup. CI/CD only targets non-main slots, so previews can never disrupt the live main deployment. You can run several ephemeral slots per environment up to the configured limit, then promote the winning slot to main or discard it.

How preview environments work

1. 1

   Push a commit or open a pull request

   A webhook build is triggered. CI/CD resolves a non-main deployment slot for the incoming commit SHA — the main deployment is never automatically overwritten.

2. 2

   SeaGit deploys an isolated dark release

   The ephemeral deployment ships as its own Helm release with its own DNS subdomain (dep-name.domain.com), inside the same environment as main — real infrastructure, real add-ons, zero traffic impact on production.

3. 3

   Test on a real, isolated URL

   Share the preview URL, run checks and validate against production-like Kubernetes in your own cloud account.

4. 4

   Promote or discard

   Promote the slot to main (or Mark as main), or remove it to free a slot. Automation rules can power ephemeral clusters down to control cost.

What teams use preview environments for

• →Preview every pull request on its own URL before merging.
• →Dark-launch a feature to real infrastructure with no impact on live traffic.
• →Give QA, product and stakeholders a stable, production-like link to review.
• →Run parallel experiments across multiple ephemeral slots per environment.

Preview environments are one reason teams pick SeaGit over a single-slot PaaS — see how it compares to Heroku, Vercel and Railway.

Preview environments — FAQ

What is an ephemeral (preview) environment?

An ephemeral environment is a temporary, isolated deployment of your application spun up from a specific commit or pull request, on its own URL, so you can test changes against real infrastructure without touching production. On SeaGit these are ephemeral deployments — real dark releases in the same environment as your main deployment, with no traffic impact.

How are SeaGit preview environments different from review apps?

Classic review apps run on a vendor’s shared infrastructure. SeaGit ephemeral deployments run on managed Kubernetes in your own AWS, Azure or GCP account, each with its own isolated URL (dep-name.domain.com) and its own Helm release, so a preview is a true production-like slice — same environment, real add-ons, no markup.

How many preview environments can I run?

Ephemeral deployments are guaranteed per environment up to the max_deployments_per_instance limit configured on the environment. When the limit is reached you push to an existing ephemeral slot or remove one before creating a new slot. CI/CD only targets non-main slots, so the main deployment is never disrupted.

Do preview environments cost extra?

You pay only your own cloud provider for the compute an ephemeral deployment uses, with no SeaGit infrastructure markup. Automation rules can scale or power ephemeral clusters on a schedule to keep preview costs down.

How do I promote a preview to production?

After validating an ephemeral deployment you either Promote it (copy its configuration and deploy to the main slot) or Mark as main (shift the is_main flag to that slot). Both are available from the UI and the API.