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Change a Cloider app's port, start command and branch

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The Settings tab holds what an app is run with: the Port it listens on and its Start command, plus, for an app created from a repository, the Branch it deploys from and Auto deploy on push. Saving applies the change to the running app in the cheapest way that can carry it. This page explains each setting, what saving does, and how to change them from every tool.

At a glance​

SettingApplies toSaving does
PortEvery appRedeploys the running version on the new port, no rebuild
Start commandApps built by buildpacksRebuilds the source the app is serving, as a new version
BranchGit appsNothing until the next push or Deploy latest commit
Auto deploy on pushGit appsTurns deploys on push on or off
Image, Tag, registry loginImage appsChecks them with the registry, then deploys when the tag points at a different image
Deploy hookImage appsShows the URL that deploys the app, or replaces it with Regenerate
  • Port and start command changes are refused while a build is running or the app is paused (the Save changes button says why: A build is already running or Resume the app to change its settings).
  • On an app that has never deployed, the new values are saved and used by its next build.
  • The app's name, environment variables and domains are elsewhere: see Environment variables and Domains. An app can't be renamed.
The Settings tab of the api app with Port 8080, an empty Start command, and the Repository section with branch main and Auto deploy on push switched on
The Settings tab of a git app.

Change the port​

The port is where Cloider sends the app's traffic, and the container receives it as the PORT environment variable. Change it when your app listens on a different port than the one detected, for example a Dockerfile image that always listens on 80.

Saving a new port redeploys the image the app is already running: the container restarts with the new PORT, and traffic moves to the new port. The app goes Deploying, then Starting, then Ready once something answers on the new port. No new build or version is created.

A wrong port takes the app down

If nothing listens on the new port within 5 minutes, the app goes Failed and stops answering, since traffic now goes to a port nobody serves. Put the right port back on Settings to recover. An app that reads $PORT (every buildpack app, and Dockerfile apps written to) follows the change on its own.

  1. Open the app and go to the Settings tab.
  2. Change Port (1 to 65535).
  3. Click Save changes. The toast says Your app is redeploying on its new port.

Change the start command​

The start command is what your app runs when it starts. Where it goes depends on how the app's image is made:

  • Buildpack build: Cloider writes it into the source as a Procfile line, web: <command>, so it becomes part of the image. Saving a new one rebuilds the source the app is serving: a new version is built and deployed, and the Builds tab opens on it.

  • Your own Dockerfile, or an image you built: the container runs it with sh -c in place of the image's ENTRYPOINT and CMD, so the image needs a shell. Saving a new one only redeploys the image the app is running, in a few seconds.

  • Leave it empty to let the project decide, through its own Procfile, its language's convention (such as the start script of package.json), or the image's own ENTRYPOINT and CMD.

  • One line, at most 1000 characters. Use $PORT for the port: gunicorn app:app --bind 0.0.0.0:$PORT.

  • A static site has no command; setting one makes Cloider build the source with buildpacks instead.

  1. Open the app and go to the Settings tab.
  2. Type the command in Start command, for example node dist/server.js, or clear it.
  3. Click Save changes. A buildpack app's toast says Your app is rebuilding to start on the new command., an image or Dockerfile app's Your app is redeploying with its new settings.

Change the branch or auto deploy​

A git app has a Repository section with the Branch every deploy is taken from and the Auto deploy on push switch. Neither deploys anything by itself: the next push, or Deploy latest commit on the Builds tab, uses them. A branch that doesn't exist isn't checked when you save; the next deploy fails with a message naming it.

cloider app git api --branch release
cloider app git api --auto-deploy=false

On GitLab and Bitbucket, turning auto deploy on also adds the webhook that delivers pushes, which needs the Maintainer role (GitLab) or admin access (Bitbucket); without it, auto deploy switches itself back off. If the connection behind the repository is gone or suspended, the section says so and the app can't deploy from git. See Deploy from git for every tool.

Change an image app's image, tag or login​

An app created from a Docker image has an Image section below the start command, with the Image, the Tag and The image is private switch for its login. Saving checks them with the registry first and refuses what it can't pull, then deploys when the tag now points at a different image. An empty Token or password keeps the saved one for the same username.

cloider app image admin --tag v4
cloider app image admin --no-login

The Deploy hook section below it shows the URL that deploys the app when your CI calls it. See Deploy from CI with a deploy hook.

The Settings tab of the admin image app with the Port, the Image section holding ghcr.io/acme/admin, tag v3 and the acme-ci login, and the Deploy hook section showing its URL and curl examples
The Settings tab of an image app: an Image section and the deploy hook.

Change a cron job's schedule​

A cron job has a Schedule instead of a port. Saving a new one redeploys the job on it in a few seconds, on the same version. See Change the schedule.

Where are pause and delete?​

Pause, Resume and Delete are in the actions menu (the three dots) of each app on the Apps list, and in the CLI as cloider app pause, resume and delete. See Pause, resume and delete.

Troubleshooting​

MessageCause and fix
App port must not be empty / App port must be between 1 and 65535Enter a valid port
Start command must be a single lineRemove line breaks; chain commands with && or move them into a script
Start command must be at most 1000 charactersMove the command into a script in your source and run that
This app is building, wait for that build to finish before changing its settings!Wait for the running build
This app is paused. Resume it before deploying a new version!Resume the app, then save
The settings were saved but the app could not be redeployed!The values are saved; save again or deploy a new version to apply them
The app went Failed after a port changeNothing answers on the new port. Set the port your app listens on
A new start command fails with sh: not foundThe image has no shell to run it with, like a distroless image. Clear the start command and change the image's CMD instead
nothing to change, give --port or --start-command (CLI)Pass at least one of the two flags

Next steps​

Frequently asked questions

How do I change the port of a Cloider app?

Change Port on the app's Settings tab and save, run cloider app update <app> --port <port>, or PUT /api/apps/<id>/settings. The running version is redeployed on the new port without a rebuild.

Does changing the start command rebuild the app?

For a buildpack app, yes: the start command is written into the image as a Procfile line, so saving a new one rebuilds the source the app is serving as a new version. An app with its own Dockerfile or running an image you built runs the start command with sh -c in place of the image's ENTRYPOINT and CMD, so saving a new one only redeploys it.

Can I rename a Cloider app?

No. An app keeps the name it was created with. Create a new app with the new name and move its domains and variables over if you need a different name.

What happens if I set the wrong port?

The app is redeployed on the new port and, if nothing answers there within 5 minutes, it goes Failed and stops serving. Set the correct port again to bring it back.

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