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Launch variables

Two ways to weave a variable's value into the template — inline inside a string, or as a whole-node replacement at a specific location.

Inline: $$var__NAME​

Use it anywhere inside a string — an image tag, a URL, an environment value, a label value.

services:
  web:
    image: ghcr.io/acme/app:$$var__TAG
    environment:
      DATABASE_URL: "postgres://user:$$var__DB_PASSWORD@db:5432/app"
      PUBLIC_URL: "https://$$var__SUBDOMAIN.$$root_domain"
    labels:
      fibe.gg/expose: external:$$var__PORT
      fibe.gg/subdomain: $$var__SUBDOMAIN

$$root_domain is special — Fibe always replaces it with the launching Marquee's root domain. You don't need to declare it.

Whole-node: path: / paths:​

Bind a variable to a specific location inside the template. The whole value at that location is replaced.

x-fibe.gg:
  variables:
    REPLICAS:
      name: "Web replicas"
      default: 2
      path: services.web.deploy.replicas
    DEBUG:
      name: "Debug mode"
      default: false
      paths:
        - services.web.environment.DEBUG
        - services.worker.environment.DEBUG

See Variable placement for the path syntax.

Which form to choose​

UsageBest form
Whole scalar value (env entry, replica count, label value)path: / paths:
Fragment inside a larger string (URL, tag prefix)$$var__NAME
Replacing an existing Compose ${VAR} reference$$var__
Same value in many placespaths: with an array

Defaulting​

When the launcher doesn't supply a value, Fibe uses:

  1. The variable's default, if set.
  2. A generated value if random: true.
  3. Otherwise, an error if the variable is required: true.

Random values​

  • Set random: true and the launcher doesn't have to supply anything.
  • The generated value is persisted with the launch and reused on subsequent compiles — your database password doesn't reset every time.
  • Mark a variable secret or sensitive to nudge the launcher UI to mask the value.

Validation patterns​

Constrain what a launcher can type. The validation is a regular expression wrapped in slashes:

validation: "/^[a-z][a-z0-9-]*$/"     # slug-like
validation: "/^[0-9]+$/"               # integer-as-string
validation: "/^[A-Za-z0-9_.-]+$/"      # image tag

Leave it empty or omit it when any value is fine.

A example​

x-fibe.gg:
  variables:
    APP_NAME:
      name: "Application name"
      required: true
      default: "myapp"
      validation: "/^[a-z][a-z0-9-]*$/"
      paths:
        - services.web.environment.APP_NAME
        - services.worker.environment.APP_NAME

    SUBDOMAIN:
      name: "Subdomain"
      default: "demo"
      validation: "/^[a-z][a-z0-9-]*$/"
      path: services.web.labels.fibe.gg/subdomain

    DB_PASSWORD:
      name: "Database password"
      required: true
      random: true
      secret: true
      paths:
        - services.web.environment.DB_PASS
        - services.db.environment.POSTGRES_PASSWORD

    REPLICAS:
      name: "Web replicas"
      default: 2
      path: services.web.deploy.replicas

    DEBUG:
      name: "Debug mode"
      default: false
      paths:
        - services.web.environment.DEBUG
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