configurations/

configurations example

Shows how an operator routes per-deployment values to a library that declares a configuration, how a composite remaps the alias for everything inside its call, and how the factory defines a configuration of its own from a resource.

The stack defines three greet.say actions and two greeter.greeting composite call sites. The leaves and call sites that omit a meta key use the default alias; others select the formal alias either directly with @configuration: or by remapping inside a composite with @configurations:. The fancy configuration is internal: the factory derives its prefix from the greet.phrase.flourish resource's computed output, so it never appears in config.ub (an operator entry for it is rejected), and the action that selects it runs after the resource it derives from. A real library would use the same mechanism to point one library at something another library created (a cluster created here, configuring its own client library). Prefer configuration fields that hold credential sources over short-lived secrets: the value is computed once per run, so a token that expires in minutes belongs behind a field the library exchanges per call.

Try it

go run ./cmd/unobin compile \
  -p examples/configurations/main.ub \
  -o /tmp/configurations-build \
  --replace-unobin="$(pwd)" \
  --build

cd /tmp/configurations-build
export UB_STATE_KEY="$(head -c 32 /dev/urandom | base64)"
./configurations plan --allow-version-mismatch \
  -c "${OLDPWD}/examples/configurations/dev.ub" \
  -o /tmp/plan.json
./configurations apply /tmp/plan.json
./configurations output -c "${OLDPWD}/examples/configurations/dev.ub"

Expected output:

casual:      "hello: world"
casual-wrap: "hello: wrapped"
fancy:       "** Salutations **: world"
formal:      "Good day: world"
formal-wrap: "Good day: wrapped"

Failures

The plan-time validator catches misuse before any work happens:

• Mistype an alias: @configuration: greet.formel produces @configuration greet.formel: configuration not declared.
• Remove the default entry while something still uses it: the node that does reports library "greet" requires a configuration; define configurations.greet.default in config.ub or in the factory.
• Supply a value for an internal name: configurations.greet.fancy in config.ub produces defined internally by the factory; remove this entry from config.ub.
• Cross-import remap: @configurations: { greet: aws.formal } produces @configurations.greet: right-hand side import "aws" must match the key.