vlovgr / ciris

Lightweight, extensible, and validated configuration loading in Scala

Website GitHub

Typelevel Travis Codecov Gitter Version

Ciris

Lightweight, extensible, and validated configuration loading in Scala, Scala.js, and Scala Native.
The core library is dependency-free, while modules provide integrations with external libraries.

The name comes from being an abbreviation of the word configurations.
Ciris' logo was inspired by the epyllion Ciris from Appendix Vergiliana.

The Ciris is an epyllion in 541 hexameters describing the myth of Nisus, the king of Megara and his daughter Scylla.
After the city falls and Scylla is taken prisoner on the Cretan ships, Amphitrite transforms her into the ciris seabird.

Ciris is a new project under active development. Feedback and contributions are welcome.

Introduction

Ciris encourages compile-time safety by defining as much as possible of your configurations in Scala. For the data which cannot reside in code, Ciris helps you to load and decode values, while dealing with errors. Validation is encoded by using appropriate data types, with available integrations to libraries such as cats, enumeratum, refined, spire, and squants.

Ciris is intended as an alternative to configuration files, and libraries like Lightbend Config, in situations where it's easy to change and deploy software. Ciris aims to make it easy, safe, and secure to work with configurations, by eliminating many common configuration errors, by preventing errors from occurring as early as possible, and by loading secret configuration values directly from vault services (like, for example, Kubernetes Secrets and AWS Systems Manager).

The usage guide provides a more detailed introduction to Ciris. See also the presentation Refined types for validated configurations and follow-up blog post Validated Configurations with Ciris for a short introduction to the library and configurations with refined types.

Getting Started

To get started with SBT, simply add the following lines to your build.sbt file.
For an overview, usage instructions, and examples, please see the usage guide.

val cirisVersion = "0.7.2"

libraryDependencies ++= Seq(
  "is.cir" %% "ciris-cats",
  "is.cir" %% "ciris-cats-effect",
  "is.cir" %% "ciris-core",
  "is.cir" %% "ciris-enumeratum",
  "is.cir" %% "ciris-generic",
  "is.cir" %% "ciris-refined",
  "is.cir" %% "ciris-spire",
  "is.cir" %% "ciris-squants"
).map(_ % cirisVersion)

Make sure to replace %% with %%% above if you are using Scala.js or Scala Native.
Libraries are published for Scala 2.10, 2.11, and 2.12, and Java 8 where possible.
For changes between versions, please see the release notes.

Refer to the table below for platform and version support across modules.

Module Scala Scala.js Scala Native
ciris-cats ✓ 2.10, 2.11, 2.12 ✓ 0.6 (2.10, 2.11, 2.12) 𐄂
ciris-cats-effect ✓ 2.10, 2.11, 2.12 ✓ 0.6 (2.10, 2.11, 2.12) 𐄂
ciris-core ✓ 2.10, 2.11, 2.12 ✓ 0.6 (2.10, 2.11, 2.12) ✓ 0.3 (2.11)
ciris-enumeratum ✓ 2.10, 2.11, 2.12 ✓ 0.6 (2.10, 2.11, 2.12) 𐄂
ciris-generic ✓ 2.10, 2.11, 2.12 ✓ 0.6 (2.10, 2.11, 2.12) ✓ 0.3 (2.11)
ciris-refined ✓ 2.10, 2.11, 2.12 ✓ 0.6 (2.10, 2.11, 2.12) 𐄂
ciris-spire ✓ 2.10, 2.11, 2.12 ✓ 0.6 (2.10, 2.11, 2.12) 𐄂
ciris-squants ✓ 2.10, 2.11, 2.12 ✓ 0.6 (2.10, 2.11, 2.12) 𐄂

Backwards binary compatibility for the library is guaranteed between minor versions.
For example, 0.7.x is backwards binary compatible with 0.7.y for any x > y.
More recent minor versions are drop-in replacements for earlier minor versions.

The only required module is ciris-core, the rest are optional library integrations.
For an explanation of how to use the modules, see the Modules Overview section.

  • The ciris-cats module provides typeclasses and typeclass instances from cats.
  • The ciris-cats-effect module provides typeclasses for effect types from cats-effect.
  • The ciris-enumeratum module allows loading enumeratum enumerations.
  • The ciris-generic module allows loading more types with shapeless.
  • The ciris-refined module allows loading refined refinement types.
  • The ciris-spire module allows loading spire number types.
  • The ciris-squants module allows loading squants data types.

If you're using ciris-generic with Scala 2.10, you'll need to include the Macro Paradise compiler plugin.

libraryDependencies += compilerPlugin("org.scalamacros" % "paradise" % "2.1.1" cross CrossVersion.patch)

If you're using ciris-cats or ciris-cats-effect with Scala 2.11.9 or later, you should enable partial unification:

scalacOptions += "-Ypartial-unification"

or, if you need to support Scala 2.10.6 or later, you can use the sbt-partial-unification plugin.

addSbtPlugin("org.lyranthe.sbt" % "partial-unification" % "1.1.0")

Ammonite

To start an Ammonite REPL with Ciris loaded and imported, simply run the following.

curl -Ls try.cir.is | sh

You will need to have a JDK installed. The script will then:

  • download and install the latest available version of coursier,
  • use coursier to fetch Ammonite and the latest Ciris version,
  • start an Ammonite REPL with Ciris already imported.

To use Typelevel Scala with literal types enabled, instead use the following.

curl -Ls try.cir.is/typelevel | sh

If you already have the Ammonite REPL installed, you can load Ciris using the following commands.

import $ivy.`is.cir::ciris-cats:0.7.2`, ciris.cats._
import $ivy.`is.cir::ciris-cats-effect:0.7.2`, ciris.cats.effect._
import $ivy.`is.cir::ciris-core:0.7.2`, ciris._, ciris.syntax._
import $ivy.`is.cir::ciris-enumeratum:0.7.2`, ciris.enumeratum._
import $ivy.`is.cir::ciris-generic:0.7.2`, ciris.generic._
import $ivy.`is.cir::ciris-refined:0.7.2`, ciris.refined._, ciris.refined.syntax._
import $ivy.`is.cir::ciris-spire:0.7.2`, ciris.spire._
import $ivy.`is.cir::ciris-squants:0.7.2`, ciris.squants._

External Libraries

Below is an incomplete list of third-party libraries that integrate with Ciris.
If your library is not included in the list, then please open a pull request.

Documentation

For an overview, with examples and explanations of the most common use cases, please refer to the usage guide.
If you're looking for a more detailed code-centric overview, you can instead take a look at the API documentation.

Participation

Ciris embraces pure, typeful, idiomatic functional programming in Scala, and wants to provide a safe and friendly environment for teaching, learning, and contributing as described in the Typelevel Code of Conduct. It is expected that participants follow the code of conduct in all official channels, including on GitHub and in the Gitter chat room.

If you would like to be involved in building Ciris, check out the contributing guide.

License

Ciris is available under the MIT license, available at https://opensource.org/licenses/MIT and in the license file.