https://github.com/pureharm/pureharm-config-ciris
Pureharm style library for ciris config library
https://github.com/pureharm/pureharm-config-ciris
cats-effect ciris pureharm scala
Last synced: 3 months ago
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Pureharm style library for ciris config library
- Host: GitHub
- URL: https://github.com/pureharm/pureharm-config-ciris
- Owner: pureharm
- License: apache-2.0
- Created: 2021-04-01T14:14:48.000Z (about 4 years ago)
- Default Branch: main
- Last Pushed: 2021-08-05T16:40:28.000Z (almost 4 years ago)
- Last Synced: 2025-01-19T14:17:20.369Z (5 months ago)
- Topics: cats-effect, ciris, pureharm, scala
- Language: Scala
- Homepage:
- Size: 43 KB
- Stars: 1
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
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README
# pureharm-config-ciris
See [changelog](./CHANGELOG.md).
## scala versions
- 2.13: JVM
- 3: JVM
## modules
The available modules are.
- `"com.busymachines" %% s"pureharm-config-ciris" % "0.2.0"`. Which has these as its main dependencies:
- [cats-effect](https://github.com/typelevel/cats-effect) `3.2.1`
- [ciris](https://github.com/vlovgr/ciris/releases) `2.1.1`
- [ip4s](https://github.com/Comcast/ip4s/releases) `3.0.3`
- [pureharm-core-sprout](https://github.com/busymachines/pureharm-core/releases) `0.3.0`
- [pureharm-core-anomaly](https://github.com/busymachines/pureharm-core/releases) `0.3.0`
- `"com.busymachines" %% s"pureharm-config-ciris-ip4s" % "0.2.0"`. This module brings in aliases, and `ciris.ConfigDecoder` for ip4s datatypes like `Port`, `Host,` etc. Extremely useful for strongly typed stuff
- [cats-effect](https://github.com/typelevel/cats-effect) `3.2.1`
- [ciris](https://github.com/vlovgr/ciris/releases) `2.1.1`
- [ip4s](https://github.com/Comcast/ip4s/releases) `3.0.3`
## usage
The encouraged style to use this library is to create your own "config" package in your app, which contains the opiniated way of doing configs in your application. That's why `pureharm-config-ciris` provides a straightforward way of achieving this, while allowing you to add your own stuff on top.
```scala
package busymachines.test
import cats._
import cats.effect._
import cats.implicits._
import busymachines.pureharm.sprout._
import busymachines.pureharm.config
/** Recommended to do something similar once in your app. To define your prefered "flavor" of reading configs.
*
* In this case we basically explicitely say that we only get config values from environment variables.
*/
object myconfig
extends config.PureharmConfigAllAliases with config.PureharmConfigAllImplicits with config.CirisIp4sInstances {
sealed trait EnvVar
/** Single source of truth for the env vars in the system
*/
object EnvVar {
case object PH_DB_PORT extends EnvVar
case object PH_DB_HOST extends EnvVar
case object PH_DB_NAME extends EnvVar
case object PH_SERVER_PORT extends EnvVar
case object PH_SERVER_HOST extends EnvVar
}
/** This alias allows us some bit of typesafety in our app
*/
def env(s: EnvVar): ConfigValue[CirisEffect, String] = ciris.env(s.toString)
}
/** If it typechecks, ship it!
*/
object CirisConfigExample {
import com.comcast.ip4s._
import myconfig._
type DBPort = DBPort.Type
object DBPort extends Sprout[Port]
type DBHost = DBHost.Type
object DBHost extends Sprout[Host]
type DBName = DBName.Type
object DBName extends Sprout[String]
//in a real world app these might come from a different module that doesn't even depend on config
case class DBConfig(
port: DBPort,
host: DBHost,
name: DBName,
)
type ServerPort = ServerPort.Type
object ServerPort extends Sprout[Port]
type ServerHost = ServerHost.Type
object ServerHost extends Sprout[Host]
//in a real world app these might come from a different module that doesn't even depend on config
case class ServerConfig(
port: ServerPort,
name: ServerHost,
)
//an example of a top-level module config that loads everything at once
case class ExampleConfig(
db: DBConfig,
server: ServerConfig,
)
object ExampleConfig {
def load[F[_]: Config: Monad]: F[ExampleConfig] = for {
db <- DBConfigLoader.load[F]
server <- ServerConfigLoader.load[F]
} yield ExampleConfig(
db,
server,
)
private object DBConfigLoader extends ConfigLoader[DBConfig] {
override def configValue: ConfigValue[CirisEffect, DBConfig] =
(
env(EnvVar.PH_DB_PORT).as[DBPort].default(DBPort(port"5432")),
env(EnvVar.PH_DB_HOST).as[DBHost].default(DBHost(host"localhost")),
env(EnvVar.PH_DB_NAME).as[DBName].default(DBName("example_db_name")),
).parMapN(DBConfig.apply)
}
private object ServerConfigLoader extends ConfigLoader[ServerConfig] {
override def configValue: ConfigValue[CirisEffect, ServerConfig] = (
env(EnvVar.PH_DB_PORT).as[ServerPort].default(ServerPort(port"21312")),
env(EnvVar.PH_DB_HOST).as[ServerHost].default(ServerHost(host"localhost")),
).parMapN(ServerConfig.apply)
}
}
/** Instantiate the Config[F] capability once, pass along everywhere where used.
*/
object MyIOApp extends cats.effect.IOApp.Simple {
override def run: IO[Unit] = runF[IO]
def runF[F[_]: Async]: F[Unit] = {
implicit val config: Config[F] = Config.async[F]
for {
exampleConfig <- ExampleConfig.load[F]
_ <- Async[F].blocking(
println(s"pass along the $exampleConfig config to the rest of your app in bits and pieces you need")
)
} yield ()
}
}
}
```
## Copyright and License
All code is available to you under the Apache 2.0 license, available
at [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0) and also in
the [LICENSE](./LICENSE) file.