main.wisp.config.WispConfig.kt Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of wisp-config Show documentation
a module containing config helpers
There is a newer version: 2024.11.14.031606-bddeae6
package wisp.config

import com.sksamuel.hoplite.ConfigLoader
import com.sksamuel.hoplite.ConfigLoaderBuilder
import com.sksamuel.hoplite.json.JsonPropertySource
import com.sksamuel.hoplite.sources.InputStreamPropertySource
import com.sksamuel.hoplite.toml.TomlPropertySource
import com.sksamuel.hoplite.yaml.YamlPropertySource
import wisp.resources.ClasspathResourceLoaderBackend
import wisp.resources.EnvironmentResourceLoaderBackend
import wisp.resources.FilesystemLoaderBackend
import wisp.resources.ResourceLoader

/**
 * WispConfig is a wrapper around the Hoplite config library:
 * https://github.com/sksamuel/hoplite
 *
 * Config precedence is in order of sources added for loading, so if you want an environment
 * config file to override values in the default file, it has to be added first.
 *
 * Note that config values from Environment Variables, System Properties and User Settings are
 * always loaded first, see: https://github.com/sksamuel/hoplite#property-sources for details.
 *
 * Secrets in config are automatically handled, see:
 * https://github.com/sksamuel/hoplite#masked-values
 *
 * Note that if you are passing configuration fragments within Wisp, your config class should
 * implement [Config]
 */
object WispConfig {

    /**
     * Get a config builder.
     *
     * Example use:
     *
     * val myConfig = WispConfig.builder()
     *                ...
     *                .addWispConfigSources(...)
     *                ...
     *                .build()
     *                .loadConfigOrThrow()
     * Note that if you are passing configuration fragments within Wisp, MyConfig should implement
     * [Config]
     *
     * @return [ConfigLoader.Builder]
     */
    fun builder(): ConfigLoaderBuilder = ConfigLoader.builder()
}

/**
 * Config location and format (default yaml).  The location should be in a format that
 * [ResourceLoader] understands.
 */
data class ConfigSource @JvmOverloads constructor(val configLocation: String, val format: String = "yml")

/**
 * Add the config sources in the order supplied. If the config source location does not
 * exist it is silently skipped, i.e. the config locations are optional.
 */
fun ConfigLoaderBuilder.addWispConfigSources(
    configSources: List,
    resourceLoader: ResourceLoader = ResourceLoader.SYSTEM
): ConfigLoaderBuilder {

    addPreprocessor(PrefixResourceLoaderPreprocessor(ClasspathResourceLoaderBackend.SCHEME, resourceLoader))
    addPreprocessor(PrefixResourceLoaderPreprocessor(FilesystemLoaderBackend.SCHEME, resourceLoader))
    addPreprocessor(PrefixResourceLoaderPreprocessor(EnvironmentResourceLoaderBackend.SCHEME, resourceLoader))

    configSources
        .filter {
            (resourceLoader.exists(it.configLocation))
        }
        .forEach {
            val configContents = resourceLoader.utf8(it.configLocation)!!
            when (it.format) {
                "yml", "yaml" ->
                    this.addSource(YamlPropertySource(configContents))
                "json" ->
                    this.addSource(JsonPropertySource(configContents))
                "toml" ->
                    this.addSource(TomlPropertySource(configContents))
                else ->
                    this.addSource(
                        InputStreamPropertySource(
                            configContents.byteInputStream(Charsets.UTF_8),
                            it.format,
                            it.configLocation
                        )
                    )
            }
        }

    return this
}