com.snowplowanalytics.iglu.client.resolver.registries.Http4sRegistryLookup.scala Maven / Gradle / Ivy

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Resolver for Iglu schema repositories backed by a http4s client
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/*
 * Copyright (c) 2023 Snowplow Analytics Ltd. All rights reserved.
 *
 * This program is licensed to you under the Apache License Version 2.0,
 * and you may not use this file except in compliance with the Apache License Version 2.0.
 * You may obtain a copy of the Apache License Version 2.0 at http://www.apache.org/licenses/LICENSE-2.0.
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the Apache License Version 2.0 is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Apache License Version 2.0 for the specific language governing permissions and limitations there under.
 */
package com.snowplowanalytics.iglu.client.resolver.registries

import cats.data.EitherT
import cats.effect.Concurrent
import cats.effect.kernel.Async
import cats.implicits._
import com.snowplowanalytics.iglu.core.circe.CirceIgluCodecs._
import com.snowplowanalytics.iglu.core.{SchemaKey, SchemaList}
import io.circe.Json
import org.http4s.circe._
import org.http4s.client.{Client => HttpClient}
import org.http4s.{EntityDecoder, Header, Headers, Method, Request, Status, Uri}
import org.http4s.client.middleware.{Retry, RetryPolicy}
import org.typelevel.ci.CIString

import scala.util.control.NonFatal
import scala.concurrent.duration.{DurationInt, FiniteDuration}

object Http4sRegistryLookup {

  def apply[F[_]: Async](client: HttpClient[F]): RegistryLookup[F] =
    apply(client, maxRetry = 5, maxWait = 5.seconds)

  def apply[F[_]: Async](
    client: HttpClient[F],
    maxRetry: Int,
    maxWait: FiniteDuration
  ): RegistryLookup[F] =
    fromClient(Retry[F](retryPolicy(maxRetry, maxWait), redactHeadersWhen)(client))

  private def retryPolicy[F[_]](maxRetry: Int, maxWait: FiniteDuration): RetryPolicy[F] = {
    val backoff = RetryPolicy.exponentialBackoff(maxWait, maxRetry)
    RetryPolicy(
      backoff,
      { case (_, result) => RetryPolicy.isErrorOrRetriableStatus(result) }
    )
  }

  private def fromClient[F[_]: Async](client: HttpClient[F]): RegistryLookup[F] =
    new RegistryLookup.StdRegistryLookup[F] {
      def httpLookup(
        registry: Registry.Http,
        schemaKey: SchemaKey
      ): F[Either[RegistryError, Json]] =
        lookupImpl(client, registry.http, schemaKey).value

      def httpList(
        registry: Registry.Http,
        vendor: String,
        name: String,
        model: Int
      ): F[Either[RegistryError, SchemaList]] =
        listImpl(client, registry.http, vendor, name, model).value
    }

  private def lookupImpl[F[_]: Concurrent](
    client: HttpClient[F],
    http: Registry.HttpConnection,
    key: SchemaKey
  ): EitherT[F, RegistryError, Json] =
    for {
      uri <- EitherT.fromEither[F](toPath(http, key))
      headers = http.apikey.fold[Headers](Headers.empty)(apikey =>
        Headers(Header.Raw(CIString("apikey"), apikey))
      )
      response =
        runRequest[F, Json](client, Request[F](method = Method.GET, uri = uri, headers = headers))
      result <- EitherT(response)
    } yield result

  private def listImpl[F[_]: Concurrent](
    client: HttpClient[F],
    http: Registry.HttpConnection,
    vendor: String,
    name: String,
    model: Int
  ): EitherT[F, RegistryError, SchemaList] =
    for {
      uri <- EitherT.fromEither[F](toSubpath(http, vendor, name, model))
      headers = http.apikey.fold[Headers](Headers.empty)(apikey =>
        Headers(Header.Raw(CIString("apikey"), apikey))
      )
      response = runRequest[F, SchemaList](
        client,
        Request[F](method = Method.GET, uri = uri, headers = headers)
      )
      result <- EitherT(response)
    } yield result

  private def toPath(cxn: Registry.HttpConnection, key: SchemaKey): Either[RegistryError, Uri] =
    Uri
      .fromString(s"${cxn.uri.toString.stripSuffix("/")}/schemas/${key.toPath}")
      .leftMap(e => RegistryError.ClientFailure(e.message))

  private def toSubpath(
    cxn: Registry.HttpConnection,
    vendor: String,
    name: String,
    model: Int
  ): Either[RegistryError, Uri] =
    Uri
      .fromString(s"${cxn.uri.toString.stripSuffix("/")}/schemas/$vendor/$name/jsonschema/$model")
      .leftMap(e => RegistryError.ClientFailure(e.message))

  private def runRequest[F[_]: Concurrent, A: EntityDecoder[F, *]](
    client: HttpClient[F],
    req: Request[F]
  ): F[Either[RegistryError, A]] = {
    val responseResult = client.run(req).use[Either[RegistryError, A]] {
      case Status.Successful(response) =>
        response
          .as[A]
          .map(_.asRight[RegistryError])
          .handleError { e =>
            RegistryError.ClientFailure(s"Could not decode server response. $e").asLeft[A]
          }
      case Status.ClientError(response) if response.status.code == 404 =>
        (RegistryError.NotFound: RegistryError).asLeft[A].pure[F]
      case Status.ServerError(response) =>
        response.bodyText.compile.string.map { body =>
          val error = s"Unexpected server response: $body"
          RegistryError.RepoFailure(error).asLeft
        }
      case Status.ClientError(response) =>
        response.bodyText.compile.string.map { body =>
          val error = s"Unexpected server response: $body"
          RegistryError.ClientFailure(error).asLeft
        }
      case response =>
        response.bodyText.compile.string.map { body =>
          val error = s"Unexpected response: $body"
          RegistryError.ClientFailure(error).asLeft
        }
    }

    responseResult.recover { case NonFatal(exception) =>
      val error = Option(exception.getMessage).getOrElse(exception.toString)
      RegistryError.ClientFailure(error).asLeft
    }
  }

  private implicit def schemaListDecoder[F[_]: Concurrent]: EntityDecoder[F, SchemaList] =
    jsonOf[F, SchemaList]

  private def redactHeadersWhen(header: CIString) =
    (Headers.SensitiveHeaders + CIString("apikey")).contains(header)
}