# Istio Agent

This document describes the internal architecture of Istio agent.

## High Level overview

![High Level overview](docs/overview.svg)

At a high level, the Istio agent acts as an intermediate proxy between Istiod and Envoy. This is done
at two levels. For distributing workload certificates, Envoy will send [SDS](https://www.envoyproxy.io/docs/envoy/latest/configuration/security/secret)

    if (configuredLoggers.add(logger)) {
      logger.useParentHandlers = false
      // log based on levels at startup to avoid logging each frame
      logger.level =
        when {
          Log.isLoggable(tag, Log.DEBUG) -> Level.FINE
          Log.isLoggable(tag, Log.INFO) -> Level.INFO
          else -> Level.WARNING
        }
      logger.addHandler(AndroidLogHandler)
    }
  }

        pj--trigger-->c
    end
```

At a high level, each client job will find the correct generator for the request, generate the required configuration, and send it.

#### Optimizations

A naive implementation would simply regenerate all resources, of all subscribed types, for each client, on any configuration change. However, this scales poorly. As a result, we have many levels of optimizations to avoid doing this work.

import org.jetbrains.kotlin.analysis.low.level.api.fir.compile.isForeignValue
import org.jetbrains.kotlin.analysis.low.level.api.fir.providers.jvmClassNameIfDeserialized
import org.jetbrains.kotlin.analysis.low.level.api.fir.sessions.llFirSession
import org.jetbrains.kotlin.analysis.low.level.api.fir.util.getContainingFile
import org.jetbrains.kotlin.analysis.low.level.api.fir.util.originalDeclaration

  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "noCache"),
    level = DeprecationLevel.ERROR,
  )
  fun noCache(): Boolean = noCache

  @JvmName("-deprecated_noStore")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "noStore"),
    level = DeprecationLevel.ERROR,
  )
  fun noStore(): Boolean = noStore

  @JvmName("-deprecated_maxAgeSeconds")

    message = "moved to val",
    replaceWith = ReplaceWith(expression = "tlsVersion"),
    level = DeprecationLevel.ERROR,
  )
  fun tlsVersion(): TlsVersion = tlsVersion

  @JvmName("-deprecated_cipherSuite")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "cipherSuite"),
    level = DeprecationLevel.ERROR,
  )
  fun cipherSuite(): CipherSuite = cipherSuite

    message = "moved to val",
    replaceWith = ReplaceWith(expression = "keyManager"),
    level = DeprecationLevel.ERROR,
  )
  fun keyManager(): X509KeyManager = keyManager

  @JvmName("-deprecated_trustManager")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "trustManager"),
    level = DeprecationLevel.ERROR,
  )
  fun trustManager(): X509TrustManager = trustManager

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package mockwebserver3.junit4

import java.io.IOException
import java.util.logging.Level
import java.util.logging.Logger
import mockwebserver3.MockWebServer
import okhttp3.ExperimentalOkHttpApi
import org.junit.rules.ExternalResource

/**
 * Runs MockWebServer for the duration of a single test method.

  @Deprecated(
    message = "moved to toUrl()",
    replaceWith = ReplaceWith(expression = "toUrl()"),
    level = DeprecationLevel.ERROR,
  )
  fun url(): URL = toUrl()

  @JvmName("-deprecated_uri")
  @Deprecated(
    message = "moved to toUri()",
    replaceWith = ReplaceWith(expression = "toUri()"),
    level = DeprecationLevel.ERROR,
  )
  fun uri(): URI = toUri()

  @JvmName("-deprecated_scheme")

  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "url"),
    level = DeprecationLevel.ERROR,
  )
  fun url(): HttpUrl = url

  @JvmName("-deprecated_method")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "method"),
    level = DeprecationLevel.ERROR,
  )
  fun method(): String = method

  @JvmName("-deprecated_headers")