# 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)

  {{- end }}
  {{- if .Values.global.logAsJson }}
    - --log_as_json
  {{- end }}
    lifecycle:
      postStart:
        exec:
          command:
          - pilot-agent
          - wait
          - --url=http://localhost:15020/healthz/ready
    env:
    - name: ISTIO_META_GENERATOR
      value: grpc
    - name: OUTPUT_CERTS
      value: /var/lib/istio/data

  return reinterpret_cast<TF_CoordinationServiceAgent*>(
      cc_ctx->coordination_service_agent());
}

bool TF_CoordinationServiceIsInitialized(TF_CoordinationServiceAgent* agent) {
  if (agent == nullptr) return false;
  auto* cc_agent = reinterpret_cast<tsl::CoordinationServiceAgent*>(agent);
  return cc_agent->IsInitialized();
}

void TF_CoordinationServiceInsertKeyValue(const char* key, int64_t key_size,

  @Test fun ofMapAcceptsEmptyValue() {
    val headers = mapOf("User-Agent" to "").toHeaders()
    assertThat(headers.value(0)).isEqualTo("")
  }

  @Test fun ofMapTrimsKey() {
    val headers = mapOf(" User-Agent " to "OkHttp").toHeaders()
    assertThat(headers.name(0)).isEqualTo("User-Agent")
  }

  @Test fun ofMapTrimsValue() {
    val headers = mapOf("User-Agent" to " OkHttp ").toHeaders()

    }

    public void test_getUserAgentType_IE9() {
        getMockRequest().addHeader("user-agent", "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.0; Trident/5.0)");
        assertEquals(UserAgentType.IE, userAgentHelper.getUserAgentType());
    }

    public void test_getUserAgentType_IE10() {
        getMockRequest().addHeader("user-agent", "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)");

public class UserAgentHelper {
    protected static final String USER_AGENT = "user-agent";

    protected static final String USER_AGENT_TYPE = "ViewHelper.UserAgent";

    public UserAgentType getUserAgentType() {
        return LaRequestUtil.getOptionalRequest().map(request -> {
            UserAgentType uaType = (UserAgentType) request.getAttribute(USER_AGENT_TYPE);
            if (uaType == null) {

@needs_py310
@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"User-Agent": "testclient"}),
        ("/items", {"X-Header": "notvalid"}, 200, {"User-Agent": "testclient"}),
        ("/items", {"User-Agent": "FastAPI test"}, 200, {"User-Agent": "FastAPI test"}),
    ],
)
def test(path, headers, expected_status, expected_response, client: TestClient):

@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"User-Agent": "testclient"}),
        ("/items", {"X-Header": "notvalid"}, 200, {"User-Agent": "testclient"}),
        ("/items", {"User-Agent": "FastAPI test"}, 200, {"User-Agent": "FastAPI test"}),
    ],
)
def test(path, headers, expected_status, expected_response):
    response = client.get(path, headers=headers)

LINUX_AGENT_BINARIES:=./cni/cmd/istio-cni \
  ./cni/cmd/install-cni \
  $(AGENT_BINARIES)

BINARIES:=$(STANDARD_BINARIES) $(AGENT_BINARIES) $(LINUX_AGENT_BINARIES)

# List of binaries that have their size tested
RELEASE_SIZE_TEST_BINARIES:=pilot-discovery pilot-agent istioctl envoy ztunnel client server

-Dorg.gradle.daemon.idletimeout=120000 -Dorg.gradle.daemon.registry.base=C:\\some\\agent\\workspace\\build\\daemon -Dorg.gradle.native.dir=C:\\some\\agent\\workspace\\intTestHomeDir\\worker-1\\native -Dorg.gradle.deprecation.trace=true -Djava.io.tmpdir=C:\\some\\agent\\workspace\\subprojects\\osgi\\build\\tmp -Dfile.encoding=windows-1252 -Dorg.gradle.classloaderscope.strict=true -ea -ea "-Dorg.gradle.appname=gradle" -classpath "C:\\some\\agent\\workspace\\subprojects\\osgi\\build\\integ test\\bin\\..\\lib\\gra...