[前チャプターのHTTPSについて](https.md){.internal-link target=_blank}では、HTTPSがどのようにAPIを暗号化するのかについて学びました。

通常、アプリケーションサーバにとって**外部の**コンポーネントである**TLS Termination Proxy**によって提供されることが一般的です。このプロキシは通信の暗号化を担当します。

さらにセキュアな通信において、HTTPS証明書の定期的な更新を行いますが、これはTLS Termination Proxyと同じコンポーネントが担当することもあれば、別のコンポーネントが担当することもあります。

### HTTPS 用ツールの例
TLS Termination Proxyとして使用できるツールには以下のようなものがあります：

* Traefik
    * 証明書の更新を自動的に処理 ✨
* Caddy
    * 証明書の更新を自動的に処理 ✨
* Nginx

```

#### Memory Issues
```java
// Reduce concurrent threads and batch sizes
crawler.crawlerContext.setNumOfThread(5);
crawler.crawlerContext.setMaxAccessCount(1000);
```

#### SSL/TLS Issues
```java
// Configure SSL settings
container.singleton("httpClient", HcHttpClient.class, client -> {
    client.setTrustAllCertificates(true);  // For testing only
});
```

### Debug Logging

import okhttp3.internal.http2.Http2Stream
import okhttp3.internal.http2.Settings
import okhttp3.internal.http2.StreamResetException
import okhttp3.internal.isHealthy
import okhttp3.internal.tls.OkHostnameVerifier
import okio.Buffer

/**
 * A connection to a remote web server capable of carrying 1 or more concurrent streams.
 *

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.tls.internal.der

import java.math.BigInteger
import java.net.ProtocolException
import java.text.ParseException
import java.text.SimpleDateFormat
import java.util.Date
import java.util.TimeZone

if ! [ -d ~/.aws ]; then
	mkdir -p ~/.aws
fi
cat >~/.aws/credentials <<EOF
[enterprise]
region = us-east-1
aws_access_key_id = minio
aws_secret_access_key = minio123
EOF

# Create certificates for TLS enabled MinIO
echo -n "Setup certs for MinIO instances ..."
wget -O certgen https://github.com/minio/certgen/releases/latest/download/certgen-linux-amd64 && chmod +x certgen
./certgen --host localhost
mkdir -p /tmp/certs

cleanup

export MINIO_CI_CD=1
export MINIO_BROWSER=off
export MINIO_ROOT_USER="minio"
export MINIO_ROOT_PASSWORD="minio123"
TEST_MINIO_ENC_KEY="MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDA"

# Create certificates for TLS enabled MinIO
echo -n "Setup certs for MinIO instances ..."
wget -O certgen https://github.com/minio/certgen/releases/latest/download/certgen-linux-amd64 && chmod +x certgen
./certgen --host localhost
mkdir -p /tmp/certs

import okhttp3.java.net.cookiejar.JavaNetCookieJar
import okhttp3.okio.LoggingFilesystem
import okhttp3.testing.Flaky
import okhttp3.testing.PlatformRule
import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.HeldCertificate
import okio.Buffer
import okio.BufferedSink
import okio.ByteString
import okio.ForwardingSource
import okio.GzipSink
import okio.Path.Companion.toPath
import okio.buffer

pkg archive/zip, type FileHeader struct, Modified time.Time
pkg archive/zip, type FileHeader struct, NonUTF8 bool
pkg bufio, method (*Reader) Size() int
pkg bufio, method (*Writer) Size() int
pkg crypto/tls, const ECDSAWithSHA1 = 515
pkg crypto/tls, const ECDSAWithSHA1 SignatureScheme
pkg crypto/x509, const CANotAuthorizedForExtKeyUsage = 9
pkg crypto/x509, const CANotAuthorizedForExtKeyUsage InvalidReason

 * blast radius possible. If an HTTP/2 stream is active, canceling will cancel that stream but not
 * the other streams sharing its connection. But if the TLS handshake is still in progress then
 * canceling may break the entire connection.
 */
class RealCall(
  val client: OkHttpClient,
  /** The application's original request unadulterated by redirects or auth headers. */

  - [alpha] Simplifies bootstrapping of TLS secured communication between the API server and kubelet. ([docs](http://kubernetes.io/docs/admin/master-node-communication/#kubelet-tls-bootstrap)) ([kubernetes/features#43](https://github.com/kubernetes/enhancements/issues/43))