HTTPリクエストのKeep-AliveとPrxoy対応など (#5226)

* DriveのKeep-Alive, Proxy と APのProxy対応

* request系でKeep-Aliveするように

* fix lookup-dns-cache.d.ts

* remove debug output

src/services/drive/s3.ts

@@ -0,0 +1,31 @@
+import * as S3 from 'aws-sdk/clients/s3';
+import config from '../../config';
+import { Meta } from '../../models/entities/meta';
+import * as httpsProxyAgent from 'https-proxy-agent';
+import * as agentkeepalive from 'agentkeepalive';
+
+const httpsAgent = config.proxy
+	? new httpsProxyAgent(config.proxy)
+	: new agentkeepalive.HttpsAgent({
+			freeSocketTimeout: 30 * 1000
+		});
+
+export function getS3(meta: Meta) {
+	const conf = {
+		endpoint: meta.objectStorageEndpoint,
+		accessKeyId: meta.objectStorageAccessKey,
+		secretAccessKey: meta.objectStorageSecretKey,
+		region: meta.objectStorageRegion,
+		sslEnabled: meta.objectStorageUseSSL,
+		httpOptions: {
+		}
+	} as S3.ClientConfiguration;
+
+	if (meta.objectStorageUseSSL) {
+		conf.httpOptions!.agent = httpsAgent;
+	}
+
+	const s3 = new S3(conf);
+
+	return s3;
+}