From 371ef60ab67e1ff9de3adc2eaf92f3e89cf97efc Mon Sep 17 00:00:00 2001
From: bluehorn07 <bluehornblues@gmail.com>
Date: Tue, 19 Mar 2024 08:42:35 +0900
Subject: [PATCH] istio envoy access logging

---
 .../istio/2024-03-16-istio-envoy-logging.md   | 96 +++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 _posts/development/istio/2024-03-16-istio-envoy-logging.md

diff --git a/_posts/development/istio/2024-03-16-istio-envoy-logging.md b/_posts/development/istio/2024-03-16-istio-envoy-logging.md
new file mode 100644
index 0000000..ec9c47c
--- /dev/null
+++ b/_posts/development/istio/2024-03-16-istio-envoy-logging.md
@@ -0,0 +1,96 @@
+---
+title: "Istio Envoy Logging"
+toc: true
+toc_sticky: true
+categories: ["Kubernetes", "Istio"]
+excerpt: ""
+last_modified_at: 2024-03-18
+---
+
+
+# 사전 준비
+
+```bash
+k apply -f https://raw.githubusercontent.com/istio/istio/master/samples/helloworld/helloworld.yaml
+```
+
+# Enable Access Logging
+
+## Telemetry API
+
+```yaml
+apiVersion: telemetry.istio.io/v1alpha1
+kind: Telemetry
+metadata:
+  name: default-ns-logging
+  namespace: default
+spec:
+  accessLogging:
+    - providers:
+      - name: envoy
+```
+
+```bash
+$ k exec -it ... -- sh
+~ $ curl http://helloworld.default.svc.cluster.local:5000/hello
+---
+$ k exec -it helloworld... -c istio-proxy -- sh
+...
+[2024-03-18T23:08:48.020Z] "GET /hello HTTP/1.1" 200 - via_upstream - "-" 0 59 52 51 "-" "curl/8.6.0" "a0698764-a04d-48c8-8914-045808d19898" "helloworld.default.svc.cluster.local:5000" "10.42.0.4:5000" inbound|5000|| 127.0.0.6:60873 10.42.0.4:5000 10.42.0.6:48352 outbound_.5000_._.helloworld.default.svc.cluster.local default
+...
+[2024-03-18T23:10:51.528Z] "GET /hello HTTP/1.1" 200 - via_upstream - "-" 0 59 38 37 "-" "curl/7.88.1" "5c3abfa9-c806-490b-a5ec-a6659f866490" "helloworld.default.svc.cluster.local:5000" "10.42.0.5:5000" outbound|5000||helloworld.default.svc.cluster.local 10.42.0.4:55914 10.43.135.30:5000 10.42.0.4:41438 - default
+...
+```
+
+## Mesh Config
+
+```yaml
+spec:
+  meshConfig:
+    accessLogFile: /dev/stdout
+```
+
+또는
+
+```bash
+$ istioctl install --set meshConfig.accessLogFile=/dev/stdout
+```
+
+## 둘다 써보기
+
+일단 Telemetry API 방식과 Mesh Config 방식 둘다 독립적이다! 처음엔 둘다 세팅을 해야 로깅이 되는 줄 알았는데, 그게 아니라 둘 중 어떤 방법을 써도 Envoy Logging이 된다!
+
+다만, 차이점은 Telemetry API는 네임스페이스와 워크로드 Selector를 통해 로깅 대상을 선택할 수 있어서 좀더 세밀한(fine-grained) 로그 제어가 가능하다.
+
+...
+
+# Access Log Format
+
+Access Log가 어떤 정보들을 보여주는지 좀더 살펴보자.
+
+## inbound, outbound 구분 가능
+
+Envoy 용어들 잠깐 정리
+
+- upstream
+  - host
+  - cluster
+  - local address
+- downstream
+  - local address
+  - remote address
+
+## Request 기본 정보 확인 가능
+
+## Response 정보 확인 가능
+
+
+```bash
+[2024-03-18T23:08:48.020Z] "GET /hello HTTP/1.1" 200 - via_upstream - "-" 0 59 52 51 "-" "curl/8.6.0" "a0698764-a04d-48c8-8914-045808d19898" "helloworld.default.svc.cluster.local:5000" "10.42.0.4:5000" inbound|5000|| 127.0.0.6:60873 10.42.0.4:5000 10.42.0.6:48352 outbound_.5000_._.helloworld.default.svc.cluster.local default
+...
+[2024-03-18T23:10:51.528Z] "GET /hello HTTP/1.1" 200 - via_upstream - "-" 0 59 38 37 "-" "curl/7.88.1" "5c3abfa9-c806-490b-a5ec-a6659f866490" "helloworld.default.svc.cluster.local:5000" "10.42.0.5:5000" outbound|5000||helloworld.default.svc.cluster.local 10.42.0.4:55914 10.43.135.30:5000 10.42.0.4:41438 - default
+```
+
+# 참고자료
+
+- https://istio.io/latest/docs/tasks/observability/logs/access-log/
\ No newline at end of file