notes about envoy

_posts/2024-12-16-istio.md

@@ -3,7 +3,7 @@ layout: post
 title: Istio
 date: 2024-12-16 13:10 -0800
 categories: [network]
-tags: [network, istio, envoy]
+tags: [network, istio]
 ---
 
 Istio used to have a micro-service architecture. However, starting from v1.5,
@@ -68,6 +68,8 @@ It runs in the istio-proxy container. Ex below:
 
 ```
 /usr/local/bin/pilot-agent proxy sidecar --domain filebeat.svc.cluster.local --proxyLogLevel=warning --proxyComponentLogLevel=misc:error --log_output_level=default:info --concurrency 2
+
+/usr/local/bin/envoy -c etc/istio/proxy/envoy-rev0.json --restart-epoch 0 --drain-time-s 45 --drain-strategy immediate --parent-shutdown-time-s 60 --service-cluster airflow.data --service-node sidecar~172.31.76.240~airflow-worker-0.data~data.svc.cluster.local --local-address-ip-version v4 --bootstrap-version 3 --disable-hot-restart --log-format %Y-%m-%dT%T.%fZ.%l.envoy %n.%v -l warning --component-log-level misc:error --concurrency 2
 ```
 
 It is mainly responsible for managing envoy proxy sidecar.
@@ -262,24 +264,3 @@ for more details.
 ## Useful commands
 
 - `istioctl version`: quickly get all running versions.
-
-## Envoy
-
-Envoy is a proxy solution. There are so many proxies in the market: nginx,
-haproxy, trafik and etc, but why does Envoy stand out? It is because the xDS
-APIs, or a fancier name, xDS protocol. Envoy project incubated a protocol that
-allows dynamically changing proxy configurations using a channel between proxy
-and the management server.
-
-Alex Burnos has a
-[great article](https://medium.com/@aburnos/data-plane-control-plane-and-their-apis-explained-d0a3fa7291f3)
-talking about data plane, control plane and universal data plan API. Just to
-copy his explanation here:
-
-- data plane: proxies
-- control plane: management server
-- data plan API: the API for proxies and management server to talk to each
-  other, i.e., xDS APIs.
-
-See Envoy's golang implementation of data-plane-api:
-https://github.com/envoyproxy/go-control-plane.

_posts/2024-12-18-envoy.md

@@ -0,0 +1,82 @@
+---
+layout: post
+title: Envoy
+date: 2024-12-18 10:55 -0800
+categories: [network]
+tags: [network, envoy]
+---
+
+Envoy is a proxy solution. There are so many proxies in the market: nginx,
+haproxy, trafik and etc, but why does Envoy stand out? It is because the xDS
+APIs, or a fancier name, xDS protocol. Envoy project incubated a protocol that
+allows dynamically changing proxy configurations using a channel between proxy
+and the management server.
+
+Alex Burnos has a
+[great article](https://medium.com/@aburnos/data-plane-control-plane-and-their-apis-explained-d0a3fa7291f3)
+talking about data plane, control plane and universal data plan API. Just to
+copy his explanation here:
+
+- data plane: proxies
+- control plane: management server
+- data plan API: the API for proxies and management server to talk to each
+  other, i.e., xDS APIs.
+
+See Envoy's golang implementation of data-plane-api:
+<https://github.com/envoyproxy/go-control-plane>.
+
+## Build
+
+Follow the
+[official doc](https://github.com/envoyproxy/envoy/blob/ac61d8e000adc56d7505517cb4d6af5b82e08d22/bazel/README.md).
+
+```
+brew install bazelisk
+cd ~/code/envoy
+
+# release build. Be cautious: too slow. Use a debug build instead.
+bazel build -c opt envoy
+
+# debug build
+bazel build --jobs=7 -c dbg envoy
+```
+
+A gentle reminder: It took hours to build Envoy. There are over 14k source
+files to compile. The
+[official doc](https://www.envoyproxy.io/docs/envoy/latest/faq/build/speed)
+recommends using a machine with 36+ cores to build it.
+
+```
+INFO: Elapsed time: 4138.131s, Critical Path: 348.04s
+INFO: 14847 processes: 3209 internal, 11636 darwin-sandbox, 1 local, 1 worker.
+```
+
+Command to generate compilation database as following.
+
+```
+TEST_TMPDIR=/tmp tools/gen_compilation_database.py
+```
+
+It failed in my Macbook M1. To mitigate this issue, I need to comment out the
+`test` and `contrib` source code before running the python script.
+
+```
+diff --git a/tools/gen_compilation_database.py b/tools/gen_compilation_database.py
+index 8153c1ad30..5d1cd470db 100755
+--- a/tools/gen_compilation_database.py
++++ b/tools/gen_compilation_database.py
+@@ -131,8 +131,6 @@ if __name__ == "__main__":
+     parser.add_argument(
+         'bazel_targets', nargs='*', default=[
+             "//source/...",
+-            "//test/...",
+-            "//contrib/...",
+         ])
+```
+
+## How to debug Envoy?
+
+Envoy has a set of admin endpoints for debug purpose. It even has an admin web
+UI. see
+[doc](https://www.envoyproxy.io/docs/envoy/latest/start/quick-start/admin). So
+we can know its internal state.