HAProxy Telemetry

HAProxy SPOE events/OTEL spans mapping

@startuml
participant User

User -> HAProxy: tcp
activate HAProxy

HAProxy -> SPOA: on-client-session
activate SPOA
SPOA -> "SPAN/HAProxy session"
activate "SPAN/HAProxy session"
"SPAN/HAProxy session" -> "SPAN/Client session": child-of
activate "SPAN/Client session"
SPOA --> HAProxy
deactivate SPOA

HAProxy -> SPOA: on-frontend-tcp-request
activate SPOA
SPOA --> "SPAN/Client session"
"SPAN/Client session" -> "SPAN/Frontend TCP request": child-of
activate "SPAN/Frontend TCP request"
HAProxy -> HAProxy: frontend/tcp-request content rules
SPOA --> HAProxy
deactivate SPOA

HAProxy -> SPOA: on-frontend-http-request
activate SPOA
SPOA --> "SPAN/Frontend TCP request"
"SPAN/Frontend TCP request" -> "SPAN/Frontend HTTP request": follows from
activate "SPAN/Frontend HTTP request"
deactivate "SPAN/Frontend TCP request"
SPOA --> HAProxy
deactivate SPOA
HAProxy -> HAProxy: frontend/http-request content rules

HAProxy -> SPOA: on-backend-tcp-request
activate SPOA
SPOA --> "SPAN/Frontend HTTP request"
"SPAN/Frontend HTTP request" -> "SPAN/Backend TCP request": follows from
activate "SPAN/Backend TCP request"
deactivate "SPAN/Frontend HTTP request"
SPOA --> HAProxy
deactivate SPOA
HAProxy -> HAProxy: backend/tcp-request content rules

HAProxy -> SPOA: on-backend-http-request
activate SPOA
SPOA --> "SPAN/Backend TCP request"
"SPAN/Backend TCP request" -> "SPAN/Backend HTTP request": follows from
activate "SPAN/Backend HTTP request"
deactivate "SPAN/Backend TCP request"
SPOA --> HAProxy
deactivate SPOA
HAProxy -> HAProxy: backend/http-request content rules

HAProxy -> SPOA: on-server-session
activate SPOA
SPOA --> "SPAN/HAProxy session"
"SPAN/HAProxy session" -> "SPAN/Server session": child-of
activate "SPAN/Server session"
SPOA --> "SPAN/Backend HTTP request"
deactivate "SPAN/Backend HTTP request"
SPOA --> HAProxy
deactivate SPOA

HAProxy -> SPOA: on-tcp-response
activate SPOA
SPOA --> "SPAN/Server session"
"SPAN/Server session" -> "SPAN/TCP response": child of
activate "SPAN/TCP response"
SPOA --> HAProxy
deactivate SPOA


HAProxy -> SPOA: on-http-response
activate SPOA
SPOA --> "SPAN/TCP response"
"SPAN/TCP response" -> "SPAN/HTTP response"
activate "SPAN/HTTP response"
deactivate "SPAN/TCP response"
SPOA --> "SPAN/Server session"
deactivate "SPAN/Server session"
SPOA --> "SPAN/HTTP response"
deactivate "SPAN/HTTP response"
SPOA --> "SPAN/Client session"
deactivate "SPAN/Client session"
SPOA --> "SPAN/HAProxy session"
deactivate "SPAN/HAProxy session"
SPOA --> HAProxy
deactivate SPOA


HAProxy -> User: http/response


deactivate HAProxy

@enduml

Development setup

Overview

      |     |
      |     |
  7001v     v8001
  +-----------------+
  | HAProxy~1       |
  |                 |
  |        +------+ |
  |        | SPOE | |
  |        +----+-+ |
  |             |   |
  |             v   |
  | +----+----+-----+
  | |    |    | cBLU|
  +-+-+--+--+-+--+--+             +-------------------+
      |     |    |                | 700x with SPOA {d}|
      |     |    \-------\        | 800x no SPOA  cFE7|
  7002v     v8002        |        +-------------------/
  +-----------------+    |
  | HAProxy~2       |    |
  |                 |    |
  |        +------+ |    |       (devenv/conf/haproxy~2.conf)
  |        | SPOE | |    |       (devenv/conf/spoe.cfg)
  |        +----+-+ |    |
  |             |   |    |
  |   backends  v   |    |
  |   +-------+-----+    |
  |   |       | cBLU|    |   +-------------+
  +---+--+----+--+--+    \-->|    SPOA     |
         |       |     :7000 |             |
         |       +---------->|        cBLU |
         |          SPOP     +-----+-------+
         |                         |
   :8080 v                         v
  +------------+             +-------------+
  | FakeServer +------------>| OTEL/jaeger |
  +------------+             +-------------+

Start local setup

Start local haproxy + fake-server + jaeger

cd devenv/
docker-compose up -d
curl http://localhost:7000

Jaeger UI	http://localhost:16686/
HAProxy stats	http://localhost:7004/;norefresh
Rust SPOA	:7001

Start SPOA

RUST_BACKTRACE=1 cargo run

Resources

• SPOP specifications: http://www.haproxy.org/download/2.6/doc/SPOE.txt

• "Official" HAProxy SPOA "sample" (in c): https://github.com/haproxy/spoa-example

• "Official" HAProxy SPOA open tracing "sample" (in c): https://github.com/haproxytech/spoa-opentracing

• HAProxy SPOA example (in rust): https://github.com/vkill/haproxy-spoa-example

• "Extending HAProxy with the Stream Processing Offload Engine" : https://www.haproxy.com/fr/blog/extending-haproxy-with-the-stream-processing-offload-engine/