codingconcepts/dp

A simple dynamic proxy

dp

A simple dynamic proxy

Installation

Find the release that matches your architecture on the releases page.

Download the tar, extract the executable, and move it into your PATH:

$ tar -xvf dp_0.1.0_macos_arm64.tar.gz

Usage

$ dp -h

Usage of dp:
  -ctl-port int
        port number for proxy control requests (default 3000)
  -debug
        enable debug-level logging
  -port int
        port number for proxy requests (default 26257)
  -version
        show the application version

Local example

Dependencies:

• CockroachDB

Start first cluster

cockroach demo --sql-port 26001 --http-port 8001 --insecure

Start second cluster

cockroach demo --sql-port 26002 --http-port 8002 --insecure

Run the load balancer

go run dp.go \
--port 26000 \
--ctl-port 3000

Add and activate the first cluster in the load balancer

curl http://localhost:3000/groups \
  -H 'Content-Type:application/json' \
  -d '{"name": "first", "servers": ["localhost:26001"]}'

curl http://localhost:3000/activate \
  -H 'Content-Type:application/json' \
  -d '{"groups": ["first"]}'

Run a command against the first cluster (making use of the see CLI)

see -n 1 \
cockroach sql \
--url "postgres://root@localhost:26000/defaultdb?sslmode=disable" \
-e "SELECT crdb_internal.cluster_id()"

Add the second cluster to the load balancer

curl http://localhost:3000/groups \
  -H 'Content-Type:application/json' \
  -d '{"name": "second", "servers": ["localhost:26002"]}'

Toggle the load balancer to the second cluster and observe the cluster id change

curl http://localhost:3000/activate \
  -H 'Content-Type:application/json' \
  -d '{"groups": ["second"]}'

Drain and observe everything go to shit

curl http://localhost:3000/activate \
  -H 'Content-Type:application/json' \
  -d '{"groups": []}'

Teardown

pkill -9 cockroach dp main
rm -rf inflight_trace_dump

Todos

• Wrap terminateSignal and mu in server struct
• Better error handling