A slow TCP proxy
Do you want your server to be slower? Sloxy can help!
We wanted a way to simulate a slow network for testing Postico. There are a lot of potential solutions out there.
All of them seemed too complicated, so I wrote my own.
Sloxy listens for incoming TCP connections. It then connects to the destination address, and forwards all data with a delay.
Sloxy can enforce a maximum bandwidth and add a constant delay.
Sloxy allows multiple connections to the server.
Sloxy enforces limits both when sending and when receive. This means the minimum network round-trip time is twice the configured delay.
Sloxy requires 6 arguments:
./sloxy listen_addr listen_port destination_addr destination_port speed_limit delay
listen_addr is the IP address you listen on.
Typically 127.0.0.1, or 0.0.0.0 if you want to listen on all interfaces.
listen_port the port to listen on.
destination_addr is the IP address of the server.
destination_port is the port the server runs on.
speed_limit is the maximum number of bytes per second.
delay is the transmission delay in seconds.
To make PostgreSQL infuriatingly slow, type:
./sloxy 127.0.0.1 5433 127.0.0.1 5432 1000 0.1
Then connect to port 5433 instead of 5432:
psql postgres://127.0.0.1:5433
Just type make sloxy in the Terminal. Yes, I know that there is no makefile. Make can still do it.
Argument validation could be better. Right now sloxy only makes sure there are 6 arguments.
Sloxy only supports numeric IPv4 addresses. Would be nice if we could type hostnames instead.