Wez Furlong
2cba4196c5
A downside of pulling in rocksdb is that it is a pretty big C++ library and musl/alpine don't really get on with it. Switch to using the latest ubuntu LTS image as our base.
2.6 KiB
kumomta
Concepts
Queuing
Messages are assigned to a queue upon reception. The system can support arbitrarily named queues but the convention is to construct the queue name from some metadata associated with the message:
tenant- some kind of sender or customer identifier or identity derived either from the message itself or authentication of the injection session.campaign- a sender-provided label that can be used to logically group a set of related messages, perhaps generated from the same campaign.- destination domain - the site where the email will be routed
These three pieces of information are combined to produce the name of the queue
in the form campaign:tenant@domain.
Debugging/Tracing
This will launch the server using the policy defined in simple_policy.lua:
KUMOD_LOG=kumod=trace cargo run -p kumod -- --policy simple_policy.lua
Metrics
If the http listener is enabled, the /metrics endpoint will return a set of metrics
for prometheus to scrape.
You can manually review them with curl:
$ curl 'http://127.0.0.1:8000/metrics'
# HELP connection_count connection_count
# TYPE connection_count gauge
connection_count{service="esmtp_listener"} 1
connection_count{service="smtp_client:(alt1|alt2|alt3|alt4)?.gmail-smtp-in.l.google.com."} 0
# HELP delayed_count delayed_count
# TYPE delayed_count gauge
delayed_count{queue="gmail.com"} 1
Contributing
Ensure that the code is formatted before submitting a PR.
You need to install StyLua to format lua:
$ cargo install stylua --features lua54
Then you can format both the rust and the lua code:
$ make fmt
Docker build
To build a lightweight alpine-based docker image:
$ ./docker/kumod/build-docker-image.sh
...
$ docker image ls kumomta/kumod
REPOSITORY TAG IMAGE ID CREATED SIZE
kumomta/kumod latest bbced15ff4d1 3 minutes ago 116MB
You can then run that image; this invocation mounts the kumo
src dir at /config and then the KUMO_POLICY environment
variable is used to override the default /config/policy.lua
path to use the SMTP sink policy script sink.lua,
which will accept and discard all mail:
$ sudo docker run --rm -p 2025:25 \
-v .:/config \
--name kumo-sink \
--env KUMO_POLICY="/config/sink.lua" \
kumomta/kumod
Fuzzing
Some components have fuzzer coverage. To run it, follow the setup from the Rust Fuzz Book
Then:
$ cd crates/rfc5321/
$ cargo +nightly fuzz run parser