prerequisites

1. Have an account on Snowflake
2. Clojure 1.11+
3. Have an user with a role that has the sufficient privileges on all relevant objects.
   • Such role must have:
     • USAGE on the database.
     • CREATE STREAM and USAGE on the schema.
     • INSERT on the table(s).
4. Set up a key pair for the user.
   • Create a key pair

     openssl genrsa 2048 | openssl pkcs8 -topk8 -inform PEM -out snowflake_rsa_key.p8 -nocrypt
     openssl rsa -in snowflake_rsa_key.p8 -pubout -out snowflake_rsa_key.pub

   • Associate the public key with the user in Snowflake.

     alter user testuser set rsa_public_key='MII...';
     desc user testuser;

5. Configure the service using config.edn. See config.example.edn for an example.
6. While it's not required, setting the APP_NAME environment variable to an unique and fixed string per container/process is recommended to avoid creating unlimited channels when the container/process restarts. Otherwise, an UUID is generated and used.

running directly

env APP_NAME=myapp clj -M -m emqx.core

running with repl

clj

(require '[emqx.config :as config])
(require '[emqx.channel :as chan])
(let [{:keys [:app-name :client :channels]} (config/get-config!)]
  (chan/start-client client)
  (doseq [chan-params channels]
    (chan/ensure-streaming-agent app-name chan-params)
    (mqtt/start-client chan-params)))

uberjar

clj -T:build uber

java -jar target/emqx-snowflake-proxy-0.0.0-standalone.jar

docker

docker build . -t emqx/emqx-snowflake-proxy
docker run -v ./config.edn:/opt/proxy/config.edn ghcr.io/emqx/emqx-snowflake-proxy

testing

env APP_NAME=myapp clj -X:test

# only tests marked as :integration
clj -X:test :includes '[:integration]'

# except tests marked as :integration
clj -X:test :excludes '[:integration]'

# only a few namespaces
clj -X:test :nses '[emqx.adapter-test]'

formatting

clj -M:fmt/check
clj -M:fmt/fix

Or install cljfmt.

cljfmt check
cljfmt fix