# Kashka
Elixir Kafka REST proxy client for [Confluent REST Proxy](https://docs.confluent.io/current/kafka-rest/index.html).
## Examples
### Produce
```elixir
{:ok, conn} = Kashka.Kafka.produce("http://localhost:8082/", "topic_name', [%{value: %{foo: "bar"}}])
:ok == Kashka.Kafka.close(conn)
```
See `Kashka.Kafka.produce/4` for details.
### Consume
```elixir
defmodule TestModule do
@behaviour Kashka.GenConsumer
def init(conn, _args) do
{:ok, conn, :state}
end
def handle_message_set(conn, :state, message_set) do
IO.inspect(message_set)
#[%{"key" => nil, "offset" => 0, "partition" => 0, "topic" => "test_name", "value" => %{"foo" => "bar"}}]
{:ok, conn, :state}
end
end
args = [
url: "http://localhost:8082/",
instance_id: "my",
consumer_group: "consumer_group",
topics: ["topic_name"],
module: TestModule,
delete_on_exists: false,
retry_on_exists: true,
consumer_opts: %{"auto.offset.reset": :earliest, "auto.commit.enable": true},
]
{:ok, pid} = GenConsumer.start_link(args)
```
See `Kashka.GenConsumer` for details.
### More
See [tests](https://github.com/funbox/kashka/blob/master/test/kashka/gen_consumer_test.exs) for more examples.
### Kafka URL explanation
Kafka URL can be a String or a Keyword list. Keyword list can contain `url`, `headers`, `fix_schema`, `fix_port`, `fix_host` keys.
Examples:
```elixir
[url: "http://127.0.0.1:8811", headers: [{"host", "smth.com"}]]
```
With `fix_* keys`:
```elixir
[url: "http://127.0.0.1", fix_port: true, fix_schema: true, fix_host: true, headers: [{"host", "smth.com"}]]
```
`fix_*` keys used to automatically preprocess the URL returned from the consumer creation method.
For example if `create_consumer` method returns
`https://smth1.com:443/comsumers/group/instances/name` as a `base_uri`,
it is transformed to `http://127.0.0.1:80/comsumers/group/instances/name` with host header `smth1.com`.
It can be helpful while connecting to Kafka REST API through Nginx proxy.
`protocols:` option can be used for explicit specification of HTTP protocols negotiation with Kafka REST server.
It can take the following values: `:http1`, `:http2` or `:any` by default.
## How to run tests
1. Run `doker-compose up`.
2. Run `mix test` in separate terminal.
## Roadmap
* Make protection from endless loop in `Kashka.Http.request`.
* Correctly process other errors in `Kashka.Http.request`.
[](https://funbox.ru)
