chore(redis sink): Refactor to use StreamSink (vectordotdev#18220)

* Update Redis sink to stream sink

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Update Redis sink to stream sink

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Clippy

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Removed unused encoder file

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Small bit of module documentation

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Tidies up comments and added a datavolume integration test

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Delete unused redis.rs

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Remove spurious comment

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Update request builder doc comments

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

* Removed Response impl

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

---------

Signed-off-by: Stephen Wakely <fungus.humungus@gmail.com>

src/sinks/redis/config.rs

@@ -0,0 +1,162 @@
+use redis::{aio::ConnectionManager, RedisResult};
+use snafu::prelude::*;
+
+use crate::sinks::prelude::*;
+
+use super::{sink::RedisSink, RedisCreateFailedSnafu};
+
+/// Redis data type to store messages in.
+#[configurable_component]
+#[derive(Clone, Copy, Debug, Derivative)]
+#[derivative(Default)]
+#[serde(rename_all = "lowercase")]
+pub enum DataTypeConfig {
+    /// The Redis `list` type.
+    ///
+    /// This resembles a deque, where messages can be popped and pushed from either end.
+    ///
+    /// This is the default.
+    #[derivative(Default)]
+    List,
+
+    /// The Redis `channel` type.
+    ///
+    /// Redis channels function in a pub/sub fashion, allowing many-to-many broadcasting and receiving.
+    Channel,
+}
+
+/// List-specific options.
+#[configurable_component]
+#[derive(Clone, Copy, Debug, Derivative, Eq, PartialEq)]
+#[serde(rename_all = "lowercase")]
+pub struct ListOption {
+    /// The method to use for pushing messages into a `list`.
+    pub(super) method: Method,
+}
+
+/// Method for pushing messages into a `list`.
+#[configurable_component]
+#[derive(Clone, Copy, Debug, Derivative, Eq, PartialEq)]
+#[derivative(Default)]
+#[serde(rename_all = "lowercase")]
+pub enum Method {
+    /// Use the `rpush` method.
+    ///
+    /// This pushes messages onto the tail of the list.
+    ///
+    /// This is the default.
+    #[derivative(Default)]
+    RPush,
+
+    /// Use the `lpush` method.
+    ///
+    /// This pushes messages onto the head of the list.
+    LPush,
+}
+
+#[derive(Clone, Copy, Debug, Default)]
+pub struct RedisDefaultBatchSettings;
+
+impl SinkBatchSettings for RedisDefaultBatchSettings {
+    const MAX_EVENTS: Option<usize> = Some(1);
+    const MAX_BYTES: Option<usize> = None;
+    const TIMEOUT_SECS: f64 = 1.0;
+}
+
+/// Configuration for the `redis` sink.
+#[configurable_component(sink("redis", "Publish observability data to Redis."))]
+#[derive(Clone, Debug)]
+#[serde(deny_unknown_fields)]
+pub struct RedisSinkConfig {
+    #[configurable(derived)]
+    pub(super) encoding: EncodingConfig,
+
+    #[configurable(derived)]
+    #[serde(default)]
+    pub(super) data_type: DataTypeConfig,
+
+    #[configurable(derived)]
+    #[serde(alias = "list")]
+    pub(super) list_option: Option<ListOption>,
+
+    /// The URL of the Redis endpoint to connect to.
+    ///
+    /// The URL _must_ take the form of `protocol://server:port/db` where the protocol can either be
+    /// `redis` or `rediss` for connections secured via TLS.
+    #[configurable(metadata(docs::examples = "redis://127.0.0.1:6379/0"))]
+    #[serde(alias = "url")]
+    pub(super) endpoint: String,
+
+    /// The Redis key to publish messages to.
+    #[configurable(validation(length(min = 1)))]
+    #[configurable(metadata(docs::examples = "syslog:{{ app }}", docs::examples = "vector"))]
+    pub(super) key: Template,
+
+    #[configurable(derived)]
+    #[serde(default)]
+    pub(super) batch: BatchConfig<RedisDefaultBatchSettings>,
+
+    #[configurable(derived)]
+    #[serde(default)]
+    pub(super) request: TowerRequestConfig,
+
+    #[configurable(derived)]
+    #[serde(
+        default,
+        deserialize_with = "crate::serde::bool_or_struct",
+        skip_serializing_if = "crate::serde::skip_serializing_if_default"
+    )]
+    pub(super) acknowledgements: AcknowledgementsConfig,
+}
+
+impl GenerateConfig for RedisSinkConfig {
+    fn generate_config() -> toml::Value {
+        toml::from_str(
+            r#"
+            url = "redis://127.0.0.1:6379/0"
+            key = "vector"
+            data_type = "list"
+            list.method = "lpush"
+            encoding.codec = "json"
+            batch.max_events = 1
+            "#,
+        )
+        .unwrap()
+    }
+}
+
+#[async_trait::async_trait]
+#[typetag::serde(name = "redis")]
+impl SinkConfig for RedisSinkConfig {
+    async fn build(&self, _cx: SinkContext) -> crate::Result<(VectorSink, Healthcheck)> {
+        if self.key.is_empty() {
+            return Err("`key` cannot be empty.".into());
+        }
+        let conn = self.build_client().await.context(RedisCreateFailedSnafu)?;
+        let healthcheck = RedisSinkConfig::healthcheck(conn.clone()).boxed();
+        let sink = RedisSink::new(self, conn)?;
+        Ok((super::VectorSink::from_event_streamsink(sink), healthcheck))
+    }
+
+    fn input(&self) -> Input {
+        Input::new(self.encoding.config().input_type() & DataType::Log)
+    }
+
+    fn acknowledgements(&self) -> &AcknowledgementsConfig {
+        &self.acknowledgements
+    }
+}
+
+impl RedisSinkConfig {
+    pub(super) async fn build_client(&self) -> RedisResult<ConnectionManager> {
+        let client = redis::Client::open(self.endpoint.as_str())?;
+        client.get_tokio_connection_manager().await
+    }
+
+    async fn healthcheck(mut conn: ConnectionManager) -> crate::Result<()> {
+        redis::cmd("PING")
+            .query_async(&mut conn)
+            .await
+            .map_err(Into::into)
+    }
+}