feat: add outbox

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/crunch-postgres/build.rs

@@ -0,0 +1,5 @@
+// generated by `sqlx migrate build-script`
+fn main() {
+    // trigger recompilation when a new migration is added
+    println!("cargo:rerun-if-changed=migrations");
+}

crates/crunch-postgres/migrations/20231003181849_initial.sql

@@ -0,0 +1,8 @@
+-- Add migration script here
+CREATE TABLE outbox (
+    id UUID NOT NULL,
+    metadata JSONB NOT NULL,
+    content BYTEA NOT NULL,
+    inserted_time TIMESTAMPTZ NOT NULL DEFAULT now(),
+    state VARCHAR NOT NULL,
+);

crates/crunch-postgres/src/lib.rs

@@ -1 +1,33 @@
+use async_trait::async_trait;
+use crunch_traits::{errors::PersistenceError, EventInfo};
+use sqlx::{postgres::PgPoolOptions, Pool, Postgres};
 
+pub struct PostgresPersistence {
+    pool: Pool<Postgres>,
+}
+
+impl PostgresPersistence {
+    pub async fn new(dsn: &str) -> anyhow::Result<Self> {
+        let pool = PgPoolOptions::new().max_connections(5).connect(dsn).await?;
+
+        sqlx::migrate!().run(&pool).await?;
+
+        Ok(Self { pool })
+    }
+}
+
+#[async_trait]
+impl crunch_traits::Persistence for PostgresPersistence {
+    async fn insert(&self, event_info: &EventInfo, content: Vec<u8>) -> anyhow::Result<()> {
+        todo!()
+    }
+    async fn next(&self) -> Option<String> {
+        todo!()
+    }
+    async fn get(&self, event_id: &str) -> Result<Option<(EventInfo, Vec<u8>)>, PersistenceError> {
+        todo!()
+    }
+    async fn update_published(&self, event_id: &str) -> Result<(), PersistenceError> {
+        todo!()
+    }
+}