WIP: Fill in Ingress trait definition

src/adapters/ingresses/mod.rs

@@ -1,7 +1,28 @@
-pub trait Ingress {}
+use async_trait::async_trait;
+use miette::Result;
+
+/// Ingresses are responsible for (1) controlling how much traffic the canary
+/// gets (hence the name ingress, since it functions like a virtual LB) and
+/// (2) deploying, yanking, and promoting both the canary and the baseline.
+#[async_trait]
+pub trait Ingress {
+    /// Deploy the canary app. Do not assign it any traffic.
+    async fn deploy(&mut self) -> Result<()>;
+
+    // TODO: define the other methods on this type.
+    // async fn yank_canary(&mut self) -> Result<()>;
+    // async fn promote_canary(&mut self) -> Result<()>;
+    // async fn set_canary_traffic(&mut self, percent: u8);
+}
 
 pub struct MockIngress;
-impl Ingress for MockIngress {}
+
+#[async_trait]
+impl Ingress for MockIngress {
+    async fn deploy(&mut self) -> Result<()> {
+        todo!()
+    }
+}
 
 impl From<MockIngress> for BoxIngress {
     fn from(value: MockIngress) -> Self {
@@ -12,3 +33,6 @@ impl From<MockIngress> for BoxIngress {
 /// Convenience alias since this type is often dynamically
 /// dispatched.
 pub type BoxIngress = Box<dyn Ingress>;
+
+#[cfg(test)]
+mod tests {}