build webhook cancel build before triggering another - better behavior for back-to-back pushes

bin/core/src/api/listener/resources.rs

@@ -1,4 +1,4 @@
-use std::{str::FromStr, sync::OnceLock};
+use std::{str::FromStr, sync::OnceLock, time::Duration};
 
 use anyhow::{Context, anyhow};
 use komodo_client::{
@@ -23,6 +23,7 @@ use crate::{
   },
   helpers::update::init_execution_update,
   resource,
+  state::action_states,
 };
 
 use super::{ANY_BRANCH, ListenerLockCache};
@@ -37,11 +38,6 @@ impl super::CustomSecret for Build {
   }
 }
 
-fn build_locks() -> &'static ListenerLockCache {
-  static BUILD_LOCKS: OnceLock<ListenerLockCache> = OnceLock::new();
-  BUILD_LOCKS.get_or_init(Default::default)
-}
-
 pub async fn handle_build_webhook<B: super::ExtractBranch>(
   build: Build,
   body: String,
@@ -50,12 +46,6 @@ pub async fn handle_build_webhook<B: super::ExtractBranch>(
     return Ok(());
   }
 
-  // Acquire and hold lock to make a task queue for
-  // subsequent listener calls on same resource.
-  // It would fail if we let it go through from action state busy.
-  let lock = build_locks().get_or_insert_default(&build.id).await;
-  let _lock = lock.lock().await;
-
   // Use the correct target branch when using linked repo.
   let branch = if build.config.linked_repo.is_empty() {
     build.config.branch
@@ -69,13 +59,45 @@ pub async fn handle_build_webhook<B: super::ExtractBranch>(
 
   B::verify_branch(&body, &branch)?;
 
+  // Cancel if currently building
+  if action_states()
+    .build
+    .get(&build.id)
+    .await
+    .and_then(|states| {
+      states.get().ok().map(|states| states.building)
+    })
+    .unwrap_or_default()
+  {
+    let user = git_webhook_user().to_owned();
+    let cancel = ExecuteRequest::CancelBuild(CancelBuild {
+      build: build.id.clone(),
+    });
+    let update = init_execution_update(&cancel, &user).await?;
+    let ExecuteRequest::CancelBuild(cancel) = cancel else {
+      unreachable!()
+    };
+
+    cancel
+      .resolve(&ExecuteArgs {
+        user,
+        update,
+        task_id: Uuid::new_v4(),
+      })
+      .await
+      .ok();
+    
+    poll_build_until_cancelled(&build.id).await?;
+  }
+
   let user = git_webhook_user().to_owned();
-  let req = ExecuteRequest::RunBuild(RunBuild { build: build.id });
-  let update = init_execution_update(&req, &user).await?;
-  let ExecuteRequest::RunBuild(req) = req else {
+  let run = ExecuteRequest::RunBuild(RunBuild { build: build.id });
+  let update = init_execution_update(&run, &user).await?;
+  let ExecuteRequest::RunBuild(run) = run else {
     unreachable!()
   };
-  req
+
+  run
     .resolve(&ExecuteArgs {
       user,
       update,
@@ -83,9 +105,32 @@ pub async fn handle_build_webhook<B: super::ExtractBranch>(
     })
     .await
     .map_err(|e| e.error)?;
+
   Ok(())
 }
 
+async fn poll_build_until_cancelled(
+  build_id: &String,
+) -> anyhow::Result<()> {
+  let action_states = action_states();
+  // Poll to ensure cancelled
+  for _ in 0..10 {
+    if !action_states
+      .build
+      .get(build_id)
+      .await
+      .and_then(|states| {
+        states.get().ok().map(|states| states.building)
+      })
+      .unwrap_or_default()
+    {
+      return Ok(());
+    }
+    tokio::time::sleep(Duration::from_secs(1)).await;
+  }
+  Err(anyhow!("Build still running after cancel"))
+}
+
 // ======
 //  REPO
 // ======