5 files changed, 118 insertions, 4 deletions
diff --git a/tvix/castore/src/blobservice/combinator.rs b/tvix/castore/src/blobservice/combinator.rs
index 067eff96f488..0bce657e9176 100644
--- a/tvix/castore/src/blobservice/combinator.rs
+++ b/tvix/castore/src/blobservice/combinator.rs
@@ -1,8 +1,11 @@
+use std::sync::Arc;
+
 use futures::{StreamExt, TryStreamExt};
 use tokio_util::io::{ReaderStream, StreamReader};
 use tonic::async_trait;
 use tracing::{instrument, warn};
 
+use crate::composition::{CompositionContext, ServiceBuilder};
 use crate::B3Digest;
 
 use super::{naive_seeker::NaiveSeeker, BlobReader, BlobService, BlobWriter};
@@ -93,6 +96,32 @@ where
     }
 }
 
+#[derive(serde::Deserialize, Debug, Clone)]
+#[serde(deny_unknown_fields)]
+pub struct CombinedBlobServiceConfig {
+    local: String,
+    remote: String,
+}
+
+#[async_trait]
+impl ServiceBuilder for CombinedBlobServiceConfig {
+    type Output = dyn BlobService;
+    async fn build<'a>(
+        &'a self,
+        _instance_name: &str,
+        context: &CompositionContext<dyn BlobService>,
+    ) -> Result<Arc<dyn BlobService>, Box<dyn std::error::Error + Send + Sync>> {
+        let (local, remote) = futures::join!(
+            context.resolve(self.local.clone()),
+            context.resolve(self.remote.clone())
+        );
+        Ok(Arc::new(CombinedBlobService {
+            local: local?,
+            remote: remote?,
+        }))
+    }
+}
+
 fn make_chunked_reader<BS>(
     // This must consume, as we can't retain references to blob_service,
     // as it'd add a lifetime to BlobReader in general, which will get
diff --git a/tvix/castore/src/blobservice/grpc.rs b/tvix/castore/src/blobservice/grpc.rs
index 85250da99d05..56a2ebf00038 100644
--- a/tvix/castore/src/blobservice/grpc.rs
+++ b/tvix/castore/src/blobservice/grpc.rs
@@ -1,4 +1,5 @@
 use super::{BlobReader, BlobService, BlobWriter, ChunkedReader};
+use crate::composition::{CompositionContext, ServiceBuilder};
 use crate::{
     proto::{self, stat_blob_response::ChunkMeta},
     B3Digest,
@@ -180,6 +181,27 @@ where
     }
 }
 
+#[derive(serde::Deserialize, Debug)]
+#[serde(deny_unknown_fields)]
+pub struct GRPCBlobServiceConfig {
+    url: String,
+}
+
+#[async_trait]
+impl ServiceBuilder for GRPCBlobServiceConfig {
+    type Output = dyn BlobService;
+    async fn build<'a>(
+        &'a self,
+        _instance_name: &str,
+        _context: &CompositionContext<dyn BlobService>,
+    ) -> Result<Arc<dyn BlobService>, Box<dyn std::error::Error + Send + Sync + 'static>> {
+        let client = proto::blob_service_client::BlobServiceClient::new(
+            crate::tonic::channel_from_url(&self.url.parse()?).await?,
+        );
+        Ok(Arc::new(GRPCBlobService::from_client(client)))
+    }
+}
+
 pub struct GRPCBlobWriter<W: tokio::io::AsyncWrite> {
     /// The task containing the put request, and the inner writer, if we're still writing.
     task_and_writer: Option<(JoinHandle<Result<proto::PutBlobResponse, Status>>, W)>,
diff --git a/tvix/castore/src/blobservice/memory.rs b/tvix/castore/src/blobservice/memory.rs
index 873d06b461de..0205dcf7bd70 100644
--- a/tvix/castore/src/blobservice/memory.rs
+++ b/tvix/castore/src/blobservice/memory.rs
@@ -6,6 +6,7 @@ use tonic::async_trait;
 use tracing::instrument;
 
 use super::{BlobReader, BlobService, BlobWriter};
+use crate::composition::{CompositionContext, ServiceBuilder};
 use crate::B3Digest;
 
 #[derive(Clone, Default)]
@@ -37,6 +38,22 @@ impl BlobService for MemoryBlobService {
     }
 }
 
+#[derive(serde::Deserialize, Debug)]
+#[serde(deny_unknown_fields)]
+pub struct MemoryBlobServiceConfig {}
+
+#[async_trait]
+impl ServiceBuilder for MemoryBlobServiceConfig {
+    type Output = dyn BlobService;
+    async fn build<'a>(
+        &'a self,
+        _instance_name: &str,
+        _context: &CompositionContext<dyn BlobService>,
+    ) -> Result<Arc<dyn BlobService>, Box<dyn std::error::Error + Send + Sync + 'static>> {
+        Ok(Arc::new(MemoryBlobService::default()))
+    }
+}
+
 pub struct MemoryBlobWriter {
     db: Arc<RwLock<HashMap<B3Digest, Vec<u8>>>>,
 
diff --git a/tvix/castore/src/blobservice/mod.rs b/tvix/castore/src/blobservice/mod.rs
index 50acd40bf769..83fb5b674bb2 100644
--- a/tvix/castore/src/blobservice/mod.rs
+++ b/tvix/castore/src/blobservice/mod.rs
@@ -1,6 +1,8 @@
 use std::io;
+
 use tonic::async_trait;
 
+use crate::composition::{Registry, ServiceBuilder};
 use crate::proto::stat_blob_response::ChunkMeta;
 use crate::B3Digest;
 
@@ -16,11 +18,11 @@ mod object_store;
 pub mod tests;
 
 pub use self::chunked_reader::ChunkedReader;
-pub use self::combinator::CombinedBlobService;
+pub use self::combinator::{CombinedBlobService, CombinedBlobServiceConfig};
 pub use self::from_addr::from_addr;
-pub use self::grpc::GRPCBlobService;
-pub use self::memory::MemoryBlobService;
-pub use self::object_store::ObjectStoreBlobService;
+pub use self::grpc::{GRPCBlobService, GRPCBlobServiceConfig};
+pub use self::memory::{MemoryBlobService, MemoryBlobServiceConfig};
+pub use self::object_store::{ObjectStoreBlobService, ObjectStoreBlobServiceConfig};
 
 /// The base trait all BlobService services need to implement.
 /// It provides functions to check whether a given blob exists,
@@ -101,3 +103,11 @@ impl BlobReader for io::Cursor<&'static [u8; 0]> {}
 impl BlobReader for io::Cursor<Vec<u8>> {}
 impl BlobReader for io::Cursor<bytes::Bytes> {}
 impl BlobReader for tokio::fs::File {}
+
+/// Registers the builtin BlobService implementations with the registry
+pub(crate) fn register_blob_services(reg: &mut Registry) {
+    reg.register::<Box<dyn ServiceBuilder<Output = dyn BlobService>>, super::blobservice::ObjectStoreBlobServiceConfig>("objectstore");
+    reg.register::<Box<dyn ServiceBuilder<Output = dyn BlobService>>, super::blobservice::MemoryBlobServiceConfig>("memory");
+    reg.register::<Box<dyn ServiceBuilder<Output = dyn BlobService>>, super::blobservice::CombinedBlobServiceConfig>("combined");
+    reg.register::<Box<dyn ServiceBuilder<Output = dyn BlobService>>, super::blobservice::GRPCBlobServiceConfig>("grpc");
+}
diff --git a/tvix/castore/src/blobservice/object_store.rs b/tvix/castore/src/blobservice/object_store.rs
index d2d0a288a557..bd8c2bd747fb 100644
--- a/tvix/castore/src/blobservice/object_store.rs
+++ b/tvix/castore/src/blobservice/object_store.rs
@@ -1,4 +1,5 @@
 use std::{
+    collections::HashMap,
     io::{self, Cursor},
     pin::pin,
     sync::Arc,
@@ -18,6 +19,7 @@ use tracing::{debug, instrument, trace, Level};
 use url::Url;
 
 use crate::{
+    composition::{CompositionContext, ServiceBuilder},
     proto::{stat_blob_response::ChunkMeta, StatBlobResponse},
     B3Digest, B3HashingReader,
 };
@@ -269,6 +271,40 @@ impl BlobService for ObjectStoreBlobService {
     }
 }
 
+fn default_avg_chunk_size() -> u32 {
+    256 * 1024
+}
+
+#[derive(serde::Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct ObjectStoreBlobServiceConfig {
+    object_store_url: String,
+    #[serde(default = "default_avg_chunk_size")]
+    avg_chunk_size: u32,
+    #[serde(default)]
+    object_store_options: HashMap<String, String>,
+}
+
+#[async_trait]
+impl ServiceBuilder for ObjectStoreBlobServiceConfig {
+    type Output = dyn BlobService;
+    async fn build<'a>(
+        &'a self,
+        _instance_name: &str,
+        _context: &CompositionContext<dyn BlobService>,
+    ) -> Result<Arc<dyn BlobService>, Box<dyn std::error::Error + Send + Sync + 'static>> {
+        let (object_store, path) = object_store::parse_url_opts(
+            &self.object_store_url.parse()?,
+            &self.object_store_options,
+        )?;
+        Ok(Arc::new(ObjectStoreBlobService {
+            object_store: Arc::new(object_store),
+            base_path: path,
+            avg_chunk_size: self.avg_chunk_size,
+        }))
+    }
+}
+
 /// Reads blob contents from a AsyncRead, chunks and uploads them.
 /// On success, returns a [StatBlobResponse] pointing to the individual chunks.
 #[instrument(skip_all, fields(base_path=%base_path, min_chunk_size, avg_chunk_size, max_chunk_size), err)]