Added initial implementation for Google Cloud Storage

.gitignore

@@ -2,6 +2,7 @@ bazel-*
 target/
 .vscode/
 .zed
+.idea/
 .cache
 .terraform*
 .config

nativelink-config/src/stores.rs

@@ -72,12 +72,33 @@ pub enum StoreSpec {
     ///     "delay": 0.3,
     ///     "jitter": 0.5
     ///   },
-    ///   "multipart_max_concurrent_uploads": 10
+    ///   "max_concurrent_uploads": 10
     /// }
     /// ```
     ///
     experimental_s3_store(S3Spec),
 
+    /// GCS store will use Google's GCS service as a backend to store
+    /// the files. This configuration can be used to share files
+    /// across multiple instances.
+    ///
+    /// **Example JSON Config:**
+    /// ```json
+    /// "experimental_gcs_store": {
+    ///   "project_id": "sample-project",
+    ///   "bucket": "test-bucket",
+    ///   "key_prefix": "test-prefix-index/",
+    ///   "retry": {
+    ///     "max_retries": 6,
+    ///     "delay": 0.3,
+    ///     "jitter": 0.5
+    ///   },
+    ///   "multipart_max_concurrent_uploads": 10
+    /// }
+    /// ```
+    ///
+    experimental_gcs_store(GcsSpec),
+
     /// Verify store is used to apply verifications to an underlying
     /// store implementation. It is strongly encouraged to validate
     /// as much data as you can before accepting data from a client,
@@ -787,6 +808,78 @@ pub struct S3Spec {
     pub disable_http2: bool,
 }
 
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
+#[serde(deny_unknown_fields)]
+pub struct GcsSpec {
+    /// Project ID for the GCS service
+    #[serde(default, deserialize_with = "convert_string_with_shellexpand")]
+    pub project_id: String,
+
+    /// Bucket name to use as the backend
+    #[serde(default, deserialize_with = "convert_string_with_shellexpand")]
+    pub bucket: String,
+
+    /// If you wish to prefix the location in GCS. If None, no prefix will be used.
+    #[serde(default)]
+    pub key_prefix: Option<String>,
+
+    /// Retry configuration to use when a network request fails.
+    #[serde(default)]
+    pub retry: Retry,
+
+    /// If the number of seconds since the `last_modified` time of the object
+    /// is greater than this value, the object will not be considered
+    /// "existing". This allows for external tools to delete objects that
+    /// have not been uploaded in a long time. If a client receives a `NotFound`
+    /// the client should re-upload the object.
+    ///
+    /// There should be sufficient buffer time between how long the expiration
+    /// configuration of the external tool is and this value. Keeping items
+    /// around for a few days is generally a good idea.
+    ///
+    /// Default: 0. Zero means never consider an object expired.
+    #[serde(default, deserialize_with = "convert_duration_with_shellexpand")]
+    pub consider_expired_after_s: u32,
+
+    /// The maximum buffer size to retain in case of a retryable error
+    /// during upload. Setting this to zero will disable upload buffering;
+    /// this means that in the event of a failure during upload, the entire
+    /// upload will be aborted and the client will likely receive an error.
+    ///
+    /// Default: 5MB.
+    pub max_retry_buffer_per_request: Option<usize>,
+
+    /// Size of chunks for resumeable uploads (in bytes).
+    /// Must be a multiple of 256 KB.
+    ///
+    /// Default: 8MB.
+    pub resumable_chunk_size: Option<usize>,
+
+    /// Maximum number of concurrent uploads for resumable operations
+    ///
+    /// Default: 10.
+    pub max_concurrent_uploads: Option<usize>,
+
+    /// Optional endpoint override for testing
+    /// Example: "localhost:8080" for local development
+    ///
+    /// Default: None (uses production GCS endpoint)
+    #[serde(default)]
+    pub endpoint: Option<String>,
+
+    /// Allow unencrypted HTTP connections. Only use this for local testing.
+    ///
+    /// Default: false
+    #[serde(default)]
+    pub insecure_allow_http: bool,
+
+    /// Disable http/2 connections and only use http/1.1.
+    ///
+    /// Default: false
+    #[serde(default)]
+    pub disable_http2: bool,
+}
+
 #[allow(non_camel_case_types)]
 #[derive(Serialize, Deserialize, Debug, Clone, Copy)]
 pub enum StoreType {

nativelink-store/BUILD.bazel

@@ -31,6 +31,7 @@ rust_library(
         "src/size_partitioning_store.rs",
         "src/store_manager.rs",
         "src/verify_store.rs",
+        "src/gcs_store.rs",
     ],
     proc_macro_deps = [
         "@crates//:async-trait",
@@ -52,9 +53,11 @@ rust_library(
         "@crates//:bytes",
         "@crates//:bytes-utils",
         "@crates//:const_format",
+        "@crates//:crc32c",
         "@crates//:filetime",
         "@crates//:fred",
         "@crates//:futures",
+        "@crates//:googleapis-tonic-google-storage-v2",
         "@crates//:hex",
         "@crates//:http-body",
         "@crates//:hyper-0.14.31",
@@ -70,6 +73,7 @@ rust_library(
         "@crates//:tokio-util",
         "@crates//:tonic",
         "@crates//:tracing",
+        "@crates//:urlencoding",
         "@crates//:uuid",
     ],
 )

nativelink-store/Cargo.toml

@@ -24,6 +24,7 @@ byteorder = { version = "1.5.0", default-features = false }
 bytes = { version = "1.9.0", default-features = false }
 bytes-utils = { version = "0.1.4", default-features = false }
 const_format = { version = "0.2.34", default-features = false }
+crc32c = "0.6.8"
 filetime = "0.2.25"
 fred = { version = "10.0.1", default-features = false, features = [
   "i-std",
@@ -38,6 +39,7 @@ fred = { version = "10.0.1", default-features = false, features = [
   "sentinel-auth",
   "subscriber-client",
 ] }
+googleapis-tonic-google-storage-v2 = "0.17.0"
 patricia_tree = { version = "0.8.0", default-features = false }
 futures = { version = "0.3.31", default-features = false }
 hex = { version = "0.4.3", default-features = false }
@@ -54,9 +56,10 @@ serde = { version = "1.0.216", default-features = false }
 tokio = { version = "1.42.0", features = ["fs", "rt-multi-thread", "signal", "io-util"], default-features = false }
 tokio-stream = { version = "0.1.17", features = ["fs"], default-features = false }
 tokio-util = { version = "0.7.13" }
-tonic = { version = "0.12.3", features = ["transport", "tls"], default-features = false }
+tonic = { version = "0.12.3", features = ["transport", "tls", "tls-native-roots"], default-features = false }
 tracing = { version = "0.1.41", default-features = false }
 uuid = { version = "1.11.0", default-features = false, features = ["v4", "serde"] }
+urlencoding = "2.1.3"
 
 [dev-dependencies]
 nativelink-macro = { path = "../nativelink-macro" }

nativelink-store/src/default_store_factory.rs

@@ -29,6 +29,7 @@ use crate::dedup_store::DedupStore;
 use crate::existence_cache_store::ExistenceCacheStore;
 use crate::fast_slow_store::FastSlowStore;
 use crate::filesystem_store::FilesystemStore;
+use crate::gcs_store::GcsStore;
 use crate::grpc_store::GrpcStore;
 use crate::memory_store::MemoryStore;
 use crate::noop_store::NoopStore;
@@ -51,6 +52,7 @@ pub fn store_factory<'a>(
         let store: Arc<dyn StoreDriver> = match backend {
             StoreSpec::memory(spec) => MemoryStore::new(spec),
             StoreSpec::experimental_s3_store(spec) => S3Store::new(spec, SystemTime::now).await?,
+            StoreSpec::experimental_gcs_store(spec) => GcsStore::new(spec, SystemTime::now).await?,
             StoreSpec::redis_store(spec) => RedisStore::new(spec.clone())?,
             StoreSpec::verify(spec) => VerifyStore::new(
                 spec,