storage: introduce new backend localdisk in nydusd

Cargo.toml

@@ -68,6 +68,7 @@ nydus-rafs = { version = "0.2.0", path = "rafs", features = [
     "backend-oss",
     "backend-s3",
     "backend-http-proxy",
+    "backend-localdisk",
 ] }
 nydus-storage = { version = "0.6.0", path = "storage" }
 nydus-utils = { version = "0.4.0", path = "utils" }

api/src/config.rs

@@ -239,6 +239,8 @@ pub struct BackendConfigV2 {
     /// Type of storage backend.
     #[serde(rename = "type")]
     pub backend_type: String,
+    /// Configuration for local disk backend.
+    pub localdisk: Option<LocalDiskConfig>,
     /// Configuration for local filesystem backend.
     pub localfs: Option<LocalFsConfig>,
     /// Configuration for OSS backend.
@@ -255,6 +257,14 @@ impl BackendConfigV2 {
     /// Validate storage backend configuration.
     pub fn validate(&self) -> bool {
         match self.backend_type.as_str() {
+            "localdisk" => match self.localdisk.as_ref() {
+                Some(v) => {
+                    if v.device_path.is_empty() {
+                        return false;
+                    }
+                }
+                None => return false,
+            },
             "localfs" => match self.localfs.as_ref() {
                 Some(v) => {
                     if v.blob_file.is_empty() && v.dir.is_empty() {
@@ -315,6 +325,17 @@ impl BackendConfigV2 {
         true
     }
 
+    /// Get configuration information for localdisk
+    pub fn get_localdisk_config(&self) -> Result<&LocalDiskConfig> {
+        if &self.backend_type != "localdisk" {
+            Err(einval!("backend type is not 'localdisk'"))
+        } else {
+            self.localdisk
+                .as_ref()
+                .ok_or_else(|| einval!("no configuration information for localdisk"))
+        }
+    }
+
     /// Get configuration information for localfs
     pub fn get_localfs_config(&self) -> Result<&LocalFsConfig> {
         if &self.backend_type != "localfs" {
@@ -371,6 +392,14 @@ impl BackendConfigV2 {
     }
 }
 
+/// Configuration information for localdisk storage backend.
+#[derive(Clone, Debug, Default, Deserialize, Eq, PartialEq, Serialize)]
+pub struct LocalDiskConfig {
+    /// Mounted block device path or original localdisk image file path.
+    #[serde(default)]
+    pub device_path: String,
+}
+
 /// Configuration information for localfs storage backend.
 #[derive(Clone, Debug, Default, Deserialize, Eq, PartialEq, Serialize)]
 pub struct LocalFsConfig {
@@ -962,7 +991,7 @@ struct BackendConfig {
     #[serde(rename = "type")]
     pub backend_type: String,
     /// Configuration for storage backend.
-    /// Possible value: `LocalFsConfig`, `RegistryConfig`, `OssConfig`.
+    /// Possible value: `LocalFsConfig`, `RegistryConfig`, `OssConfig`, `LocalDiskConfig`.
     #[serde(rename = "config")]
     pub backend_config: Value,
 }
@@ -973,6 +1002,7 @@ impl TryFrom<&BackendConfig> for BackendConfigV2 {
     fn try_from(value: &BackendConfig) -> std::result::Result<Self, Self::Error> {
         let mut config = BackendConfigV2 {
             backend_type: value.backend_type.clone(),
+            localdisk: None,
             localfs: None,
             oss: None,
             s3: None,
@@ -981,6 +1011,9 @@ impl TryFrom<&BackendConfig> for BackendConfigV2 {
         };
 
         match value.backend_type.as_str() {
+            "localdisk" => {
+                config.localdisk = Some(serde_json::from_value(value.backend_config.clone())?);
+            }
             "localfs" => {
                 config.localfs = Some(serde_json::from_value(value.backend_config.clone())?);
             }
@@ -1200,7 +1233,7 @@ pub(crate) struct BlobCacheEntryConfig {
     backend_type: String,
     /// Configuration for storage backend, corresponding to `FactoryConfig::BackendConfig::backend_config`.
     ///
-    /// Possible value: `LocalFsConfig`, `RegistryConfig`, `OssConfig`.
+    /// Possible value: `LocalFsConfig`, `RegistryConfig`, `OssConfig`, `LocalDiskConfig`.
     backend_config: Value,
     /// Type of blob cache, corresponding to `FactoryConfig::CacheConfig::cache_type`.
     ///
@@ -1456,6 +1489,15 @@ mod tests {
         assert_eq!(config.alt_dirs, vec!["dir1", "dir2"]);
     }
 
+    #[test]
+    fn test_localdisk_config() {
+        let content = r#"{
+            "device_path": "device_path"
+        }"#;
+        let config: LocalDiskConfig = serde_json::from_str(content).unwrap();
+        assert_eq!(config.device_path, "device_path");
+    }
+
     #[test]
     fn test_backend_config() {
         let config = BackendConfig {

blobfs/Cargo.toml

@@ -32,6 +32,7 @@ baekend-s3 = ["nydus-rafs/backend-s3"]
 backend-oss = ["nydus-rafs/backend-oss"]
 backend-registry = ["nydus-rafs/backend-registry"]
 backend-http-proxy = ["nydus-rafs/backend-http-proxy"]
+backend-localdisk = ["nydus-rafs/backend-localdisk"]
 
 [package.metadata.docs.rs]
 all-features = true

clib/Cargo.toml

@@ -24,3 +24,4 @@ baekend-s3 = ["nydus-rafs/backend-s3"]
 backend-oss = ["nydus-rafs/backend-oss"]
 backend-registry = ["nydus-rafs/backend-registry"]
 backend-http-proxy = ["nydus-rafs/backend-http-proxy"]
+backend-localdisk = ["nydus-rafs/backend-localdisk"]

docs/nydusd.md

@@ -151,6 +151,31 @@ We are working on enabling cloud-hypervisor support for nydus.
 }
 ```
 
+##### Localdisk Backend (Experimental)
+Using this backend enables Nydus to support reading blobs from block devices. This feature will be useful in Confidential Computing or Hybrid Image scenarios.
+
+The localdisk backend adds support for storing images in disks. In this scenario, each layer of the blob is stored in partitions, and multiple partitions are addressed in the local raw disk via the GUID partition table (GPT), which means that this disk stores the entire image.
+
+Currently, generating a localdisk image through nydusify is not supported for the time being. You need to use the nydus-localdisk tool to complete this step.
+Document located at: https://github.com/adamqqqplay/nydus-localdisk/blob/master/README.md
+
+```
+{
+  "device": {
+    "backend": {
+      "type": "localdisk",
+      "config": {
+        // Mounted block device path or original localdisk image file path.
+        "device_path": "/dev/loop1"
+        //"device_path": "/home/user/ubuntu.img"
+      }
+    },
+    ...
+  },
+  ...
+}
+```
+
 ##### OSS backend with blobcache
 
 ```

rafs/Cargo.toml

@@ -43,6 +43,7 @@ backend-oss = ["nydus-storage/backend-oss"]
 backend-s3 = ["nydus-storage/backend-s3"]
 backend-registry = ["nydus-storage/backend-registry"]
 backend-http-proxy = ["nydus-storage/backend-http-proxy"]
+backend-localdisk = ["nydus-storage/backend-localdisk"]
 
 [package.metadata.docs.rs]
 all-features = true

storage/Cargo.toml

@@ -33,6 +33,7 @@ tokio = { version = "1.19.0", features = ["macros", "rt", "rt-multi-thread", "sy
 url = { version = "2.1.1", optional = true }
 vm-memory = "0.9"
 fuse-backend-rs = "0.10"
+gpt = { version = "3.0.0", optional = true }
 
 nydus-api = { version = "0.2", path = "../api" }
 nydus-utils = { version = "0.4", path = "../utils", features = ["zran"] }
@@ -45,6 +46,7 @@ tar = "0.4.38"
 regex = "1.7.0"
 
 [features]
+backend-localdisk = ["gpt"]
 backend-localfs = []
 backend-oss = ["base64", "httpdate", "hmac", "sha1", "reqwest", "url"]
 backend-registry = ["base64", "reqwest", "url"]

storage/README.md

@@ -1,7 +1,7 @@
 # nydus-storage
 
 The core storage subsystem for [Nydus Image Service](https://nydus.dev/) to:
-- Fetch blob objects from storage backend such as Registry, OSS, S3 and file systems etc.
+- Fetch blob objects from storage backend such as Registry, OSS, S3, local disk and file systems etc.
 - Load data from storage backend on demand.
 - Cache blob objects on local storage.