feat(monocore): implement initial mc pull functionality (#132)

* feat(monocore): implement initial image pull functionality

- Add pull_image command to monocore CLI
- Implement DockerRegistry pull_image functionality
- Add stub for SandboxesRegistry pull_image
- Add monoimage module for Sandboxes Registry integration
- Update OCI reference parsing to handle digests
- Add database migrations for image and layer tracking
- Remove Lock subcommand from MonocoreSubcommand enum

* feat(moncore): implement Docker image layer extraction

- Add layer extraction functionality to save downloaded layers
- Update database schema for layer chains and configs
- Add existence checks for images and layers to prevent re-downloads
- Improve logging with more detailed information
- Remove full_json storage from configs table
- Rename layer_stacks to layer_chains for better semantics
- Make Reference struct fields settable for registry fallback

* feat(core): implement OCI layer handling and filesystem metadata management

This commit adds support for handling OCI container image layers and improves filesystem metadata management across the codebase. Key changes include:

- Add rootfs.rs module for OCI layer handling with support for:
  - Creating monofs filesystems from OCI layers
  - Merging multiple layers following OCI layer semantics
  - Handling whiteouts and opaque directories
  - Preserving Unix metadata (mode, uid, gid, timestamps)

- Refactor filesystem metadata handling:
  - Move Unix metadata constants to shared location
  - Remove redundant symlink depth tracking
  - Improve permission handling during filesystem operations
  - Filesystem metadata structure has changed with the removal of symlink_depth field

- Update dependencies:
  - Upgrade rand to 0.9.0
  - Add async-recursion workspace dependency
  - Add monofs dependency to monocore

* feat(image): implement monofs layer creation and merging for Docker images

This commit adds functionality to create and merge monofs layers from pulled Docker
container images. Key changes include:

- Add new DB functions for saving/updating image and layer CIDs
- Implement monofs layer creation from extracted OCI layers
- Add layer merging to create final rootfs from ordered layers
- Update image pulling to store CIDs and verify layer completeness
- Add helper functions for layer CID management and verification
- Add tests for Docker image pulling and nginx file verification
- Add CID error handling to MonocoreError enum

The changes enable proper storage and tracking of monofs layers in the database,
with verification of layer completeness and proper merging order.

Cargo.toml

@@ -45,12 +45,13 @@ tracing-subscriber = "0.3"
 clap = { version = "4.5", features = ["color", "derive"] }
 getset = "0.1"
 procspawn = "1.0"
-rand = "0.8"
+rand = "0.9"
 reqwest = { version = "0.12", features = ["stream", "json"] }
 reqwest-middleware = "0.3"                                        # Cannot upgrade to 0.4 due to https://github.com/TrueLayer/reqwest-middleware/issues/204
 reqwest-retry = "0.6"                                             # Cannot upgrade to 0.7 due to https://github.com/TrueLayer/reqwest-middleware/issues/204
 monoutils-store = { version = "0.2", path = "./monoutils-store" }
 monoutils = { version = "0.2", path = "./monoutils" }
+monofs = { version = "0.2", path = "./monofs" }
 multihash = "0.19"
 multihash-codetable = "0.1"
 chrono = { version = "0.4", features = ["serde"] }
@@ -65,3 +66,4 @@ pretty-error-debug = "0.3"
 serde_ipld_dagcbor = "0.6"
 sqlx = { version = "0.8", features = ["sqlite", "runtime-tokio-rustls"] }
 regex = "1.10"
+async-recursion = "1.1"

monocore/Cargo.toml

@@ -77,6 +77,9 @@ ipnetwork = { version = "0.21.0", features = ["serde"] }
 sqlx.workspace = true
 monoutils.workspace = true
 regex.workspace = true
+monoutils-store.workspace = true
+monofs.workspace = true
+async-recursion.workspace = true
 
 [dev-dependencies]
 test-log.workspace = true

monocore/bin/monocore.rs

@@ -10,14 +10,25 @@ use monocore::{
 
 #[tokio::main]
 async fn main() -> MonocoreResult<()> {
+    tracing_subscriber::fmt::init();
+
     // Parse command line arguments
     let args = MonocoreArgs::parse();
     match args.subcommand {
         Some(MonocoreSubcommand::Init { path }) => {
-            tracing::info!("Initializing monocore project...");
+            tracing::info!("Initializing monocore project: path={path:?}");
             management::init_menv(path).await?;
             tracing::info!("Successfully initialized monocore project");
         }
+        Some(MonocoreSubcommand::Pull {
+            image,
+            image_group,
+            name,
+        }) => {
+            tracing::info!("Pulling image: name={name}, image={image}, image_group={image_group}");
+            management::pull_image(name, image, image_group).await?;
+            tracing::info!("Successfully pulled image");
+        }
         Some(_) => (), // TODO: implement other subcommands
         None => {
             MonocoreArgs::command().print_help()?;