完善对ctr的包装

app/src/handlers.rs

@@ -10,7 +10,8 @@ pub async fn create_container(
 ) -> impl Responder {
     let cid = info.container_id.clone();
     let image = info.image.clone();
-    service.create_container(image, cid).await;
+    let ns = info.ns.clone();
+    service.create_container(&image, &cid, &ns).await.unwrap();
     HttpResponse::Ok().json("Container created successfully!")
 }
 
@@ -20,12 +21,18 @@ pub async fn remove_container(
     info: web::Json<RemoveContainerInfo>,
 ) -> impl Responder {
     let container_id = info.container_id.clone();
-    service.remove_container(container_id).await;
+    let ns = info.ns.clone();
+    service.remove_container(&container_id, &ns).await.unwrap();
     HttpResponse::Ok().json("Container removed successfully!")
 }
 
-pub async fn get_container_list(service: web::Data<Arc<Service>>) -> impl Responder {
-    let container_list = service.get_container_list().await.unwrap();
+/// 获取容器列表
+pub async fn get_container_list(
+    service: web::Data<Arc<Service>>,
+    info: web::Json<GetContainerListQuery>,
+) -> impl Responder {
+    let ns = info.ns.clone();
+    let container_list = service.get_container_list(&ns).await.unwrap();
     HttpResponse::Ok().json(container_list)
 }
 

app/src/types.rs

@@ -4,14 +4,17 @@ use serde::{Deserialize, Serialize};
 pub struct CreateContainerInfo {
     pub container_id: String,
     pub image: String,
+    pub ns: String,
 }
 
 #[derive(Serialize, Deserialize)]
 pub struct RemoveContainerInfo {
     pub container_id: String,
+    pub ns: String,
 }
 
 #[derive(Deserialize)]
 pub struct GetContainerListQuery {
     pub status: Option<String>,
+    pub ns: String,
 }

service/Cargo.toml

@@ -11,4 +11,7 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 log = "0.4"
 env_logger = "0.10"
-prost-types = "0.13.4"
+prost-types = "0.13.4"
+oci-spec =  "0.6" 
+sha2 = "0.10"
+hex = "0.4"

service/src/lib.rs

@@ -1,25 +1,30 @@
-pub mod spec; 
+pub mod spec;
 
 use containerd_client::{
     services::v1::{
-        container::Runtime, Container, CreateContainerRequest, CreateTaskRequest,
-        DeleteContainerRequest, DeleteTaskRequest, GetImageRequest, KillRequest,
-        ListContainersRequest, ListTasksRequest, StartRequest, WaitRequest,
+        container::Runtime,
+        snapshots::{MountsRequest, PrepareSnapshotRequest},
+        Container, CreateContainerRequest, CreateTaskRequest, DeleteContainerRequest,
+        DeleteTaskRequest, GetImageRequest, KillRequest, ListContainersRequest, ListTasksRequest,
+        ReadContentRequest, StartRequest, WaitRequest,
     },
     tonic::Request,
+    types::Mount,
     with_namespace, Client,
 };
+use oci_spec::image::{Arch, ImageConfiguration, ImageIndex, ImageManifest, MediaType, Os};
 use prost_types::Any;
+use sha2::{Digest, Sha256};
+use spec::generate_spec;
 use std::{
-    collections::HashMap,
-    fs::{self, File},
+    fs,
     sync::{Arc, Mutex},
     time::Duration,
 };
 use tokio::time::timeout;
 
 // config.json,dockerhub密钥
-const DOCKER_CONFIG_DIR: &str = "/var/lib/faasd/.docker/";
+// const DOCKER_CONFIG_DIR: &str = "/var/lib/faasd/.docker/";
 // 命名空间（容器的）
 const NAMESPACE: &str = "default";
 
@@ -37,21 +42,59 @@ impl Service {
         })
     }
 
-    pub async fn create_container(&self, image: String, cid: String) {
-        let spec = include_str!("../../container_spec.json").to_string();
+    async fn prepare_snapshot(&self, cid: &str, ns: &str) -> Result<Vec<Mount>, Err> {
+        let parent_snapshot = self.get_parent_snapshot(cid, ns).await?;
+        let req = PrepareSnapshotRequest {
+            snapshotter: "overlayfs".to_string(),
+            key: cid.to_string(),
+            parent: parent_snapshot,
+            ..Default::default()
+        };
+        let resp = self
+            .client
+            .lock()
+            .unwrap()
+            .snapshots()
+            .prepare(with_namespace!(req, ns))
+            .await?
+            .into_inner()
+            .mounts;
+
+        Ok(resp)
+    }
+
+    pub async fn create_container(
+        &self,
+        image_name: &str,
+        cid: &str,
+        ns: &str,
+    ) -> Result<(), Err> {
+        let namespace = match ns {
+            "" => spec::DEFAULT_NAMESPACE,
+            _ => ns,
+        };
+
+        let _mount = self.prepare_snapshot(cid, ns).await?;
+
+        let spec_path = generate_spec(&cid, ns).unwrap();
+        let spec = fs::read_to_string(spec_path).unwrap();
+
         let spec = Any {
             type_url: "types.containerd.io/opencontainers/runtime-spec/1/Spec".to_string(),
             value: spec.into_bytes(),
         };
+
         let mut containers_client = self.client.lock().unwrap().containers();
         let container = Container {
             id: cid.to_string(),
-            image,
+            image: image_name.to_string(),
             runtime: Some(Runtime {
                 name: "io.containerd.runc.v2".to_string(),
                 options: None,
             }),
             spec: Some(spec),
+            snapshotter: "overlayfs".to_string(),
+            snapshot_key: cid.to_string(),
             ..Default::default()
         };
 
@@ -59,38 +102,49 @@ impl Service {
             container: Some(container),
         };
 
-        let req = with_namespace!(req, NAMESPACE);
+        let req = with_namespace!(req, namespace);
 
         let _resp = containers_client
             .create(req)
             .await
             .expect("Failed to create container");
 
-        println!("Container: {:?} created", cid);
+        // println!("Container: {:?} created", cid);
+        Ok(())
     }
 
-    pub async fn remove_container(&self, container_id: String) {
+    pub async fn remove_container(&self, cid: &str, ns: &str) -> Result<(), Err> {
+        let namespace = match ns {
+            "" => NAMESPACE,
+            _ => ns,
+        };
         let c = self.client.lock().unwrap();
-        let mut containers_client = c.containers();
-        let request = Request::new(ListContainersRequest {
+        let request = ListContainersRequest {
             ..Default::default()
-        });
+        };
+        let mut cc = c.containers();
 
-        let responce = containers_client.list(request).await.unwrap().into_inner();
+        let responce = cc
+            .list(with_namespace!(request, namespace))
+            .await?
+            .into_inner();
         let container = responce
             .containers
             .iter()
-            .find(|container| container.id == container_id);
+            .find(|container| container.id == cid);
 
         if let Some(container) = container {
-            let mut tasks_client = c.tasks();
+            let mut tc = c.tasks();
 
-            let request = Request::new(ListTasksRequest {
-                filter: format!("container=={}", container_id),
+            let request = ListTasksRequest {
+                filter: format!("container=={}", cid),
                 ..Default::default()
-            });
-            let responce = tasks_client.list(request).await.unwrap().into_inner();
-            drop(tasks_client);
+            };
+            let responce = tc
+                .list(with_namespace!(request, namespace))
+                .await?
+                .into_inner();
+            drop(tc);
             if let Some(task) = responce
                 .tasks
                 .iter()
@@ -104,79 +158,104 @@ impl Service {
                 // TASK_EXITED (4) — 任务已退出
                 // TASK_PAUSED (5) — 任务已暂停
                 // TASK_FAILED (6) — 任务失败
-                self.delete_task(&task.container_id).await;
+                self.delete_task(&task.container_id, ns).await;
             }
 
             let delete_request = DeleteContainerRequest {
                 id: container.id.clone(),
                 ..Default::default()
             };
-            let delete_request = with_namespace!(delete_request, NAMESPACE);
 
-            let _ = containers_client
-                .delete(delete_request)
+            let _ = cc
+                .delete(with_namespace!(delete_request, namespace))
                 .await
                 .expect("Failed to delete container");
 
-            println!("Container: {:?} deleted", containers_client);
+            // println!("Container: {:?} deleted", cc);
         } else {
             todo!("Container not found");
         }
-        drop(containers_client);
+        drop(cc);
+        Ok(())
     }
 
-    pub async fn create_and_start_task(&self, container_id: String) {
-        let tmp = std::env::temp_dir().join("containerd-client-test");
-        println!("Temp dir: {:?}", tmp);
-        fs::create_dir_all(&tmp).expect("Failed to create temp directory");
-        let stdin = tmp.join("stdin");
-        let stdout = tmp.join("stdout");
-        let stderr = tmp.join("stderr");
-        File::create(&stdin).expect("Failed to create stdin");
-        File::create(&stdout).expect("Failed to create stdout");
-        File::create(&stderr).expect("Failed to create stderr");
+    pub async fn create_and_start_task(&self, cid: &str, ns: &str) -> Result<(), Err> {
+        // let tmp = std::env::temp_dir().join("containerd-client-test");
+        // println!("Temp dir: {:?}", tmp);
+        // fs::create_dir_all(&tmp).expect("Failed to create temp directory");
+        // let stdin = tmp.join("stdin");
+        // let stdout = tmp.join("stdout");
+        // let stderr = tmp.join("stderr");
+        // File::create(&stdin).expect("Failed to create stdin");
+        // File::create(&stdout).expect("Failed to create stdout");
+        // File::create(&stderr).expect("Failed to create stderr");
 
-        let mut tasks_client = self.client.lock().unwrap().tasks();
+        let namespace = match ns {
+            "" => spec::DEFAULT_NAMESPACE,
+            _ => ns,
+        };
+        self.create_task(cid, namespace).await?;
+        self.start_task(cid, namespace).await?;
+        Ok(())
+    }
 
+    async fn create_task(&self, cid: &str, ns: &str) -> Result<(), Err> {
+        let c = self.client.lock().unwrap();
+        let mut sc = c.snapshots();
+        let req = MountsRequest {
+            snapshotter: "overlayfs".to_string(),
+            key: cid.to_string(),
+        };
+        let mounts = sc
+            .mounts(with_namespace!(req, ns))
+            .await?
+            .into_inner()
+            .mounts;
+        drop(sc);
+        let mut tc = c.tasks();
         let req = CreateTaskRequest {
-            container_id: container_id.clone(),
-            stdin: stdin.to_str().unwrap().to_string(),
-            stdout: stdout.to_str().unwrap().to_string(),
-            stderr: stderr.to_str().unwrap().to_string(),
+            container_id: cid.to_string(),
+            rootfs: mounts,
             ..Default::default()
         };
-        let req = with_namespace!(req, NAMESPACE);
+        let _resp = tc.create(with_namespace!(req, ns)).await?;
 
-        let _resp = tasks_client
-            .create(req)
-            .await
-            .expect("Failed to create task");
-
-        println!("Task: {:?} created", container_id);
-
-        let req = StartRequest {
-            container_id: container_id.to_string(),
-            ..Default::default()
-        };
-        let req = with_namespace!(req, NAMESPACE);
-
-        let _resp = tasks_client.start(req).await.expect("Failed to start task");
-
-        println!("Task: {:?} started", container_id);
+        Ok(())
     }
 
-    pub async fn kill_task(&self, container_id: String) {
-        let mut tasks_client = self.client.lock().unwrap().tasks();
-        let kill_request = Request::new(KillRequest {
-            container_id: container_id.to_string(),
+    async fn start_task(&self, cid: &str, ns: &str) -> Result<(), Err> {
+        let req = StartRequest {
+            container_id: cid.to_string(),
+            ..Default::default()
+        };
+        let _resp = self
+            .client
+            .lock()
+            .unwrap()
+            .tasks()
+            .start(with_namespace!(req, ns))
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn kill_task(&self, cid: String, ns: &str) -> Result<(), Err> {
+        let namespace = match ns {
+            "" => NAMESPACE,
+            _ => ns,
+        };
+        let mut c = self.client.lock().unwrap().tasks();
+        let kill_request = KillRequest {
+            container_id: cid.to_string(),
             signal: 15,
             all: true,
             ..Default::default()
-        });
-        tasks_client
-            .kill(kill_request)
+        };
+        c.kill(with_namespace!(kill_request, namespace))
             .await
             .expect("Failed to kill task");
+
+        Ok(())
     }
     pub async fn pause_task() {
         todo!()
@@ -184,62 +263,74 @@ impl Service {
     pub async fn resume_task() {
         todo!()
     }
-    pub async fn delete_task(&self, container_id: &str) {
+    pub async fn delete_task(&self, cid: &str, ns: &str) {
+        let namespace = match ns {
+            "" => NAMESPACE,
+            _ => ns,
+        };
+        let mut c = self.client.lock().unwrap().tasks();
         let time_out = Duration::from_secs(30);
-        let mut tc = self.client.lock().unwrap().tasks();
         let wait_result = timeout(time_out, async {
-            let wait_request = Request::new(WaitRequest {
-                container_id: container_id.to_string(),
+            let wait_request = WaitRequest {
+                container_id: cid.to_string(),
                 ..Default::default()
-            });
+            };
 
-            let _ = tc.wait(wait_request).await?;
+            let _ = c.wait(with_namespace!(wait_request, namespace)).await?;
             Ok::<(), Err>(())
         })
         .await;
 
-        let kill_request = Request::new(KillRequest {
-            container_id: container_id.to_string(),
+        let kill_request = KillRequest {
+            container_id: cid.to_string(),
             signal: 15,
             all: true,
             ..Default::default()
-        });
-        tc.kill(kill_request).await.expect("Failed to kill task");
+        };
+        c.kill(with_namespace!(kill_request, namespace))
+            .await
+            .expect("Failed to kill task");
 
         match wait_result {
             Ok(Ok(_)) => {
                 let req = DeleteTaskRequest {
-                    container_id: container_id.to_string(),
+                    container_id: cid.to_string(),
                 };
-                let req = with_namespace!(req, NAMESPACE);
 
-                let _resp = tc.delete(req).await.expect("Failed to delete task");
-                println!("Task: {:?} deleted", container_id);
+                let _resp = c
+                    .delete(with_namespace!(req, namespace))
+                    .await
+                    .expect("Failed to delete task");
+                println!("Task: {:?} deleted", cid);
             }
             _ => {
-                let kill_request = Request::new(KillRequest {
-                    container_id: container_id.to_string(),
+                let kill_request = KillRequest {
+                    container_id: cid.to_string(),
                     signal: 9,
                     all: true,
                     ..Default::default()
-                });
-                tc.kill(kill_request)
+                };
+                c.kill(with_namespace!(kill_request, namespace))
                     .await
                     .expect("Failed to FORCE kill task");
             }
         }
     }
 
-    pub async fn get_container_list(&self) -> Result<Vec<String>, tonic::Status> {
-        let mut cc = self.client.lock().unwrap().containers();
+    pub async fn get_container_list(&self, ns: &str) -> Result<Vec<String>, tonic::Status> {
+        let namespace = match ns {
+            "" => NAMESPACE,
+            _ => ns,
+        };
+        let mut c = self.client.lock().unwrap().containers();
 
         let request = ListContainersRequest {
             ..Default::default()
         };
 
-        let request = with_namespace!(request, NAMESPACE);
+        let request = with_namespace!(request, namespace);
 
-        let response = cc.list(request).await?;
+        let response = c.list(request).await?;
 
         Ok(response
             .into_inner()
@@ -249,7 +340,9 @@ impl Service {
             .collect())
     }
 
-    pub async fn get_task_list() {}
+    pub async fn get_task_list() {
+        todo!()
+    }
 
     pub fn prepare_image(&self) {
         todo!()
@@ -261,6 +354,174 @@ impl Service {
     pub fn get_resolver(&self) {
         todo!()
     }
+
+    async fn handle_index(&self, data: &Vec<u8>, ns: &str) -> Option<ImageConfiguration> {
+        let image_index: ImageIndex = ::serde_json::from_slice(&data).unwrap();
+        let img_manifest_dscr = image_index
+            .manifests()
+            .iter()
+            .find(|manifest_entry| match manifest_entry.platform() {
+                Some(p) => {
+                    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+                    {
+                        matches!(p.architecture(), &Arch::Amd64) && matches!(p.os(), &Os::Linux)
+                    }
+                    #[cfg(target_arch = "aarch64")]
+                    {
+                        matches!(p.architecture(), &Arch::ARM64) && matches!(p.os(), Os::Linux)
+                        //&& matches!(p.variant().as_ref().map(|s| s.as_str()), Some("v8"))
+                    }
+                }
+                None => false,
+            })
+            .unwrap();
+
+        let req = ReadContentRequest {
+            digest: img_manifest_dscr.digest().to_owned(),
+            offset: 0,
+            size: 0,
+        };
+
+        let mut c = self.client.lock().unwrap().content();
+        let resp = c
+            .read(with_namespace!(req, ns))
+            .await
+            .expect("Failed to read content")
+            .into_inner()
+            .message()
+            .await
+            .expect("Failed to read content message")
+            .unwrap()
+            .data;
+
+        self.handle_manifest(&resp, ns).await
+    }
+
+    async fn handle_manifest(&self, data: &Vec<u8>, ns: &str) -> Option<ImageConfiguration> {
+        let img_manifest: ImageManifest = ::serde_json::from_slice(&data).unwrap();
+        let img_manifest_dscr = img_manifest.config();
+
+        let req = ReadContentRequest {
+            digest: img_manifest_dscr.digest().to_owned(),
+            offset: 0,
+            size: 0,
+        };
+        let mut c = self.client.lock().unwrap().content();
+
+        let resp = c
+            .read(with_namespace!(req, ns))
+            .await
+            .unwrap()
+            .into_inner()
+            .message()
+            .await
+            .unwrap()
+            .unwrap()
+            .data;
+
+        ::serde_json::from_slice(&resp).unwrap()
+    }
+
+    pub async fn get_img_config(&self, name: &str, ns: &str) -> Option<ImageConfiguration> {
+        let mut c = self.client.lock().unwrap().images();
+
+        let req = GetImageRequest {
+            name: name.to_string(),
+        };
+        let resp = c
+            .get(with_namespace!(req, ns))
+            .await
+            .map_err(|e| {
+                eprintln!(
+                    "Failed to get the config of {} in namespace {}: {}",
+                    name, ns, e
+                );
+                e
+            })
+            .ok()?
+            .into_inner();
+
+        let img_dscr = resp.image?.target?;
+        let media_type = MediaType::from(img_dscr.media_type.as_str());
+
+        let req = ReadContentRequest {
+            digest: img_dscr.digest,
+            ..Default::default()
+        };
+
+        let mut c = self.client.lock().unwrap().content();
+
+        let resp = c
+            .read(with_namespace!(req, ns))
+            .await
+            .map_err(|e| {
+                eprintln!(
+                    "Failed to read content for {} in namespace {}: {}",
+                    name, ns, e
+                );
+                e
+            })
+            .ok()?
+            .into_inner()
+            .message()
+            .await
+            .map_err(|e| {
+                eprintln!(
+                    "Failed to read message for {} in namespace {}: {}",
+                    name, ns, e
+                );
+                e
+            })
+            .ok()?
+            .ok_or_else(|| {
+                eprintln!("No data found for {} in namespace {}", name, ns);
+                std::io::Error::new(std::io::ErrorKind::NotFound, "No data found")
+            })
+            .ok()?
+            .data;
+
+        let img_config = match media_type {
+            MediaType::ImageIndex => self.handle_index(&resp, ns).await.unwrap(),
+            MediaType::ImageManifest => self.handle_manifest(&resp, ns).await.unwrap(),
+            MediaType::Other(media_type) => match media_type.as_str() {
+                "application/vnd.docker.distribution.manifest.list.v2+json" => {
+                    self.handle_index(&resp, ns).await.unwrap()
+                }
+                "application/vnd.docker.distribution.manifest.v2+json" => {
+                    self.handle_manifest(&resp, ns).await.unwrap()
+                }
+                _ => {
+                    eprintln!("Unexpected media type '{}'", media_type);
+                    return None;
+                }
+            },
+            _ => {
+                eprintln!("Unexpected media type '{}'", media_type);
+                return None;
+            }
+        };
+        Some(img_config)
+    }
+
+    async fn get_parent_snapshot(&self, name: &str, ns: &str) -> Result<String, Err> {
+        let img_config = self.get_img_config(name, ns).await.unwrap();
+
+        let mut iter = img_config.rootfs().diff_ids().iter();
+        let mut ret = iter
+            .next()
+            .map_or_else(String::new, |layer_digest| layer_digest.clone());
+
+        while let Some(layer_digest) = iter.next() {
+            let mut hasher = Sha256::new();
+            hasher.update(ret.as_bytes());
+            ret.push_str(&format!(",{}", layer_digest));
+            hasher.update(" ");
+            hasher.update(layer_digest);
+            let digest = ::hex::encode(hasher.finalize());
+            ret = format!("sha256:{digest}");
+        }
+        Ok(ret)
+    }
 }
 //容器是容器，要先启动，然后才能运行任务
 //要想删除一个正在运行的Task，必须先kill掉这个task，然后才能删除。

service/src/spec.rs

@@ -9,95 +9,100 @@ const VERSION_DEV: &str = ""; // 对应开发分支
 
 const RWM: &str = "rwm";
 const DEFAULT_ROOTFS_PATH: &str = "rootfs";
+pub const DEFAULT_NAMESPACE: &str = "default";
+const PATH_TO_SPEC_PREFIX: &str = "/tmp/containerd-spec";
 
-const DEFAULT_UNIX_ENV:&str="PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin";
+// const DEFAULT_UNIX_ENV: &str = "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin";
 
 const PID_NAMESPACE: &str = "pid";
 const NETWORK_NAMESPACE: &str = "network";
 const MOUNT_NAMESPACE: &str = "mount";
 const IPC_NAMESPACE: &str = "ipc";
 const UTS_NAMESPACE: &str = "uts";
-const USER_NAMESPACE: &str = "user";
-const CGROUP_NAMESPACE: &str = "cgroup";
-const TIME_NAMESPACE: &str = "time";
-
 
 #[derive(Serialize, Deserialize, Debug)]
-struct Spec {
-    ociVersion: String,
-    root: Root,
-    process: Process,
-    linux: Linux,
-    mounts: Vec<Mount>,
+pub struct Spec {
+    #[serde(rename = "ociVersion")]
+    pub oci_version: String,
+    pub root: Root,
+    pub process: Process,
+    pub linux: Linux,
+    pub mounts: Vec<Mount>,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
-struct Root {
-    path: String,
+pub struct Root {
+    pub path: String,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
-struct Process {
-    cwd: String,
-    noNewPrivileges: bool,
-    user: User,
-    capabilities: LinuxCapabilities,
-    rlimits: Vec<POSIXRlimit>,
+pub struct Process {
+    pub cwd: String,
+    #[serde(rename = "noNewPrivileges")]
+    pub no_new_privileges: bool,
+    pub user: User,
+    pub capabilities: LinuxCapabilities,
+    pub rlimits: Vec<POSIXRlimit>,
+    pub args: Vec<String>,
+    pub env: Vec<String>,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
-struct User {
-    uid: u32,
-    gid: u32,
+pub struct User {
+    pub uid: u32,
+    pub gid: u32,
+    #[serde(rename = "additionalGids")]
+    pub additional_gids: Vec<u32>,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
-struct Mount {
-    destination: String,
-    type_: String,
-    source: String,
-    options: Vec<String>,
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-struct LinuxCapabilities {
-    bounding: Vec<String>,
-    permitted: Vec<String>,
-    effective: Vec<String>,
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-struct POSIXRlimit {
+pub struct Mount {
+    pub destination: String,
     #[serde(rename = "type")]
-    type_: String,
-    hard: u64,
-    soft: u64,
+    pub type_: String,
+    pub source: String,
+    pub options: Vec<String>,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
-struct Linux {
-    masked_paths: Vec<String>,
-    readonly_paths: Vec<String>,
-    cgroups_path: String,
-    resources: LinuxResources,
-    namespaces: Vec<LinuxNamespace>,
+pub struct LinuxCapabilities {
+    pub bounding: Vec<String>,
+    pub permitted: Vec<String>,
+    pub effective: Vec<String>,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
-struct LinuxResources {
-    devices: Vec<LinuxDeviceCgroup>,
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-struct LinuxDeviceCgroup {
-    allow: bool,
-    access: String,
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-struct LinuxNamespace {
+pub struct POSIXRlimit {
+    pub hard: u64,
+    pub soft: u64,
     #[serde(rename = "type")]
-    type_: String,
+    pub type_: String,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Linux {
+    pub masked_paths: Vec<String>,
+    pub readonly_paths: Vec<String>,
+    pub cgroups_path: String,
+    pub resources: LinuxResources,
+    pub namespaces: Vec<LinuxNamespace>,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct LinuxResources {
+    pub devices: Vec<LinuxDeviceCgroup>,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct LinuxDeviceCgroup {
+    pub allow: bool,
+    pub access: String,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct LinuxNamespace {
+    #[serde(rename = "type")]
+    pub type_: String,
 }
 
 pub fn default_unix_caps() -> Vec<String> {
@@ -252,16 +257,20 @@ fn get_version() -> String {
     )
 }
 
-fn populate_default_unix_spec(id: &str, ns: &str) -> Spec {
+pub fn populate_default_unix_spec(id: &str, ns: &str) -> Spec {
     Spec {
-        ociVersion: get_version(),
+        oci_version: get_version(),
         root: Root {
             path: DEFAULT_ROOTFS_PATH.to_string(),
         },
         process: Process {
             cwd: String::from("/"),
-            noNewPrivileges: true,
-            user: User { uid: 0, gid: 0 },
+            no_new_privileges: true,
+            user: User {
+                uid: 0,
+                gid: 0,
+                additional_gids: vec![],
+            },
             capabilities: LinuxCapabilities {
                 bounding: default_unix_caps(),
                 permitted: default_unix_caps(),
@@ -272,6 +281,8 @@ fn populate_default_unix_spec(id: &str, ns: &str) -> Spec {
                 hard: 1024,
                 soft: 1024,
             }],
+            args: vec![],
+            env: vec![],
         },
         linux: Linux {
             masked_paths: default_masked_parhs(),
@@ -280,7 +291,7 @@ fn populate_default_unix_spec(id: &str, ns: &str) -> Spec {
             resources: LinuxResources {
                 devices: vec![LinuxDeviceCgroup {
                     allow: false,
-                    access: String::from("rwm"),
+                    access: RWM.to_string(),
                 }],
             },
             namespaces: default_unix_namespaces(),
@@ -289,9 +300,19 @@ fn populate_default_unix_spec(id: &str, ns: &str) -> Spec {
     }
 }
 
-fn save_spec_to_file(spec: &Spec, path: &str) -> Result<(), std::io::Error> {
+pub fn save_spec_to_file(spec: &Spec, path: &str) -> Result<(), std::io::Error> {
     let file = File::create(path)?;
     serde_json::to_writer(file, spec)?;
     Ok(())
 }
 
+pub fn generate_spec(id: &str, ns: &str) -> Result<String, std::io::Error> {
+    let namespace = match ns {
+        "" => DEFAULT_NAMESPACE,
+        _ => ns,
+    };
+    let spec = populate_default_unix_spec(id, ns);
+    let path = format!("{}/{}/{}.json", PATH_TO_SPEC_PREFIX, namespace, id);
+    save_spec_to_file(&spec, &path)?;
+    Ok(path)
+}