Merge pull request #194 from utam0k/refactoring/rootless-lifetime

reduce the number of clones by introducing lifetime to rootless.

src/container/builder_impl.rs

@@ -14,7 +14,7 @@ use crate::{
 
 use super::{Container, ContainerStatus};
 
-pub(super) struct ContainerBuilderImpl {
+pub(super) struct ContainerBuilderImpl<'a> {
     /// Flag indicating if an init or a tenant container should be created
     pub init: bool,
     /// Interface to operating system primitives
@@ -24,7 +24,7 @@ pub(super) struct ContainerBuilderImpl {
     /// Id of the container
     pub container_id: String,
     /// OCI complient runtime spec
-    pub spec: Spec,
+    pub spec: &'a Spec,
     /// Root filesystem of the container
     pub rootfs: PathBuf,
     /// File which will be used to communicate the pid of the
@@ -33,7 +33,7 @@ pub(super) struct ContainerBuilderImpl {
     /// Socket to communicate the file descriptor of the ptty
     pub console_socket: Option<FileDescriptor>,
     /// Options for rootless containers
-    pub rootless: Option<Rootless>,
+    pub rootless: Option<Rootless<'a>>,
     /// Path to the Unix Domain Socket to communicate container start
     pub notify_path: PathBuf,
     /// Container state
@@ -42,7 +42,7 @@ pub(super) struct ContainerBuilderImpl {
     pub preserve_fds: i32,
 }
 
-impl ContainerBuilderImpl {
+impl<'a> ContainerBuilderImpl<'a> {
     pub(super) fn create(&mut self) -> Result<()> {
         self.run_container()?;
 
@@ -58,7 +58,7 @@ impl ContainerBuilderImpl {
         let namespaces: Namespaces = linux.namespaces.clone().into();
 
         // create the parent and child process structure so the parent and child process can sync with each other
-        let (mut parent, parent_channel) = parent::ParentProcess::new(self.rootless.clone())?;
+        let (mut parent, parent_channel) = parent::ParentProcess::new(&self.rootless)?;
         let child = child::ChildProcess::new(parent_channel)?;
 
         // This init_args will be passed to the container init process,
@@ -70,7 +70,7 @@ impl ContainerBuilderImpl {
             spec: self.spec.clone(),
             rootfs: self.rootfs.clone(),
             console_socket: self.console_socket.clone(),
-            rootless: self.rootless.clone(),
+            is_rootless: self.rootless.is_some(),
             notify_path: self.notify_path.clone(),
             preserve_fds: self.preserve_fds,
             child,

src/container/init_builder.rs

@@ -72,7 +72,7 @@ impl InitContainerBuilder {
             pid_file: self.base.pid_file,
             console_socket: csocketfd,
             use_systemd: self.use_systemd,
-            spec,
+            spec: &spec,
             rootfs,
             rootless,
             notify_path,

src/container/tenant_builder.rs

@@ -111,7 +111,7 @@ impl TenantContainerBuilder {
             pid_file: self.base.pid_file,
             console_socket: csocketfd,
             use_systemd,
-            spec,
+            spec: &spec,
             rootfs,
             rootless,
             notify_path: notify_path.clone(),

src/process/init.rs

@@ -13,7 +13,6 @@ use crate::{
     notify_socket::NotifyListener,
     process::child,
     rootfs,
-    rootless::Rootless,
     stdio::FileDescriptor,
     syscall::{linux::LinuxSyscall, Syscall},
     tty, utils,
@@ -96,7 +95,7 @@ pub struct ContainerInitArgs {
     /// Socket to communicate the file descriptor of the ptty
     pub console_socket: Option<FileDescriptor>,
     /// Options for rootless containers
-    pub rootless: Option<Rootless>,
+    pub is_rootless: bool,
     /// Path to the Unix Domain Socket to communicate container start
     pub notify_path: PathBuf,
     /// File descriptos preserved/passed to the container init process.
@@ -133,7 +132,7 @@ pub fn container_init(args: ContainerInitArgs) -> Result<()> {
     // namespace will be created, check
     // https://man7.org/linux/man-pages/man7/user_namespaces.7.html for more
     // information
-    if args.rootless.is_some() {
+    if args.is_rootless {
         // child needs to be dumpable, otherwise the non root parent is not
         // allowed to write the uid/gid maps
         prctl::set_dumpable(true).unwrap();

src/process/mod.rs

@@ -12,8 +12,8 @@ pub mod parent;
 /// Used to describe type of process after fork.
 /// Parent and child processes mean the same thing as in a normal fork call
 /// InitProcess is specifically used to indicate the process which will run the command of container
-pub enum Process {
-    Parent(parent::ParentProcess),
+pub enum Process<'a> {
+    Parent(parent::ParentProcess<'a>),
     Child(child::ChildProcess),
 }
 /// Maximum event capacity of polling

src/process/parent.rs

@@ -21,22 +21,22 @@ use oci_spec::LinuxIdMapping;
 const PARENT: Token = Token(0);
 
 /// Contains receiving end of pipe to child process and a poller for that.
-pub struct ParentProcess {
-    child_channel: ChildChannel,
+pub struct ParentProcess<'a> {
+    child_channel: ChildChannel<'a>,
 }
 
 // Poll is used to register and listen for various events
 // by registering it with an event source such as receiving end of a pipe
-impl ParentProcess {
+impl<'a> ParentProcess<'a> {
     /// Create new Parent process structure
-    pub fn new(rootless: Option<Rootless>) -> Result<(Self, ParentChannel)> {
+    pub fn new(rootless: &'a Option<Rootless>) -> Result<(Self, ParentChannel)> {
         let (parent_channel, child_channel) = Self::setup_pipes(rootless)?;
         let parent = Self { child_channel };
 
         Ok((parent, parent_channel))
     }
 
-    fn setup_pipes(rootless: Option<Rootless>) -> Result<(ParentChannel, ChildChannel)> {
+    fn setup_pipes(rootless: &'a Option<Rootless>) -> Result<(ParentChannel, ChildChannel<'a>)> {
         let (send_to_parent, receive_from_child) = pipe::new()?;
         let (send_to_child, receive_from_parent) = pipe::new()?;
 
@@ -122,15 +122,15 @@ impl ParentChannel {
     }
 }
 
-struct ChildChannel {
+struct ChildChannel<'a> {
     sender: Sender,
     receiver: Receiver,
     poll: Poll,
-    rootless: Option<Rootless>,
+    rootless: &'a Option<Rootless<'a>>,
 }
 
-impl ChildChannel {
-    fn new(sender: Sender, mut receiver: Receiver, rootless: Option<Rootless>) -> Result<Self> {
+impl<'a> ChildChannel<'a> {
+    fn new(sender: Sender, mut receiver: Receiver, rootless: &'a Option<Rootless>) -> Result<Self> {
         let poll = Poll::new()?;
         poll.registry()
             .register(&mut receiver, PARENT, Interest::READABLE)?;
@@ -201,7 +201,7 @@ impl ChildChannel {
         let rootless = self.rootless.as_ref().unwrap();
         write_id_mapping(
             &format!("/proc/{}/uid_map", target_pid),
-            &rootless.uid_mappings,
+            rootless.uid_mappings,
             rootless.newuidmap.as_deref(),
         )
     }
@@ -210,7 +210,7 @@ impl ChildChannel {
         let rootless = self.rootless.as_ref().unwrap();
         write_id_mapping(
             &format!("/proc/{}/gid_map", target_pid),
-            &rootless.gid_mappings,
+            rootless.gid_mappings,
             rootless.newgidmap.as_deref(),
         )
     }

src/rootless.rs

@@ -7,24 +7,24 @@ use oci_spec::{Linux, LinuxIdMapping, Mount, Spec};
 use crate::namespaces::Namespaces;
 
 #[derive(Debug, Clone)]
-pub struct Rootless {
+pub struct Rootless<'a> {
     /// Location of the newuidmap binary
     pub newuidmap: Option<PathBuf>,
     /// Location of the newgidmap binary
     pub newgidmap: Option<PathBuf>,
     /// Mappings for user ids
-    pub uid_mappings: Vec<LinuxIdMapping>,
+    pub uid_mappings: &'a Vec<LinuxIdMapping>,
     /// Mappings for group ids
-    pub gid_mappings: Vec<LinuxIdMapping>,
+    pub gid_mappings: &'a Vec<LinuxIdMapping>,
 }
 
-impl From<&Linux> for Rootless {
-    fn from(linux: &Linux) -> Self {
+impl<'a> From<&'a Linux> for Rootless<'a> {
+    fn from(linux: &'a Linux) -> Self {
         Self {
             newuidmap: None,
             newgidmap: None,
-            uid_mappings: linux.uid_mappings.clone(),
-            gid_mappings: linux.gid_mappings.clone(),
+            uid_mappings: linux.uid_mappings.as_ref(),
+            gid_mappings: linux.gid_mappings.as_ref(),
         }
     }
 }