Initial implementation of resource-control via systemd and dbus

src/cgroups/v1/pids.rs

@@ -1,4 +1,4 @@
-use std::path::{Path};
+use std::path::Path;
 
 use anyhow::Result;
 
@@ -10,10 +10,7 @@ pub struct Pids {}
 impl Controller for Pids {
     type Resource = LinuxPids;
 
-    fn apply(
-        linux_resources: &LinuxResources,
-        cgroup_root: &Path,
-    ) -> Result<()> {
+    fn apply(linux_resources: &LinuxResources, cgroup_root: &Path) -> Result<()> {
         log::debug!("Apply pids cgroup config");
 
         if let Some(pids) = &linux_resources.pids {

src/cgroups/v1/util.rs

@@ -3,7 +3,7 @@ use std::{collections::HashMap, path::PathBuf};
 use anyhow::{anyhow, Result};
 use procfs::process::Process;
 
-use super::{ControllerType, controller_type::CONTROLLERS};
+use super::{controller_type::CONTROLLERS, ControllerType};
 
 pub fn list_subsystem_mount_points() -> Result<HashMap<ControllerType, PathBuf>> {
     let mut mount_paths = HashMap::with_capacity(CONTROLLERS.len());

src/cgroups/v2/systemd_manager.rs

@@ -261,9 +261,10 @@ mod tests {
 
     #[test]
     fn get_cgroups_path_works_with_a_complex_slice() -> Result<()> {
-        let cgroups_path =
-            SystemDCGroupManager::destructure_cgroups_path(PathBuf::from("test-a-b.slice:docker:foo"))
-                .expect("");
+        let cgroups_path = SystemDCGroupManager::destructure_cgroups_path(PathBuf::from(
+            "test-a-b.slice:docker:foo",
+        ))
+        .expect("");
 
         assert_eq!(
             SystemDCGroupManager::construct_cgroups_path(cgroups_path)?,
@@ -275,9 +276,10 @@ mod tests {
 
     #[test]
     fn get_cgroups_path_works_with_a_simple_slice() -> Result<()> {
-        let cgroups_path =
-            SystemDCGroupManager::destructure_cgroups_path(PathBuf::from("machine.slice:libpod:foo"))
-                .expect("");
+        let cgroups_path = SystemDCGroupManager::destructure_cgroups_path(PathBuf::from(
+            "machine.slice:libpod:foo",
+        ))
+        .expect("");
 
         assert_eq!(
             SystemDCGroupManager::construct_cgroups_path(cgroups_path)?,

src/dbus/client.rs

@@ -1,5 +1,8 @@
+use crate::dbus::systemd_manager::OrgFreedesktopSystemd1Manager;
 use anyhow::Result;
+use dbus::arg::{RefArg, Variant};
 use dbus::blocking::Connection;
+use oci_spec::LinuxResources;
 use std::time::Duration;
 use std::vec::Vec;
 
@@ -15,19 +18,90 @@ impl Client {
         Ok(Client { conn })
     }
 
-    /// start_unit starts a specific unit under systemd. See https://www.freedesktop.org/wiki/Software/systemd/dbus
+    /// start_transient_unit is a higher level API for starting a unit
+    /// for a specific container under systemd.
+    /// See https://www.freedesktop.org/wiki/Software/systemd/dbus
     /// for more details.
-    pub fn start_unit(&self, unit_name: &str, _properties: Vec<&str>) -> Result<()> {
+    pub fn start_transient_unit_for_container(
+        &self,
+        container_name: &str,
+        unit_name: &str,
+        linux_resources: LinuxResources,
+    ) -> Result<()> {
         let proxy = self.conn.with_proxy(
-            "org.freedesktop.systemd1.Manager",
-            "/",
+            "org.freedesktop.systemd1",
+            "/org/freedesktop/systemd1",
             Duration::from_millis(5000),
         );
-        let (_job_id,): (i32,) = proxy.method_call(
-            "org.freedesktop.systemd1.Manager",
-            "StartTransientUnit",
-            (unit_name, "replace"),
-        )?;
+
+        let mut properties = Vec::<Property>::new();
+        properties.push(
+            PropDescription::new(format!("youki container {}", container_name).as_str()).into(),
+        );
+
+        let slice = "machine.slice";
+        // if we create a slice, the parent is defined via a Wants=
+        // otherwise, we use Slice=
+        if unit_name.ends_with("slice") {
+            properties.push(PropWants::new(slice).into());
+        } else {
+            properties.push(PropSlice::new(slice).into());
+        }
+
+        proxy.start_transient_unit(unit_name, "replace", properties, vec![])?;
         Ok(())
     }
 }
+
+type Property = (&'static str, Variant<Box<dyn RefArg>>);
+
+struct PropDescription(Property);
+
+impl PropDescription {
+    fn new(desc: &str) -> Self {
+        return PropDescription((
+            "Description",
+            Variant(Box::new(desc.to_string()) as Box<dyn RefArg>),
+        ));
+    }
+}
+
+impl From<PropDescription> for Property {
+    fn from(p: PropDescription) -> Self {
+        p.0
+    }
+}
+
+struct PropWants(Property);
+
+impl PropWants {
+    fn new(unit: &str) -> Self {
+        return PropWants((
+            "Wants",
+            Variant(Box::new(unit.to_string()) as Box<dyn RefArg>),
+        ));
+    }
+}
+
+impl From<PropWants> for Property {
+    fn from(p: PropWants) -> Self {
+        p.0
+    }
+}
+
+struct PropSlice(Property);
+
+impl PropSlice {
+    fn new(slice: &str) -> Self {
+        return PropSlice((
+            "Slice",
+            Variant(Box::new(slice.to_string()) as Box<dyn RefArg>),
+        ));
+    }
+}
+
+impl From<PropSlice> for Property {
+    fn from(p: PropSlice) -> Self {
+        p.0
+    }
+}

src/dbus/mod.rs

@@ -1,2 +1,2 @@
-mod client;
-pub use client::Client;
+pub mod client;
+mod systemd_manager;