Refactor realm launching code into separate module.

libcitadel/src/realm/launcher.rs

@@ -0,0 +1,241 @@
+use std::fs;
+use std::fmt::Write;
+
+use crate::{Realm,Result};
+use std::path::{Path, PathBuf};
+use crate::realm::network::NetworkConfig;
+
+const NSPAWN_FILE_TEMPLATE: &str = "\
+[Exec]
+Boot=true
+$NETWORK_CONFIG
+
+[Files]
+BindReadOnly=/opt/share
+BindReadOnly=/storage/citadel-state/resolv.conf:/etc/resolv.conf
+
+$EXTRA_BIND_MOUNTS
+
+$EXTRA_FILE_OPTIONS
+
+";
+
+const REALM_SERVICE_TEMPLATE: &str = "\
+[Unit]
+Description=Application Image $REALM_NAME instance
+
+[Service]
+
+DevicePolicy=closed
+$DEVICE_ALLOW
+
+Environment=SYSTEMD_NSPAWN_SHARE_NS_IPC=1
+ExecStart=/usr/bin/systemd-nspawn --quiet --notify-ready=yes --keep-unit $NETNS_ARG --machine=$REALM_NAME --link-journal=auto --directory=$ROOTFS
+
+KillMode=mixed
+Type=notify
+RestartForceExitStatus=133
+SuccessExitStatus=133
+";
+
+const SYSTEMD_NSPAWN_PATH: &str = "/run/systemd/nspawn";
+const SYSTEMD_UNIT_PATH: &str = "/run/systemd/system";
+
+pub struct RealmLauncher<'a> {
+    realm: &'a Realm,
+    service: String,
+    devices: Vec<String>,
+}
+
+impl <'a> RealmLauncher <'a> {
+    pub fn new(realm: &'a Realm) -> Self {
+        let service = format!("realm-{}.service", realm.name());
+        RealmLauncher {
+            realm, service,
+            devices: Vec::new(),
+        }
+    }
+
+    fn add_devices(&mut self) {
+        let config = self.realm.config();
+
+        if config.kvm() {
+            self.add_device("/dev/kvm");
+        }
+        if config.gpu() {
+            self.add_device("/dev/dri/renderD128");
+            if config.gpu_card0() {
+                self.add_device("/dev/dri/card0");
+            }
+        }
+    }
+
+    fn add_device(&mut self, device: &str) {
+        if Path::new(device).exists() {
+            self.devices.push(device.to_string());
+        }
+    }
+
+    pub fn remove_launch_config_files(&self) -> Result<()> {
+        let nspawn_path = self.realm_nspawn_path();
+        if nspawn_path.exists() {
+            fs::remove_file(&nspawn_path)?;
+        }
+        let service_path = self.realm_service_path();
+        if service_path.exists() {
+            fs::remove_file(&service_path)?;
+        }
+        Ok(())
+    }
+
+    pub fn write_launch_config_files(&mut self, rootfs: &Path, netconfig: &mut NetworkConfig) -> Result<()> {
+        if self.devices.is_empty() {
+            self.add_devices();
+        }
+        let nspawn_path = self.realm_nspawn_path();
+        let nspawn_content = self.generate_nspawn_file(netconfig)?;
+        self.write_launch_config_file(&nspawn_path, &nspawn_content)
+            .map_err(|e| format_err!("failed to write nspawn config file {}: {}", nspawn_path.display(), e))?;
+
+        let service_path = self.realm_service_path();
+        let service_content = self.generate_service_file(rootfs);
+        self.write_launch_config_file(&service_path, &service_content)
+            .map_err(|e| format_err!("failed to write service config file {}: {}", service_path.display(), e))?;
+
+        Ok(())
+    }
+
+    pub fn realm_service_name(&self) -> &str {
+        &self.service
+    }
+
+    /// Write the string `content` to file `path`. If the directory does
+    /// not already exist, create it.
+    fn write_launch_config_file(&self, path: &Path, content: &str) -> Result<()> {
+        match path.parent() {
+            Some(parent) => {
+                if !parent.exists() {
+                    fs::create_dir_all(parent)?;
+                }
+            },
+            None => bail!("config file path {} has no parent?", path.display()),
+        };
+        fs::write(path, content)?;
+        Ok(())
+    }
+
+    fn generate_nspawn_file(&mut self, netconfig: &mut NetworkConfig) -> Result<String> {
+        Ok(NSPAWN_FILE_TEMPLATE
+            .replace("$EXTRA_BIND_MOUNTS", &self.generate_extra_bind_mounts()?)
+            .replace("$EXTRA_FILE_OPTIONS", &self.generate_extra_file_options()?)
+            .replace("$NETWORK_CONFIG", &self.generate_network_config(netconfig)?))
+    }
+
+    fn generate_extra_bind_mounts(&self) -> Result<String> {
+        let config = self.realm.config();
+        let mut s = String::new();
+
+        if config.ephemeral_home() {
+            writeln!(s, "TemporaryFileSystem=/home/user:mode=755,uid=1000,gid=1000")?;
+        } else {
+            writeln!(s, "Bind={}:/home/user", self.realm.base_path_file("home").display())?;
+        }
+
+        if config.shared_dir() && Path::new("/realms/Shared").exists() {
+            writeln!(s, "Bind=/realms/Shared:/home/user/Shared")?;
+        }
+
+        for dev in &self.devices {
+            writeln!(s, "Bind={}", dev)?;
+        }
+
+        if config.sound() {
+            writeln!(s, "BindReadOnly=/run/user/1000/pulse:/run/user/host/pulse")?;
+        }
+
+        if config.x11() {
+            writeln!(s, "BindReadOnly=/tmp/.X11-unix")?;
+        }
+
+        if config.wayland() {
+            writeln!(s, "BindReadOnly=/run/user/1000/wayland-0:/run/user/host/wayland-0")?;
+        }
+
+        for bind in config.extra_bindmounts() {
+            if Self::is_valid_bind_item(bind) {
+                writeln!(s, "Bind={}", bind)?;
+            }
+        }
+
+        for bind in config.extra_bindmounts_ro() {
+            if Self::is_valid_bind_item(bind) {
+                writeln!(s, "BindReadOnly={}", bind)?;
+            }
+        }
+        Ok(s)
+    }
+
+    fn is_valid_bind_item(item: &str) -> bool {
+        !item.contains('\n')
+    }
+
+    fn generate_extra_file_options(&self) -> Result<String> {
+        let mut s = String::new();
+        if self.realm.readonly_rootfs() {
+            writeln!(s, "ReadOnly=true")?;
+            writeln!(s, "Overlay=+/var::/var")?;
+        }
+        Ok(s)
+    }
+
+    fn generate_network_config(&mut self, netconfig: &mut NetworkConfig) -> Result<String> {
+        let config = self.realm.config();
+        let mut s = String::new();
+        if config.network() {
+            if config.has_netns() {
+                return Ok(s);
+            }
+            let zone = config.network_zone();
+            let addr = if let Some(addr) = config.reserved_ip() {
+                netconfig.allocate_reserved(zone, self.realm.name(), addr)?
+            } else {
+                netconfig.allocate_address_for(zone, self.realm.name())?
+            };
+            let gw = netconfig.gateway(zone)?;
+            writeln!(s, "Environment=IFCONFIG_IP={}", addr)?;
+            writeln!(s, "Environment=IFCONFIG_GW={}", gw)?;
+            writeln!(s, "[Network]")?;
+            writeln!(s, "Zone=clear")?;
+        } else {
+            writeln!(s, "[Network]")?;
+            writeln!(s, "Private=true")?;
+        }
+        Ok(s)
+    }
+
+    fn generate_service_file(&self, rootfs: &Path) -> String {
+        let rootfs = rootfs.display().to_string();
+        let netns_arg = match self.realm.config().netns() {
+            Some(netns) => format!("--network-namespace-path=/run/netns/{}", netns),
+            None => "".into(),
+        };
+
+        let mut s = String::new();
+        for dev in &self.devices {
+            writeln!(s, "DeviceAllow={}", dev).unwrap();
+        }
+
+        REALM_SERVICE_TEMPLATE.replace("$REALM_NAME", self.realm.name())
+            .replace("$ROOTFS", &rootfs)
+            .replace("$NETNS_ARG", &netns_arg)
+            .replace("$DEVICE_ALLOW", &s)
+    }
+
+    fn realm_service_path(&self) -> PathBuf {
+        PathBuf::from(SYSTEMD_UNIT_PATH).join(self.realm_service_name())
+    }
+
+    fn realm_nspawn_path(&self) -> PathBuf {
+        PathBuf::from(SYSTEMD_NSPAWN_PATH).join(format!("{}.nspawn", self.realm.name()))
+    }
+}

libcitadel/src/realm/mod.rs

@@ -9,6 +9,7 @@ pub (crate) mod network;
 pub(crate) mod create;
 pub(crate) mod events;
 mod systemd;
+mod launcher;
 
 pub(crate) use self::network::BridgeAllocator;
 

libcitadel/src/realm/systemd.rs

@@ -1,13 +1,9 @@
 use std::process::Command;
-use std::path::{Path,PathBuf};
-use std::fs;
-use std::fmt::Write;
+use std::path::Path;
 use std::env;
 
 const SYSTEMCTL_PATH: &str = "/usr/bin/systemctl";
 const MACHINECTL_PATH: &str = "/usr/bin/machinectl";
-const SYSTEMD_NSPAWN_PATH: &str = "/run/systemd/nspawn";
-const SYSTEMD_UNIT_PATH: &str = "/run/systemd/system";
 
 use crate::Result;
 
@@ -15,6 +11,7 @@ use crate::Realm;
 use std::sync::Mutex;
 use std::process::Stdio;
 use crate::realm::network::NetworkConfig;
+use crate::realm::launcher::RealmLauncher;
 
 pub struct Systemd {
     network: Mutex<NetworkConfig>,
@@ -28,8 +25,10 @@ impl Systemd {
     }
 
     pub fn start_realm(&self, realm: &Realm, rootfs: &Path) -> Result<()> {
-        self.write_realm_launch_config(realm, rootfs)?;
-        self.systemctl_start(&self.realm_service_name(realm))?;
+        let mut lock = self.network.lock().unwrap();
+        let mut launcher = RealmLauncher::new(realm);
+        launcher.write_launch_config_files(rootfs, &mut lock)?;
+        self.systemctl_start(&launcher.realm_service_name())?;
         if realm.config().ephemeral_home() {
             self.setup_ephemeral_home(realm)?;
         }
@@ -69,18 +68,15 @@ impl Systemd {
     }
 
     pub fn stop_realm(&self, realm: &Realm) -> Result<()> {
-        self.systemctl_stop(&self.realm_service_name(realm))?;
-        self.remove_realm_launch_config(realm)?;
+        let launcher = RealmLauncher::new(realm);
+        self.systemctl_stop(&launcher.realm_service_name())?;
+        launcher.remove_launch_config_files()?;
 
         let mut network = self.network.lock().unwrap();
         network.free_allocation_for(realm.config().network_zone(), realm.name())?;
         Ok(())
     }
 
-    fn realm_service_name(&self, realm: &Realm) -> String {
-        format!("realm-{}.service", realm.name())
-    }
-
     fn systemctl_start(&self, name: &str) -> Result<bool> {
         self.run_systemctl("start", name)
     }
@@ -182,193 +178,4 @@ impl Systemd {
         cmd.status().map_err(|e| format_err!("failed to execute{}: {}", MACHINECTL_PATH, e))?;
         Ok(())
     }
-
-
-    fn realm_service_path(&self, realm: &Realm) -> PathBuf {
-        PathBuf::from(SYSTEMD_UNIT_PATH).join(self.realm_service_name(realm))
-    }
-
-    fn realm_nspawn_path(&self, realm: &Realm) -> PathBuf {
-        PathBuf::from(SYSTEMD_NSPAWN_PATH).join(format!("{}.nspawn", realm.name()))
-    }
-
-    fn remove_realm_launch_config(&self, realm: &Realm) -> Result<()> {
-        let nspawn_path = self.realm_nspawn_path(realm);
-        if nspawn_path.exists() {
-            fs::remove_file(&nspawn_path)?;
-        }
-        let service_path = self.realm_service_path(realm);
-        if service_path.exists() {
-            fs::remove_file(&service_path)?;
-        }
-        Ok(())
-    }
-
-    fn write_realm_launch_config(&self, realm: &Realm, rootfs: &Path) -> Result<()> {
-        let nspawn_path = self.realm_nspawn_path(realm);
-        let nspawn_content = self.generate_nspawn_file(realm)?;
-        self.write_launch_config_file(&nspawn_path, &nspawn_content)
-            .map_err(|e| format_err!("failed to write nspawn config file {}: {}", nspawn_path.display(), e))?;
-
-        let service_path = self.realm_service_path(realm);
-        let service_content = self.generate_service_file(realm, rootfs);
-        self.write_launch_config_file(&service_path, &service_content)
-            .map_err(|e| format_err!("failed to write service config file {}: {}", service_path.display(), e))?;
-
-        Ok(())
-    }
-
-    /// Write the string `content` to file `path`. If the directory does
-    /// not already exist, create it.
-    fn write_launch_config_file(&self, path: &Path, content: &str) -> Result<()> {
-        match path.parent() {
-            Some(parent) => {
-                if !parent.exists() {
-                    fs::create_dir_all(parent)?;
-                }
-            },
-            None => bail!("config file path {} has no parent?", path.display()),
-        };
-        fs::write(path, content)?;
-        Ok(())
-    }
-
-    fn generate_nspawn_file(&self, realm: &Realm) -> Result<String> {
-        Ok(NSPAWN_FILE_TEMPLATE
-            .replace("$EXTRA_BIND_MOUNTS", &self.generate_extra_bind_mounts(realm)?)
-            .replace("$EXTRA_FILE_OPTIONS", &self.generate_extra_file_options(realm)?)
-            .replace("$NETWORK_CONFIG", &self.generate_network_config(realm)?))
-    }
-
-    fn generate_extra_bind_mounts(&self, realm: &Realm) -> Result<String> {
-        let config = realm.config();
-        let mut s = String::new();
-
-        if config.ephemeral_home() {
-            writeln!(s, "TemporaryFileSystem=/home/user:mode=755,uid=1000,gid=1000")?;
-        } else {
-            writeln!(s, "Bind={}:/home/user", realm.base_path_file("home").display())?;
-        }
-
-        if config.shared_dir() && Path::new("/realms/Shared").exists() {
-            writeln!(s, "Bind=/realms/Shared:/home/user/Shared")?;
-        }
-
-        if config.kvm() {
-            writeln!(s, "Bind=/dev/kvm")?;
-        }
-
-        if config.gpu() {
-            writeln!(s, "Bind=/dev/dri/renderD128")?;
-            if config.gpu_card0() {
-                writeln!(s, "Bind=/dev/dri/card0")?;
-            }
-        }
-
-        if config.sound() {
-            writeln!(s, "Bind=/dev/snd")?;
-            writeln!(s, "Bind=/dev/shm")?;
-            writeln!(s, "BindReadOnly=/run/user/1000/pulse:/run/user/host/pulse")?;
-        }
-
-        if config.x11() {
-            writeln!(s, "BindReadOnly=/tmp/.X11-unix")?;
-        }
-
-        if config.wayland() {
-            writeln!(s, "BindReadOnly=/run/user/1000/wayland-0:/run/user/host/wayland-0")?;
-        }
-
-        for bind in config.extra_bindmounts() {
-            if self.is_valid_bind_item(bind) {
-                writeln!(s, "Bind={}", bind)?;
-            }
-        }
-
-        for bind in config.extra_bindmounts_ro() {
-            if self.is_valid_bind_item(bind) {
-                writeln!(s, "BindReadOnly={}", bind)?;
-            }
-        }
-        Ok(s)
-    }
-
-    fn is_valid_bind_item(&self, item: &str) -> bool {
-        !item.contains('\n')
-    }
-
-    fn generate_extra_file_options(&self, realm: &Realm) -> Result<String> {
-        let mut s = String::new();
-        if realm.readonly_rootfs() {
-            writeln!(s, "ReadOnly=true")?;
-            writeln!(s, "Overlay=+/var::/var")?;
-        }
-        Ok(s)
-    }
-
-    fn generate_network_config(&self, realm: &Realm) -> Result<String> {
-        let config = realm.config();
-        let mut s = String::new();
-        if config.network() {
-            if config.has_netns() {
-                return Ok(s);
-            }
-            let mut netconf = self.network.lock().unwrap();
-            let zone = config.network_zone();
-            let addr = if let Some(addr) = config.reserved_ip() {
-                netconf.allocate_reserved(zone, realm.name(), addr)?
-            } else {
-                netconf.allocate_address_for(zone, realm.name())?
-            };
-            let gw = netconf.gateway(zone)?;
-            writeln!(s, "Environment=IFCONFIG_IP={}", addr)?;
-            writeln!(s, "Environment=IFCONFIG_GW={}", gw)?;
-            writeln!(s, "[Network]")?;
-            writeln!(s, "Zone=clear")?;
-        } else {
-            writeln!(s, "[Network]")?;
-            writeln!(s, "Private=true")?;
-        }
-        Ok(s)
-    }
-
-    fn generate_service_file(&self, realm: &Realm, rootfs: &Path) -> String {
-        let rootfs = rootfs.display().to_string();
-        let netns_arg = match realm.config().netns() {
-            Some(netns) => format!("--network-namespace-path=/run/netns/{}", netns),
-            None => "".into(),
-        };
-
-        REALM_SERVICE_TEMPLATE.replace("$REALM_NAME", realm.name()).replace("$ROOTFS", &rootfs).replace("$NETNS_ARG", &netns_arg)
-    }
 }
-
-
-pub const NSPAWN_FILE_TEMPLATE: &str = r###"
-[Exec]
-Boot=true
-$NETWORK_CONFIG
-
-[Files]
-BindReadOnly=/opt/share
-BindReadOnly=/storage/citadel-state/resolv.conf:/etc/resolv.conf
-
-$EXTRA_BIND_MOUNTS
-
-$EXTRA_FILE_OPTIONS
-
-"###;
-
-pub const REALM_SERVICE_TEMPLATE: &str = r###"
-[Unit]
-Description=Application Image $REALM_NAME instance
-
-[Service]
-Environment=SYSTEMD_NSPAWN_SHARE_NS_IPC=1
-ExecStart=/usr/bin/systemd-nspawn --quiet --notify-ready=yes --keep-unit $NETNS_ARG --machine=$REALM_NAME --link-journal=auto --directory=$ROOTFS
-
-KillMode=mixed
-Type=notify
-RestartForceExitStatus=133
-SuccessExitStatus=133
-"###;