feat: implement kernel / initrd oci image support (#103)

* feat: implement kernel / initrd oci image support

* fix: implement image urls more faithfully
This commit is contained in:
Alex Zenla
2024-04-22 12:48:45 -07:00
committed by GitHub
parent 1b90eedbcd
commit 82576df7b7
18 changed files with 470 additions and 262 deletions

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use std::{
collections::{hash_map::Entry, HashMap},
path::PathBuf,
sync::Arc,
time::Duration,
};
use anyhow::Result;
use krata::v1::{
common::{Guest, GuestErrorInfo, GuestExitInfo, GuestNetworkState, GuestState, GuestStatus},
control::GuestChangedEvent,
};
use krataoci::packer::service::OciPackerService;
use kratart::{GuestInfo, Runtime};
use log::{error, info, trace, warn};
use tokio::{
select,
sync::{
mpsc::{channel, Receiver, Sender},
Mutex, RwLock,
},
task::JoinHandle,
time::sleep,
};
use uuid::Uuid;
use crate::{
db::GuestStore,
event::{DaemonEvent, DaemonEventContext},
glt::GuestLookupTable,
};
use self::start::GuestStarter;
mod start;
const PARALLEL_LIMIT: u32 = 5;
#[derive(Debug)]
enum GuestReconcilerResult {
Unchanged,
Changed { rerun: bool },
}
struct GuestReconcilerEntry {
task: JoinHandle<()>,
sender: Sender<()>,
}
impl Drop for GuestReconcilerEntry {
fn drop(&mut self) {
self.task.abort();
}
}
#[derive(Clone)]
pub struct GuestReconciler {
glt: GuestLookupTable,
guests: GuestStore,
events: DaemonEventContext,
runtime: Runtime,
packer: OciPackerService,
kernel_path: PathBuf,
initrd_path: PathBuf,
tasks: Arc<Mutex<HashMap<Uuid, GuestReconcilerEntry>>>,
guest_reconciler_notify: Sender<Uuid>,
reconcile_lock: Arc<RwLock<()>>,
}
impl GuestReconciler {
#[allow(clippy::too_many_arguments)]
pub fn new(
glt: GuestLookupTable,
guests: GuestStore,
events: DaemonEventContext,
runtime: Runtime,
packer: OciPackerService,
guest_reconciler_notify: Sender<Uuid>,
kernel_path: PathBuf,
initrd_path: PathBuf,
) -> Result<Self> {
Ok(Self {
glt,
guests,
events,
runtime,
packer,
kernel_path,
initrd_path,
tasks: Arc::new(Mutex::new(HashMap::new())),
guest_reconciler_notify,
reconcile_lock: Arc::new(RwLock::with_max_readers((), PARALLEL_LIMIT)),
})
}
pub async fn launch(self, mut notify: Receiver<Uuid>) -> Result<JoinHandle<()>> {
Ok(tokio::task::spawn(async move {
if let Err(error) = self.reconcile_runtime(true).await {
error!("runtime reconciler failed: {}", error);
}
loop {
select! {
x = notify.recv() => match x {
None => {
break;
},
Some(uuid) => {
if let Err(error) = self.launch_task_if_needed(uuid).await {
error!("failed to start guest reconciler task {}: {}", uuid, error);
}
let map = self.tasks.lock().await;
if let Some(entry) = map.get(&uuid) {
if let Err(error) = entry.sender.send(()).await {
error!("failed to notify guest reconciler task {}: {}", uuid, error);
}
}
}
},
_ = sleep(Duration::from_secs(5)) => {
if let Err(error) = self.reconcile_runtime(false).await {
error!("runtime reconciler failed: {}", error);
}
}
};
}
}))
}
pub async fn reconcile_runtime(&self, initial: bool) -> Result<()> {
let _permit = self.reconcile_lock.write().await;
trace!("reconciling runtime");
let runtime_guests = self.runtime.list().await?;
let stored_guests = self.guests.list().await?;
let non_existent_guests = runtime_guests
.iter()
.filter(|x| !stored_guests.iter().any(|g| *g.0 == x.uuid))
.collect::<Vec<_>>();
for guest in non_existent_guests {
warn!("destroying unknown runtime guest {}", guest.uuid);
if let Err(error) = self.runtime.destroy(guest.uuid).await {
error!(
"failed to destroy unknown runtime guest {}: {}",
guest.uuid, error
);
}
self.guests.remove(guest.uuid).await?;
}
for (uuid, mut stored_guest) in stored_guests {
let previous_guest = stored_guest.clone();
let runtime_guest = runtime_guests.iter().find(|x| x.uuid == uuid);
match runtime_guest {
None => {
let mut state = stored_guest.state.as_mut().cloned().unwrap_or_default();
if state.status() == GuestStatus::Started {
state.status = GuestStatus::Starting.into();
}
stored_guest.state = Some(state);
}
Some(runtime) => {
self.glt.associate(uuid, runtime.domid).await;
let mut state = stored_guest.state.as_mut().cloned().unwrap_or_default();
if let Some(code) = runtime.state.exit_code {
state.status = GuestStatus::Exited.into();
state.exit_info = Some(GuestExitInfo { code });
} else {
state.status = GuestStatus::Started.into();
}
state.network = Some(guestinfo_to_networkstate(runtime));
stored_guest.state = Some(state);
}
}
let changed = stored_guest != previous_guest;
if changed || initial {
self.guests.update(uuid, stored_guest).await?;
let _ = self.guest_reconciler_notify.try_send(uuid);
}
}
Ok(())
}
pub async fn reconcile(&self, uuid: Uuid) -> Result<bool> {
let _runtime_reconcile_permit = self.reconcile_lock.read().await;
let Some(mut guest) = self.guests.read(uuid).await? else {
warn!(
"notified of reconcile for guest {} but it didn't exist",
uuid
);
return Ok(false);
};
info!("reconciling guest {}", uuid);
self.events
.send(DaemonEvent::GuestChanged(GuestChangedEvent {
guest: Some(guest.clone()),
}))?;
let start_status = guest.state.as_ref().map(|x| x.status()).unwrap_or_default();
let result = match start_status {
GuestStatus::Starting => self.start(uuid, &mut guest).await,
GuestStatus::Exited => self.exited(&mut guest).await,
GuestStatus::Destroying => self.destroy(uuid, &mut guest).await,
_ => Ok(GuestReconcilerResult::Unchanged),
};
let result = match result {
Ok(result) => result,
Err(error) => {
guest.state = Some(guest.state.as_mut().cloned().unwrap_or_default());
guest.state.as_mut().unwrap().status = GuestStatus::Failed.into();
guest.state.as_mut().unwrap().error_info = Some(GuestErrorInfo {
message: error.to_string(),
});
warn!("failed to start guest {}: {}", guest.id, error);
GuestReconcilerResult::Changed { rerun: false }
}
};
info!("reconciled guest {}", uuid);
let status = guest.state.as_ref().map(|x| x.status()).unwrap_or_default();
let destroyed = status == GuestStatus::Destroyed;
let rerun = if let GuestReconcilerResult::Changed { rerun } = result {
let event = DaemonEvent::GuestChanged(GuestChangedEvent {
guest: Some(guest.clone()),
});
if destroyed {
self.guests.remove(uuid).await?;
let mut map = self.tasks.lock().await;
map.remove(&uuid);
} else {
self.guests.update(uuid, guest.clone()).await?;
}
self.events.send(event)?;
rerun
} else {
false
};
Ok(rerun)
}
async fn start(&self, uuid: Uuid, guest: &mut Guest) -> Result<GuestReconcilerResult> {
let starter = GuestStarter {
kernel_path: &self.kernel_path,
initrd_path: &self.initrd_path,
packer: &self.packer,
glt: &self.glt,
runtime: &self.runtime,
};
starter.start(uuid, guest).await
}
async fn exited(&self, guest: &mut Guest) -> Result<GuestReconcilerResult> {
if let Some(ref mut state) = guest.state {
state.set_status(GuestStatus::Destroying);
Ok(GuestReconcilerResult::Changed { rerun: true })
} else {
Ok(GuestReconcilerResult::Unchanged)
}
}
async fn destroy(&self, uuid: Uuid, guest: &mut Guest) -> Result<GuestReconcilerResult> {
if let Err(error) = self.runtime.destroy(uuid).await {
trace!("failed to destroy runtime guest {}: {}", uuid, error);
}
let domid = guest.state.as_ref().map(|x| x.domid);
if let Some(domid) = domid {
self.glt.remove(uuid, domid).await;
}
info!("destroyed guest {}", uuid);
guest.state = Some(GuestState {
status: GuestStatus::Destroyed.into(),
network: None,
exit_info: None,
error_info: None,
host: self.glt.host_uuid().to_string(),
domid: domid.unwrap_or(u32::MAX),
});
Ok(GuestReconcilerResult::Changed { rerun: false })
}
async fn launch_task_if_needed(&self, uuid: Uuid) -> Result<()> {
let mut map = self.tasks.lock().await;
match map.entry(uuid) {
Entry::Occupied(_) => {}
Entry::Vacant(entry) => {
entry.insert(self.launch_task(uuid).await?);
}
}
Ok(())
}
async fn launch_task(&self, uuid: Uuid) -> Result<GuestReconcilerEntry> {
let this = self.clone();
let (sender, mut receiver) = channel(10);
let task = tokio::task::spawn(async move {
'notify_loop: loop {
if receiver.recv().await.is_none() {
break 'notify_loop;
}
'rerun_loop: loop {
let rerun = match this.reconcile(uuid).await {
Ok(rerun) => rerun,
Err(error) => {
error!("failed to reconcile guest {}: {}", uuid, error);
false
}
};
if rerun {
continue 'rerun_loop;
}
break 'rerun_loop;
}
}
});
Ok(GuestReconcilerEntry { task, sender })
}
}
pub fn guestinfo_to_networkstate(info: &GuestInfo) -> GuestNetworkState {
GuestNetworkState {
guest_ipv4: info.guest_ipv4.map(|x| x.to_string()).unwrap_or_default(),
guest_ipv6: info.guest_ipv6.map(|x| x.to_string()).unwrap_or_default(),
guest_mac: info.guest_mac.as_ref().cloned().unwrap_or_default(),
gateway_ipv4: info.gateway_ipv4.map(|x| x.to_string()).unwrap_or_default(),
gateway_ipv6: info.gateway_ipv6.map(|x| x.to_string()).unwrap_or_default(),
gateway_mac: info.gateway_mac.as_ref().cloned().unwrap_or_default(),
}
}

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use std::collections::HashMap;
use std::path::{Path, PathBuf};
use anyhow::{anyhow, Result};
use futures::StreamExt;
use krata::launchcfg::LaunchPackedFormat;
use krata::v1::common::GuestOciImageSpec;
use krata::v1::common::{guest_image_spec::Image, Guest, GuestState, GuestStatus, OciImageFormat};
use krataoci::packer::{service::OciPackerService, OciPackedFormat};
use kratart::{launch::GuestLaunchRequest, Runtime};
use log::info;
use tokio::fs::{self, File};
use tokio::io::AsyncReadExt;
use tokio_tar::Archive;
use uuid::Uuid;
use crate::{
glt::GuestLookupTable,
reconcile::guest::{guestinfo_to_networkstate, GuestReconcilerResult},
};
// if a kernel is >= 100MB, that's kinda scary.
const OCI_SPEC_TAR_FILE_MAX_SIZE: usize = 100 * 1024 * 1024;
pub struct GuestStarter<'a> {
pub kernel_path: &'a Path,
pub initrd_path: &'a Path,
pub packer: &'a OciPackerService,
pub glt: &'a GuestLookupTable,
pub runtime: &'a Runtime,
}
impl GuestStarter<'_> {
pub async fn oci_spec_tar_read_file(
&self,
file: &Path,
oci: &GuestOciImageSpec,
) -> Result<Vec<u8>> {
if oci.format() != OciImageFormat::Tar {
return Err(anyhow!(
"oci image spec for {} is required to be in tar format",
oci.digest
));
}
let image = self
.packer
.recall(&oci.digest, OciPackedFormat::Tar)
.await?;
let Some(image) = image else {
return Err(anyhow!("image {} was not found in tar format", oci.digest));
};
let mut archive = Archive::new(File::open(&image.path).await?);
let mut entries = archive.entries()?;
while let Some(entry) = entries.next().await {
let mut entry = entry?;
let path = entry.path()?;
if entry.header().size()? as usize > OCI_SPEC_TAR_FILE_MAX_SIZE {
return Err(anyhow!(
"file {} in image {} is larger than the size limit",
file.to_string_lossy(),
oci.digest
));
}
if path == file {
let mut buffer = Vec::new();
entry.read_to_end(&mut buffer).await?;
return Ok(buffer);
}
}
Err(anyhow!(
"unable to find file {} in image {}",
file.to_string_lossy(),
oci.digest
))
}
pub async fn start(&self, uuid: Uuid, guest: &mut Guest) -> Result<GuestReconcilerResult> {
let Some(ref spec) = guest.spec else {
return Err(anyhow!("guest spec not specified"));
};
let Some(ref image) = spec.image else {
return Err(anyhow!("image spec not provided"));
};
let oci = match image.image {
Some(Image::Oci(ref oci)) => oci,
None => {
return Err(anyhow!("oci spec not specified"));
}
};
let task = spec.task.as_ref().cloned().unwrap_or_default();
let image = self
.packer
.recall(
&oci.digest,
match oci.format() {
OciImageFormat::Unknown => OciPackedFormat::Squashfs,
OciImageFormat::Squashfs => OciPackedFormat::Squashfs,
OciImageFormat::Erofs => OciPackedFormat::Erofs,
OciImageFormat::Tar => {
return Err(anyhow!("tar image format is not supported for guests"));
}
},
)
.await?;
let Some(image) = image else {
return Err(anyhow!(
"image {} in the requested format did not exist",
oci.digest
));
};
let kernel = if let Some(ref spec) = spec.kernel {
let Some(Image::Oci(ref oci)) = spec.image else {
return Err(anyhow!("kernel image spec must be an oci image"));
};
self.oci_spec_tar_read_file(&PathBuf::from("kernel/image"), oci)
.await?
} else {
fs::read(&self.kernel_path).await?
};
let initrd = if let Some(ref spec) = spec.initrd {
let Some(Image::Oci(ref oci)) = spec.image else {
return Err(anyhow!("initrd image spec must be an oci image"));
};
self.oci_spec_tar_read_file(&PathBuf::from("krata/initrd"), oci)
.await?
} else {
fs::read(&self.initrd_path).await?
};
let info = self
.runtime
.launch(GuestLaunchRequest {
format: LaunchPackedFormat::Squashfs,
uuid: Some(uuid),
name: if spec.name.is_empty() {
None
} else {
Some(spec.name.clone())
},
image,
kernel,
initrd,
vcpus: spec.vcpus,
mem: spec.mem,
env: task
.environment
.iter()
.map(|x| (x.key.clone(), x.value.clone()))
.collect::<HashMap<_, _>>(),
run: empty_vec_optional(task.command.clone()),
debug: false,
})
.await?;
self.glt.associate(uuid, info.domid).await;
info!("started guest {}", uuid);
guest.state = Some(GuestState {
status: GuestStatus::Started.into(),
network: Some(guestinfo_to_networkstate(&info)),
exit_info: None,
error_info: None,
host: self.glt.host_uuid().to_string(),
domid: info.domid,
});
Ok(GuestReconcilerResult::Changed { rerun: false })
}
}
fn empty_vec_optional<T>(value: Vec<T>) -> Option<Vec<T>> {
if value.is_empty() {
None
} else {
Some(value)
}
}