Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Less anxiety-inducing return values #771

Merged
merged 2 commits into from
Sep 30, 2024
Merged

Less anxiety-inducing return values #771

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
81de422
Less anxiety-inducing `Vm::{get, state_watcher}`
hawkw Sep 30, 2024
ce6bb51
Make PUT /instance/state 503 when waiting to init
hawkw Sep 30, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
34 changes: 7 additions & 27 deletions bin/propolis-server/src/lib/server.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -343,14 +343,7 @@ async fn instance_get_common(
rqctx: &RequestContext<Arc<DropshotEndpointContext>>,
) -> Result<api::InstanceSpecGetResponse, HttpError> {
let ctx = rqctx.context();
ctx.vm.get().await.map_err(|e| match e {
VmError::NotCreated | VmError::WaitingToInitialize => {
not_created_error()
}
_ => HttpError::for_internal_error(format!(
"unexpected error from VM controller: {e}"
)),
})
ctx.vm.get().await.ok_or_else(not_created_error)
}

#[endpoint {
Expand Down Expand Up @@ -393,14 +386,7 @@ async fn instance_state_monitor(
let ctx = rqctx.context();
let gen = request.into_inner().gen;
let mut state_watcher =
ctx.vm.state_watcher().await.map_err(|e| match e {
VmError::NotCreated | VmError::WaitingToInitialize => {
not_created_error()
}
_ => HttpError::for_internal_error(format!(
"unexpected error from VM controller: {e}"
)),
})?;
ctx.vm.state_watcher().await.ok_or_else(not_created_error)?;

loop {
let last = state_watcher.borrow().clone();
Expand Down Expand Up @@ -440,9 +426,10 @@ async fn instance_state_put(
.put_state(requested_state)
.map(|_| HttpResponseUpdatedNoContent {})
.map_err(|e| match e {
VmError::NotCreated | VmError::WaitingToInitialize => {
not_created_error()
}
VmError::WaitingToInitialize => HttpError::for_unavail(
None,
"instance is still initializing".to_string(),
),
VmError::ForbiddenStateChange(reason) => HttpError::for_status(
Some(format!("instance state change not allowed: {}", reason)),
hyper::StatusCode::FORBIDDEN,
Expand Down Expand Up @@ -614,14 +601,7 @@ async fn instance_migrate_status(
.state_watcher()
.await
.map(|rx| HttpResponseOk(rx.borrow().migration.clone()))
.map_err(|e| match e {
VmError::NotCreated | VmError::WaitingToInitialize => {
not_created_error()
}
_ => HttpError::for_internal_error(format!(
"unexpected error from VM controller: {e}"
)),
})
.ok_or_else(not_created_error)
}

/// Issues a snapshot request to a crucible backend.
Expand Down
33 changes: 20 additions & 13 deletions bin/propolis-server/src/lib/vm/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -165,9 +165,6 @@ pub(crate) enum VmError {
#[error("VM operation result channel unexpectedly closed")]
ResultChannelClosed,

#[error("VM not created")]
NotCreated,

#[error("VM is currently initializing")]
WaitingToInitialize,

Expand Down Expand Up @@ -317,18 +314,23 @@ impl Vm {

/// Returns the state, properties, and instance spec for the instance most
/// recently wrapped by this `Vm`.
pub(super) async fn get(&self) -> Result<InstanceSpecGetResponse, VmError> {
///
/// # Returns
///
/// - `Some` if the VM has been created.
/// - `None` if no VM has ever been created.
pub(super) async fn get(&self) -> Option<InstanceSpecGetResponse> {
let guard = self.inner.read().await;
match &guard.state {
// If no VM has ever been created, there's nothing to get.
VmState::NoVm => Err(VmError::NotCreated),
VmState::NoVm => None,

// If the VM is active, pull the required data out of its objects.
VmState::Active(vm) => {
let spec =
vm.objects().lock_shared().await.instance_spec().clone();
let state = vm.external_state_rx.borrow().clone();
Ok(InstanceSpecGetResponse {
Some(InstanceSpecGetResponse {
properties: vm.properties.clone(),
spec: VersionedInstanceSpec::V0(spec.into()),
state: state.state,
Expand All @@ -340,7 +342,7 @@ impl Vm {
// machine.
VmState::WaitingForInit(vm)
| VmState::Rundown(vm)
| VmState::RundownComplete(vm) => Ok(InstanceSpecGetResponse {
| VmState::RundownComplete(vm) => Some(InstanceSpecGetResponse {
properties: vm.properties.clone(),
state: vm.external_state_rx.borrow().state,
spec: VersionedInstanceSpec::V0(vm.spec.clone().into()),
Expand All @@ -350,16 +352,21 @@ impl Vm {

/// Yields a handle to the most recent instance state receiver wrapped by
/// this `Vm`.
pub(super) async fn state_watcher(
&self,
) -> Result<InstanceStateRx, VmError> {
///
/// # Returns
///
/// - `Some` if the VM has been created.
/// - `None` if no VM has ever been created.
pub(super) async fn state_watcher(&self) -> Option<InstanceStateRx> {
let guard = self.inner.read().await;
match &guard.state {
VmState::NoVm => Err(VmError::NotCreated),
VmState::Active(vm) => Ok(vm.external_state_rx.clone()),
VmState::NoVm => None,
VmState::Active(vm) => Some(vm.external_state_rx.clone()),
VmState::WaitingForInit(vm)
| VmState::Rundown(vm)
| VmState::RundownComplete(vm) => Ok(vm.external_state_rx.clone()),
| VmState::RundownComplete(vm) => {
Some(vm.external_state_rx.clone())
}
}
}

Expand Down
Loading