feat: capacity limit for volumes

Add mechanism for limiting the total volume size on the system
by rejecting volume creation requests from REST.
Includes BDDs, although the resize limit is not yet implemented.

Signed-off-by: chriswldenyer <christopher.denyer@mayadata.io>

control-plane/agents/src/bin/core/volume/service.rs

@@ -301,10 +301,29 @@ impl Service {
         })
     }
 
+    /// Determine the total volume size on the system.
+    #[tracing::instrument(level = "info", skip(self), err, fields(volume.uuid))]
+    async fn total_volume_size(&self) -> Result<u64, SvcError> {
+        let volumes = self.registry.volumes().await;
+        let mut total: u64 = 0;
+        for vol in volumes.iter() {
+            total += vol.spec().size;
+        }
+        Ok(total)
+    }
+
     /// Create a volume using the given parameters.
     #[tracing::instrument(level = "info", skip(self), err, fields(volume.uuid = %request.uuid))]
     pub(super) async fn create_volume(&self, request: &CreateVolume) -> Result<Volume, SvcError> {
         let _permit = self.create_volume_permit().await?;
+        let capacity_limit = request.capacity_limit();
+        if let Some(limit) = capacity_limit {
+            let total_volume_size = self.total_volume_size().await?;
+            let this_volume_size = request.size();
+            if total_volume_size + this_volume_size > limit {
+                return Err(SvcError::VolWouldExceedCapacity {});
+            }
+        }
         OperationGuardArc::<VolumeSpec>::create(&self.registry, request).await?;
         self.registry.volume(&request.uuid).await
     }

control-plane/agents/src/common/errors.rs

@@ -334,6 +334,8 @@ pub enum SvcError {
     DrainNotAllowedWhenHAisDisabled {},
     #[snafu(display("Target switchover is not allowed without HA"))]
     SwitchoverNotAllowedWhenHAisDisabled {},
+    #[snafu(display("The volume would exceed the capacity"))]
+    VolWouldExceedCapacity {},
 }
 
 impl SvcError {
@@ -934,6 +936,12 @@ impl From<SvcError> for ReplyError {
                 source,
                 extra,
             },
+            SvcError::VolWouldExceedCapacity {} => ReplyError {
+                kind: ReplyErrorKind::OutOfRange,
+                resource: ResourceKind::Volume,
+                source,
+                extra,
+            },
         }
     }
 }

control-plane/grpc/proto/v1/volume/volume.proto

@@ -263,6 +263,8 @@ message CreateVolumeRequest {
   bool thin = 8;
   // Affinity Group related information.
   optional AffinityGroup affinity_group = 9;
+  // maximum total volume size
+  optional uint64 capacity_limit = 10;
 }
 
 // Publish a volume on a node

control-plane/grpc/src/operations/volume/traits.rs

@@ -890,6 +890,8 @@ pub trait CreateVolumeInfo: Send + Sync + std::fmt::Debug {
     fn thin(&self) -> bool;
     /// Affinity Group related information.
     fn affinity_group(&self) -> Option<AffinityGroup>;
+    /// Capacity Limit
+    fn capacity_limit(&self) -> Option<u64>;
 }
 
 impl CreateVolumeInfo for CreateVolume {
@@ -924,6 +926,10 @@ impl CreateVolumeInfo for CreateVolume {
     fn affinity_group(&self) -> Option<AffinityGroup> {
         self.affinity_group.clone()
     }
+
+    fn capacity_limit(&self) -> Option<u64> {
+        self.capacity_limit
+    }
 }
 
 /// Intermediate structure that validates the conversion to CreateVolumeRequest type.
@@ -972,6 +978,10 @@ impl CreateVolumeInfo for ValidatedCreateVolumeRequest {
     fn affinity_group(&self) -> Option<AffinityGroup> {
         self.inner.affinity_group.clone().map(|ag| ag.into())
     }
+
+    fn capacity_limit(&self) -> Option<u64> {
+        self.inner.capacity_limit
+    }
 }
 
 impl ValidateRequestTypes for CreateVolumeRequest {
@@ -1008,6 +1018,7 @@ impl From<&dyn CreateVolumeInfo> for CreateVolume {
             labels: data.labels(),
             thin: data.thin(),
             affinity_group: data.affinity_group(),
+            capacity_limit: data.capacity_limit(),
         }
     }
 }
@@ -1025,6 +1036,7 @@ impl From<&dyn CreateVolumeInfo> for CreateVolumeRequest {
                 .map(|labels| crate::common::StringMapValue { value: labels }),
             thin: data.thin(),
             affinity_group: data.affinity_group().map(|ag| ag.into()),
+            capacity_limit: data.capacity_limit(),
         }
     }
 }

control-plane/rest/src/versions/v0.rs

@@ -231,6 +231,7 @@ impl CreateVolumeBody {
             labels: self.labels.clone(),
             thin: self.thin,
             affinity_group: self.affinity_group.clone(),
+            capacity_limit: None,
         }
     }
     /// Convert into rpc request type.

control-plane/stor-port/src/types/v0/transport/volume.rs

@@ -455,6 +455,8 @@ pub struct CreateVolume {
     pub thin: bool,
     /// Affinity Group related information.
     pub affinity_group: Option<AffinityGroup>,
+    /// Maximum total system volume size.
+    pub capacity_limit: Option<u64>,
 }
 
 /// Create volume request.

tests/bdd/features/volume/capacity_limit/creation.feature

@@ -0,0 +1,22 @@
+Feature: Volume creation capacity limit
+
+  Background:
+    Given a control plane, Io-Engine instances and a pool
+
+  Scenario: attempted creation exceeding the capacity limit
+    Given a gRPC request to create a volume
+    When the request includes a capacity limit
+    And the volume creation would result in the capacity limit being exceeded
+    Then volume creation should fail with an out-of-range error
+
+  Scenario: attempted creation within the capacity limit
+    Given a gRPC request to create a volume
+    When the request includes a capacity limit
+    And the volume creation would not result in the capacity limit being exceeded
+    Then volume creation should succeed
+
+  Scenario: attempted creation with no capacity limit
+    Given a gRPC request to create a volume
+    When the request does not include a capacity limit
+    Then volume creation should succeed
+

tests/bdd/features/volume/capacity_limit/resize.feature

@@ -0,0 +1,22 @@
+Feature: Volume resize capacity limit
+
+  Background:
+    Given a control plane, Io-Engine instances and a pool
+
+  Scenario: attempted volume resize exceeding the capacity limit
+    Given a gRPC request to resize a volume
+    When the request includes a capacity limit
+    And the volume resize would result in the capacity limit being exceeded
+    Then volume resize should fail with an out-of-range error
+
+  Scenario: attempted resize within the capacity limit
+    Given a gRPC request to resize a volume
+    When the request includes a capacity limit
+    And the volume resize would not result in the capacity limit being exceeded
+    Then volume resize should succeed
+
+  Scenario: attempted creation with no capacity limit
+    Given a gRPC request to resize a volume
+    When the request does not include a capacity limit
+    Then volume resize should succeed
+