Add Client Caching (#236)

Caching the data is all well and good, but we need to cache the client
too to avoid creating a new one for listing images and flavors during
cluster creation.

Author: spjmurray

charts/kubernetes/Chart.yaml

@@ -4,8 +4,8 @@ description: A Helm chart for deploying Unikorn Kubernetes Service
 
 type: application
 
-version: v0.2.64
-appVersion: v0.2.64
+version: v0.2.65-rc1
+appVersion: v0.2.65-rc1
 
 icon: https://raw.githubusercontent.com/unikorn-cloud/assets/main/images/logos/dark-on-light/icon.png
 

go.mod

@@ -15,7 +15,7 @@ require (
 	github.com/stretchr/testify v1.10.0
 	github.com/unikorn-cloud/core v0.1.96-rc1
 	github.com/unikorn-cloud/identity v0.2.63
-	github.com/unikorn-cloud/region v0.1.54
+	github.com/unikorn-cloud/region v0.1.55-rc1
 	go.opentelemetry.io/otel v1.35.0
 	go.opentelemetry.io/otel/sdk v1.35.0
 	gopkg.in/ini.v1 v1.67.0

go.sum

@@ -179,8 +179,8 @@ github.com/unikorn-cloud/core v0.1.96-rc1 h1:TgSMyHhUWYmWgLXiTWNUsroO3F2LtTJ/k+n
 github.com/unikorn-cloud/core v0.1.96-rc1/go.mod h1:stInT6j9sM9KzDHgNxBtmrdDIAxQuIZI1/TCGo0jNK8=
 github.com/unikorn-cloud/identity v0.2.63 h1:cG3Aa3LmweqOwNtOeq9W29/aoJ4wY0uiulLNzWwn7TY=
 github.com/unikorn-cloud/identity v0.2.63/go.mod h1:xuOIyB4wDAz4+kJfZk2q+8MqGj+9IhVbd0Q38iqBY24=
-github.com/unikorn-cloud/region v0.1.54 h1:orGCMLIMUmSWLOlBBha6q5SgXKAlzFqQJRVhneD4/so=
-github.com/unikorn-cloud/region v0.1.54/go.mod h1:wLNamsGnGIpGTQYFsjyuvelLu5LdtKiniZu0rXu8oUo=
+github.com/unikorn-cloud/region v0.1.55-rc1 h1:rnEqKMthOboBi1Coi+FQ/IfAU6jYbYfO9yP+Iaselss=
+github.com/unikorn-cloud/region v0.1.55-rc1/go.mod h1:wLNamsGnGIpGTQYFsjyuvelLu5LdtKiniZu0rXu8oUo=
 github.com/x448/float16 v0.8.4 h1:qLwI1I70+NjRFUR3zs1JPUCgaCXSh3SW62uAKT1mSBM=
 github.com/x448/float16 v0.8.4/go.mod h1:14CWIYCyZA/cWjXOioeEpHeN/83MdbZDRQHoFcYsOfg=
 github.com/xlab/treeprint v1.2.0 h1:HzHnuAF1plUN2zGlAFHbSQP2qJ0ZAD3XF5XD7OesXRQ=

pkg/server/handler/region/region.go

@@ -56,10 +56,12 @@ type ClientGetterFunc func(context.Context) (regionapi.ClientWithResponsesInterf
 
 // Client provides a caching layer for retrieval of region assets, and lazy population.
 type Client struct {
-	clientGetter ClientGetterFunc
-	regionCache  *cache.LRUExpireCache[string, []regionapi.RegionRead]
-	flavorCache  *cache.LRUExpireCache[string, []regionapi.Flavor]
-	imageCache   *cache.LRUExpireCache[string, []regionapi.Image]
+	clientGetter  ClientGetterFunc
+	client        regionapi.ClientWithResponsesInterface
+	clientTimeout time.Time
+	regionCache   *cache.LRUExpireCache[string, []regionapi.RegionRead]
+	flavorCache   *cache.LRUExpireCache[string, []regionapi.Flavor]
+	imageCache    *cache.LRUExpireCache[string, []regionapi.Image]
 }
 
 // New returns a new client.
@@ -74,12 +76,26 @@ func New(clientGetter ClientGetterFunc) *Client {
 
 // Client returns a client.
 func (c *Client) Client(ctx context.Context) (regionapi.ClientWithResponsesInterface, error) {
-	return c.clientGetter(ctx)
+	if time.Now().Before(c.clientTimeout) {
+		return c.client, nil
+	}
+
+	client, err := c.clientGetter(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: the timeout should be driven by the token expiry, so we need to expose
+	// that eventually.
+	c.client = client
+	c.clientTimeout = time.Now().Add(10 * time.Minute)
+
+	return client, nil
 }
 
 // Get gets a specific region.
 func (c *Client) Get(ctx context.Context, organizationID, regionID string) (*regionapi.RegionDetailRead, error) {
-	client, err := c.clientGetter(ctx)
+	client, err := c.Client(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -103,7 +119,7 @@ func (c *Client) list(ctx context.Context, organizationID string) ([]regionapi.R
 		return regions, nil
 	}
 
-	client, err := c.clientGetter(ctx)
+	client, err := c.Client(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -147,7 +163,7 @@ func (c *Client) Flavors(ctx context.Context, organizationID, regionID string) (
 		return flavors, nil
 	}
 
-	client, err := c.clientGetter(ctx)
+	client, err := c.Client(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -181,7 +197,7 @@ func (c *Client) Images(ctx context.Context, organizationID, regionID string) ([
 		return images, nil
 	}
 
-	client, err := c.clientGetter(ctx)
+	client, err := c.Client(ctx)
 	if err != nil {
 		return nil, err
 	}