rest: refresh vended credentials

Currently credential lifetimes are tied to the table instead, only load
table refreshes the credentials. This commit caches and refreshes the
credentials based on the response included in the table load response
and refreshes it dynamically.

Author: rockwotj

catalog/rest/rest.go

@@ -38,14 +38,14 @@ import (
 
 	"github.com/apache/iceberg-go"
 	"github.com/apache/iceberg-go/catalog"
-	iceio "github.com/apache/iceberg-go/io"
 	"github.com/apache/iceberg-go/table"
 	"github.com/apache/iceberg-go/view"
 	"github.com/aws/aws-sdk-go-v2/aws"
 	v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
 	"github.com/aws/aws-sdk-go-v2/config"
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/clientcredentials"
+	"golang.org/x/sync/semaphore"
 )
 
 var _ catalog.Catalog = (*Catalog)(nil)
@@ -675,16 +675,45 @@ func checkValidNamespace(ident table.Identifier) error {
 	return nil
 }
 
-func (r *Catalog) tableFromResponse(ctx context.Context, identifier []string, metadata table.Metadata, loc string, config iceberg.Properties) (*table.Table, error) {
+func (r *Catalog) tableFromResponse(_ context.Context, identifier []string, metadata table.Metadata, loc string, config iceberg.Properties) (*table.Table, error) {
+	refresher := &vendedCredentialRefresher{
+		mu:          semaphore.NewWeighted(1),
+		identifier:  identifier,
+		location:    loc,
+		props:       config,
+		fetchConfig: r.fetchTableConfig,
+	}
+
 	return table.New(
 		identifier,
 		metadata,
 		loc,
-		iceio.LoadFSFunc(config, loc),
+		refresher.loadFS,
 		r,
 	), nil
 }
 
+func (r *Catalog) fetchTableConfig(ctx context.Context, ident []string) (iceberg.Properties, error) {
+	ns, tbl, err := splitIdentForPath(ident)
+	if err != nil {
+		return nil, err
+	}
+
+	ret, err := doGet[loadTableResponse](ctx, r.baseURI, []string{"namespaces", ns, "tables", tbl},
+		r.cl, map[int]error{http.StatusNotFound: catalog.ErrNoSuchTable})
+	if err != nil {
+		return nil, err
+	}
+
+	config := maps.Clone(r.props)
+	maps.Copy(config, ret.Metadata.Properties())
+	for k, v := range ret.Config {
+		config[k] = v
+	}
+
+	return config, nil
+}
+
 func (r *Catalog) ListTables(ctx context.Context, namespace table.Identifier) iter.Seq2[table.Identifier, error] {
 	return func(yield func(table.Identifier, error) bool) {
 		pageSize := r.getPageSize(ctx)

catalog/rest/vended_creds.go

@@ -0,0 +1,127 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package rest
+
+import (
+	"context"
+	"maps"
+	"strconv"
+	"time"
+
+	"github.com/apache/iceberg-go"
+	iceio "github.com/apache/iceberg-go/io"
+	"golang.org/x/sync/semaphore"
+)
+
+const (
+	keyS3TokenExpiresAtMs = "s3.session-token-expires-at-ms"
+	keyAdlsSasExpiresAtMs = "adls.sas-token-expires-at-ms"
+	keyGcsOAuthExpiresAt  = "gcs.oauth2.token-expires-at"
+	keyExpirationTime     = "expiration-time"
+
+	defaultVendedCredentialsTTL = 60 * time.Minute
+)
+
+var credentialExpiryKeys = []string{
+	keyS3TokenExpiresAtMs,
+	keyAdlsSasExpiresAtMs,
+	keyGcsOAuthExpiresAt,
+	keyExpirationTime,
+}
+
+func parseCredentialExpiry(config iceberg.Properties) (time.Time, bool) {
+	for _, key := range credentialExpiryKeys {
+		if v, ok := config[key]; ok {
+			ms, err := strconv.ParseInt(v, 10, 64)
+			if err == nil && ms > 0 {
+				return time.UnixMilli(ms), true
+			}
+		}
+	}
+
+	return time.Time{}, false
+}
+
+type vendedCredentialRefresher struct {
+	mu        *semaphore.Weighted
+	cachedIO  iceio.IO
+	expiresAt time.Time
+
+	identifier []string
+	location   string
+	props      iceberg.Properties
+
+	fetchConfig func(ctx context.Context, ident []string) (iceberg.Properties, error)
+
+	nowFunc func() time.Time // for testing
+}
+
+func (v *vendedCredentialRefresher) now() time.Time {
+	if v.nowFunc != nil {
+		return v.nowFunc()
+	}
+
+	return time.Now()
+}
+
+func (v *vendedCredentialRefresher) loadFS(ctx context.Context) (iceio.IO, error) {
+	if err := v.mu.Acquire(ctx, 1); err != nil {
+		return nil, err
+	}
+	defer v.mu.Release(1)
+
+	if v.cachedIO != nil && !v.now().After(v.expiresAt) {
+		return v.cachedIO, nil
+	}
+
+	var config iceberg.Properties
+	if v.cachedIO == nil {
+		config = v.props
+	} else {
+		freshConfig, err := v.fetchConfig(ctx, v.identifier)
+		if err != nil {
+			return v.cachedIO, nil
+		}
+
+		config = make(iceberg.Properties, len(v.props)+len(freshConfig))
+		maps.Copy(config, v.props)
+		maps.Copy(config, freshConfig)
+	}
+
+	newIO, err := iceio.LoadFS(ctx, config, v.location)
+	if err != nil {
+		if v.cachedIO != nil {
+			return v.cachedIO, nil
+		}
+
+		return nil, err
+	}
+
+	v.cachedIO = newIO
+	v.expiresAt = v.expiresAtFromConfig(config)
+
+	return v.cachedIO, nil
+}
+
+func (v *vendedCredentialRefresher) expiresAtFromConfig(config iceberg.Properties) time.Time {
+	if exp, ok := parseCredentialExpiry(config); ok {
+		return exp
+	}
+
+	return v.now().Add(defaultVendedCredentialsTTL)
+}