Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/parsers/avro/schema_registry.go

@@ -0,0 +1,134 @@
+package avro
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/linkedin/goavro/v2"
+)
+
+type schemaAndCodec struct {
+	Schema string
+	Codec  *goavro.Codec
+}
+
+type schemaRegistry struct {
+	url      string
+	username string
+	password string
+	cache    map[int]*schemaAndCodec
+	client   *http.Client
+	mu       sync.RWMutex
+}
+
+const schemaByID = "%s/schemas/ids/%d"
+
+func newSchemaRegistry(addr, caCertPath string) (*schemaRegistry, error) {
+	var client *http.Client
+	var tlsCfg *tls.Config
+	if caCertPath != "" {
+		caCert, err := os.ReadFile(caCertPath)
+		if err != nil {
+			return nil, err
+		}
+		caCertPool := x509.NewCertPool()
+		caCertPool.AppendCertsFromPEM(caCert)
+		tlsCfg = &tls.Config{
+			RootCAs: caCertPool,
+		}
+	}
+	client = &http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: tlsCfg,
+			MaxIdleConns:    10,
+			IdleConnTimeout: 90 * time.Second,
+		},
+	}
+
+	u, err := url.Parse(addr)
+	if err != nil {
+		return nil, fmt.Errorf("parsing registry URL failed: %w", err)
+	}
+
+	var username, password string
+	if u.User != nil {
+		username = u.User.Username()
+		password, _ = u.User.Password()
+	}
+
+	registry := &schemaRegistry{
+		url:      u.String(),
+		username: username,
+		password: password,
+		cache:    make(map[int]*schemaAndCodec),
+		client:   client,
+	}
+
+	return registry, nil
+}
+
+// Helper function to make managing lock easier
+func (sr *schemaRegistry) getSchemaAndCodecFromCache(id int) (*schemaAndCodec, error) {
+	// Read-lock the cache map before access.
+	sr.mu.RLock()
+	defer sr.mu.RUnlock()
+	if v, ok := sr.cache[id]; ok {
+		return v, nil
+	}
+	return nil, fmt.Errorf("schema %d not in cache", id)
+}
+
+func (sr *schemaRegistry) getSchemaAndCodec(id int) (*schemaAndCodec, error) {
+	v, err := sr.getSchemaAndCodecFromCache(id)
+	if err == nil {
+		return v, nil
+	}
+
+	req, err := http.NewRequest(http.MethodGet, fmt.Sprintf(schemaByID, sr.url, id), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	if sr.username != "" {
+		req.SetBasicAuth(sr.username, sr.password)
+	}
+
+	resp, err := sr.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var jsonResponse map[string]interface{}
+	if err := json.NewDecoder(resp.Body).Decode(&jsonResponse); err != nil {
+		return nil, err
+	}
+
+	schema, ok := jsonResponse["schema"]
+	if !ok {
+		return nil, errors.New("malformed response from schema registry: no 'schema' key")
+	}
+
+	schemaValue, ok := schema.(string)
+	if !ok {
+		return nil, fmt.Errorf("malformed response from schema registry: %v cannot be cast to string", schema)
+	}
+	codec, err := goavro.NewCodec(schemaValue)
+	if err != nil {
+		return nil, err
+	}
+	retval := &schemaAndCodec{Schema: schemaValue, Codec: codec}
+	// Lock the cache map before update.
+	sr.mu.Lock()
+	defer sr.mu.Unlock()
+	sr.cache[id] = retval
+	return retval, nil
+}