zero/telemetry: add reporter (#4855)

internal/zero/grpcconn/config.go

@@ -0,0 +1,121 @@
+package grpcconn
+
+import (
+	"crypto/tls"
+	"fmt"
+	"net"
+	"net/url"
+	"regexp"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+// config is the configuration for the gRPC client
+type config struct {
+	connectionURI string
+	// requireTLS is whether TLS should be used or cleartext
+	requireTLS bool
+	// opts are additional options to pass to the gRPC client
+	opts []grpc.DialOption
+}
+
+// NewConfig returns a new Config from an endpoint string, that has to be in a URL format.
+// The endpoint can be either http:// or https:// that will be used to determine whether TLS should be used.
+// if port is not specified, it will be inferred from the scheme (80 for http, 443 for https).
+func getConfig(endpoint string) (*config, error) {
+	c := new(config)
+	err := c.parseEndpoint(endpoint)
+	if err != nil {
+		return nil, fmt.Errorf("invalid endpoint: %w", err)
+	}
+	c.buildTLSOptions()
+	return c, nil
+}
+
+// GetConnectionURI returns connection string conforming to https://github.com/grpc/grpc/blob/master/doc/naming.md
+func (c *config) GetConnectionURI() string {
+	return c.connectionURI
+}
+
+// GetDialTimeout returns the timeout for the dial operation
+func (c *config) GetDialTimeout() time.Duration {
+	return time.Hour
+}
+
+// RequireTLS returns whether TLS should be used or cleartext
+func (c *config) RequireTLS() bool {
+	return c.requireTLS
+}
+
+// GetDialOptions returns the dial options to pass to the gRPC client
+func (c *config) GetDialOptions() []grpc.DialOption {
+	return c.opts
+}
+
+func (c *config) buildTLSOptions() {
+	creds := insecure.NewCredentials()
+	if c.requireTLS {
+		creds = credentials.NewTLS(&tls.Config{
+			MinVersion: tls.VersionTLS12,
+		})
+	}
+	c.opts = append(c.opts, grpc.WithTransportCredentials(creds))
+}
+
+func (c *config) parseEndpoint(endpoint string) error {
+	u, err := url.Parse(endpoint)
+	if err != nil {
+		return fmt.Errorf("error parsing endpoint url: %w", err)
+	}
+
+	if u.Path != "" && u.Path != "/" {
+		return fmt.Errorf("endpoint path is not supported: %s", u.Path)
+	}
+
+	host, port, err := splitHostPort(u.Host)
+	if err != nil {
+		return fmt.Errorf("error splitting host and port: %w", err)
+	}
+
+	var requireTLS bool
+	if u.Scheme == "http" {
+		requireTLS = false
+		if port == "" {
+			port = "80"
+		}
+	} else if u.Scheme == "https" {
+		requireTLS = true
+		if port == "" {
+			port = "443"
+		}
+	} else {
+		return fmt.Errorf("unsupported url scheme: %s", u.Scheme)
+	}
+
+	c.connectionURI = fmt.Sprintf("dns:%s:%s", host, port)
+	c.requireTLS = requireTLS
+
+	return nil
+}
+
+var rePort = regexp.MustCompile(`:(\d+)$`)
+
+func splitHostPort(hostport string) (host, port string, err error) {
+	if hostport == "" {
+		return "", "", fmt.Errorf("empty hostport")
+	}
+	if rePort.MatchString(hostport) {
+		host, port, err = net.SplitHostPort(hostport)
+		if host == "" {
+			return "", "", fmt.Errorf("empty host")
+		}
+		if port == "" {
+			return "", "", fmt.Errorf("empty port")
+		}
+		return host, port, err
+	}
+	return hostport, "", nil
+}