Files
gatus/client/grpc.go
2025-11-07 15:19:13 -05:00

72 lines
2.3 KiB
Go

package client
import (
"context"
"crypto/tls"
"net"
"time"
"github.com/TwiN/logr"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/credentials/insecure"
health "google.golang.org/grpc/health/grpc_health_v1"
)
// PerformGRPCHealthCheck dials a gRPC target and performs the standard Health/Check RPC.
// Returns whether a connection was established, the serving status string, an error (if any), and the elapsed duration.
func PerformGRPCHealthCheck(address string, useTLS bool, cfg *Config) (bool, string, error, time.Duration) {
if cfg == nil {
cfg = GetDefaultConfig()
}
ctx, cancel := context.WithTimeout(context.Background(), cfg.Timeout)
defer cancel()
var opts []grpc.DialOption
// Transport credentials
if useTLS {
tlsCfg := &tls.Config{InsecureSkipVerify: cfg.Insecure}
if cfg.HasTLSConfig() && cfg.TLS.isValid() == nil {
tlsCfg = configureTLS(tlsCfg, *cfg.TLS)
}
opts = append(opts, grpc.WithTransportCredentials(credentials.NewTLS(tlsCfg)))
} else {
opts = append(opts, grpc.WithTransportCredentials(insecure.NewCredentials()))
}
// Custom dialer for DNS resolver or SSH tunnel
opts = append(opts, grpc.WithContextDialer(func(ctx context.Context, addr string) (net.Conn, error) {
if cfg.ResolvedTunnel != nil {
return cfg.ResolvedTunnel.Dial("tcp", addr)
}
if cfg.HasCustomDNSResolver() {
resolverCfg, err := cfg.parseDNSResolver()
if err != nil {
// Shouldn't happen because already validated; log and fall back
logr.Errorf("[client.PerformGRPCHealthCheck] invalid DNS resolver: %v", err)
} else {
d := &net.Dialer{Resolver: &net.Resolver{PreferGo: true, Dial: func(ctx context.Context, network, _ string) (net.Conn, error) {
d := net.Dialer{}
return d.DialContext(ctx, resolverCfg.Protocol, resolverCfg.Host+":"+resolverCfg.Port)
}}}
return d.DialContext(ctx, "tcp", addr)
}
}
var d net.Dialer
return d.DialContext(ctx, "tcp", addr)
}))
start := time.Now()
conn, err := grpc.DialContext(ctx, address, opts...)
if err != nil {
return false, "", err, time.Since(start)
}
defer conn.Close()
client := health.NewHealthClient(conn)
resp, err := client.Check(ctx, &health.HealthCheckRequest{Service: ""})
if err != nil {
return false, "", err, time.Since(start)
}
return true, resp.GetStatus().String(), nil, time.Since(start)
}