78 lines
2.1 KiB
Go
78 lines
2.1 KiB
Go
package checks
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import (
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"context"
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"crypto/tls"
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"fmt"
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"strings"
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"time"
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"google.golang.org/grpc"
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"google.golang.org/grpc/credentials"
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hv1 "google.golang.org/grpc/health/grpc_health_v1"
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"google.golang.org/grpc/resolver"
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)
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var ErrGRPCUnhealthy = fmt.Errorf("gRPC application didn't report service healthy")
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// GrpcHealthProbe connects to gRPC application and queries health service for application/service status.
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type GrpcHealthProbe struct {
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server string
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request *hv1.HealthCheckRequest
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timeout time.Duration
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dialOptions []grpc.DialOption
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}
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// NewGrpcHealthProbe constructs GrpcHealthProbe from target string in format
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// server[/service]
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// If service is omitted, health of the entire application is probed
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func NewGrpcHealthProbe(target string, timeout time.Duration, tlsConfig *tls.Config) *GrpcHealthProbe {
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serverAndService := strings.SplitN(target, "/", 2)
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request := hv1.HealthCheckRequest{}
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if len(serverAndService) > 1 {
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request.Service = serverAndService[1]
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}
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var dialOptions = []grpc.DialOption{}
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if tlsConfig != nil {
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dialOptions = append(dialOptions, grpc.WithTransportCredentials(credentials.NewTLS(tlsConfig)))
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} else {
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dialOptions = append(dialOptions, grpc.WithInsecure())
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}
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return &GrpcHealthProbe{
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request: &request,
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timeout: timeout,
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dialOptions: dialOptions,
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}
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}
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// Check if the target of this GrpcHealthProbe is healthy
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// If nil is returned, target is healthy, otherwise target is not healthy
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func (probe *GrpcHealthProbe) Check(target string) error {
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serverAndService := strings.SplitN(target, "/", 2)
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serverWithScheme := fmt.Sprintf("%s:///%s", resolver.GetDefaultScheme(), serverAndService[0])
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ctx, cancel := context.WithTimeout(context.Background(), probe.timeout)
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defer cancel()
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connection, err := grpc.DialContext(ctx, serverWithScheme, probe.dialOptions...)
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if err != nil {
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return err
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}
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defer connection.Close()
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client := hv1.NewHealthClient(connection)
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response, err := client.Check(ctx, probe.request)
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if err != nil {
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return err
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}
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if response == nil || response.Status != hv1.HealthCheckResponse_SERVING {
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return ErrGRPCUnhealthy
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}
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return nil
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}
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