Imports github.com/opentracing/opentracing-go github.com/opentracing/opentracing-go/ext github.com/openzipkin/zipkin-go-opentracing golang.org/x/net/context google.golang.org/grpc google.golang.org/grpc/metadata Standard library imports flag fmt grpclb/etcdv3 grpclb/services/server2/pb grpclb/tracing log net os os/signal syscall time