grpc-dump intercepts all gRPC requests and responses and logs all the request metadata in a JSON stream.
These streams can be used for all sorts of applications including:
jq to easily filter and transform the data for analysis.grpc-fixture to intercept future gRPC requests from the application and replay the responses saved in the dump.grpc-replay to replay the requests exactly as the client made them and check that the server still responds the same way.Usage of grpc-dump:
-cert string
Certificate file to use for serving using TLS.
-destination string
Destination server to forward requests to if no destination can be inferred from the request itself. This is generally only used for clients not supporting HTTP proxies.
-key string
Key file to use for serving using TLS.
-port int
Port to listen on.
-proto_descriptors string
A comma separated list of proto descriptors to load gRPC service definitions from.
-proto_roots string
A comma separated list of directories to search for gRPC service definitions.
-system_proxy
Automatically configure system to use this as the proxy for all connections.
The output of grpc-dump is split between stdout and stderr. Messages designed for humans (e.g. info and warning logs) are written to stderr while the machine-readable JSON stream is written to stdout.
The JSON stream is a newline separated list of JSON objects (designed to be easily processed by tools like jq).
Each message has the format:
{
"service" : "gRPC Service name",
"method" : "gRPC Method name",
"messages" : [
{
"message_origin" : "server|client",
"timestamp" : "RFC3339 timestamp",
"raw_message" : "base64 encoded bytes of the raw protobuf",
"message" : {
// The parsed representation of the message
}
}
],
"error" : { // present if the gRPC status is not OK
"code" : "Status code string",
"message" : "the gRPC error message"
},
"metadata" : { // the metadata present in the gRPC context
"metadataKey" : ["metadataValue"]
}
}
For troubleshooting see the generic grpc-proxy troubleshooting steps here.