grpc-mock is yet another grpc mock server inspired by GripMock.
grpc-mock implements the grpc mock server by reflections of .proto
files instead of code generation that GripMock does.
Use go
tool to install:
go get github.com/monlabs/grpc-mock/cmd/gmock
Step 1: Write your proto file which should contains at least one service
.
helloworld.proto
syntax = "proto3";
package helloworld;
// The greeting service definition.
service Greeter {
// Sends a greeting
rpc SayHello (HelloRequest) returns (HelloReply) {}
}
// The request message containing the user's name.
message HelloRequest {
string name = 1;
}
// The response message containing the greetings
message HelloReply {
string message = 1;
}
Step 2: Write the stub files in JSON
format for the services defined in the proto file.
stubs/helloworld.json
[
{
"service": "helloworld.Greeter",
"method": "SayHello",
"in": {
"equals": {
"name": "hi"
}
},
"out": {
"data": {
"message": "lemon"
}
}
},
{
"service": "helloworld.Greeter",
"method": "SayHello",
"in": {
"matches": {
"name": "^[0-9]+$"
}
},
"out": {
"data": {
"message": "hi numbers"
}
}
}
]
Step 3: Start the grpc mock server.
./stubs
is the directory where all stub files reside.
grpc-mock -mock-addr :22222 -import-path . -proto helloworld.proto -stub-dir ./stubs
The flag mock-addr
defines the address mock server listens on.
Step 4: Ready to test it.
We use grpcurl
to invoke rpc methods.
grpcurl -plaintext -d '{"name": "01"}' localhost:22222 helloworld.Greeter/SayHello
The output is:
{
"message": "hi numbers"
}
More examples
The input and expected output comprise of a Stub
. When a request is received, the mock server tries to match the stub with the request, and then reponds with the expected output in the matched stub. There're two ways to manage your stubs: static and dynamic.
Like in the example above, you save the stubs in files. Let the mock server load them on starting.
You also can start the mock server without specified stubs and call the admin API to dynamically add stubs. The API server runs on :22220
.
GET /v1/stubs
: get all stubs.POST /v1/stubs
: create stubs.DELETE /v1/stubs
: delete stubs.
grpc-mock has the same matching rules as gripmock.