Running pact mock service as a docker container with interactions

[rashmy-dev]

Hi,
I am running into an issue when running pact mock service as a docker container with a specific set of interactions. Could you please help in resolving this issue?

Here is what I did -

1. Write a go pact contract test for Provider using the example here. Note I changed it to use V4. Below is my modified code.
2. I ran the test code and it generated the pact contract file as shown below.
3. Next, I downloaded the latest docker image "pactfoundation/pact-cli"
4. Started the docker container using the below command to start the mock service with the generated pact file.

docker run -dit \
  --rm \
  --name pact-mock-service \
  -p 1234:1234 \
  -v /home/myuser/pact-testing/pacts:/tmp/pacts \
  pactfoundation/pact-cli:latest \
  mock-service \
  -p 1234 \
  --host 0.0.0.0 \
  --pact-dir /tmp/pacts

6. Next, if I access the endpoint curl http://localhost:1234/products/10, I get the error {"message":"No interaction found for GET /products/10","interaction_diffs":[]}
   NOTE: I have given the absolute path where the generated pact file exists when running the docker and when running docker exec -it pact-mock-service ls /tmp/pacts. it shows the file as existing.

Go Test Code

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"testing"

	"github.com/pact-foundation/pact-go/v2/consumer"
	"github.com/pact-foundation/pact-go/v2/matchers"
	"github.com/stretchr/testify/assert"
)

type S = matchers.S

func TestProductAPIClient(t *testing.T) {
	// Specify the two applications in the integration we are testing
	// NOTE: this can usually be extracted out of the individual test for re-use)
	mockProvider, err := consumer.NewV4Pact(consumer.MockHTTPProviderConfig{
		Consumer: "PactGoProductAPIConsumer",
		Provider: "PactGoProductAPI",
	})
	assert.NoError(t, err)

	// Arrange: Setup our expected interactions
	err = mockProvider.
		AddInteraction().
		Given("A product with ID 10 exists").
		UponReceiving("A request for Product 10").
		WithRequest("GET", "/products/10").
		WillRespondWith(200, func(b *consumer.V4ResponseBuilder) {
			b.BodyMatch(&Product{})
		}).
		ExecuteTest(t, func(config consumer.MockServerConfig) error {
			// Act: test our API client behaves correctly
			// Initialise the API client and point it at the Pact mock server
			client := newClient(config.Host, config.Port)

			// Execute the API client
			product, err := client.GetProduct("10")

			// Assert: check the result
			assert.NoError(t, err)
			assert.Equal(t, 10, product.ID)

			return err
		})

	assert.NoError(t, err)
}

// Product domain model
type Product struct {
	ID    int    `json:"id" pact:"example=10"`
	Name  string `json:"name" pact:"example=Billy"`
	Price string `json:"price" pact:"example=23.33"`
}

// Product API Client to test
type productAPIClient struct {
	port int
	host string
}

func newClient(host string, port int) *productAPIClient {
	return &productAPIClient{
		host: host,
		port: port,
	}
}

func (u *productAPIClient) GetProduct(id string) (*Product, error) {
	resp, err := http.Get(fmt.Sprintf("http://%s:%d:%s%s", u.host, u.port, "/products/", id))

	if err != nil {
		return nil, err
	}

	product := new(Product)
	err = json.NewDecoder(resp.Body).Decode(product)
	if err != nil {
		return nil, err
	}

	return product, err
}

Generated pact file from the above test

{
  "consumer": {
    "name": "PactGoProductAPIConsumer"
  },
  "interactions": [
    {
      "description": "A request for Product 10",
      "pending": false,
      "providerStates": [
        {
          "name": "A product with ID 10 exists"
        }
      ],
      "request": {
        "method": "GET",
        "path": "/products/10"
      },
      "response": {
        "body": {
          "content": {
            "id": 10,
            "name": "Billy",
            "price": "23.33"
          },
          "contentType": "application/json",
          "encoded": false
        },
        "headers": {
          "Content-Type": [
            "application/json"
          ]
        },
        "matchingRules": {
          "body": {
            "$.id": {
              "combine": "AND",
              "matchers": [
                {
                  "match": "type"
                }
              ]
            },
            "$.name": {
              "combine": "AND",
              "matchers": [
                {
                  "match": "type"
                }
              ]
            },
            "$.price": {
              "combine": "AND",
              "matchers": [
                {
                  "match": "type"
                }
              ]
            }
          }
        },
        "status": 200
      },
      "transport": "http",
      "type": "Synchronous/HTTP"
    }
  ],
  "metadata": {
    "pactRust": {
      "ffi": "0.4.23",
      "mockserver": "1.2.10",
      "models": "1.2.5"
    },
    "pactSpecification": {
      "version": "4.0"
    }
  },
  "provider": {
    "name": "PactGoProductAPI"
  }
}

[mefellows]

This is not how the pact-mock-service is supposed to be used. The service is designed to be an administrative system used by the Pact SDKs to manage the pact consumer test. For the API, see https://github.com/pact-foundation/pact-mock_service.

It's superseded by the FFI.

I think you want to create a stub API from an existing Pact file - if so, you can use https://github.com/pact-foundation/pact-stub-server for that.

[rashmy-dev]

Thank you for the reply. The pact-stub-server is indeed what I needed.

My intention was two-fold -

1. Write Consumer Contract Tests and pass them off to the Provider service team.
2. Use the generated pact file to run the Provider as a mock service locally or in CI/CD pipeline to execute the integration tests of my own service. This would allow running my service API integration tests without invoking the actual dependent service in most of the pipelines expect for scheduled run where I can switch the tests to use the endpoint of the actual dependent service.