Microcks Testcontainers Go

Go library for Testcontainers that enables embedding Microcks into your Go unit tests with lightweight, throwaway instance thanks to containers

Build Status

Latest released version is v0.2.0.

Current development version is v0.2.1.

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OpenSSF best practices on Microcks core

Community

• Documentation
• Microcks Community and community meeting
• Join us on Discord, on GitHub Discussions or CNCF Slack #microcks channel

To get involved with our community, please make sure you are familiar with the project's Code of Conduct.

How to use it?

Include it into your project dependencies

To get the latest version, use go1.21+ and fetch using the go get command. For example:

go get microcks.io/testcontainers-go@latest

To get a specific version, use go1.22+ and fetch the desired version using the go get command. For example:

go get microcks.io/testcontainers-go@v0.2.0

Startup the container

You just have to specify the container image you'd like to use. This library requires a Microcks uber distribution (with no MongoDB dependency).

import (
    microcks "microcks.io/testcontainers-go"
)

microcksContainer, err := microcks.Run(ctx, "quay.io/microcks/microcks-uber:nightly")

Import content in Microcks

To use Microcks mocks or contract-testing features, you first need to import OpenAPI, Postman Collection, GraphQL or gRPC artifacts. Artifacts can be imported as main/Primary ones or as secondary ones. See Multi-artifacts support for details.

You can do it before starting the container using simple paths:

import (
    microcks "microcks.io/testcontainers-go"
)

microcksContainer, err := microcks.Run(ctx, 
    "quay.io/microcks/microcks-uber:nightly",
    microcks.WithMainArtifact("testdata/apipastries-openapi.yaml"),
    microcks.WithSecondaryArtifact("testdata/apipastries-postman-collection.json"),
)

or once the container started using ImportAsMainArtifact and ImportAsSecondaryArtifact functions:

status, err := microcksContainer.ImportAsMainArtifact(context.Background(), "testdata/apipastries-openapi.yaml")
if err != nil {
    log.Fatal(err)
}

status, err = microcksContainer.ImportAsSecondaryArtifact(context.Background(), "testdata/apipastries-postman-collection.json")
if err != nil {
    log.Fatal(err)
}

status if the status of the Http response from the microcks container and should be equal to 201 in case of success.

Please refer to our microcks_test for comprehensive example on how to use it.

Using mock endpoints for your dependencies

During your test setup, you'd probably need to retrieve mock endpoints provided by Microcks containers to setup your base API url calls. You can do it like this:

baseApiUrl := microcksContainer.RestMockEndpoint(ctx, "API Pastries", "0.0.1")

The container provides methods for different supported API styles/protocols (Soap, GraphQL, gRPC,...).

The container also provides HttpEndpoint() for raw access to those API endpoints.

Launching new contract-tests

If you want to ensure that your application under test is conformant to an OpenAPI contract (or many contracts), you can launch a Microcks contract/conformance test using the local server port you're actually running:

import (
    client "microcks.io/go-client"
    microcks "microcks.io/testcontainers-go"
)

// Build a new TestRequest.
testRequest := client.TestRequest{
    ServiceId:    "API Pastries:0.0.1",
    RunnerType:   client.TestRunnerTypeOPENAPISCHEMA,
    TestEndpoint: "http://bad-impl:3001",
    Timeout:      2000,
}

testResult, err := microcksContainer.TestEndpoint(context.Background(), &testRequest)
require.NoError(t, err)

require.False(t, testResult.Success)
require.Equal(t, "http://bad-impl:3001", testResult.TestedEndpoint)

The testResult gives you access to all details regarding success of failure on different test cases.

Advanced features with MicrocksContainersEnsemble

The MicrocksContainer referenced above supports essential features of Microcks provided by the main Microcks container. The list of supported features is the following:

• Mocking of REST APIs using different kinds of artifacts,
• Contract-testing of REST APIs using OPEN_API_SCHEMA runner/strategy,
• Mocking and contract-testing of SOAP WebServices,
• Mocking and contract-testing of GraphQL APIs,
• Mocking and contract-testing of gRPC APIs.

To support features like Asynchronous API and POSTMAN contract-testing, we introduced MicrocksContainersEnsemble that allows managing additional Microcks services. MicrocksContainersEnsemble allow you to implement Different levels of API contract testing in the Inner Loop with Testcontainers!

A MicrocksContainersEnsemble conforms to Testcontainers lifecycle methods and presents roughly the same interface as a MicrocksContainer. You can create and build an ensemble that way:

import (
    ensemble "microcks.io/testcontainers-go/ensemble"
)

ensembleContainers, err := ensemble.RunContainers(ctx, 
    ensemble.WithMainArtifact("testdata/apipastries-openapi.yaml"),
    ensemble.WithSecondaryArtifact("testdata/apipastries-postman-collection.json"),
)

A MicrocksContainer is wrapped by an ensemble and is still available to import artifacts and execute test methods. You have to access it using:

microcks := ensemble.GetMicrocksContainer();
microcks.ImportAsMainArtifact(...);
microcks.Logs(...);

Please refer to our ensemble tests for comprehensive example on how to use it.

Postman contract-testing

On this ensemble you may want to enable additional features such as Postman contract-testing:

import (
    ensemble "microcks.io/testcontainers-go/ensemble"
)

ensembleContainers, err := ensemble.RunContainers(ctx,
    // Microcks container in ensemble
    ensemble.WithMainArtifact("testdata/apipastries-openapi.yaml"),
    ensemble.WithSecondaryArtifact("testdata/apipastries-postman-collection.json"),

    // Postman container in ensemble
    ensemble.WithPostman(true),
)

You can execute a POSTMAN test using an ensemble that way:

// Build a new TestRequest.
testRequest := client.TestRequest{
    ServiceId:    "API Pastries:0.0.1",
    RunnerType:   client.TestRunnerTypePOSTMAN,
    TestEndpoint: "http://good-impl:3003",
    Timeout:      2000,
}

testResult := ensemble.
    GetMicrocksContainer().
    TestEndpoint(context.Background(), testRequest);

Asynchronous API support

Asynchronous API feature need to be explicitly enabled as well. In the case you want to use it for mocking purposes, you'll have to specify additional connection details to the broker of your choice. See an example below with connection to a Kafka broker:

ensembleContainers, err := ensemble.RunContainers(ctx,
	// ...
	ensemble.WithAsyncFeature(),
	ensemble.WithKafkaConnection(kafka.Connection{
		BootstrapServers: "kafka:9092",
	}),
)

Using mock endpoints for your dependencies

Once started, the ensembleContainers.GetAsyncMinionContainer() provides methods for retrieving mock endpoint names for the different supported protocols (WebSocket, Kafka, SQS and SNS).

kafkaTopic := ensembleContainers.
	GetAsyncMinionContainer().
	KafkaMockTopic("Pastry orders API", "0.1.0", "SUBSCRIBE pastry/orders")

Launching new contract-tests

Using contract-testing techniques on Asynchronous endpoints may require a different style of interacting with the Microcks container. For example, you may need to:

• Start the test making Microcks listen to the target async endpoint,
• Activate your System Under Tests so that it produces an event,
• Finalize the Microcks tests and actually ensure you received one or many well-formed events.

For that the MicrocksContainer now provides a TestEndpointAsync(ctx context.Context, testRequest *client.TestRequest, testResult chan *client.TestResult) method that actually uses a channel. Once invoked, you may trigger your application events and then wait to receive the future result to assert like this:

// Start the test, making Microcks listen the endpoint provided in testRequest
testResultChan := make(chan *client.TestResult)
go ensembleContainers.GetMicrocksContainer().TestEndpointAsync(ctx, &testRequest, testResultChan)

// Here below: activate your app to make it produce events on this endpoint.
// myapp.invokeBusinessMethodThatTriggerEvents();

// Now retrieve the final test result and assert.
testResult := <-testResultChan
require.NoError(t, err)
require.True(t, testResult.Success)