Elasticsearch¶

Since testcontainers-go v0.24.0

Introduction¶

The Testcontainers module for Elasticsearch.

Adding this module to your project dependencies¶

Please run the following command to add the Elasticsearch module to your Go dependencies:

go get github.com/testcontainers/testcontainers-go/modules/elasticsearch

Usage example¶

Creating a Elasticsearch container

ctx := context.Background()
elasticsearchContainer, err := elasticsearch.RunContainer(ctx, testcontainers.WithImage("docker.elastic.co/elasticsearch/elasticsearch:8.9.0"))
if err != nil {
    panic(err)
}
defer func() {
    if err := elasticsearchContainer.Terminate(ctx); err != nil {
        panic(err)
    }
}()

Module reference¶

The Elasticsearch module exposes one entrypoint function to create the Elasticsearch container, and this function receives two parameters:

func RunContainer(ctx context.Context, opts ...testcontainers.ContainerCustomizer) (*ElasticsearchContainer, error)

context.Context, the Go context.
testcontainers.ContainerCustomizer, a variadic argument for passing options.

Container Options¶

When starting the Elasticsearch container, you can pass options in a variadic way to configure it.

Image¶

If you need to set a different Elasticsearch Docker image, you can use testcontainers.WithImage with a valid Docker image for Elasticsearch. E.g. testcontainers.WithImage("docker.elastic.co/elasticsearch/elasticsearch:8.0.0").

Image Substitutions¶

Since testcontainers-go v0.26.0

In more locked down / secured environments, it can be problematic to pull images from Docker Hub and run them without additional precautions.

An image name substitutor converts a Docker image name, as may be specified in code, to an alternative name. This is intended to provide a way to override image names, for example to enforce pulling of images from a private registry.

Testcontainers for Go exposes an interface to perform this operations: ImageSubstitutor, and a No-operation implementation to be used as reference for custom implementations:

Image Substitutor InterfaceNoop Image Substitutor

// ImageSubstitutor represents a way to substitute container image names
type ImageSubstitutor interface {
    // Description returns the name of the type and a short description of how it modifies the image.
    // Useful to be printed in logs
    Description() string
    Substitute(image string) (string, error)
}

type NoopImageSubstitutor struct{}

// Description returns a description of what is expected from this Substitutor,
// which is used in logs.
func (s NoopImageSubstitutor) Description() string {
    return "NoopImageSubstitutor (noop)"
}

// Substitute returns the original image, without any change
func (s NoopImageSubstitutor) Substitute(image string) (string, error) {
    return image, nil
}

Using the WithImageSubstitutors options, you could define your own substitutions to the container images. E.g. adding a prefix to the images so that they can be pulled from a Docker registry other than Docker Hub. This is the usual mechanism for using Docker image proxies, caches, etc.

Wait Strategies¶

If you need to set a different wait strategy for the container, you can use testcontainers.WithWaitStrategy with a valid wait strategy.

Info

The default deadline for the wait strategy is 60 seconds.

At the same time, it's possible to set a wait strategy and a custom deadline with testcontainers.WithWaitStrategyAndDeadline.

Startup Commands¶

Since testcontainers-go v0.25.0

Testcontainers exposes the WithStartupCommand(e ...Executable) option to run arbitrary commands in the container right after it's started.

Info

To better understand how this feature works, please read the Create containers: Lifecycle Hooks documentation.

It also exports an Executable interface, defining one single method: AsCommand(), which returns a slice of strings to represent the command and positional arguments to be executed in the container.

You could use this feature to run a custom script, or to run a command that is not supported by the module right after the container is started.

Docker type modifiers¶

If you need an advanced configuration for the container, you can leverage the following Docker type modifiers:

testcontainers.WithConfigModifier
testcontainers.WithHostConfigModifier
testcontainers.WithEndpointSettingsModifier

Please read the Create containers: Advanced Settings documentation for more information.

Elasticsearch password¶

If you need to set a different password to request authorization when performing HTTP requests to the container, you can use the WithPassword option. By default, the username is set to elastic, and the password is set to changeme.

Info

In versions of Elasticsearch prior to 8.0.0, the default password is empty.

Custom Password

ctx := context.Background()
elasticsearchContainer, err := elasticsearch.RunContainer(
    ctx,
    testcontainers.WithImage("docker.elastic.co/elasticsearch/elasticsearch:7.9.2"),
    elasticsearch.WithPassword("foo"),
)
if err != nil {
    panic(err)
}
defer func() {
    err := elasticsearchContainer.Terminate(ctx)
    if err != nil {
        panic(err)
    }
}()

Configuring the access to the Elasticsearch container¶

The Elasticsearch container exposes its settings in order to configure the client to connect to it. With those settings it's very easy to setup up our preferred way to connect to the container. We are going to show you two ways to connect to the container, using the HTTP client from the standard library, and using the Elasticsearch client.

Info

The TLS access is only supported on Elasticsearch 8 and above, so please pay attention to how the below examples are using the CACert and URL settings.

Using the standard library's HTTP client¶

Create an HTTP client

client := http.DefaultClient

if esContainer.Settings.CACert == nil {
    return client
}

// configure TLS transport based on the certificate bytes that were retrieved from the container
caCertPool := x509.NewCertPool()
caCertPool.AppendCertsFromPEM(esContainer.Settings.CACert)

client.Transport = &http.Transport{
    TLSClientConfig: &tls.Config{
        RootCAs: caCertPool,
    },
}

The esContainer instance is obtained from the elasticsearch.RunContainer function.

In the case you configured the Elasticsearch container to set up a password, you'll need to add the Authorization header to the request. You can use the SetBasicAuth method from the HTTP request to generate the header value.

Using an authenticated client

req.SetBasicAuth(esContainer.Settings.Username, esContainer.Settings.Password)

Using the Elasticsearch client¶

First, you must install the Elasticsearch Go client, so please read their install guide for more information.

Create an Elasticsearch client

ctx := context.Background()
elasticsearchContainer, err := elasticsearch.RunContainer(
    ctx,
    testcontainers.WithImage("docker.elastic.co/elasticsearch/elasticsearch:8.9.0"),
    elasticsearch.WithPassword("foo"),
)
if err != nil {
    panic(err)
}
defer func() {
    err := elasticsearchContainer.Terminate(ctx)
    if err != nil {
        panic(err)
    }
}()

cfg := es.Config{
    Addresses: []string{
        elasticsearchContainer.Settings.Address,
    },
    Username: "elastic",
    Password: elasticsearchContainer.Settings.Password,
    CACert:   elasticsearchContainer.Settings.CACert,
}

esClient, err := es.NewClient(cfg)
if err != nil {
    panic(err)
}

resp, err := esClient.Info()
if err != nil {
    panic(err)
}
defer resp.Body.Close()