ScyllaDB

Not available until the next release of testcontainers-go main

Introduction

The Testcontainers module for ScyllaDB, a NoSQL database fully compatible with Apache Cassandra and DynamoDB, allows you to create a ScyllaDB container for testing purposes.

Adding this module to your project dependencies

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

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

Usage example

Creating a ScyllaDB container

    ctx := context.Background()

    // runScyllaDBContainerWithCustomCommands {
    scyllaContainer, err := scylladb.Run(ctx,
        "scylladb/scylla:6.2",
        scylladb.WithCustomCommands("--memory=1G", "--smp=2"),
    )
    // }
    defer func() {
        if err := testcontainers.TerminateContainer(scyllaContainer); err != nil {
            log.Printf("failed to terminate container: %s", err)
        }
    }()
    if err != nil {
        log.Printf("failed to start container: %s", err)
        return
    }

    state, err := scyllaContainer.State(ctx)
    if err != nil {
        log.Printf("failed to get container state: %s", err)
        return
    }

    fmt.Println(state.Running)

    connectionHost, err := scyllaContainer.NonShardAwareConnectionHost(ctx)
    if err != nil {
        log.Printf("failed to get connection host: %s", err)
        return
    }

    if err := runGoCQLExampleTest(connectionHost); err != nil {
        log.Printf("failed to run Go CQL example test: %s", err)
        return
    }

    // Output:
    // true

 ⋯

    ctx := context.Background()

    // runScyllaDBContainerWithAlternator {

    scyllaContainer, err := scylladb.Run(ctx,
        "scylladb/scylla:6.2",
        scylladb.WithAlternator(),
    )
    // }
    defer func() {
        if err := testcontainers.TerminateContainer(scyllaContainer); err != nil {
            log.Printf("failed to terminate container: %s", err)
        }
    }()
    if err != nil {
        log.Printf("failed to start container: %s", err)
        return
    }

    state, err := scyllaContainer.State(ctx)
    if err != nil {
        log.Printf("failed to get container state: %s", err)
        return
    }

    fmt.Println(state.Running)

    // scyllaDbAlternatorConnectionHost {
    // the alternator port is the default port 8000
    _, err = scyllaContainer.AlternatorConnectionHost(ctx)
    // }
    if err != nil {
        log.Printf("failed to get connection host: %s", err)
        return
    }

    // Output:
    // true

 ⋯

    ctx := context.Background()

    // runScyllaDBContainerWithShardAwareness {
    scyllaContainer, err := scylladb.Run(ctx,
        "scylladb/scylla:6.2",
        scylladb.WithShardAwareness(),
    )
    // }
    defer func() {
        if err := testcontainers.TerminateContainer(scyllaContainer); err != nil {
            log.Printf("failed to terminate container: %s", err)
        }
    }()
    if err != nil {
        log.Printf("failed to start container: %s", err)
        return
    }

    state, err := scyllaContainer.State(ctx)
    if err != nil {
        log.Printf("failed to get container state: %s", err)
        return
    }

    fmt.Println(state.Running)

    // scyllaDbShardAwareConnectionHost {
    connectionHost, err := scyllaContainer.ShardAwareConnectionHost(ctx)
    // }
    if err != nil {
        log.Printf("failed to get connection host: %s", err)
        return
    }

    if err := runGoCQLExampleTest(connectionHost); err != nil {
        log.Printf("failed to run Go CQL example test: %s", err)
        return
    }

    // Output:
    // true

 ⋯

    // runScyllaDBContainerWithConfig {
    ctx := context.Background()

    cfgBytes := `cluster_name: 'Amazing ScyllaDB Test'
num_tokens: 256
commitlog_sync: periodic
commitlog_sync_period_in_ms: 10000
commitlog_segment_size_in_mb: 32
schema_commitlog_segment_size_in_mb: 128
seed_provider:
  - class_name: org.apache.cassandra.locator.SimpleSeedProvider
    parameters:
      - seeds: "127.0.0.1"
listen_address: localhost
native_transport_port: 9042
native_shard_aware_transport_port: 19042
read_request_timeout_in_ms: 5000
write_request_timeout_in_ms: 2000
cas_contention_timeout_in_ms: 1000
endpoint_snitch: SimpleSnitch
rpc_address: localhost
api_port: 10000
api_address: 127.0.0.1
batch_size_warn_threshold_in_kb: 128
batch_size_fail_threshold_in_kb: 1024
partitioner: org.apache.cassandra.dht.Murmur3Partitioner
commitlog_total_space_in_mb: -1
murmur3_partitioner_ignore_msb_bits: 12
strict_is_not_null_in_views: true
maintenance_socket: ignore
enable_tablets: true
`

    scyllaContainer, err := scylladb.Run(ctx,
        "scylladb/scylla:6.2",
        scylladb.WithConfig(strings.NewReader(cfgBytes)),
    )
    // }
    defer func() {
        if err := testcontainers.TerminateContainer(scyllaContainer); err != nil {
            log.Printf("failed to terminate container: %s", err)
        }
    }()
    if err != nil {
        log.Printf("failed to start container: %s", err)
        return
    }

 ⋯

    // runBaseScyllaDBContainer {
    ctx := context.Background()

    scyllaContainer, err := scylladb.Run(ctx,
        "scylladb/scylla:6.2",
        scylladb.WithShardAwareness(),
    )
    defer func() {
        if err := testcontainers.TerminateContainer(scyllaContainer); err != nil {
            log.Printf("failed to terminate container: %s", err)
        }
    }()
    if err != nil {
        log.Printf("failed to start container: %s", err)
        return
    }
    // }

    state, err := scyllaContainer.State(ctx)
    if err != nil {
        log.Printf("failed to get container state: %s", err)
        return
    }

    fmt.Println(state.Running)

    // scyllaDbNonShardAwareConnectionHost {
    connectionHost, err := scyllaContainer.NonShardAwareConnectionHost(ctx)
    // }
    if err != nil {
        log.Printf("failed to get connection host: %s", err)
        return
    }

    if err := runGoCQLExampleTest(connectionHost); err != nil {
        log.Printf("failed to run Go CQL example test: %s", err)
        return
    }

    // Output:
    // true

Module Reference

Run function

• Not available until the next release of testcontainers-go main

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

func Run(ctx context.Context, img string, opts ...testcontainers.ContainerCustomizer) (*ScyllaDBContainer, error)

• context.Context, the Go context.
• string, the Docker image to use.
• testcontainers.ContainerCustomizer, a variadic argument for passing options.

Info

By default, we add the --developer-mode=1 flag to the ScyllaDB container to disable the various checks Scylla performs. Also in scenarios in which static partitioning is not desired - like mostly-idle cluster without hard latency requirements, the --overprovisioned command-line option is recommended. This enables certain optimizations for ScyllaDB to run efficiently in an overprovisioned environment. You can change it by using the WithCustomCommand function.

Container Options

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

Image

If you need to set a different ScyllaDB Docker image, you can set a valid Docker image as the second argument in the Run function. Eg:

scylladb.Run(context.Background(), "scylladb/scylla:6.2.1")
// OR
scylladb.Run(context.Background(), "scylladb/scylla:5.6")

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 operation: 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.

WithEnv

• Since testcontainers-go v0.29.0

If you need to either pass additional environment variables to a container or override them, you can use testcontainers.WithEnv for example:

postgres, err = postgresModule.Run(ctx, "postgres:15-alpine", testcontainers.WithEnv(map[string]string{"POSTGRES_INITDB_ARGS": "--no-sync"}))

WithHostPortAccess

• Since testcontainers-go v0.31.0

If you need to access a port that is already running in the host, you can use testcontainers.WithHostPortAccess for example:

postgres, err = postgresModule.Run(ctx, "postgres:15-alpine", testcontainers.WithHostPortAccess(8080))

To understand more about this feature, please read the Exposing host ports to the container documentation.

WithLogConsumers

• Since testcontainers-go v0.28.0

If you need to consume the logs of the container, you can use testcontainers.WithLogConsumers with a valid log consumer. An example of a log consumer is the following:

type TestLogConsumer struct {
    Msgs []string
}

func (g *TestLogConsumer) Accept(l Log) {
    g.Msgs = append(g.Msgs, string(l.Content))
}

WithLogger

• Since testcontainers-go v0.29.0

If you need to either pass logger to a container, you can use testcontainers.WithLogger.

Info

Consider calling this before other "With" functions as these may generate logs.

In this example we also use the testcontainers-go log.TestLogger, which writes to the passed in testing.TB using Logf. The result is that we capture all logging from the container into the test context meaning its hidden behind go test -v and is associated with the relevant test, providing the user with useful context instead of appearing out of band.

func TestHandler(t *testing.T) {
    logger := log.TestLogger(t)
    ctr, err := postgresModule.Run(ctx, "postgres:15-alpine", testcontainers.WithLogger(logger))
    CleanupContainer(t, ctr)
    require.NoError(t, err)
    // Do something with container.
}

Please read the Following Container Logs documentation for more information about creating log consumers.

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 the following methods:

• AsCommand(), which returns a slice of strings to represent the command and positional arguments to be executed in the container;
• Options(), which returns the slice of functional options with the Docker's ExecConfigs used to create the command in the container (the working directory, environment variables, user executing the command, etc) and the possible output format (Multiplexed).

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.

Ready Commands

• Since testcontainers-go v0.28.0

Testcontainers exposes the WithAfterReadyCommand(e ...Executable) option to run arbitrary commands in the container right after it's ready, which happens when the defined wait strategies have finished with success.

Info

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

It leverages the Executable interface 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 ready.

WithNetwork

• Since testcontainers-go v0.27.0

By default, the container is started in the default Docker network. If you want to use an already existing Docker network you created in your code, you can use the network.WithNetwork(aliases []string, nw *testcontainers.DockerNetwork) option, which receives an alias as parameter and your network, attaching the container to it, and setting the network alias for that network.

In the case you need to retrieve the network name, you can simply read it from the struct's Name field. E.g. nw.Name.

Warning

This option is not checking whether the network exists or not. If you use a network that doesn't exist, the container will start in the default Docker network, as in the default behavior.

WithNewNetwork

• Since testcontainers-go v0.27.0

If you want to attach your containers to a throw-away network, you can use the network.WithNewNetwork(ctx context.Context, aliases []string, opts ...network.NetworkCustomizer) option, which receives an alias as parameter, creating the new network with a random name, attaching the container to it, and setting the network alias for that network.

In the case you need to retrieve the network name, you can use the Networks(ctx) method of the Container interface, right after it's running, which returns a slice of strings with the names of the networks where the container is attached.

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.

Customising the ContainerRequest

This option will merge the customized request into the module's own ContainerRequest.

container, err := Run(ctx, "postgres:13-alpine",
    /* Other module options */
    testcontainers.CustomizeRequest(testcontainers.GenericContainerRequest{
        ContainerRequest: testcontainers.ContainerRequest{
            Cmd: []string{"-c", "log_statement=all"},
        },
    }),
)

The above example is updating the predefined command of the image, appending them to the module's command.

Info

This can't be used to replace the command, only to append options.

With Database Configuration File (scylla.yaml)

• Not available until the next release of testcontainers-go main

In the case you have a custom config file for ScyllaDB, it's possible to copy that file into the container before it's started, using the WithConfig(r io.Reader) function.

With Config YAML

    ctx := context.Background()

    cfgBytes := `cluster_name: 'Amazing ScyllaDB Test'
num_tokens: 256
commitlog_sync: periodic
commitlog_sync_period_in_ms: 10000
commitlog_segment_size_in_mb: 32
schema_commitlog_segment_size_in_mb: 128
seed_provider:
  - class_name: org.apache.cassandra.locator.SimpleSeedProvider
    parameters:
      - seeds: "127.0.0.1"
listen_address: localhost
native_transport_port: 9042
native_shard_aware_transport_port: 19042
read_request_timeout_in_ms: 5000
write_request_timeout_in_ms: 2000
cas_contention_timeout_in_ms: 1000
endpoint_snitch: SimpleSnitch
rpc_address: localhost
api_port: 10000
api_address: 127.0.0.1
batch_size_warn_threshold_in_kb: 128
batch_size_fail_threshold_in_kb: 1024
partitioner: org.apache.cassandra.dht.Murmur3Partitioner
commitlog_total_space_in_mb: -1
murmur3_partitioner_ignore_msb_bits: 12
strict_is_not_null_in_views: true
maintenance_socket: ignore
enable_tablets: true
`

    scyllaContainer, err := scylladb.Run(ctx,
        "scylladb/scylla:6.2",
        scylladb.WithConfig(strings.NewReader(cfgBytes)),
    )

Warning

You should provide a valid ScyllaDB configuration file as an io.Reader when using the function, otherwise the container will fail to start. The configuration file should be a valid YAML file and follows the ScyllaDB configuration file.

With Shard Awareness

• Not available until the next release of testcontainers-go main

If you want to test ScyllaDB with shard awareness, you can use the WithShardAwareness function. This function will configure the ScyllaDB container to use the 19042 port and ask the container to wait until the port is ready.

With Shard Awareness

scyllaContainer, err := scylladb.Run(ctx,
    "scylladb/scylla:6.2",
    scylladb.WithShardAwareness(),
)

With Alternator (DynamoDB Compatible API)

• Not available until the next release of testcontainers-go main

If you want to test ScyllaDB with the Alternator API, you can use the WithAlternator function. This function will configure the ScyllaDB container to use the port any port you want and ask the container to wait until the port is ready. By default, you can choose the port 8000.

With Alternator API

scyllaContainer, err := scylladb.Run(ctx,
    "scylladb/scylla:6.2",
    scylladb.WithAlternator(),
)

With Custom Commands

• Not available until the next release of testcontainers-go main

If you need to pass any flag to the ScyllaDB container, you can use the WithCustomCommand function. This also rewrites predefined commands like --developer-mode=1. You can check the ScyllaDB Docker Best Practices for more information.

With Custom Commands

scyllaContainer, err := scylladb.Run(ctx,
    "scylladb/scylla:6.2",
    scylladb.WithCustomCommands("--memory=1G", "--smp=2"),
)

Container Methods

The ScyllaDB container exposes the following methods:

ConnectionHost methods

• Not available until the next release of testcontainers-go main

There exist three methods to get the host and port of the ScyllaDB container, depending on the feature you want.

If you just want to test it with a single node and a single core, you can use the NonShardAwareConnectionHost method. However, if you're planning to use more than one core, you should use the ShardAwareConnectionHost method, which uses the shard-awareness 19042 port.

Else, if you're planning to use the Alternator API, you should use the AlternatorConnectionHost method, which uses the default port 8000.

Non-shard-aware connection hostShard-aware connection hostAlternator host

connectionHost, err := scyllaContainer.NonShardAwareConnectionHost(ctx)

connectionHost, err := scyllaContainer.ShardAwareConnectionHost(ctx)

// the alternator port is the default port 8000
_, err = scyllaContainer.AlternatorConnectionHost(ctx)