Toxiproxy¶

Introduction¶

The Testcontainers module for Toxiproxy.

Adding this module to your project dependencies¶

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

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

Usage example¶

Creating a Toxiproxy container

ctx := context.Background()

toxiproxyContainer, err := tctoxiproxy.Run(
    ctx,
    "ghcr.io/shopify/toxiproxy:2.12.0",
)
defer func() {
    if err := testcontainers.TerminateContainer(toxiproxyContainer); err != nil {
        log.Printf("failed to terminate container: %s", err)
    }
}()
if err != nil {
    log.Printf("failed to start container: %s", err)
    return
}

Module Reference¶

Run function¶

Since v0.37.0

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

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

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

Container Ports¶

The Toxiproxy container exposes the following ports:

8474/tcp, the Toxiproxy control port, exported as toxiproxy.ControlPort.

Image¶

Use the second argument in the Run function to set a valid Docker image. In example: Run(context.Background(), "shopify/toxiproxy:2.12.0").

Container Options¶

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

WithProxy¶

Since v0.37.0

The WithProxy option allows you to specify a proxy to be created on the Toxiproxy container. This option allocates a random port on the host and exposes it to the Toxiproxy container, allowing you to create a unique proxy for a given service, starting from the 8666/tcp port.

func WithProxy(name string, upstream string) Option

If this option is used in combination with the WithConfigFile option, the proxy defined in this option is added to the proxies defined in the config file.

Info

If you add proxies in a programmatic manner using the Toxiproxy client, then you need to manually add exposed ports in the Toxiproxy container.

WithConfigFile¶

Since v0.37.0

The WithConfigFile option allows you to specify a config file for the Toxiproxy container, in the form of an io.Reader representing the JSON file with the Toxiproxy configuration, in the valid format of the Toxiproxy configuration file.

Configuration file

[
    {
        "name": "redis",
        "listen": "0.0.0.0:8666",
        "upstream": "redis:6379",
        "enabled": true
    }
]

func WithConfigFile(r io.Reader) testcontainers.CustomizeRequestOption

If this option is used in combination with the WithProxy option, the proxies defined in this option are added to the proxies defined with the WithProxy option.

The following options are exposed by the testcontainers package.

Basic Options¶

WithExposedPorts Since v0.37.0
WithEnv Since v0.29.0
WithWaitStrategy Since v0.20.0
WithAdditionalWaitStrategy Not available until the next release main
WithWaitStrategyAndDeadline Since v0.20.0
WithAdditionalWaitStrategyAndDeadline Not available until the next release main
WithEntrypoint Since v0.37.0
WithEntrypointArgs Since v0.37.0
WithCmd Since v0.37.0
WithCmdArgs Since v0.37.0
WithLabels Since v0.37.0

Lifecycle Options¶

WithLifecycleHooks Not available until the next release main
WithAdditionalLifecycleHooks Not available until the next release main
WithStartupCommand Since v0.25.0
WithAfterReadyCommand Since v0.28.0

Files & Mounts Options¶

Build Options¶

WithDockerfile Since v0.37.0

Logging Options¶

WithLogConsumers Since v0.28.0
WithLogConsumerConfig Not available until the next release main
WithLogger Since v0.29.0

Image Options¶

WithAlwaysPull Not available until the next release main
WithImageSubstitutors Since v0.26.0
WithImagePlatform Not available until the next release main

Networking Options¶

WithNetwork Since v0.27.0
WithNetworkByName Not available until the next release main
WithBridgeNetwork Not available until the next release main
WithNewNetwork Since v0.27.0

Advanced Options¶

WithHostPortAccess Since v0.31.0
WithConfigModifier Since v0.20.0
WithHostConfigModifier Since v0.20.0
WithEndpointSettingsModifier Since v0.20.0
CustomizeRequest Since v0.20.0
WithName Not available until the next release main
WithNoStart Not available until the next release main

Experimental Options¶

WithReuseByName Since v0.37.0

Container Methods¶

The Toxiproxy container exposes the following methods:

ProxiedEndpoint¶

Since v0.37.0

The ProxiedEndpoint method returns the host and port of the proxy for a given port. It's used to create new connections to the proxied service, and it returns an error in case the port has no proxy.

func (c *Container) ProxiedEndpoint(port int) (string, string, error)

Get Proxied EndpointRead Proxied Endpoint

proxiedRedisHost, proxiedRedisPort, err := toxiproxyContainer.ProxiedEndpoint(8666)
if err != nil {
    log.Printf("failed to get toxiproxy container port: %s", err)
    return
}

// Create a redis client that connects to the toxiproxy container.
// We are defining a read timeout of 2 seconds, because we are adding
// a latency toxic of 1.1 seconds to the request.
redisURI := fmt.Sprintf("redis://%s:%s?read_timeout=2s", proxiedRedisHost, proxiedRedisPort)

The above examples show how to get the proxied endpoint and use it to create a new connection to the proxied service, in this case a Redis client.

URI¶

Since v0.37.0

The URI method returns the URI of the Toxiproxy container, used to create a new Toxiproxy client.

func (c *Container) URI() string

Creating a Toxiproxy client

toxiURI, err := toxiproxyContainer.URI(ctx)
if err != nil {
    log.Printf("failed to get toxiproxy container uri: %s", err)
    return
}

toxiproxyClient := toxiproxy.NewClient(toxiURI)

the toxiproxy package comes from the github.com/Shopify/toxiproxy/v2/client package.
the toxiproxyContainer variable has been created by the Run function.

Examples¶

Programmatically create a proxy¶

Expose port manuallyCreating a proxyCreating a Redis clientAdding a latency toxic

const proxyPort = "8666"

// No need to create a proxy, as we are programmatically adding it below.
toxiproxyContainer, err := tctoxiproxy.Run(
    ctx,
    "ghcr.io/shopify/toxiproxy:2.12.0",
    network.WithNetwork([]string{"toxiproxy"}, nw),
    // explicitly expose the ports that will be proxied using the programmatic API
    // of the toxiproxy client. Otherwise, the ports will not be exposed and the
    // toxiproxy client will not be able to connect to the proxy.
    testcontainers.WithExposedPorts(proxyPort+"/tcp"),
)
defer func() {
    if err := testcontainers.TerminateContainer(toxiproxyContainer); err != nil {
        log.Printf("failed to terminate container: %s", err)
    }
}()
if err != nil {
    log.Printf("failed to start container: %s", err)
    return
}

// Create the proxy using the network alias of the redis container,
// as they run on the same network.
proxy, err := toxiproxyClient.CreateProxy("redis", "0.0.0.0:"+proxyPort, "redis:6379")
if err != nil {
    log.Printf("failed to create proxy: %s", err)
    return
}

// Create a redis client that connects to the toxiproxy container.
// We are defining a read timeout of 2 seconds, because we are adding
// a latency toxic of 1 second to the request, +/- 100ms jitter.
redisURI := fmt.Sprintf("redis://%s:%s?read_timeout=2s", toxiproxyProxyHostIP, toxiproxyProxyPort.Port())

options, err := redis.ParseURL(redisURI)
if err != nil {
    log.Printf("failed to parse url: %s", err)
    return
}

redisCli := redis.NewClient(options)
defer func() {
    if err := redisCli.FlushAll(ctx).Err(); err != nil {
        log.Printf("failed to flush redis: %s", err)
    }
}()

const (
    latency = 1_000
    jitter  = 200
)
// Add a latency toxic to the proxy
_, err = proxy.AddToxic("latency_down", "latency", "downstream", 1.0, toxiproxy.Attributes{
    "latency": latency,
    "jitter":  jitter,
})
if err != nil {
    log.Printf("failed to add toxic: %s", err)
    return
}