Chainlink Testing Framework

The Chainlink Testing Framework is a blockchain development framework written in Go. Its primary purpose is to help chainlink developers create extensive integration, e2e, performance, and chaos tests to ensure the stability of the chainlink project. It can also be helpful to those who just want to use chainlink oracles in their projects to help test their contracts, or even for those that aren't using chainlink.

If you're looking to implement a new chain integration for the testing framework, head over to the blockchain directory for more info.

k8s package

We have a k8s package we are using in tests, it provides:

• cdk8s based wrappers
• High-level k8s API
• Automatic port forwarding

You can also use this package to spin up standalone environments.

Local k8s cluster

Read here about how to spin up a local cluster

Install

Set up deps, you need to have node 14.x.x, helm and yarn

Then use

make install_deps

Optional Nix

We have setup a nix shell which will produce a reliable environment that will behave the same locally and in ci. To use it instead of the above you will need to install nix

To start the nix shell run:

make nix_shell

If you install direnv you wil be able to have your environment start the nix shell as soon as you cd into it once you have allowed the directory via:

direnv allow

Running tests in k8s

To read how to run a test in k8s, read here

Usage

With env vars (deprecated)

Create an env in a separate file and run it

export CHAINLINK_IMAGE="public.ecr.aws/chainlink/chainlink"
export CHAINLINK_TAG="1.4.0-root"
export CHAINLINK_ENV_USER="Satoshi"
go run k8s/examples/simple/env.go

For more features follow tutorial

With TOML config

It should be noted that using env vars for configuring CL nodes in k8s is deprecated. TOML config should be used instead:

[ChainlinkImage]
image="public.ecr.aws/chainlink/chainlink"
version="v2.8.0"

Check the example here: env.go

Development

Running standalone example environment

go run k8s/examples/simple/env.go

If you have another env of that type, you can connect by overriding environment name

ENV_NAMESPACE="..."  go run k8s/examples/chainlink/env.go

Add more presets here

Add more programmatic examples here

If you have chaosmesh installed in your cluster you can pull and generated CRD in go like that

make chaosmesh

If you need to check your system tests coverage, use that

Chainlink Charts

This repository contains helm charts used by the chainlink organization mostly in QA.

Chart Repository

You can add the published chart repository by pointing helm to the gh-pages branch with a personal access token (PAT) that has at least read-only access to the repository.

helm repo add chainlink-qa https://raw.githubusercontent.com/smartcontractkit/qa-charts/gh-pages/
helm search repo chainlink

Releasing Charts

The following cases will trigger a chart release once a PR is merged into the main branch. Modified packages or new packages get added and pushed to the gh-pages branch of the qa-charts repository.

• An existing chart is version bumped
• A new chart is added

Removed charts do not trigger a re-publish, the packages have to be removed and the index file regenerated in the gh-pages branch of the qa-charts repository.

Note: The qa-charts repository is scheduled to look for changes to the charts once every hour. This can be expedited by going to that repo and running the cd action via github UI.

Simulated EVM chains

We have extended support for execution layer clients in simulated networks. Following ones are supported:

• Geth
• Nethermind
• Besu
• Erigon

When it comes to consensus layer we currently support only Prysm.

The easiest way to start a simulated network is to use a builder. It allows to configure the network in a fluent way and then start it. For example:

builder := NewEthereumNetworkBuilder()
cfg, err: = builder.
    WithEthereumVersion(EthereumVersion_Eth2).
    WithExecutionLayer(ExecutionLayer_Geth).
    Build()

Since we support both eth1 (aka pre-Merge) and eth2 (aka post-Merge) client versions, you need to specify which one you want to use. You can do that by calling WithEthereumVersion method. There's no default provided. The only exception is when you use custom docker images (instead of default ones), because then we can determine which version it is based on the image version.

If you want your test to execute as fast as possible go for eth1 since it's either using a fake PoW or PoA consensus and is much faster than eth2 which uses PoS consensus (where there is a minimum viable length of slot/block, which is 4 seconds; for eth1 it's 1 second). If you want to test the latest features, changes or forks in the Ethereum network and have your tests running on a network which is as close as possible to Ethereum Mainnet, go for eth2.

Every component has some default Docker image it uses, but builder has a method that allows to pass custom one:

builder := NewEthereumNetworkBuilder()
cfg, err: = builder.
    WithEthereumVersion(EthereumVersion_Eth2).
    WithConsensusLayer(ConsensusLayer_Prysm).
    WithExecutionLayer(ExecutionLayer_Geth).
    WithCustomDockerImages(map[ContainerType]string{
        ContainerType_Geth: "my-custom-geth-pos-image:my-version"}).
    Build()

When using a custom image you can even further simplify the builder by calling only WithCustomDockerImages method. Based on the image name and version we will determine which execution layer client it is and whether it's eth1 or eth2 client:

builder := NewEthereumNetworkBuilder()
cfg, err: = builder.
    WithCustomDockerImages(map[ContainerType]string{
        ContainerType_Geth: "ethereum/client-go:v1.13.10"}).
    Build()

In the case above we would launch a Geth client with eth2 network and Prysm consensus layer.

You can also configure epochs at which hardforks will happen. Currently only Deneb is supported. Epoch must be >= 1. Example:

builder := NewEthereumNetworkBuilder()
cfg, err: = builder.
    WithConsensusType(ConsensusType_PoS).
    WithConsensusLayer(ConsensusLayer_Prysm).
    WithExecutionLayer(ExecutionLayer_Geth).
    WithEthereumChainConfig(EthereumChainConfig{
        HardForkEpochs: map[string]int{"Deneb": 1},
    }).
    Build()

Command line

You can start a simulated network with a single command:

go run docker/test_env/cmd/main.go start-test-env private-chain

By default it will start a network with 1 node running Geth and Prysm. It will use default chain id of 1337 and won't wait for the chain to finalize at least one epoch. Once the chain is started it will save the network configuration in a JSON file, which then you can use in your tests to connect to that chain (and thus save time it takes to start a new chain each time you run your test).

Following cmd line flags are available:

  -c, --chain-id int             chain id (default 1337)
  -l, --consensus-layer string   consensus layer (prysm) (default "prysm")
  -t, --consensus-type string    consensus type (pow or pos) (default "pos")
  -e, --execution-layer string   execution layer (geth, nethermind, besu or erigon) (default "geth")
  -w, --wait-for-finalization    wait for finalization of at least 1 epoch (might take up to 5 mintues)
      --consensus-client-image string   custom Docker image for consensus layer client
      --execution-layer-image string    custom Docker image for execution layer client
      --validator-image string          custom Docker image for validator

To connect to that environment in your tests use the following code:

	builder := NewEthereumNetworkBuilder()
	cfg, err := builder.
		WihtExistingConfigFromEnvVar().
		Build()

    if err != nil {
        return err
    }

	net, rpc, err := cfg.Start()
    if err != nil {
        return err
    }

Builder will read the location of chain configuration from env var named PRIVATE_ETHEREUM_NETWORK_CONFIG_PATH (it will be printed in the console once the chain starts).

net is an instance of blockchain.EVMNetwork, which contains characteristics of the network and can be used to connect to it using an EVM client. rpc variable contains arrays of public and private RPC endpoints, where "private" means URL that's accessible from the same Docker network as the chain is running in.

Using LogStream

LogStream is a package that allows to connect to a Docker container and then flush logs to configured targets. Currently 3 targets are supported:

• file - saves logs to a file in ./logs folder
• loki - sends logs to Loki
• in-memory - stores logs in memory

It can be configured to use multiple targets at once. If no target is specified, it becomes a no-op.

LogStream has to be configured by passing an instance of LoggingConfig to the constructor.

When you connect a contaier LogStream will create a new consumer and start a detached goroutine that listens to logs emitted by that container and which reconnects and re-requests logs if listening fails for whatever reason. Retry limit and timeout can both be configured using functional options. In most cases one container should have one consumer, but it's possible to have multiple consumers for one container.

LogStream stores all logs in gob temporary file. To actually send/save them, you need to flush them. When you do it, LogStream will decode the file and send logs to configured targets. If log handling results in an error it won't be retried and processing of logs for given consumer will stop (if you think we should add a retry mechanism please let us know).

Important: Flushing and accepting logs is blocking operation. That's because they both share the same cursor to temporary file and otherwise it's position would be racey and could result in mixed up logs.

Configuration

Basic LogStream TOML configuration is following:

[LogStream]
log_targets=["file"]
log_producer_timeout="10s"
log_producer_retry_limit=10

You can find it here: logging_default.toml

When using in-memory or file target no other configuration variables are required. When using loki target, following ones must be set:

[Logging.Loki]
tenant_id="promtail"
url="https://change.me"
basic_auth_secret="my-secret-auth"
bearer_token_secret="bearer-token"

Also, do remember that different URL should be used when running in CI and everywhere else. In CI it should be a public endpoint, while in local environment it should be a private one.

If your test has a Grafana dashboard in order for the url to be correctly printed you should provide the following config:

[Logging.Grafana]
url="http://grafana.somwhere.com/my_dashboard"

Initialisation

First you need to create a new instance:

// t - instance of *testing.T (can be nil)
// testConfig.Logging - pointer to logging part of TestConfig
ls := logstream.NewLogStream(t, testConfig.Logging)

Listening to logs

If using testcontainers-go Docker containers it is recommended to use life cycle hooks for connecting and disconnecting LogStream from the container. You can do that when creating ContainerRequest in the following way:

containerRequest := &tc.ContainerRequest{
		LifecycleHooks: []tc.ContainerLifecycleHooks{
			{PostStarts: []tc.ContainerHook{
				func(ctx context.Context, c tc.Container) error {
					if ls != nil {
						return n.ls.ConnectContainer(ctx, c, "custom-container-prefix-can-be-empty")
					}
					return nil
				},
			},
				PostStops: []tc.ContainerHook{
					func(ctx context.Context, c tc.Container) error {
						if ls != nil {
							return n.ls.DisconnectContainer(c)
						}
						return nil
					},
				}},
		},
	}

You can print log location for each target using this function: (m *LogStream) PrintLogTargetsLocations(). For file target it will print relative folder path, for loki it will print URL of a Grafana Dashboard scoped to current execution and container ids. For in-memory target it's no-op.

It is recommended to shutdown LogStream at the end of your tests. Here's an example:

t.Cleanup(func() {
    l.Warn().Msg("Shutting down Log Stream")

    if t.Failed() || os.Getenv("TEST_LOG_COLLECT") == "true" {
        // we can't do much if this fails, so we just log the error
        _ = logStream.FlushLogsToTargets()
        // this will log log locations for each target (for file it will be a folder, for Loki Grafana dashboard -- remember to provide it's url in config!)
        logStream.PrintLogTargetsLocations()
        // this will save log locations in test summary, so that they can be easily accessed in GH's step summary
        logStream.SaveLogLocationInTestSummary()
    }

    // we can't do much if this fails, so we just log the error
    _ = logStream.Shutdown(testcontext.Get(b.t))
    })

or in a bit shorter way:

t.Cleanup(func() {
    l.Warn().Msg("Shutting down Log Stream")

    if t.Failed() || os.Getenv("TEST_LOG_COLLECT") == "true" {
        // this will log log locations for each target (for file it will be a folder, for Loki Grafana dashboard -- remember to provide it's url in config!)
        logStream.PrintLogTargetsLocations()
        // this will save log locations in test summary, so that they can be easily accessed in GH's step summary
    }

    // we can't do much if this fails
    _ = logStream.FlushAndShutdown()
    })

Grouping test execution

When running tests in CI you're probably interested in grouping logs by test execution, so that you can easily find the logs in Loki. To do that your job should set RUN_ID environment variable. In GHA it's recommended to set it to workflow id. If that variable is not set, then a run id will be automatically generated and saved in .run.id file, so that it can be shared by tests that are part of the same execution, but are running in different processes.

Test Summary

In order to facilitate displaying information in GH's step summary testsummary package was added. It exposes a single function AddEntry(testName, key string, value interface{}) . When you call it, it either creates a test summary JSON file or appends to it. The result is a map of keys with values.

Example:

{
   "file":[
      {
         "test_name":"TestOCRv2Basic",
         "value":"./logs/TestOCRv2Basic-2023-12-01T18-00-59-TestOCRv2Basic-38ac1e52-d0a6-48"
      }
   ],
   "loki":[
      {
         "test_name":"TestOCRv2Basic",
         "value":"https://grafana.ops.prod.cldev.sh/d/ddf75041-1e39-42af-aa46-361fe4c36e9e/ci-e2e-tests-logs?orgId=1\u0026var-run_id=TestOCRv2Basic-38ac1e52-d0a6-48\u0026var-container_id=cl-node-a179ca7d\u0026var-container_id=cl-node-76798f87\u0026var-container_id=cl-node-9ff7c3ae\u0026var-container_id=cl-node-43409b09\u0026var-container_id=cl-node-3b6810bd\u0026var-container_id=cl-node-69fed256\u0026from=1701449851165\u0026to=1701450124925"
      }
   ]
}

In GHA after tests have ended we can use tools like jq to extract the information we need and display it in step summary.

TOML Config

Basic and universal building blocks for TOML-based config are provided by config package. For more information do read this.

ECR Mirror

An ecr mirror can be used to push images used often in order to bypass rate limit issues from dockerhub. The list of image mirrors can be found in the matrix here. This currently works with images with version numbers in dockerhub. Support for gcr is coming in the future. The images must also have a version number so putting latest will not work. We have a separate list for one offs we want that can be added to here that does work with gcr and latest images. Note however for latest it will only pull it once and will not update it in our mirror if the latest on the public repository has changed, in this case it is preferable to update it manually when you know that you need the new latest and the update will not break your tests.

For images in the mirrors you can use the INTERNAL_DOCKER_REPO environment variable when running tests and it will use that mirror in place of the public repository.

We have two ways to add new images to the ecr. The first two requirements are that you create the ecr repository with the same name as the one in dockerhub out in aws and then add that ecr to the infra permissions (ask TT if you don't know how to do this).

1. If it does not have version numbers or is gcr then you can add it here
2. You can add to the mirror matrix the new image name and an expression to get the latest versions added when the workflow runs. You can check the postgres one used in there for an example but basically the expression should filter out only the latest image or 2 for that particular version when calling the dockerhub endpoint, example curl call curl -s "https://hub.docker.com/v2/repositories/${image_name}/tags/?page_size=100" | jq -r '.results[].name' | grep -E ${image_expression} where image_name could be library/postgres and image_expression could be '^[0-9]+\.[0-9]+$'. Adding your ecr to this matrix should make sure we always have the latest versions for that expression.