e2e

AgentBaker E2E Testing

This directory contains files related to the AgentBaker E2E testing framework.

Overview

AgentBaker E2E tests verify that node bootstrapping artifacts generated by the AgentBaker API are correct and capable of integrating Azure VMs into Azure Kubernetes Service (AKS) clusters.

The E2E scenario template is defined in RunScenario. From a high-level, for each scenario,

1. a new VMSS containing a single VM will be created.
2. CSE and custom data are generated, which will then be applied to the new VM so it can bootstrap and register with the AKS cluster apiserver.
3. Liveness and health checks and then run to make sure the new VM's kubelet is posting NodeReady, and that workload pods can successfully be scheduled and run on the new node.

To write an E2E scenario,

• choose a testing cluster. There are a few defined in cluster.go, e.g,
  • ClusterKubenetAirgap
  • ClusterAzureNetwork
  • ClusterKubenet
• use NodeBootstrappingConfiugration (nbc) to setup your scenario. it is used to invoke the primary node-bootstrapping API GetLatestNodeBootstrapping. to modify agentpool properties, usually you need to set bothnbc.containerService.properties.AgentPoolProfiles[0].xxx as well as nbc.agentPoolProfile. It is because when RP invokes AgentBaker, it will set the properties in this way and in e2e we follow the pattern.
• use VMConfigMutator to set VMSS properties such as SKU when needed. Check vmss for other configs.
  it is necessary to set nbc.agentPoolProfile.VMSize to match the VMSS SKU if you choose to change.
• use Validator to include your own verification of the VM's live state, such as file existsnce, sysctl settings, etc.

sequenceDiagram
    E2E->>+ARM: Get or Create AKS Cluster
    ARM-->>-E2E: Cluster details
    E2E->>+AgentBakerCode: Fetch VM Configuration (include CSE)
    AgentBakerCode-->>-E2E: VM Configuration
    E2E->>+ARM: Create VM using fetched VM Config in cluster network
    ARM-->>-E2E: VM instance
    E2E->>+KubeAPI: Create test Pod
    KubeAPI->>+TestPod: Perform healthcheck
    TestPod-->>-KubeAPI: Healthcheck OK
    KubeAPI-->>-E2E: Test Pod ready
    E2E->>+KubeAPI: Execute test validators
    KubeAPI->>+DebugPod: Execute test validator
    DebugPod->>+VM: Execute test validator
    VM-->>-DebugPod: Test results
    DebugPod-->>-KubeAPI: Test results
    KubeAPI-->>-E2E: Final results

Running Locally

Note: if you have changed code or artifacts used to generate custom data or custom script extension payloads, you should first run make generate from the root of the AgentBaker repository.

To run the E2E test suite locally, use e2e-local.sh. This script sets up the go test command.

Check config.go for the default configuration parameters. You can override these parameters by setting ENV variables.

Create a .env file in the e2e directory to set environment variables and avoid manual setup each time you run tests. Refer to .env.sample for an example.

Running Specific Tests

Use TAGS_TO_RUN= to specify scenarios based on tags. By default, all scenarios run. Multiple tags should be comma-separated and are case-insensitive. Check logs for test tags.

Example:

TAGS_TO_RUN="os=ubuntu,arch=amd64,wasm=false,gpu=false,imagename=1804gen2containerd" ./e2e-local.sh

To exclude scenarios, use TAGS_TO_SKIP=. Scenarios with any specified tags will be skipped (this logic is different to TAGS_TO_RUN).

To run a specific test, use the test name:

TAGS_TO_RUN="name=Test_azurelinuxv2" ./e2e-local.sh
# or
go test -run Test_azurelinuxv2 -v -timeout 90m

Debugging

Set KEEP_VMSS=true to retain bootstrapped VMs for debugging. Setting this will also have the VM's private SSH key included in each scenario's log bundle. When using this flag, please ensure to run only test you need to debug, as the VMs will not be deleted after the test run.

Running Tests Manually

Run tests with custom arguments after setting required environment variables:

go test -parallel 100 -timeout 90m -v -count 1

Important go test flags:

• -v: Verbose output
• -parallel 100: Run 100 tests in parallel, default is limited to the number of cores
• -timeout 90m: Set timeout, default is 10 minutes which is often exceeded
• -count 1: Disable test caching

Cleanup

Azure resources are deleted periodically by an external garbage collector. Locally stopped tests attempt a graceful shutdown to clean up resources. Old VMs are deleted on startup unless created with KEEP_VMSS=true.

IDE Configuration

Global Settings

Set GOFLAGS="-timeout=90m -parallel=100" in your shell configuration file.

GoLand

In Run > Edit Configurations..., set -timeout=90m -parallel=100 in the Go tool arguments field.

VSCode

Add to settings.json:

{
  "go.testFlags": [
    "-parallel=100",
    "-v"
  ],
  "go.testTimeout": "90m"
}

Package Structure

The top-level package of the Golang E2E implementation is named e2e and is entirely separate from all AgentBaker packages.

The definitions and entry points for each test scenario, ran by go test, are located in scenario_test.go.

E2E VHDs.

Node images are pushed to Shared Image Gallery (SIG). Each image is tagged with branch name and build id. By default E2E tests use latest version of images from SIG with branch=refs/heads/master tag.

Using VHD Images from Custom ADO Builds

Set SIG_VERSION_TAG_NAME and SIG_VERSION_TAG_VALUE to specify custom VHD builds:

SIG_VERSION_TAG_NAME=buildId SIG_VERSION_TAG_VALUE=123456789 TAGS_TO_RUN="os=ubuntu2204" ./e2e-local.sh

Registering New VHD SKUs

When adding tests for a new VHD image, ensure to add a delete-lock to prevent the garbage collector from deleting the image version.

Scenarios

E2E scenarios can be configured with VMSS configuration mutators that change/set properties on the VMSS model used to deploy the new VM to be bootstrapped. This is primarily useful when testing out different VM SKUs, especially for GPU-enabled scenarios which affect which code paths AgentBaker will use to generate CSE and custom data

Further, in order to support E2E scenarios which test different underlying AKS cluster configurations, such as the cluster's network plugin, each E2E scenario uses one of the predefined clusters. Same cluster can be reused in different test runs. If cluster doesn't exist a new one will be created automatically.

Lastly, E2E scenarios also consist of a list of live VM validators. Each live VM validator consists of a description, a bash command which will actually be run on the newly bootstrapped VM, and an "asserter" function that will perform assertions on the contents of both the stdout and stderr streams that result from the execution of the command. The validators can be used to assert on numerous types of properties of the live VM, such as the live file system and kernel state.

Log Collection

Each E2E scenario will generate its own logs after execution. Currently, these logs consist of:

• cluster-provision.log - CSE execution log, retrieved from /var/log/azure/aks/cluster-provision.log (collected in success and CSE failure cases)
• kubelet.log - the kubelet systemd unit's logs retrived by running journalctl -u kubelet on the VM after bootstrapping has finished (collected in success and CSE failure cases)
• vmssId.txt - a single line text file containing the unique resource ID of the VMSS created by the respective scenario, mainly collected for the purposes of posthoc resource deletion (collected in all cases where the VMSS is able to be created)

These logs will be uploaded in a bundle of the format:

└── scenario-logs
    └── <scenario>
        ├── cluster-provision.log
        ├── kubelet.log
        ├── vmssId.txt

Coverage report

After a PR is created in AgentBaker's repo on GitHub, a pipeline calculating code coverage changes will automatically run.

We are utilizing coveralls to display the coverage report. The coverage report will be available in the PR's description. You can also view previous runs for the AgentBaker repo here.

We calculate code coverage for both unit tests and E2E tests.

E2E coverage report

To generate E2E coverage reports, we use code coverage changes introduced in Go 1.20.

Coverage report is generated by running AgentBaker's API server locally as a binary created with the -cover flag. E2E tests are then ran against that binary.

The following packages are used during calculation of coverage for E2E tests:

- github.com/Azure/agentbaker/apiserver
- github.com/Azure/agentbaker/cmd
- github.com/Azure/agentbaker/cmd/starter
- github.com/Azure/agentbaker/pkg/agent
- github.com/Azure/agentbaker/pkg/agent/datamodel
- github.com/Azure/agentbaker/pkg/templates

Generating E2E coverage report locally

You can generate an E2E coverage report while running the E2E tests locally. To do so, follow the steps below:

1. Build the AgentBaker server binary with -cover flag:

  cd cmd
  go build -cover -o baker -covermode count
  GOCOVERDIR=covdatafiles ./baker start &

1. Create directory for coverage report files

  mkdir -p covdatafiles

1. Run the binary

  GOCOVERDIR=covdatafiles ./baker start &

1. Run the E2E tests locally

  /bin/bash e2e/e2e-local.sh

1. Stop the binary - once the tests finish executing, you have to stop the binary with exit code 0 to generate the report. See the docs here.

  kill $(pgrep baker)

1. Display the coverage report within the terminal

  go tool covdata percent -i=./cmd/somedata