Ondatra: Open Network Device Automated Test Runner and API

Ondatra is a framework for writing and running tests against both real and containerized network devices.

For an introduction to Ondatra, take the Ondatra Tour.

Building Ondatra

To build and execute Ondatra's unit tests, run the following:

go generate ./...
go build ./...
go test $(go list ./... | grep -v /integration)

Providing a Binding

The Ondatra binding is the API layer through which Ondatra connects to and controls the devices in your test environment. For an Ondatra test to run in your environment, you must provide an implementation of the Binding interface. For testing on KNE, Ondatra comes bundled with a binding implementation for accessing KNE on your local machine. For testing on your physical devices, read how to author your own Binding implementation.

Testbed File

To run an Ondatra test, the user must specify the testbed of resources that the Ondatra test runner should reserve in advance. The testbed is specified in an external text file in protobuf text format. The protobuf Testbed message is defined in proto/testbed.proto, and an example testbed can be found in knebind/integration/testbed.textproto. As the proto definition and example show, testbed consists of the DUTs (devices under test), ATEs (automated test equipment), the links between them, as well as properties of the DUTs, ATEs, and links. It is the job of the Reserve method in the binding implementation to locate available resources that match the abstract topology and criteria specified in the testbed file.

Writing an Ondatra Test

Ondatra provides a set of fluent interfaces for configuring and interacting with network devices. See the full API reference documentation.

The Ondatra gNMI API plays a particularly central role in Ondatra tests. It provide a set of test helpers for querying telemetry and setting the state of the device via gNMI. Read more about the Ondatra gNMI API.

Running an Ondatra Test

An Ondatra test is a Go test, and so is run with go test, albeit with some additional flags to control the execution of the test:

• -testbed (required): Path to the testbed text proto file.
• -wait_time (optional): Maximum amount of time the test should wait until the testbed is ready. If not specified, the binding chooses the amount of time to wait.
• -run_time (optional): Timeout of the test run, excluding the wait time for the testbed to be ready. If not specified, no limit is imposed.
• -xml (optional): File path to write JUnit XML test results; disables normal Go test logging.
• -debug (optional): Whether the test is run in debug mode.
• -reserve (optional): Reservation id or a mapping of device and port IDs to names; allowed only in debug mode

To run a subset of the test cases of an Ondatra test, use the Go test -run flag. While the -run flag accepts an arbitrary Go regexp, to match a single test case it is usually sufficient to just pass the name of the test function:

$ go test -testbed=testbed.textproto -config=config.yaml -run=$RUN_THIS_TEST_CASE

Read the Go doc on subtests for more details on matching subtests with the -run flag.

Debugging an Ondatra Test

To run an Ondatra test in debug mode, pass the -debug flag to go test. Debug mode allows you to insert breakpoints in your code with one simple line:

ondatra.Debug().Breakpoint(t)

The Breakpoint and Breakpointf functions allow you to include custom text in the breakpoint message, too. For example:

ondatra.Debug().Breakpoint(t, "this should be unreachable")
ondatra.Debug().Breakpointf(t, "myVar has value %v", myVar)

Debug mode also offers a menu option to pause the test immediately after the testbed is reserved. This is useful if you want to manually inspect the testbed before the test cases run, or to run a separate test execution against with the same reservation.

To debug a test against a pre-allocated reservation, set the -reserve flag to the reservation ID:

$ go test -testbed=testbed.textproto -config=config.yaml -debug -reserve=123abc

To debug the test against specifically-named devices, set the -reserve flag to a comma-separated list of id=name strings at the command line, where ports are named with the syntax deviceID:portID=portName:

$ go test -testbed=testbed.textproto -config=config.yaml -debug \
    -reserve=dut=mydevice,dut:port1=Ethernet1/1,ate=myixia,ate:port2=2/3

Logging Verbosity

Ondatra always sets the Go test -v flag to true for verbose test output, so there is no need to set this flag explicitly in your test invocations.

Ondatra uses glog for its own logging. By default, glog logs to a temporary dir, but setting the -alsologtostderr flag will output those logs to stderr. You can increase the verbosity glog by setting its -v flag to a positive integer. Increasing the value of v produces increasingly verbose and granular details in the logs, as outlined in this table:

Because go test has its own -v flag, setting glog's -v value must be preceded by -args to avoid it being interpreted by go test itself. For example:

go test -alsologtostderr -args -v=1

See the glog package documentation for more information on all the glog flags.

XML Test Report

Ondatra has the ability to output test results in JUnit XML format. If you pass -xml=[path] to your go test invocation, Ondatra will use go-junit-report to translate the Go test log to an XML file at the provided path.

To attach properties to the test or individual test cases in the XML report, use the ondatra.Report() API. For example, ondatra.Report().AddTestProperty() attaches a key-value property to the currently running test case.

The help with the development of external tooling that makes use of the XML output, the report package also provides the utility functions ReadXML and ExtractProperties for decoding the XML and extracting a properties map, respectively.

Testing on KNE

You don't have to code your own binding implementation before getting started with Ondatra, because Ondatra comes packaged with a binding for KNE, and an example Ondatra test that uses that binding. See the knebind README for more on how to use the KNE binding and run the example test.