Guide

This guide will show you the way through the dense forest of available tmt features, commands and options. But don’t be afraid, we will start slowly, with the simple examples first. And then, when your eyes get accustomed to the shadow of omni-present metadata trees, we will slowly dive deeper and deeper so that you don’t miss any essential functionality which could make your life smarter, brighter and more joyful. Let’s go, follow me…

The First Steps

Installing the main package with the core functionality is quite straightforward. No worry, there are just a few dependencies:

sudo dnf install -y tmt

Enabling a simple smoke test in the continuous integration should be a joy. Just a couple of concise commands, assuming you are in your project git repository:

tmt init --template mini
vim plans/example.fmf

Open the example plan in your favorite editor and adjust the smoke test script as needed. Your very first plan can look like this:

summary: Basic smoke test
execute:
    script: foo --version

Now you’re ready to create a new pull request to check out how it’s working. During push, remote usually shows a direct link to the page with a Create button, so now it’s only two clicks away:

git add .
git checkout -b smoke-test
git commit -m "Enable a simple smoke test"
git push origin -u smoke-test

But perhaps, you are a little bit impatient and would like to see the results faster. Sure, let’s try the smoke test here and now, directly on your localhost:

tmt run --all provision --how local

If you’re a bit afraid that the test could break your machine or just want to keep your environment clean, run it in a container instead:

sudo dnf install -y tmt+provision-container
tmt run -a provision -h container

Or even in a full virtual machine if the container environment is not enough. We’ll use the libvirt to start a new virtual machine on your localhost. Be ready for a bit more dependencies here:

sudo dnf install -y tmt+provision-virtual
tmt run -a provision -h virtual

Don’t care about the disk space? Simply install tmt+all and you’ll get all available functionality at hand. Check the help to list all supported provision methods:

sudo dnf install tmt+all
tmt run provision --help

Now when you’ve met your --help friend you know everything you need to get around without getting lost in the forest of available options:

tmt --help
tmt run --help
tmt run provision --help
tmt run provision --how container --help

Go on and explore. Don’t be shy and ask, --help is eager to answer all your questions ;-)

Under The Hood

Now let’s have a brief look under the hood. For storing all config data we’re using the Flexible Metadata Format. In short, it is a yaml format extended with a couple of nice features like Inheritance or Elasticity which help to maintain even large data efficiently without unnecessary duplication.

Trees

The data are organized into trees. Similarly as with git, there is a special .fmf directory which marks the root of the fmf metadata tree. Use the init command to initialize it:

tmt init

Do not forget to include this special .fmf directory in your commits, it is essential for building the fmf tree structure which is created from all *.fmf files discovered under the fmf root.

Plans

As we’ve seen above, in order to enable testing the following plan is just enough:

execute:
    script: foo --version

Store these two lines in a *.fmf file and that’s it. Name and location of the file is completely up to you, plans are recognized by the execute key which is required. Once the newly created plan is submitted to the CI system test script will be executed.

By the way, there are several basic templates available which can be applied already during the init by using the --template option or the short version -t. The minimal template, which includes just a simple plan skeleton, is the fastest way to get started:

tmt init -t mini

Plans are used to enable testing and group relevant tests together. They describe how to discover tests for execution, how to provision the environment, how to prepare it for testing, how to execute tests, report results and finally how to finish the test job.

Here’s an example of a slightly more complex plan which changes the default provision method to container to speed up the testing process and ensures that an additional package is installed before the testing starts:

provision:
    how: container
    image: fedora:33
prepare:
    how: install
    package: wget
execute:
    how: tmt
    script: wget http://example.org/

Note that each of the steps above uses the how keyword to choose the desired method which should be applied. Steps can provide multiple implementations which enables you to choose the best one for your use case. For example to prepare the guest it’s possible to use the install method for simple package installations, ansible for more complex system setup or shell for arbitrary shell commands.

Tests

Very often testing is much more complex than running just a single shell script. There might be many scenarios covered by individual scripts. For these cases the discover step can be instructed to explore available tests from fmf metadata as well. The plan will look like this:

discover:
    how: fmf
execute:
    how: tmt

Tests, identified by the required key test, define attributes which are closely related to individual test cases such as the test script, framework, directory path where the test should be executed, maximum test duration or packages required to run the test. Here’s an example of test metadata:

summary: Fetch an example web page
test: wget http://example.org/
require: wget
duration: 1m

Instead of writing the plan and test metadata manualy, you might want to simply apply the base template which contains the plan mentioned above together with a test example including both test metadata and test script skeleton for inspiration:

tmt init --template base

Similar to plans, it is possible to choose an arbitrary name for the test. Just make sure the test key is defined. However, to organize the metadata efficiently it is recommended to keep tests and plans under separate folders, e.g. tests and plans. This will also allow you to use Inheritance to prevent unnecessary data duplication.

Stories

It’s always good to start with a “why”. Or, even better, with a story which can describe more context behind the motivation. Stories can be used to track implementation, test and documentation coverage for individual features or requirements. Thanks to this you can track everything in one place, including the project implementation progress. Stories are identified by the story attribute which every story has to define or inherit.

An example story can look like this:

story:
    As a user I want to see more detailed information for
    particular command.
example:
  - tmt tests show -v
  - tmt tests show -vvv
  - tmt tests show --verbose

In order to start experimenting with the complete set of examples covering all metadata levels, use the full template which creates a test, a plan and a story:

tmt init -t full

Core

Finally, there are certain metadata keys which can be used across all levels. Core attributes cover general metadata such as summary or description for describing the content, the enabled attribute for disabling and enabling tests, plans and stories and the link key which can be used for tracking relations between objects.

Here’s how the story above could be extended with the core attributes description and link:

description:
    Different verbose levels can be enabled by using the
    option several times.
link:
  - implemented-by: /tmt/cli.py
  - documented-by: /tmt/cli.py
  - verified-by: /tests/core/dry

Last but not least, the core attribute adjust provides a flexible way to adjust metadata based on the Context. But this is rather a large topic, so let’s keep it for another time.

Organize Data

In the previous chapter we’ve learned what Tests, Plans and Stories are used for. Now the time has come to learn how to efficiently organize them in your repository. First we’ll describe how to easily Create new tests, plans and stories, how to use Lint to verify that all metadata have correct syntax. Finally, we’ll dive into Inheritance and Elasticity which can substantially help you to minimize data duplication.

Create

When working on the test coverage, one of the most common actions is creating new tests. Use tmt test create to simply create a new test based on a template:

$ tmt test create /tests/smoke
Template (shell or beakerlib): shell
Directory '/home/psss/git/tmt/tests/smoke' created.
Test metadata '/home/psss/git/tmt/tests/smoke/main.fmf' created.
Test script '/home/psss/git/tmt/tests/smoke/test.sh' created.

As for now there are two templates available, shell for simple scripts written in shell and beakerlib with a basic skeleton demonstrating essential functions of this shell-level testing framework. If you want to be faster, specify the desired template directly on the command line using -t or --template:

$ tmt test create --template shell /tests/smoke
$ tmt test create --t beakerlib /tests/smoke

If you’d like to link relevant issues when creating a test, specify the links via [RELATION:]TARGET on the command line using --link:

$ tmt test create /tests/smoke --link foo
$ tmt test create /tests/smoke --link foo --link verifies:https://foo.com/a/b/c

In a similar way, the tmt plan create command can be used to create a new plan with templates:

tmt plan create --template mini /plans/smoke
tmt plan create --t full /plans/features

When creating many plans, for example when migrating the whole test coverage from a different tooling, it might be handy to override default template content directly from the command line. For this use individual step options such as --discover and provide desired data in the yaml format:

tmt plan create /plans/custom --template mini \
    --discover '{how: "fmf", name: "internal", url: "https://internal/repo"}' \
    --discover '{how: "fmf", name: "external", url: "https://external/repo"}'

Now it will be no surprise for you that for creating a new story the tmt story create command can be used with the very same possibility to choose the right template:

tmt story create --template full /stories/usability

Sometimes you forget something, or just things may go wrong and you need another try. In such case add -f or --force to quickly overwrite existing files with the right content.

Lint

It is easy to introduce a syntax error to one of the fmf files and make the whole tree broken. The tmt lint command performs a set of Lint Checks which compare the stored metadata against the specification and reports anything suspicious:

$ tmt lint /tests/execute/basic
/tests/execute/basic
pass C000 fmf node passes schema validation
warn C001 summary should not exceed 50 characters
pass T001 correct keys are used
pass T002 test script is defined
pass T003 directory path is absolute
pass T004 test path '/home/psss/git/tmt/tests/execute/basic' does exist
skip T005 legacy relevancy not detected
skip T006 legacy 'coverage' field not detected
skip T007 not a manual test
skip T008 not a manual test
pass T009 all requirements have type field

There is a broad variety of options to control what checks are applied on tests, plans and stories:

# Lint everything, everywhere
tmt lint

# Lint just selected plans
tmt lint /plans/features
tmt plans lint /plans/features

# Change the set of checks applied - enable some, disable others
tmt lint --enable-check T001 --disable-check C002

See the Lint Checks page for the list of available checks or use the --list-checks option. For the full list of options, see tmt lint --help.

# All checks tmt has for tests, plans and stories
tmt lint --list-checks

# All checks tmt has for tests
tmt tests lint --list-checks

You should run tmt lint before pushing changes, ideally even before you commit your changes. You can set up pre-commit to do it for you. Add to your repository’s .pre-commit-config.yaml:

repos:
- repo: https://github.com/teemtee/tmt.git
  rev: 1.29.0
  hooks:
  - id: tmt-lint

This will run tmt lint --source for all modified fmf files. There are hooks to just check tests tmt-tests-lint, plans tmt-plans-lint or stories tmt-stories-lint explicitly. From time to time you might want to run pre-commit autoupdate to refresh config to the latest version.

Inheritance

The fmf format provides a nice flexibility regarding the file location. Tests, plans and stories can be placed arbitrarily in the repo. You can pick the location which best fits your project. However, it makes sense to group similar or closely related objects together. A thoughtful structure will not only make it easier to find things and more quickly understand the content, it also allows to prevent duplication of common metadata which would be otherwise repeated many times.

Let’s have a look at some tangible example. We create separate directories for tests and plans. Under each of them there is an additional level to group related tests or plans together:

├── plans
│   ├── features
│   ├── install
│   ├── integration
│   ├── provision
│   ├── remote
│   └── sanity
└── tests
   ├── core
   ├── full
   ├── init
   ├── lint
   ├── login
   ├── run
   ├── steps
   └── unit

Vast majority of the tests is executed using a ./test.sh script which is written in beakerlib framework and almost all tests require tmt package to be installed on the system. So the following test metadata are common:

test: ./test.sh
framework: beakerlib
require: [tmt]

Instead of repating this information again and again for each test we place a main.fmf file at the top of the tests tree:

tests
├── main.fmf
├── core
├── full
├── init
...

Virtual Tests

Sometimes it might be useful to reuse test code by providing different parameter or an environment variable to the same test script. In such cases inheritance allows to easily share the common setup:

test: ./test.sh
require: curl

/fast:
    summary: Quick smoke test
    tier: 1
    duration: 1m
    environment:
        MODE: fast

/full:
    summary: Full test set
    tier: 2
    duration: 10m
    environment:
        MODE: full

In the example above, two tests are defined, both executing the same test.sh script but providing a different environment variable which instructs the test to perform a different set of actions.

Inherit Plans

If several plans share similar content it is possible to use inheritance to prevent unnecessary duplication of the data:

discover:
    how: fmf
    url: https://github.com/teemtee/tmt
prepare:
    how: ansible
    playbook: ansible/packages.yml
execute:
    how: tmt

/basic:
    summary: Quick set of basic functionality tests
    discover+:
        filter: tier:1

/features:
    summary: Detailed tests for individual features
    discover+:
        filter: tier:2

Note that a + sign should be used if you want to extend the parent data instead of replacing them. See the fmf features documentation for a detailed description of the hierarchy, inheritance and merging attributes.

Elasticity

Depending on the size of your project you can choose to store all configuration in just a single file or rather use multiple files to store each test, plan or story separately. For example, you can combine both the plan and tests like this:

/plan:
    summary:
        Verify that plugins are working
    discover:
        how: fmf
    provision:
        how: container
    prepare:
        how: install
        package: did
    execute:
        how: tmt

/tests:
    /bugzilla:
        test: did --bugzilla
    /github:
        test: did --github
    /koji:
        test: did --koji

Or you can put the plan in one file and tests into another one:

# plan.fmf
summary:
    Verify that plugins are working
discover:
    how: fmf
provision:
    how: container
prepare:
    how: install
    package: did
execute:
    how: tmt

# tests.fmf
/bugzilla:
    test: did --bugzilla
/github:
    test: did --github
/koji:
    test: did --koji

Or even each test can be defined in a separate file:

# tests/bugzilla.fmf
test: did --bugzilla

# tests/github.fmf
test: did --github

# tests/koji.fmf
test: did --koji

You can start with a single file when the project is still small. When some branch of the config grows too much, you can easily extract the large content into a new separate file.

The Trees built from the scattered files stay identical if the same name is used for the file or directory containing the data. For example, the /tests/koji test from the top main.fmf config could be moved to any of the following locations without any change to the resulting fmf tree:

# tests.fmf
/koji:
    test: did --koji

# tests/main.fmf
/koji:
    test: did --koji

# tests/koji.fmf
test: did --koji

# tests/koji/main.fmf
test: did --koji

This gives you a nice flexibility to extend the metadata when and where needed as your project organically grows.

Anchors and Aliases

When you need to specify the same variable multiple times in a single file, the yaml feature called Anchors and Aliases can come handy. You can define an anchor before an item to save it for future usage with an alias.

# Example of an anchor:
discover:
    how: fmf
    test: &stable
      - first
      - second

# Which you can then use later in the same file as an alias:
discover:
    how: fmf
    exclude: *stable

Multihost Testing

New in version 1.24.

Support for basic server/client scenarios is now available.

The prepare, execute, and finish steps are able to run a given task (test, preparation script, ansible playbook, etc.) on several guests at once. Tasks are assigned to provisioned guests by matching the where key from discover, prepare and finish phases with corresponding guests by their key and role keys. Essentially, plan author tells tmt on which guest(s) a test or script should run by listing guest name(s) or guest role(s).

The granularity of the multihost scenario is on the step phase level. The user may define multiple discover, prepare and finish phases, and everything in them will start on given guests at the same time when the previous phase completes. The practical effect is, tmt does not manage synchronization on the test level:

discover:
  - name: server-setup
    how: fmf
    test:
      - /tests/A
    where:
      - server

  - name: tests
    how: fmf
    test:
      - /tests/B
      - /tests/C
    where:
      - server
      - client

In this example, first, everything from the server-setup phase would run on guests called server, while guests with the name or role client would remain idle. When this phase completes, tmt would move to the next one, and run everything in tests on server and client guests. The phase would be started at the same time, more or less, but tmt will not even try to synchronize the execution of each test from this phase. /tests/B may still be running on server when /tests/C is already completed on client.

tmt exposes information about guests and roles to all three steps in the form of files tests and scripts can parse or import. See the Guest Topology Format for details. Information from these files can be then used to contact other guests, connect to their services, synchronization, etc.

tmt fully supports one test being executed multiple times. This is especially visible in the format of results, see Results Format. Every test is assigned a “serial number”, if the same test appears in multiple discover phases, each instance would be given a different serial number. The serial number and the guest from which a result comes from are then saved for each test result.

Note

As a well-mannered project, tmt of course has a battery of tests to make sure the multihost support does not break down. The /tests/multihost/complete test may serve as an inspiration for your experiments.

Synchronization Libraries

The test-level synchronization, as described above, is not implemented, and this is probably not going to change any time soon. For the test-level synchronization, please use dedicated libraries, e.g. one of the following:

• RHTS support in Beaker rhts-sync-block and rhts-sync-set,

• a beakerlib library by Ondrej Moris, utilizes a shared storage, two-hosts only,

• a rhts-like distributed version by Karel Srot,

• a native beakerlib library by Dalibor Pospisil, a distributed version of Ondrej Moris’s library, supporting any number of hosts.

• redis server by Jan Scotka, a simple key-value exchange solution between machines. The primary purpose is data transfer. It is not a library prepared for synchronization, but it’s possible to use it as well. See the example to learn how to set up a redis server and use it.

Current Limits

Note

For the most up-to-date list of issues related to multihost, our Github can display all isues with the multihost label.

• requirements of all tests (require, recommend) are installed on all guests. See this issue for more details.

• interaction between guests provisioned by different plugins. Think “a server from podman plugin vs client from virtual”. This is not yet supported, see this issue.

• provision step is still running in sequence, guests are provisioned one by one. This is not technically necessary, and with tools we now have for handling parallelization of other steps, provisioning deserves the same treatment, resulting in, hopefully, a noticeable speed up (especially with plugins like beaker or artemis).