Hydra/ru: Difference between revisions

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Hydra - это инструмент для непрерывного интеграционного тестирования и выпуска программного обеспечения, который использует чисто функциональный язык для описания заданий сборки и их зависимостей. Непрерывная интеграция - это простая техника, позволяющая повысить качество процесса разработки программного обеспечения. Автоматизированная система постоянно или периодически проверяет исходный код проекта, собирает его, запускает тесты и готовит отчеты для разработчиков. Таким образом, автоматически отлавливаются различные ошибки, которые могут быть случайно зафиксированы в кодовой базе.

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== Установка ==

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   services.hydra = {

   };

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* See nixos-option or the [https://search.nixos.org/options?query=services.hydra Nixos Options page] for all options

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Hydra will provide the web interface [http://localhost:3000/ at localhost] port 3000. However you need to create a new admin user (as UNIX user <code>hydra</code>) before being able to perform any changes:

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# su - hydra

     --email-address 'alice@example.org' --password-prompt --role admin

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If not configured explicitly to do otherwise, Hydra will specify localhost as the default build machine. By default, system features enabling builds to be performed in virtual machines like "kvm" or "nixos-test" are not enabled. Such jobs will be queued indefinitely. Those options can be activated as follows:

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{

   nix.buildMachines = [

     { hostName = "localhost";

       system = "x86_64-linux";

       supportedFeatures = ["kvm" "nixos-test" "big-parallel" "benchmark"];

}

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* Flake URI: an URI to a repo containing a Flake like git+https://git.myserver.net/user/repo.git

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{

       ...

     };

       inherit (self)

         packages;

}

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nix.settings.allowed-uris = [

];

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Right now it is not possible to build a single package from nixpkgs with just that input. You will need to provide a supplementary repository which defines what to build. For examples you can check the [https://github.com/makefu/hydra-example hydra-example by makefu] and in the [https://nixos.org/hydra/manual/#idm140737315920320 Hydra Manual].

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These steps are required to build the <code>hello</code> package.

# log into Hydra after creating a user with <code>hydra-create-user</code>

# create new project

* identifier: example-hello

* display name: example-hello

# Actions -> Create jobset

* identifier: hello

* Nix expression: <code>release.nix</code> in <code>hydra-example</code> -> will evaluate the file release.nix in the given input

* check interval: 60

* scheduling shares: 1

* Inputs:

{| class="wikitable"

|-

After creation, the jobset should be in the '''evaluation phase''' where inputs will be fetched. This phase may take some time as the complete <code>nixpkgs</code> repository needs to be downloaded before continuing. The result of the evaluation should be a single job which will get built.

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Since 2016, Hydra supports declarative creation of jobsets. Check out the [https://github.com/shlevy/declarative-hydra-example example repository and description by Shea Levy].

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== Hydra Internals ==

=== Definitions ===

This subsection provides an overview of the Hydra-specific definitions and how to configure them.

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A cluster of Jobs which are all coming from a single input (like a git checkout), the first thing you will need to create. Every Job should be able to be built independently from another. Most of the time the project maps to a single repository like <code>nixpkgs</code>. It is comparable to the project definition in Jenkins.

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==== Jobsets ====

A Jobset is a list of jobs which will be run. Often a jobset fits to a certain branch (master, staging, stable). A Jobset is defined by its inputs and will trigger if these inputs change. For example when a new commit onto a branch is added. Jobsets may depend on each other.

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==== Job ====

A closure which will be built as part of a job set (like a single package, iso image or tarball).

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==== Release Set ====

Defines all the jobs which are described in your release. By convention a file called<code>release.nix</code> is being used. See the [https://nixos.org/hydra/manual/#idm140737315920320 Hydra manual for Build Recipes] for a thorough description of the structure.

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==== Evaluation ====

The process of interpreting nix code into a list of <code>.drv files</code>. These files are the build recipes for all related outputs. You can introspect these files by running <code>nix show-derivation nixpkgs.hello</code>.

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Instantiation of a Job which is being triggered by being part of the release set.

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* hydra-queue-runner sometimes gets stuck even with builds are in the queue, and the builds are not scheduled. The issue is being tracked [https://github.com/NixOS/hydra/issues/366 here]. In the meantime, a workaround is to add a cron job that regularly restarts the hydra-queue-runner systemd service. Possible fix: [https://github.com/NixOS/hydra/commit/73ca325d1c0f7914640a63764c9a6d448fde5bd0]

* If you see <code>error: unexpected end-of-file</code> it can mean multiple things, some of them are:

# You have a miss-match between nix versions on the Hydra server and the builder

# It can also mean that <code>hydra-queue-runner</code> needs privileges on the build server. Reference: [https://github.com/NixOS/nix/issues/2789]

* The default timeout for git operations is 600 seconds [https://github.com/NixOS/hydra/issues/1181], which might cause fetches of large repositories like [https://github.com/NixOS/nixpkgs nixos/nixpkgs] to fail: <code>error fetching latest change from git repo at `https://github.com/nixos/nixpkgs': timeout</code>. The timeout can be increased with the following configuration.nix snippet:

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{

}

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Hydra is used for managing official Nix project releases. The project Hydra server: https://hydra.nixos.org/

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Some Hydra trackers for Nix projects:

* [https://hydra.nixos.org/project/nixpkgs Nixpkgs]

* [https://hydra.nixos.org/project/nixos NixOS]

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* [https://gist.github.com/joepie91/c26f01a787af87a96f967219234a8723 Hydra Caveats by Joepie91]

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