snapcraft io что такое
About Snaps
Snaps are app packages for desktop, cloud and IoT that are easy to install, secure, cross‐platform and dependency‐free. Snaps are discoverable and installable from the Snap Store, the app store for Linux with an audience of millions.
A snap is a bundle of an app and its dependencies that works without modification across Linux distributions.
Snapd
Snapd is the background service that manages and maintains your snaps, automatically.
Snap Store
The Snap Store provides a place to upload snaps, and for users to browse and install the software they want.
Snapcraft
Snapcraft is the command and the framework used to build and publish snaps.
A universal store
Snaps run not only on desktops but also on IoT devices, servers and clouds
Snaps work across Linux on many distributions and versions. Bundle your dependencies and assets, to simplify installs to a single standard command.
Built, published and hosted for free
Our build infrastructure and the Snap Store makes building and publishing snaps a breeze
Whether your project is hosted on GitHub or not, you can leverage our build system to both build and release to the edge channel, ensuring users always stay up‐to‐date.
Software distribution in your hands
With Snapcraft, you are in control of when and how you publish your Snap
With channels users can find their preferred balance between stability and the latest features. Though nothing is enforced, users expect the “Stable” channel to be well tested and updated less frequently, whereas the “Edge” channel is where they’ll get the latest release as soon as it’s available.
Open source, but not only
Snaps can bundle both proprietary applications and open source
If you build proprietary software you can use the “Proprietary” license. For open source projects we support SPDX expressions so you can let your users know exactly what license your project uses.
© 2021 Canonical Ltd.
Ubuntu and Canonical are registered trademarks of Canonical Ltd.
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Snapcraft lets you build with the tools you already use
With support for many languages out of the box, getting started with Snapcraft can be as simple as installing and running snapcraft.
Publish from your developer workstation
Linux, macOS or Windows
To develop snaps you have Linux support via Snaps, macOS support via homebrew and Windows support via WSL. With whichever OS you’re comfortable with, you can develop and publish snaps.
If you already have an Electron app for Windows and macOS, you only need to make minimal changes to your package.json to build a snap that’s ready to release. Get started with an Electron app.
Learn how to snap an app in 30 minutes
What language or framework does your app use?
Why are snaps good for C/C++ projects?
In just a few steps, you’ll have an example C/C++ app in the Snap Store.
Here’s how dosbox defines snapcraft.yaml:
Why are snaps good for Electron projects?
In just a few steps, you’ll have an example Electron app in the Snap Store.
Here’s how to use it with electron-quick-start:
Why are snaps good for Flutter projects?
In just a few steps, you’ll have an example Flutter app in the Snap Store.
Here’s how super-cool-app defines snapcraft.yaml:
Why are snaps good for Go projects?
Programming in Go makes it easy to create a zip of your app that runs across Linux, without dependencies. However, end user discovery and update management remain a challenge. Snaps fill this gap, letting you distribute a Go app in an app store experience for end users.
In just a few steps, you’ll have an example Go app in the Snap Store.
Here’s how httplab defines snapcraft.yaml:
Why are snaps good for Java projects?
Distributing a Java application for Linux and reaching the widest possible audience is complicated. Typically, the user has to make sure the JRE/SDK version and their environment are configured correctly. When a Linux distribution changes the delivered JRE, this can be problematic for applications. Snapcraft ensures the correct JRE is shipped alongside the application at all times.
In just a few steps, you’ll have an example Java app in the Snap Store.
Here’s how freeplane defines snapcraft.yaml:
Why are snaps good for MOOS projects?
In just a few steps, you’ll have an example MOOS app in the Snap Store.
Here’s an example snapcraft.yaml that uses MOOS:
Why are snaps good for Node.js projects?
With npm you can distribute apps to other developers, but it’s not tailored to end users. Snaps let you distribute your Node app in an app store experience.
In just a few steps, you’ll have an example Node.js app in the Snap Store.
Here’s how wethr defines snapcraft.yaml:
Why are snaps good for pre-built apps?
Distributing the Linux build of your app as a zip lets you provide one download and set of instructions for all of Linux. However, end user discovery and update management remain a challenge. Snaps fill this gap, letting you wrap your existing Linux build in an app store experience for end users.
In just a few steps, you’ll have an example pre-built app in the Snap Store.
How geekbench4 defines snapcraft.yaml
Why are snaps good for Python projects?
With PyPI you can distribute apps to other developers, but it’s not tailored to end users. Virtualenv lets you install an app’s dependencies in isolation, but it’s not automatically used for installs from PyPI. Snaps let you distribute a dependency-isolated Python app in an app store experience for end users.
In just a few steps, you’ll have an example Python app in the Snap Store.
Snapcraft overview
Snapcraft is a powerful and easy to use command line tool for building snaps. It helps you to:
On Linux distributions with snap support, the easiest way to install snapcraft is via its snap:
Snapcraft can also be installed and run on Apple’s macOS. See Install snapcraft on macOS for details.
See below for a general overview of Snapcraft’s capabilities, and see Creating a snap for a more detailed look at the process, alongside a selection of self-contained examples for some popular languages and frameworks, including Go, Python and C/C++.
If you’re using an apt installed version of snapcraft, such as the package for Ubuntu 18.04 LTS, you need to remove this ( sudo apt remove snapcraft ) and install snapcraft from its snap to access the latest features.
Working with snapcraft
At the heart of the snapcraft build process is a file called snapcraft.yaml. This file describes a snap’s build dependencies and run-time requirements, it integrates remote repositories and extensions, and runs custom scripts and hooks for better integration with CI systems.
Snapcraft 3.0, and later releases, are designed to use bases (see Base snaps) and Multipass to both simplify the build process and to confine the build environment within a virtual machine. Confining the build in this way isolates potentially conflicting libraries and other files from your host system, and vice-versa.
However, Snapcraft offers a variety of options alongside Multipass, such as building within an ephemeral environment or with LXD. See Build options for further details.
Creating snapcraft.yaml
The typical snap build process centres on iterating over the configuration of parts, plugins and interfaces within this snapcraft.yaml file:
The following lists how you might want to approach building a new snap for your application with snapcraft.yaml:
Building your snap
Critically, you can update snapcraft.yaml outside of the build environment and run snapcraft within the build environment to incorporate any external changes and continue with the build. If there are no further errors, your snap will be built.
See Debugging building snaps for common problems and their solutions.
With Multipass, the default virtual machine is assigned 2 CPUs. If you have the hardware capabilities, use the following environment variables to modify CPU and memory allocation to improve performance:
If you don’t have Multipass installed, snapcraft will first prompt for its automatic installation via a snap. If you can’t use Multipass, see Build options for alternatives.
The build process will proceed through the Snapcraft lifecycle, installing and building your project’s dependencies, as described by your snapcraft.yaml. The time this takes will depend on the complexity of your project and the capabilities of your system.
For a more comprehensive and iterative break-down of the snap building process, see Creating a snap.
ⓘ To see what’s new in each release of Snapcraft, take a look at Snapcraft release notes.
Last updated 7 months ago.
© 2021 Canonical Ltd.
Ubuntu and Canonical are registered trademarks of Canonical Ltd.
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snapd
Install latest/stable of snapd
Ubuntu 16.04 or later?
View in Desktop store
Make sure snap support is enabled in your Desktop store.
Install using the command line
Daemon and tooling that enable snap packages
Install, configure, refresh and remove snap packages. Snaps are ‘universal’ packages that work across many different Linux systems, enabling secure distribution of the latest apps and utilities for cloud, servers, desktops and the internet of things.
Start with ‘snap list’ to see installed snaps.
Details for snapd
Share this snap
Generate an embeddable card to be shared on external websites.
Create embeddable card
Share embeddable card
Customise your embeddable card using the options below.
Getting started
A snap is a bundle of an app and its dependencies that works without modification across many different Linux distributions. Snaps are discoverable and installable from the Snap Store, an app store with an audience of millions.
The following sections provide a basic overview of using snaps, from installation to management and manipulation.
Install snapd
The snapd daemon manages the snap environment on the local system. Its installation will include the snap tool for interacting with snaps. You can check both are installed by attempting to run snap version on the command line:
If all is well, version numbers for the main system components will be output, as shown above, albeit with potentially different versions and Linux distribution identifier.
If the snap command is not found, or if the command takes a while to respond before reporting that snapd is unavailable, make sure snapd is properly installed before continuing.
The «$» above represents the command line prompt. Sample commands come after this prompt with any relevant output shown below.
Find a snap
With snapd installed, snaps can be discovered, searched for, and installed from the Snap Store, from the Snap Store desktop app, and directly from the command line. For example, the following command returns a list of media players:
The ✓ alongside videolan in the above output indicates that the snap publisher has been verified.
Learn about a snap
The snap info command makes it easy to find more details about a specific snap. These details include what a snap does, who publishes it, the command(s) it provides and which channel versions are available for installation:
Install a snap
Installing a snap is straightforward:
Channels are an important snap concept. They define which release of a snap is installed and tracked for updates. The stable channel is used by default, but opting to install from a different channel is easily accomplished:
After installation, the channel being tracked can be changed with:
The sudo command ensures the command following it is executed as the root administrative user.
Run apps and commands from snaps
For example, the command installed via the VLC snap is simply vlc:
If executing a command directly doesn’t work, try prefixing it with the /snap/bin path:
Adding /snap/bin to your default $PATH makes running snaps that don’t automatically add themselves more convenient.
Where snaps store data
Most snaps use strict confinement to isolate both their execution environments and their data from your system (see Snap Confinement for further details). A confined snap that needs user-access to files will most likely use the home interface to bridge this confinement gap, allowing you to save and load files from your home directory automatically.
You can see whether the home interface is being used in the output to snap connections :
Regardless of whether the home interface is used or not, a snap can also store user data, such as a database or configuration files, within its own directory under $HOME/snap. Data within this snap-specific directory is stored in one of two further directories, depending on whether the data needs to be tied to a specific release, or whether it can be used across multiple releases.
For more details on where snaps store their data, see Data locations.
List installed snaps
Use snap list to show a list of snaps installed on your system:
Some snaps, such as core listed above, are installed by automatically by snapd to satisfy the requirements of other snaps.
Update an installed snap
Snaps are updated automatically. However, to manually check for updates, use the following command:
The above will check the channel being tracked by the snap. If a newer version of the snap is available, it will be downloaded and installed.
Changing the channel being tracked and refreshing the snap can be accomplished with a single command:
Updates are automatically installed within 6 hours of a revision being made to a tracked channel, keeping most systems up-to-date. This schedule can be tuned via configuration options.
Versions and revisions
Versions and revisions convey different details about one specific release of a snap:
The version is a string that was assigned to a project by its developers, according to their development practices. It tells the user what content to expect from a snap. The revision is an automatic number assigned by the Snap store, giving the snap a unique identity within the channel.
Neither the version nor the revision enforce an order of release. The local system will simply attempt to install whatever snap is recommended by the publisher in the channel being tracked.
Revert to a previously used snap
A snap may be reverted to a previously used revision with the snap revert command:
This operation will revert both the snap revision and the configuration data associated with the software. If the previously used revision of the snap is from a different channel, that snap will be installed but the channel being tracked won’t change.
User data, such as data generated by the snap and stored in a database, is often stored in a common directory and will not be reverted. See Data locations for more details on what information is stored and where.
A snap won’t automatically update to a version previously reverted from, and the output from snap refresh will continue to state All snaps up to date. A reverted snap will be automatically updated when a new and different revision is made available by the publisher.
However, explicitly adding the snap name to snap refresh will update the snap, regardless of whether the latest revision was previously reverted from or not:
On an Ubuntu Core system, such as Ubuntu Core 18 and Ubuntu Core 16, reverting twice will work too. This is because snapd attempts to keep three revisions of a snap: the most recently installed plus the two previous installations. On classic systems like Ubuntu 18.04 LTS or Ubuntu 16.04 LTS, two revisions are retained by default. This behaviour can be modified with the refresh.retain system option.
List all available revisions
The following command lists all revisions available for every installed snap, and also highlights which particular revisions are disabled at the moment:
A previously used snap that was reverted from will display disabled in the Notes column of the output.
Manually keeping track of which snap revisions available is generally unnecessary. A single revision will only ever be in use at a time, and snapd will remove old revisions automatically.
Disable and enable snaps
If a snaps is temporarily undesired, it can be disabled and later enabled again. This avoids having to remove and reinstall them in the system:
Remove a snap
To remove a snap from your system, along with its internal user, system and configuration data, use the remove command:
Prior to removal (except on Ubuntu Core systems), a snap’s internal user, system, and configuration data is saved as a snapshot (snapd 2.39+), and retained for 31 days.
However, a snapshot can be used to restore the state of your snap upon reinstallation. See Snapshots for further details.
Next steps
Last updated a month ago.
© 2021 Canonical Ltd.
Ubuntu and Canonical are registered trademarks of Canonical Ltd.
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