There’s a new Ubuntu LTS in town, with a whole new desktop to entice and amaze you. Jonni Bidwell rolls out the orange carpet…
Quiet your busy mind for just a moment, dear reader, and tell us what you hear. The sound of swallows, swifts and wheatears returning to their northern breeding grounds? No, listen more closely. There’s a vaguely mechanical gnawing sound from the trees over yonder.
That’s the sound of a bionic beaver, and possibly some gnomes too, and it can mean only one thing: the latest Ubuntu LTS release is here. As is tradition, our cover has been emblazoned orange, our disc editor has been kept up for days testing the daily builds, and Jonni won’t stop wittering on about Walpurgisnacht. But things have changed since the last LTS two years ago.
Back then, there was excitement about Canonical’s bold desktop projects: Unity 8, Mir and convergence. Those have all been bequeathed to the community now and Ubuntu, after seven years going its own way, has returned to the Gnome desktop.
A controversial move, but a pragmatic one too. Canonical is heading towards an IPO, and ambitious desktop projects that generate no revenue don’t attract investors.
Furthermore, Gnome 3 has matured and ripened and is no longer the scary desktop beast that it used to be, and Canonical has done a great job of customising it to be as friendly as possibly to Unity expats. Gnome is also leading the charge towards Wayland, the successor to the aging X.org display server, so Ubuntu 18.04 is a great distro for brave souls and early adopters to experiment with the future display stack (don’t worry it’s not the default yet).
Of course, if Gnome’s still not your thing there’s no shortage of other desktop flavours to try. We’ll cover the most interesting ones, and of course all the exciting changes under the hood, too – the new kernel, snap packages, not to mention Ubuntu’s server, cloud and loT offerings. Plus, we haven’t forgotten about the crazy die-hards still running 32-bit hardware. There may be no 32-bit install medium, but that doesn’t mean you can’t reap the benefits of the new Ubuntu!
Eager beavers
There’s a lot of hype surrounding the latest release of Ubuntu, codenamed Bionic Beaver. But what’s new? Let’s find out…
After 14 years of Ubuntu releases, you might think they weren’t such a big deal anymore. But make no mistake, this is big news. For one thing, it’s an LTS release so will very likely be many people’s daily driver for a good few of the next five years. Furthermore, a number of those other popular desktop distros are based on Ubuntu LTS, so this release crystallises their foundations too. And finally, this release sees Ubuntu return to the Gnome desktop after seven years of going their own way with Unity.
Install with caution
Installing Ubuntu is as easy as it’s ever been. However, this is a new release and so shouldn’t be used on systems you’re depending on day to day. You should make sure everything works from the live environment before you install it. And back up any important data before you think about hitting the install button.
Also, don’t use our install disc. Get an up-to-date ISO from www.ubuntu.com/download/desktop. This might seem like strange advice, especially given all the superlatives on the wallet, but within the confines of the covers we can at least be sensible about this. Thanks to the lugubriousness of getting a magazine printed, this is not the final release, it’s a daily image from mid-April. We’ve tested it as best we can, but we can’t say if you’ll be stricken by some heretofore undiscovered bug that takes out your BIOS (as happened in 1710), or other operating systems. You can use the zsync utility to update the ISO with minimal data transfer here (see below). This will download only the bits that have changed, which should only be a few megabytes. Once that’s done, write the refreshed ISO to a disc using your favourite burning utility or to USB using dd or Etcher.
When you begin the install, you may be pleased to find the option of a minimal install. This doesn’t save a huge amount of space (around 500MB), but does away with most of the bulky applications, leaving only a web browser and core tools. From here you can add whatever you like, so it’s great if you have different application proclivities to the Ubuntu defaults.
INSTALL UBUNTU
Download the official ISO
If you’re short on bandwidth and already running Linux, copy the ISO from our disc (it’s in the Ubuntu/ directory), install zsync and update the ISO:
$ chmod 755 bionic-desktop-amd64.iso $ mv bionic-desktop-amd64.iso ubuntu- 18.04-desktop-amd64.iso $ zsync http://releases.ubuntu. com/18.04/ubuntu-18.04-desktop-amd64. iso.zsync
Now write the new image to disc or USB.
Boot the live medium
Insert your disc or USB drive into the appropriate place and then boot your machine. The official image will work with secure boot (note that our disc will not), but finding the magic key to summon the boot menu or UEFI settings may take some trial and error on your part. F2, F10 and Del are common options. Mac users should hold down C. Select the optical drive or USB and then choose ‘Try Ubuntu without installing’.
Test and install
Check as much of your hardware as possible from the live environment (extra displays, wireless and printers). In addition, make sure you like it, because there’s no point risking your system if you don’t. If all’s well then press the install icon on the desktop, the installer will happily install alongside (or atop) Windows or other Linuxes. If you have a more exotic setup then choose the ‘Something else’ option.
Getting to Gnome you
Unity is out and Gnome is in. Despite what some would call its chequered history, Gnome’s a feature-packed desktop powerhouse.
You may have heard terrible things about Gnome: that it’s a hypermodern desktop environment more suited to phones than PCs, that it forces you to learn abstruse key combinations, that it can’t be configured, that it’s written in JavaScript… the list goes on. Though none of these are really true, the prospect of learning a whole new desktop environment may be, to say the least, daunting.
Don’t worry, though – Canonical has put a lot of effort into making Gnome friendly to people used to working in Unity. There’s the familiar colour scheme, app indicators, the signature font and window decorations and, of course, the characteristic left-hand launcher bar. You can even put icons on the desktop if you really want to. However, Canonical has been quite deliberate in not making these tweaks invasive to the desktop’s underpinnings: they’re all done through standard Gnome extensions and themes, rather than shipping patched libraries. This ensures compatibility across the Gnome ecosystem and avoids reliance on third-party extensions, but it does mean things like global menus and the more advanced features of Unity’s HUD are no more.
The Gnome release cadence happens to align nicely with Ubuntu’s bi-annual releases, so 18.04 includes (most of) the latest version, Gnome 3.28, released in mid March. This includes some great new features, many of which you can read about in our Hotpicks section on page 81. Files, which is the default file manager in Ubuntu, is based on the version from 3.26, but it has received a stylish new look (check out that funky sidebar, people!) and will be familiar to Unity users. Also familiar will be the sponsored Amazon link in the sidebar. We recommend replacing this with something useful forthwith. A shortcut to the Terminal is a good and sensible choice.
Get to know the Gnome desktop…
Dock
1 Launch and see running applications (denoted by a dot) from here.
Activities
2 Clicking here (or pressing the Super key) launches the Activities view (pictured). Helpfully, it shows previews of running apps.
Search Box
3 Start typing in the Activities view (there’s
no need to click in the box) to search Apps, Docs and more.
Calendar and Notifications area
4 Click here to control music, see any appointments (if you’ve connected an appropriate service) and see other stuff.
Status Menu
5 Network settings (including VPN), volume controls and application indicators can be found here. The button in the bottom left launches the all-important Settings app.
Applications menu
6 Click here to open/close a view of frequently used applications. You can see all installed applications from the selector at the bottom of this menu.
We’ve covered the basics of the Gnome desktop in our annotation (below left) and you’ll find a treasure trove of further information on the next page. If you really want to have Unity back, then you can install it with sudo apt install unity , but we’d strongly advise against this. It has received some bug fixes in this release, but won’t be receiving very much attention at all going forward. Oddities will occur with increasing frequency, and applications will start breaking, better to start embracing the future.
If you’ve ever used Emacs, or tried to quit Vim, then you’ll know the importance of keyboard shortcuts. You can happily prosecute your business in Gnome without knowing any of these, but learning these few will make your life easier:
» Super (Windows key) – Bring up the activities view » Super-Left/Right – Tile current application left or right (so it fully occupies one half of the screen)
» Super-Up/Down – Maximise/Restore current application
» Super-PgUp/PgDown – Switch virtual desktops » Super-Shift-PgUp/Dn – Move current application to next/previous virtual desktop
There are many more, which you can study at https://help.gnome.org/users/gnome-help/stable/ shell-keyboard-shortcuts.html.en.
Gnome has been criticised in the past for its lack of configurability, and this has traditionally been countered with the notion that users shouldn’t need to configure something that’s been well-designed. There’s some truth in this sentiment, and it’s worth trying to get used to Gnome, before resorting to extensions to ‘fix’ it.
That said, there are some things ‘missing’ from Gnome (including, but not limited to: minimise buttons, a system tray and titlebars on Gnome applications). Some of these can be remedied by installing Gnome’s Tweaks tool, or extensions (see box, right). You’ll find Tweaks in the Software application (it’s called GNOME Tweaks there), and once it’s installed it will enable you to play with many settings that were hitherto only accessible through gsettings keys.
There’s good news if you’re down with the youth, or indeed if you just like to embellish your monochromatic letters, numbers and punctuation marks with colourful/ expressive/irreverent glyphs, or creative combinations thereof. Ubuntu ships with the Noto Color Emoji font, the very same used in recent versions of Android, and recent enough versions of Fontconfig and Cairo to render them. They can be copied and pasted from the
Characters application, and will work in all Gnome applications (even the Terminal!), but sadly not LibreOffice, although that does have support for some uncoloured emojis using shortcuts such as :yin yang: .
Online accounts
One of Gnome’s many impressive tricks is its online account integration. You may not want to browse your Google drive files from Files, or see your Facebook and Flickr photos with Photos, or integrate with any proprietary service at all. But if you do, then you can. There’s also integration with open source services, such as Nextcloud.
The Night Light feature has been in Gnome for a while, but you might have missed it. Eyestrain is a big deal nowadays: we spend too long looking at displays, be they monitors or phones or VR goggles. All too often this staring goes on into the small hours, where blue light begins to cause detrimental effects, both physically and psychologically. The best cure is, of course, to take regular screen breaks and go to bed early (yes Jonni!- Ed), but when that’s not possible having your display change it’s colour temperature at sensitive times should make it easier on the eyes. Open the Settings panel, and go to Devices>Screen Display>Night Light to configure times and temperatures.
INSTALLING EXTENSIONS
There are also a great selection of Gnome extensions that provide new functionality. Only two small hurdles need to be overcome before you can avail yourself of them. Gnome extensions are installed via the https://extensions.gnome.org website. Before you can use this (as the website tells you) you’ll need two things: a ‘native host messaging application’ and a browser extension.
The former is found in the chrome-gnome-shell package available from the software application and the latter can be found by following the ‘Click here to install browser extension’ link. Now a whole world of extensions awaits you. One of the most popular, you’ll note, is User Themes, which enables you to use themes from sites such as https://gnome-look.org, by extracting them to the ~/.themes directory. Once that’s done you can select them from Tweaks.
Within the Extensions tab in Tweaks, you’ll notice two already there: Ubuntu appindicators and Ubuntu dock. These can’t be deactivated, because they’re a key part of the Ubuntu Gnome desktop. The Ubuntu dock is actually a fork of another popular extension, Dash to Dock, which you may want to check out. If you’re feeling brave, you may also want to check out what a vanilla Gnome session is like. Just do:
$ sudo apt install gnome-session
You can select the session when you log in. Look ma, no dock!
Flavours and spin-offs
Don’t worry if Gnome’s not your jam. There are other desktop flavours to enjoy and other Ubuntu-based distros, too.
First came Ubuntu (2004) and then, one year later came Kubuntu, because KDE fans wanted the Ubuntu system under their desktop of choice. Other flavours followed, some of these don’t have a release this cycle, and some are no more (such as Ubuntu Gnome). But here’s a summary of our favourites.
Ubuntu Budgie
Budgie is up-and-coming distro Solus OS’s desktop, and it’s the newest addition to the Ubuntu flavour family. It strives to be “a clean and… powerful desktop without unnecessary bloat”. One of its proudest features is the
Raven sidebar, which makes it possible to configure elements without having to go hunting around in settings applets. This is hidden by default in this release, but is accessible from an icon in the top right. By default the Raven bar houses a calendar, audio controls and a notifications area, but you can add other applets to it.
A number of titlebar applets are activated by default, including a desktop note taker, a night light control and Caffeine, which can stop unwanted screen blanking. Budgie includes the excellent Tilix terminal, which comes pre configured with a drop-down shortcut (F12). There’s the similarly excellent Geary email client too. If you like widgets on your desktop, Budgie enables you to configure them straight from the welcome screen.
Budgie is currently based on Gnome, and so includes many of the same applications in the standard Ubuntu release, as well as all the new Gnome 3.28 features. Things are changing though and Budgie 11, will be a Qt-based affair, which we look forward to very much.
Ubuntu MATE
MATE started as a fork of Gnome 2, and has been a refuge for people who yearn for those days of cascading menus, top and bottom panels, and a distinct lack of flashy desktop effects. The default look in MATE has changed though, which some users may find shocking.
Dubbed Familiar, the new layout does away with the Applications, Places and System menus of yore. But fear not, the old layout (named Traditional) can be restored easily. A number of other desktop layouts are available too, including Netbook, Mutiny (haha, a tribute to Unity) and Cupertino (featuring the Plank dock and making for a macOS-esque experience).
MATE is by no means averse to keeping up with the times, and one of the exciting changes since the last Ubuntu is the new Brisk menu. This puts MATE on a par with pretty much every other desktop environment in having a menu that’s instantly searchable. Said menu can be summoned with the Super key too. Like Kubuntu, Ubuntu MATE includes an optional Global
THE WIDER UBUNTU ECOSYSTEM
Besides the official flavours, Ubuntu provides the basis for a number of popular derivative distributions, many of which will be releasing updates soon. The most popular is Linux Mint, and we look forward very much to Mint 19, which hopefully will be released in June. We were nothing but impressed with Mint 18 (see LXF214), where we saw Mint start to move away from Gnome applications, launching its own desktop-agnostic X-apps. The goal here is to avoid the new GTK3 stylings, most notably headerbars, which broke from tradition.
The rather beautiful ElementaryOS will be getting a version bump from 0.4 to 5.0, hopefully in the not-too-distant future. Apart from confounding our ideas about how versioning should work, this reflects elementary’s growing maturity and stability. Like Mint, the team are working on the next generation of their applications, which are all written in Vala and, unlike Mint, embrace modern design paradigms – headerbars and all. The old text editor, Scratch, has grown up into a code editor, Code, which we’re particularly excited about.
If you want to test the very latest KDE technologies, the best way is probably through KDE Neon. This is not a distro in the conventional sense, because it only includes shiny new KDE software. This led to a slight oddity when one considered the vintage of the kernel and repositories from the 16.04 LTS (the idea is to have a stable base underneath all the Plasma bits). However, this will be remedied, at least temporarily, when it’s rebased to 18.04.
Helpfully, MATE comes with a tweak tool pre-installed, enabling you to choose one of its many layouts.
Keep up with elementaryOS news at https://medium.com/elementaryOS.
Menu to put at ease those who miss this feature from Unity. The distro goes one step further too, featuring a HUD (Head Up Display) that enables menu options to be searched by holding down Alt.
Kubuntu
KDE Plasma is a fabulous desktop that manages to be at once modern and still respective of the traditional desktop metaphor. Kubuntu’s take on it adds some nice touches, with a stylish dark theme and handy shortcuts. If you have a reasonably modern graphics card, then all of the nice effects (which are by no means excessive) will use hardware acceleration and won’t interfere with your work. Kubuntu uses Plasma 5.12 LTS, released in February. But PPAs will be available for Kubuntu users willing to brave installing newer libraries.
KDE has, in the past, been seen as the most memory-hungry desktop, but in our testing this ignominious crown is very much Gnome’s now (not that it really matters in an age when 16GB of RAM is all but standard). KDE is highly configurable, it comes with a choice of launchers (a ‘classic’ menus, the default ‘fancy’ menu, and a full-screen launcher a la Gnome). You can even set up a Global menubar (so application menus appear in a top panel as opposed to in the application window, a Unity feature) if you want.
Lubuntu
Lubuntu is the least resource-hungry of the Ubuntus. It will install on a Pentium II machine with 128MB of RAM and 2GB of space, but for daily use 512MB of RAM is recommended. It’s based on the aging GTK2 toolkit, which is a problem because many apps no longer build with this without significant patching, and this trend will continue over the five-year support period.
Lubuntu is transitioning to the Qt5-based LXQt desktop, but this is a complex journey, and the team don’t want to ship something unfinished (and have to support it for five years). Progress has been good, however, and the Lubuntu-next image is available for users wanting a glimpse of the future. It will be supported for nine months, by which time the project should be more suitable for a general audience.
Lubuntu Next will require slightly more grunt than its predecessor, and has slightly larger memory and disk space footprints, but should be fine on machines built in the last decade. Thanks to the extensive work that went into decoupling the KFrameworks helper libraries from the rest of KDE, the distro doesn’t bloat itself with swathes of KDE-specific libraries, as was traditionally the case when installing Qt4 programs.
LXQt 0.12 was released back in October 2017 and we’ve tested it with great results on some of our dusty hardware. Just because it’s lightweight doesn’t mean it sacrifices anything in terms of style or functionality.
Xubuntu and Ubuntu Studio
Once the only (fully featured) alternative to Gnome and KDE, the Xfce desktop used in Xubuntu has sadly been eclipsed by the likes of MATE and LXQt. The project hasn’t seen a new release since February 2015. But it’s far from stagnant (review the activity at https://git. xfce.org), the slow transition to GTK3 and the long- awaited 4.14 release is still ongoing, with the vast majority of components no longer dependent on GTK2.
KDE’S BACK IN OUR GOOD BOOKS
KDE has, in the past, been seen as the most memory-hungry desktop, but in our testing this ignominious crown is very much Gnome’s now
Xfce is also the desktop used by Ubuntu Studio, the flavour for multimedia and creative types. This release isn’t an LTS, but it’s supported for nine months and efforts to rejuvenate the Studio community are underway. The next release, 18.10, hopes to change things up a bit. Nonetheless, this releases showcases some great tools: JACK, Blender, Darktable, Ardour and many more. It’s the only distro where you’ll find all of these programs pre-installed.
KDE Plasma has its own software app, Discover. The Geology section rocks – try it!
It’s hard to write this kind of feature without some mention of the desktop backgrounds on offer – here is Xubuntu’s snazzy selection.
Lubuntu uses the LXDE desktop powered by the Openbox window manager for a bells-and-whistles free desktop.
Next-generation Ubuntu
There’s plenty of exciting new technology (besides Gnome) in this release, so have a gander and find out what’s what…
Kernel 4.14 is an LTS release too, so the kernel team will support it for at least five years. The plan was to use this for Ubuntu, but since 4.15 was released in January, and makes working with the ever-evolving KPTI patches for Spectre/Meltdown somewhat easier than the backported solutions, it was decided to use 4.15 for Ubuntu.
Kernel 4.15 has been one of the busiest releases for a long time. Besides frantic patching of Spectre and Meltdown, it also includes many exciting new features. After extensive reworking, AMD’s DC (Display Code) layer has landed, which means owners of Vega and Raven Ridge series cards (including the 2200G reviewed on page 18) can use the open source AMDGPU driver without relying on a custom kernel. It also enables that driver to work with HDMI audio on other AMD
IF IN DOUBT, REBOOT!
It’s crucial to stress that live patching isn’t a cure for rebooting in general. Updates to Systemd, for example, will often require a reboot to take effect
GPUs. Laptop users may see a battery life boost thanks to improved SATA power management. Canonical invests a lot of work into supporting the kernel (after all it’s at the heart of its cloud, server and IoT offerings, too) so we can expect features from future kernel’s to be backported to this one, even after the kernel team itself cease working on the 4.15 series.
Ubuntu’s Livepatching service is more of interest to server administrators than desktop users, but they now make use of it from the comfort of the Software and Updates application, should they wish. An Ubuntu Single Sign On account (the same that used to be used for the now-defunct Ubuntu One storage service) is required, which you can sign up for it by following the instructions there. This account will also let you log in to the Ubuntu Forums (https://ubuntuforums.org) to post any questions you may have.
Live kernel patching has been around for awhile (we first covered it in LXF200) and it’s useful if you’re in a situation where you can’t reboot, but want to apply some kernel update, particularly if it concerns security. However, it’s crucial to stress that livepatching isn’t a cure for rebooting in general. Updates to Systemd, for example, will often require a reboot to take effect, and desktop updates generally won’t take effect until you’ve at least logged out and logged back in again. Major kernel updates (for example, upgrades) will still require a reboot, and in our experience the community theme snap (see below), wouldn’t show the new session without doing so either. Consider yourselves told.
One slightly controversial new development in this release is the collection of usage statistics. Data on installed packages is collected via the popularity- contest package, which sets up a cron job to update package information daily. This package has been optional on Debian for a long time, and everything is anonymised and sent over HTTPS. Like other operating systems, when things go wrong you can send a crash report to Canonical. In some cases this will take you directly to an appropriate bug report, where you might, if you’re lucky, find a temporary workaround.
Theme refresh
Ubuntu’s long-time default Ambiance theme has been tweaked for 18.04, giving Gnome even more of a Unity look and feel. The lighter Radiance theme has also had a bit of a dust up too. Ubuntu’s Communitheme project (see https://didrocks.fr/2017/11/09/welcome-to-the- ubuntu-bionic-age-a-new-ubuntu-default-theme-call- for-participation), is well underway, but not ready for public digestion. Those willing to endure a few rough edges can try it out, thanks to it being distributed as a snap. It can be installed with sudo snap install communitheme , and sampled by restarting and selecting the communitheme session from the login screen. The community theme started from Adwiata, the default Gnome theme, and aims to be at once a complete replacement to Ambiance and a tribute to the abandoned Unity 8. Read more at Canonical Developer Didier Roche’s blog (http://bit.ly/ubuntu-bionic).
And on the subject of snaps… Snap is Canonical’s favoured approached to distro-agnostic app packaging, similar to Flatpak and AppImages. Besides making life easier for developers (by bundling all required libraries with the application) and packagers (by removing them from the equation altogether), these formats can offer
Configure updates from here. You can find Jonni’s email address in the back of the mag if you really want it.
some security benefits thanks to leveraging container technologies for increased isolation.
All the front-page items on the Software app are Snap apps, but if you search around you’ll still find software distributed in the traditional DEB format. When installing things from the Software ‘store’, the process is the same no matter the package format. The traditional apt install method is still de rigueur for DEBs, but you’ll need to learn some new command line fu for installing Snaps. We saw above how to use install a theme Snap, but they have some other tricks too. For example, to switch to the dev branch of the communitheme, use $ sudo snap refresh communitheme –edge
Replace –edge with –stable to revert to the stable branch. Snaps will be automatically updated by the Software Updater, but not with Apt. To update them from the command line, use the snap refresh command.
Ubuntu MATE 1710 broke new ground by shipping pulsemixer as a Snap, since it hadn’t been packaged for Ubuntu or Debian. This trend has now made its way into the main distro, which includes a number of pre-installed Gnome Snaps: System Monitor, Logs, Calculator and Characters. You can see these mounted in the /var/lib/ snapd directory in through the mount command.
Wayland has been the default display server in Fedora since version 25. There was talk of making it such in Ubuntu, but after experimenting with that in 1710 the default has been reverted to ye olde X.org. However, a Wayland session is available (just click the cog icon when entering your password) and our brief testing found that this worked well. Even if you’re using the proprietary Nvidia driver, which implements Wayland via EGLStreams, then Gnome should work just fine. You will probably have heard stories about screen shotting, screen recording and remote desktop sessions not working with Wayland, but these are half truths. These all work as long as the compositor supports them, and the recording applications talk to the compositor in the right way. Mercifully, Gnome’s compositor (Mutter, also its window manager) does both of these, and even has a built in screen recorder, which you can activate with Ctrl-Alt-Shift-R .
The end of 32-bit…?
As has been foretold, this is the first Ubuntu LTS that doesn’t provide any 32-bit desktop install media. That doesn’t mean your pre-neolithic hardware can’t get Ubuntu 18.04, or even that it won’t run it just fine (as long as you have enough memory), it just means you can’t get a nice ready-to-run install disc. If you’re already running 16.04 on 32-bit hardware then you should be able to upgrade without a hitch.
If you want to do a clean install, then there’s a couple of options. You can go with one of the other flavours: they all offer 32-bit media, but your best bets are Lubuntu, Ubuntu MATE or Xubuntu. If you really want to run Gnome on 32-bit hardware, you can install it on top of one of these via the ubuntu-gnome-desktop package. Another approach would be to start with the i386 server ISO, and then build a custom desktop from there. This would be a good option for building a lightweight desktop with Openbox, i3 or somesuch. Funnily enough we’ve got a feature about doing just this next month. We hope to see you there!
SDLpop, an open source version of Prince of Persia, is available as a snap.
Ubuntu enables you to send crash reports to help the team see what’s breaking. Optionally, they can also collect anonymised usage data.
BEYOND THE DESKTOP
We’ve focused on the desktop side of things, but this isn’t how Canonical makes its money and is far from the whole Ubuntu story, Ubuntu Core is Canonical’s diminutive distro that’s designed for constrained devices, particularly IoT things, and containers, Core uses the same kernel as desktop and server Ubuntu, and leverages Snap packages to provide smooth and secure installations, and upgrades, Canonical is hoping that Ubuntu Core will become popular for Edge (or Fog) computing, This is the boundary between the cloud and real world devices, where devices sit on the edge of low-powered (for example, sensor) networks and marshall their data to the cloud, Sometimes less is more, and this adage ne’er rang truer than for containers, embedded systems and IoT, To this end, Canonical now provides a minimal image – and at less than 28MB, minimal it certainly is, This isn’t to be confused with the minimal desktop install we discussed earlier, which still provides such luxuries as a desktop and such fripperies as an installer, Oh no, this is just a tarball of a filesystem that provides very little beyond a working shell,
It’s an ideal starting point for constrained situations, where just what is needed, and not a byte more, can be added in, However, it’s not suitable for installing on bare metal, because it’s not capable of booting, Many official Docker images (including Apache and Mariadb, for example) currently use the tiny Alpine Linux distro as a base, At 8MB this is still much smaller than Ubuntu’s offering, but the latter may be more preferable to container wranglers willing to accept a few megabytes in order to leverage the more familiar Apt and glibc (as opposed to apk and musl),