In our previous article, we discussed what is Snappy Ubuntu Core, and how to install it. If still haven’t read that guide and don’t know what is Snappy Ubuntu Core, read the following article.
Today, In this tutorial, let us see how to getting started with Snappy Ubuntu Core.
Snappy Ubuntu Core Usage
Log in to your Snappy Ubuntu Core system. The default username and password is ubuntu/ubuntu.
Or you can SSH from a remote system with command:
ssh ubuntu@<IP-address-of-snappy>
1. Check Snappy Ubuntu Core version
Let us check Snappy Core version first.
To do that, run:
snappy info
Sample output:
release: ubuntu-core/15.04/stable architecture: amd64 frameworks: apps: webdm
Well, as you see in the above output, the version of Snappy Ubuntu Core is 15.04 stable, and its arch is 64bit. Since it is a fresh system, it has no frameworks and only one app called “webdm”.
2. Viewing Installed applications
To list all installed apps with version, run:
snappy list -v
Sample output:
Name Date Version Developer ubuntu-core 2015-04-23 2 ubuntu* webdm 2015-04-23 0.5 sideload* generic-amd64 2015-04-23 1.1 *
The asterisk (*) tells you that this version of the component is what is currently running. If you do an update, you will get the newer version of the system to be active when you reboot.
Let us see see if there is an updated system. The update‐versions command will check the store for newer versions of any installed components. If you are fully up to date, you will see the same versions listed which are currently installed.
To check if there is an updated system, run:
snappy list -uv
Sample output:
Name Date Version ubuntu-core 2015-04-23 2 webdm* 1-01-01 0.8 generic-amd64* 1-01-01 1.1.1
As you above, we had two updates. The updated versions are marked with active flag(*).
Let us go ahead and update them using command:
sudo snappy update
Sample output:
Installing webdm (0.8) Starting download of webdm 6.16 MB / 6.16 MB [======================================] 100.00 % 246.20 KB/s Done Installing generic-amd64 (1.1.1) Starting download of generic-amd64 40.93 KB / 40.93 KB [=====================================] 100.00 % 81.89 KB/s Done Name Date Version Developer webdm 1-01-01 0.8 canonical generic-amd64 1-01-01 1.1.1 canonical
Again, run the following command to check if there is any updates.
snappy list -uv
Sample output:
Name Date Version ubuntu-core 2015-04-23 2 webdm 2015-06-03 0.8 webdm 2015-04-23 0.5 generic-amd64 2015-06-03 1.1.1
See, the webdm and generic-amd64 have been updated to the latest available version.
If you update the Ubuntu Core, you must restart to apply the changes. To reboot Snappy Ubuntu Core, Run:
sudo reboot
3. Roll back applications or frameworks
Also, we can roll back to the previous version if needed. This is the useful feature of Snappy. To roll back any application, for example generic-amd64, run:
sudo snappy rollback generic-amd64
Sample output:
Setting generic-amd64 to version 1.1
To verify the changes, run:
snappy list -v
Sample output:
Name Date Version Developer ubuntu-core 2015-04-23 2 ubuntu* webdm 2015-06-03 0.8 * webdm 2015-04-23 0.5 sideload* generic-amd64 2015-04-23 1.1 * generic-amd64 2015-06-03 1.1.1
As you see above, the generic-amd64 package shows two versions here, 1.1 and 1.1.1. The asterik (*) beside 1.1.1 shows that this is the one that is actively used.
4. Installing applications and frameworks
Well, now we will see how to install new applications and frameworks.
snappy frameworks are somewhat different from the Ubuntu for Phones click frameworks and are more flexible. Most importantly, click frameworks for Ubuntu for Phones map to a particular release and are contracts between the platform (OS) and apps. Snappy splits out the platform (OS) and the framework such that the contract is split between the framework and the platform release (OS) (the release and installed frameworks can be seen via snappy info). As such, apps will specify the release they target (implementation covered elsewhere) and any frameworks they require.
To search all available applications, run:
snappy search
Sample output:
Name Version Summary beagle.gumstix 0.1 beagle duovero.gumstix 0.1 duovero xkcd-webserver 0.5 xkcd-webserver system-status.victor 1.0.3 System status web portal overo.gumstix 0.1 overo mosquitto.kartben 1.4.2.201505120017 Mosquitto webcam-demo 1.0.1 webcam-demo pi2.lool 0.11 pi2 snake.mectors 0.0.5 Snake pepper.gumstix 0.1 pepper panda.gumstix 0.1 panda hello-dbus-fwk.canonical 1.0.0 hello-dbus-fwk docker 1.6.1.002 Docker generic-amd64 1.1.1 generic-amd64 hello-world 1.0.15 hello-world (forks not shown: 1) chatroom.ogra 0.1-8 Snappy Chatroom computexintel.mectors 0.0.3 Computex Intel crossbar.crossbar 0.10.4 Crossbar.io webdm 0.8 webdm beagleblack 1.7.1 beagleblack go-example-webserver 1.0.7 go-example-webserver config-example 1.0.6 config-example pastebinit.mvo 1.4.0.0.2 pastebinit Use --show-all to see all available forks.
You can search for a particular apps or frameworks as shown below.
snappy search webserver
Sample output:
Name Version Summary go-example-webserver 1.0.7 go-example-webserver xkcd-webserver 0.5 xkcd-webserver system-status.victor 1.0.3 System status web portal
Let me show you how to install a package.
To install an application, for example docker, run:
sudo snappy install docker
Sample output:
Installing docker Starting download of docker 8.36 MB / 8.36 MB [=======================================] 100.00 % 99.96 KB/s Done Name Date Version Developer ubuntu-core 2015-04-23 2 ubuntu docker 2015-06-03 1.6.1.002 webdm 2015-06-03 0.8 webdm 2015-04-23 0.5 sideload generic-amd64 2015-06-03 1.1.1
Remember there is no ‘apt-get’ or ‘aptitude’ or ‘dpkg’ commands in Snappy Core. If you try to install, remove or update any package using apt-get method, you will get the following error.
Ubuntu Core does not use apt-get, see 'snappy --help'!
Now, let us check if the docker application has installed or not. To do that, run:
snappy list
Sample output:
Name Date Version Developer ubuntu-core 2015-04-23 2 ubuntu docker 2015-06-03 1.6.1.002 webdm 2015-06-03 0.8 webdm 2015-04-23 0.5 sideload generic-amd64 2015-06-03 1.1.1
As you see in the above output, Docker has been installed.
5. Removing applications and frameworks
Similarly, you can install as many as applications you want. To remove an installed application, for example docker, run:
sudo snappy remove docker
Sample output:
Removing docker Waiting for docker_docker-daemon_1.6.1.002.service to stop.
Check if docker is really removed or not using command:
snappy list
Sample output:
Name Date Version Developer ubuntu-core 2015-04-23 2 ubuntu webdm 2015-06-03 0.8 webdm 2015-04-23 0.5 sideload generic-amd64 2015-06-03 1.1.1
See, Docker is no more now in Snappy core.
To completely remove all the data from the listed packages, run:
sudo snappy purge docker
To view more details about Snappy commands, run:
snappy --help
Sample output:
Usage: snappy [OPTIONS] <command> Help Options: -h, --help Show this help message Available commands: booted Flag that rootfs booted successfully build Builds a snap package (aliases: bu) config Set configuraion for a installed package. firstboot internal hw-assign Assign a hardware device to a package hw-info List assigned hardware device for a package hw-unassign Unassign a hardware device to a package info Display a summary of key attributes of the snappy system. install Install a snap package internal-run-hooks internal internal-unpack internal list List active components installed on a snappy system (aliases: li) login Log into the store purge Remove all the data from the listed packages remove Remove a snapp part rollback Rollback to a previous version of a package search Search for packages to install (aliases: se) set Set properties of system or package update Update all installed parts versions (deprecated) please use "list"
There is no man pages for Snappy commands right now. I hope Snappy developers is working on it.
Also, there is more online guides are available in Snappy official documentation page. Go and refer them if you need to learn more about Snappy.
Once you have finished, power off the Snappy Core using command:
sudo poweroff
Conclusion
Working with Snappy Ubuntu Core is pretty easy. Be you’re a normal user, developer or a system administrator, you don’t have worry about the Snappy commands. All Snappy commands are really easy to remember and use. Snappy provides a new approach to package management, improved security, simplifying tasks. The installation is really fast. And everything is available as a single package, so there is no dependencies errors or broken system. Let us welcome this new baby from Canonical and appreciate the developers efforts to make it possible.
Cheers!
