README.md

lastversion

A tiny command-line utility that helps to answer a simple question:

What is the latest stable version for a project?

... and, optionally, download/install it.

Supported project locations:

• GitHub
• GitLab
• BitBucket
• Mercurial
• SourceForge

GitHub has an API endpoint here. But if you're here, then you know how it sucks:

A release would show up in this API response only if it was filed formally using the GitHub release interface. Sometimes project authors use formal releases, and next thing you know, for the next release they won't. There is no consistency in human beings.

OK, you think you could use another API endpoint to list tags. Tags usually represent a release, however, the API does not sort them chronologically. Moreover, you might get something like "latest-stable" for a tag name's value.

In general, quite many project authors complicate things further by:

• Creating a formal release that is clearly a Release Candidate (rc in tag), but forgetting to mark it as a pre-release
• Putting extraneous text in release tag e.g. release-1.2.3 or name-1.2.3-2019 anything fancy like that
• Putting or not putting the v prefix inside release tags. Today yes, tomorrow not. I'm not consistent about it myself :)
• Switching from one version format to another, e.g. v20150121 to v2.0.1

To deal with all this mess and simply get well-formatted, last stable version (or download URL!) on the command line, you can use lastversion.

Its primary use is for build systems - whenever you want to watch specific repositories for released versions to build packages automatically. Or otherwise require getting the latest version in your automation scripts.

Like I do

lastversion does a little bit of AI to detect if releasers mistakenly filed a beta version as a stable release. It uses both of the API endpoints and incorporates logic for cleaning up human inconsistency from version information.

Synopsis

lastversion apache/incubator-pagespeed-ngx 
#> 1.13.35.2
lastversion apache/incubator-pagespeed-ngx -d 
#> downloaded incubator-pagespeed-ngx-v1.13.35.2-stable.tar.gz
lastversion apache/incubator-pagespeed-ngx -d pagespeed.tar.gz 
#> downloads with chosen filename

Installation for CentOS/RHEL 7, 8 or Amazon Linux 2

sudo yum -y install https://extras.getpagespeed.com/release-latest.rpm
sudo yum install lastversion

Installation for other systems

Installing with pip is easiest:

pip install lastversion

Usage

Typically, you would just pass a repository URL (or repo owner/name to it) as the only argument, e.g.:

lastversion https://github.com/gperftools/gperftools

Equivalently accepted invocation with same output is:

lastversion gperftools/gperftools

If you're lazy to even copy paste a project's URL, you can just type its name as argument, which will use repository search API (slower). Helps to answer what is the latest Linux version:

lastversion linux

Or wondering what is the latest version of WordPress? :

lastversion wordpress

A special value of self for the main argument, will lookup the last release of lastversion itself.

For more options to control output or behavior, see --help output:

usage: lastversion [-h] [--pre] [--verbose] [-d [FILENAME]]
                   [--format {version,assets,source,json,tag}] [--assets]
                   [--source] [-gt VER] [-b MAJOR] [--filter REGEX] [-su] [-y]
                   [--version]
                   [action] <repo or URL>

Get the latest release from GitHub/GitLab/BitBucket.

positional arguments:
  action                Special action to run, e.g. download, install, test
  <repo or URL>         GitHub/GitLab/BitBucket repository in format
                        owner/name or any URL that belongs to it

optional arguments:
  -h, --help            show this help message and exit
  --pre                 Include pre-releases in potential versions
  --verbose             Will give you idea of what is happening under the hood
  -d [FILENAME], --download [FILENAME]
                        Download with custom filename
  --format {version,assets,source,json,tag}
                        Output format
  --assets              Returns assets download URLs for last release
  --source              Returns only source URL for last release
  -gt VER, --newer-than VER
                        Output only if last version is newer than given
                        version
  -b MAJOR, --major MAJOR
                        Only consider releases of a specific major version,
                        e.g. 2.1.x
  --filter REGEX        Filters --assets result by a regular expression
  -su, --shorter-urls   A tiny bit shorter URLs produced
  -y, --assumeyes       Automatically answer yes for all questions
  --version             show program's version number and exit

The --format will affect what kind of information from the last release and in which format will be displayed, e.g.:

• version is the default. Simply outputs well-formatted version number of the latest release
• assets will output a newline-separated list of assets URLs (if any), otherwise link to sources archive
• source will output link to source archive, no matter if the release has some assets added
• json can be used by external Python modules or for debugging, it is dict/JSON output of an API call that satisfied last version checks
• tag will emit just the latest release's tag name, which useful if you're constructing download URL yourself or need the tag name otherwise

An asset is a downloadable file that typically represents an executable, or otherwise "ready to launch" project. It's what you see filed under formal releases, and is usually a compiled (for specific platform), program.

Source files, are either tarballs or zipballs of sources for the source code of release.

You can display either assets or source URLs of the latest release, by passing the corresponding --format flag, e.g. --format source

You also simply pass --source instead of --format source, and --assets instead of --format assets, as in:

lastversion --assets mautic/mautic 
#> https://github.com/mautic/mautic/archive/2.15.1/mautic-2.15.1.tar.gz

By default, lastversion filters output of --assets to be OS specific. Who needs .exe on Linux?

To override this behavior, you can use --filter, which has a regular expression as its argument. To disable OS filtering, use --filter ., this will match everything.

You can naturally use --filter in place where you would use grep, e.g. lastversion --assets --filter win REPO

Use case: How to download latest version of something

You can also use lastversion to download assets/sources for the latest release.

Download the most recent Mautic source release:

lastversion mautic/mautic --download 

Customize downloaded filename (works only for sources, which is the default):

lastversion mautic/mautic --download mautic.tar.gz

Or you can just have lastversion output sources/assets URLs and have those downloaded by something else:

wget $(lastversion --assets mautic/mautic)

This will download all assets of the newest stable Mautic, which are 2 zip files.

How this works: lastversion outputs all asset URLs, each on a new line, and wget is smart enough to download each URL. Magic :)

For releases which have no assets added, it will download source archive.

To always download source, use --source instead:

wget $(lastversion --source mautic/mautic)  

Use case: Get last version (betas are fine)

We consider latest release is the one which is stable / not marked as beta. If you think otherwise, then pass --pre switch and if the latest version of repository is a pre-release, then you'll get its version instead:

lastversion --pre mautic/mautic 
#> 2.15.2b0

Use case: version of a specific branch

For some projects, there may be several stable releases available simultaneously, in different branches. An obvious example is PHP. You can use --major flag to specify the major release version to match with, to help you find latest stable release of a branch, like so:

lastversion php/php-src --major 7.2

This will give you current stable version of PHP 7.2.x, e.g. 7.2.28.

Special use case: NGINX stable vs mainline branch version

lastversion https://nginx.org --major stable #> 1.16.1
lastversion https://nginx.org --major mainline #> 1.17.9

Behind the scenes, this checks with hg.nginx.org which is a Mercurial web repo. Those are supported as well, e.g.

lastversion https://hg.example.com/project/

Mercurial repos are rather rare these days, but support has been added primarily for NGINX.

Install an RPM asset

If a project provides .rpm assets and your system has yum or dnf, you can install the project's RPM directly, like so:

sudo lastversion install mailspring

This finds MailSpring, gets its latest release info, filters assets for .rpm and passes it to yum / dnf.

You can even set up an auto-updater cron job which will ensure you are on the latest version of a package, like so:

@daily /usr/bin/lastversion install mailspring -y 2>/dev/null

If the Mailspring GitHub repo posts a release with newer .rpm, then it will be automatically installed, making sure you are running the latest and greated Mailspring version.

You'll even get an email alert after update (standard cron feature).

Needless to say, more often than not such RPM packages have no idea about all potentially missing dependencies. Thus, only use lastversion install ... if the software is missing from the base yum repositories.

Test version parser

The test command can be used for troubleshooting or simply well formatting a string with version:

lastversion test 'blah-1.2.3-devel' # > 1.2.3.dev0
lastversion test '1.2.x' # > False (no clear version)
lastversion test '1.2.3-rc1' # > 1.2.3rc1

Scripting with lastversion

Check for NEW release

When you're building some upstream package, and you did this before, there is a known "last build" version. Automatic builds become easy with:

CURRENTLY_BUILT_VER=1.2.3 # stored somewhere, e.g. spec file in my case
LASTVER=$(lastversion repo/owner -gt ${CURRENTLY_BUILT_VER})
if [[ $? -eq 0 ]]; then
  # LASTVER is newer, update and trigger build
  # ....
fi

Here, the -gt is actually a switch passed to lastversion, which acts in a similar fashion to -gt comparison in bash.

There is more to it, if you want to make this reliable. See my ranting on RPM auto-builds with lastversion

Exit Status codes

Exit status codes are the usual means of communicating a command's execution success or failure. So lastversion follows this: successful command returns 0 while anything else is an error of some kind:

Exit status code 1 is returned for cases like no release tag existing for repository at all, or repository does not exist.

Exit status code 2 is returned for -gt version comparison negative lookup.

Exit status code 3 is returned when filtering assets of last release yields empty URL set (no match)

Tips

Getting latest version is heavy on the API, because GitHub does not allow to fetch tags in chronological order, and some repositories switch from one version format to another, so we can't just consider highest version to be latest. We have to fetch every tag's commit date, and see if it's actually more recent. Thus it's slower with larger repositories, which have potentially a lot of tags.

Thus, lastversion makes use of caching API response to be fast and light on GitHub API, It does conditional ETag validation, which, as per GitHub API will not count towards rate limit. The cache is stored in ~/.cache/lastversion on Linux systems.

It is much recommended to setup your GitHub API token in ~/.bashrc like this, to increase your rate limit:

export GITHUB_API_TOKEN=xxxxxxxxxxxxxxx

For GitLab, you can use a Personal Access Token:

export GITLAB_PA_TOKEN=xxxxxxxxxxxxxxx

Then run source ~/.bashrc. After this, lastversion will use it to get larger API calls allowance from GitHub.

Usage in a Python module

Invoke lastversion.latest function get version information for a repo.

from lastversion import lastversion
from packaging import version

latest_mautic_version = lastversion.latest("mautic/mautic", output_format='version', pre_ok=True)

print('Latest Mautic version: {}'.format(str(latest_mautic_version))

if latest_mautic_version >= version.parse('1.8.1')
    print('It is newer')

With output_format='version' (the default), the function returns a Version object, or False. So you can do things like above, namely version comparison, checking dev status, etc.

The lastversion.latest function accepts 3 arguments

• repo, in format of <owner>/<name>, or any URL under this repository, e.g. https://github.com/dvershinin/lastversion/issues
• format, which accepts same values as when you run lastversion interactively
• pre_ok, boolean for whether to include pre-releases as potential versions

Check if there is a newer kernel for your Linux machine

LATEST_KERNEL=$(lastversion linux -gt $(uname -r | cut -d '-' -f 1))
if [[ $? -eq 0 ]]; then
  echo "I better update my kernel now, because ${LATEST_KERNEL} is there"
else 
  echo "My kernel is latest and greatest."
fi