GitHub URL for latest release of the _download file_?

Question

Although this question is similar to GitHub latest release, it's actually different -- it's about a link that means "the latest version of the download file itself".

GitHub provides a "Latest" URL that redirects to the information page for the latest release. For example: https://github.com/reactiveui/ReactiveUI/releases/latest will redirect to https://github.com/reactiveui/ReactiveUI/releases/tag/5.99.6 (as I type this; or to the page for a newer version, someday).

That's great but I need a URL to the download file itself. In this example, the .zip file associated with the green download button, https://github.com/reactiveui/ReactiveUI/releases/download/5.99.6/ReactiveUI-5.99.6.zip (as I type this; or to a newer zip file, someday).

Why? I want to give the URL to curl, as part of a Travis CI script, to download the latest version.

I guessed at a few URLs like /releases/download/latest/file.zip (substituting "latest" for the version part) and /releases/download/file.zip but those 404.

Is there any way to do this -- in the context of a shell script and curl (note: not in a browser page with JS)?

Answer 1

For releases that do not contain the version number or other variable content in their assets' names, you can use a URL of the format:

https://github.com/owner/repository/releases/latest/download/ASSET.ext

As per the docs:

If you'd like to link directly to a download of your latest release asset you can link to /owner/name/releases/latest/download/asset-name.zip.

Answer 2

Here is a way to do it w/o Github if you have a single download in the release:

wget $(curl -s https://api.github.com/repos/USERNAME/REPONAME/releases/latest | grep 'browser_' | cut -d\" -f4)

It is pretty easy (though not pretty), and of course you can swap out wget for another curl call if you want to pipe it to something.

Basically, the curl call nets you a JSON structure, and I'm just using basic shell utilities to extract the URL to the download.

Answer 3

Very interesting, I haven't noticed a "latest" tag in GitHub-releases yet. As i now figured out, they're given away if you're using the "pre-release"-capabilities of GitHubs release-system. But i don't know any way to access binaries via a latest-path.

I would like to suggest you using git (which is available in your travis-vm) to download the latest tag.

Like Julien Renault describes in his blog post, you will be able to checkout the latest tag in the repository like this:

# this step should be optional
git fetch --tags

latestTag=$(git describe --tags `git rev-list --tags --max-count=1`)
git checkout $latestTag

This solution is based on the assumption that the latest tag is also the latest version.

Answer 4

I use this to get the download URLs in PowerShell 5+ (replace ACCOUNT & REPO)

Invoke-RestMethod -uri  https://api.github.com/repos/ACCOUNT/REPO/releases/latest | select -ExpandProperty assets | select -expand browser_download_url 

Note if they have more than one package this will be a list. If you want to pick a certain one find a unique part of the name i.e. win for Windows and use: (replace ACCOUNT, REPO & SELECTOR)

Invoke-RestMethod -uri  https://api.github.com/repos/ACCOUNT/REPO/releases/latest | select -ExpandProperty assets | ? { $_.name.Contains("SELECTOR")} | select -expand browser_download_url

As a bonus if you assign the above to a variable you can then grab the file and extract it with the following (assuming you assign to $uri):

Invoke-WebRequest $uri -OutFile "release.zip"
Expand-Archive .\release.zip

In PowerShell 6+ this should work on other platforms than Windows.

Answer 5

On windows, only using powershell, this works for me. It can probably be written a lot shorter.

#Downloads latest paket.bootstrapper.exe from github
$urlbase = "https://github.com"
$latestPage="$urlbase/fsprojects/Paket/releases/latest"
Write-Host "Parsing latest release page: $latestPage"
$page=Invoke-Webrequest -uri $latestPage
$latestBootStrapper=($page.Links | Where-Object { $_.href -match "bootstrapper" }).href

$dlurl="$urlbase$latestBootStrapper"
Write-Host "Downloading paket.bootstrapper.exe from $dlurl"

$wc=new-object net.webclient
$wc.UseDefaultCredentials=$true
$wc.Proxy.Credentials=$wc.Credentials
$wc.DownloadFile($dlurl, (join-path (resolve-path ".\") "paket.bootstrapper.exe"))

Answer 6

$repoName = "PowerShell/PowerShell"
$assetPattern = "*-win-x64.msi"
$extractDirectory = "C:\Users\Public\Downloads"


$releasesUri = "https://api.github.com/repos/$repoName/releases/latest"
$asset = (Invoke-WebRequest $releasesUri | ConvertFrom-Json).assets | Where-Object name -like $assetPattern
$downloadUri = $asset.browser_download_url

$extractPath = [System.IO.Path]::Combine($extractDirectory, $asset.name)
Invoke-WebRequest -Uri $downloadUri -Out $extractPath

Answer 7

You can use curl with https://api.github.com. It gives JSON output from which you can easily extract what you need with jq or your favorite json tool.

For example, using the repository in the question:

gituser=reactiveui; repo=ReactiveUI

tag_name=$(curl -sL https://api.github.com/repos/$gituser/$repo/releases/latest | jq -r '.tag_name'); echo $tag_name
# output: "16.3.10"

tarurl=$(curl -sL https://api.github.com/repos/$gituser/$repo/releases/latest | jq -r '.tarball_url'); echo $tarurl
# output: https://api.github.com/repos/reactiveui/ReactiveUI/tarball/16.3.10

zipurl=$(curl -sL https://api.github.com/repos/$gituser/$repo/releases/latest | jq -r '.zipball_url'); echo $zipurl
# output: https://api.github.com/repos/reactiveui/ReactiveUI/zipball/16.3.10

So you could get the download with a nested curl in a one-liner:

curl -OL $(curl -sL https://api.github.com/repos/filesender/filesender/releases/latest | jq -r '.tarball_url')

This will download the file, and save it with the name of its tag_name, but without extension. So you may want to rename it by appending ".tgz" or ".zip", depending on which you downloaded.

Note for Windows users: curl is now installed by default on Windows too, but beware that it must be called as curl.exe. That's because Powershell has an alias stupidly called "curl" which is not the same!

Answer 8

As @florianb pointed out, I should use git.

Originally my .travis.yml was something like:

before_install:
- curl -L https://raw.githubusercontent.com/greghendershott/travis-racket/master/install-racket.sh | bash

This would automatically get whatever the latest version is, from the repo.

But someone pointed out to me that GitHub doesn't want people to use raw.github.com for downloads. Instead people should use "releases". So I was a good doob and manually made a release each time. Then my .travis.yml was something like:

before_install:
- curl -L https://github.com/greghendershott/travis-racket/releases/download/v0.6/install-racket.sh | bash

But it's a PITA to make a release each time. Worse, all .travis.yml files need to be updated to point to the newer version of the file.

Instead -- just use git to clone the repo, and use the file within it:

before_install:
- git clone https://github.com/greghendershott/travis-racket.git
- cat travis-racket/install-racket.sh | bash # pipe to bash not sh!