[HOWTO] – Get a list of repositories from Docker Hub using PowerShell

The other day, I had the need to get a list of all the repositories from an organization in DockerHub to gather some statistics.

Being a huge advocate I wanted to do this in PowerShell, as this makes it easy to process the data further, such as exports to CSV.

To be able to do this, we first need to authenticate to their API using the /users/login endpoint. Currently, the API version Docker Hub uses is version 2. When we successfully authenticate, we obtain a JWT authentication token we need to pass on in any subsequent calls to their API, in this case, the repositories/<orgname> endpoint.

This is the code I ended up with.

$loginUrl = "https://hub.docker.com/v2/users/login/"

$username = "username"
$password = 'password'
$organization = "yourorganization"

$params = @{
  "username"        = $username
  "password"        = $password 
}

# This is a little trick to suppress the progress bar
$ProgressPreference = 'SilentlyContinue'

# First we need to get a token from Docker Hub
Write-Output "Authenticating to Docker Hub"
try {
  $loginResult = Invoke-WebRequest -Uri $loginUrl -Method Post -Body $params -UseBasicParsing  
}
catch {
  throw $Exception.Message
}
$token = ($loginResult.Content | ConvertFrom-Json).token
$header = @{Authorization = "JWT $token" }

# Then we attempt to get a list of repositories
Write-Output "Getting repositories"
$reposUrl = "https://hub.docker.com/v2/repositories/$organization/?page_size=200"
try {
  $reposList = Invoke-WebRequest -Uri $reposUrl -Headers $header -UseBasicParsing  
}
catch {
  throw $Exception.Message
}

# Finally we output the list of repositories and total count
# We convert the results from JSON
$listsObject = $reposList.Content | ConvertFrom-Json
Write-Host "$($listsObject | Select-Object -ExpandProperty Count) repositories found)"
$listsObject | Select-Object -ExpandProperty results | Out-GridView