Generating a project change log with Teamcity and Powershell

TeamCity is a popular continuous integration server that can be combined with Octopus Deploy to fully automate deployments. But one thing we’re missing is the ability to generate release notes based on Git commit messages.

Release notes are important

Getting software released to users as quickly as possible is one of the goals of continuous delivery, but it can become a mess if you don’t know which changes are included in your package.

Implementation

Consuming Teamcity REST API from Powershell is quite simple (tested on Teamcity 9.0):

<#
.SYNOPSIS
    Generates a project change log file.
.LINK
    Script posted over:
    http://open.bekk.no/generating-a-project-change-log-with-teamcity-and-powershell
#>

# Where the changelog file will be created
$outputFile = "%system.teamcity.build.tempDir%\releasenotesfile_%teamcity.build.id%.txt"
# the url of teamcity server
$teamcityUrl = "%teamcity.serverUrl%"
# username/password to access Teamcity REST API
$authToken=[Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes("%system.teamcity.auth.userId%:%system.teamcity.auth.password%"))
# Build id for the release notes
$buildId = %teamcity.build.id%

# Get the commit messages for the specified change id
# Ignore messages containing #ignore
# Ignore empty lines
Function GetCommitMessages($changeid)
{
    $request = [System.Net.WebRequest]::Create("$teamcityUrl/httpAuth/app/rest/changes/id:$changeid")     
    $request.Headers.Add("AUTHORIZATION", "$authToken");
    $xml = [xml](new-object System.IO.StreamReader $request.GetResponse().GetResponseStream()).ReadToEnd()    
    Microsoft.PowerShell.Utility\Select-Xml $xml -XPath "/change" |
        where { ($_.Node["comment"].InnerText.Length -ne 0) -and (-Not $_.Node["comment"].InnerText.Contains('#ignore'))} |
        foreach {"+ $($_.Node["user"].name) : $($_.Node["comment"].InnerText.Trim().Replace("`n"," "))`n"}
}

# Grab all the changes
$request = [System.Net.WebRequest]::Create("$teamcityUrl/httpAuth/app/rest/changes?build=id:$($buildId)")
$request.Headers.Add("AUTHORIZATION", "$authToken");
$xml = [xml](new-object System.IO.StreamReader $request.GetResponse().GetResponseStream()).ReadToEnd()

# Then get all commit messages for each of them
$changelog = Microsoft.PowerShell.Utility\Select-Xml $xml -XPath "/changes/change" | Foreach {GetCommitMessages($_.Node.id)}
$changelog > $outputFile
Write-Host "Changelog saved to ${outputFile}:"
$changelog

Pushing release notes to Octopus Deploy

Simply add — releasenotesfile to octo.exe:

octo.exe create-release 
    --server http://myoctopusserver 
    --apikey SECRET 
    --project MyProject 
    --enableservicemessages 
    --version 3.1.108 
    --deployto TESTSERVER 
    --deploymenttimeout=00:25:00 
    --releasenotesfile="D:\BuildAgent\temp\buildTmp\releasenotesfile_578.txt"

Or use the Octopus plugin:

Conclusion

With this simple PowerShell script we can create release notes from our repository information and we know exactly which changes are included in our package.