Release artifacts and artifact sources

https://docs.microsoft.com/en-us/azure/devops/pipelines/release/artifacts?view=vsts

18 minutes to read

Contributors

Alex Homer

Steve Danielson

https://github.com/elbatk

David Staheli

Note

Build and release pipelines are called definitions in TFS 2018 and in older versions. Service connections are called service endpoints in TFS 2018 and in older versions.

A release is a collection of artifacts in your DevOps CI/CD processes. An artifact is a deployable component of your application. Azure Pipelines can deploy artifacts that are produced by a wide range of artifact sources, and stored in different types of artifact repositories.

When authoring a release pipeline, you link the appropriate artifact sources to your release pipeline. For example, you might link an Azure Pipelines build pipeline or a Jenkins project to your release pipeline.

When creating a release, you specify the exact version of these artifact sources; for example, the number of a build coming from Azure Pipelines, or the version of a build coming from a Jenkins project.

After a release is created, you cannot change these versions. A release is fundamentally defined by the versioned artifacts that make up the release. As you deploy the release to various stages, you will be deploying and validating the same artifacts in all stages.

A single release pipeline can be linked to multiple artifact sources, of which one is the primary source. In this case, when you create a release, you specify individual versions for each of these sources.

Artifacts in a pipeline and release

Artifacts are central to a number of features in Azure Pipelines. Some of the features that depend on the linking of artifacts to a release pipeline are:

  • Auto-trigger releases. You can configure new releases to be automatically created whenever a new version of an artifact is produced. For more details, see Continuous deployment triggers. Note that the ability to automatically create releases is available for only some artifact sources.
  • Trigger conditions. You can configure a release to be created automatically, or the deployment of a release to a stage to be triggered automatically, when only specific conditions on the artifacts are met. For example, you can configure releases to be automatically created only when a new build is produced from a certain branch.
  • Artifact versions. You can configure a release to automatically use a specific version of the build artifacts, to always use the latest version, or to allow you to specify the version when the release is created.
  • Artifact variables. Every artifact that is part of a release has metadata associated with it, exposed to tasks through variables. This metadata includes the version number of the artifact, the branch of code from which the artifact was produced (in the case of build or source code artifacts), the pipeline that produced the artifact (in the case of build artifacts), and more. This information is accessible in the deployment tasks. For more details, see Artifact variables.
  • Work items and commits. The work items or commits that are part of a release are computed from the versions of artifacts. For example, each build in Azure Pipelines is associated with a set of work items and commits. The work items or commits in a release are computed as the union of all work items and commits of all builds between the current release and the previous release. Note that Azure Pipelines is currently able to compute work items and commits for only certain artifact sources.
  • Artifact download. Whenever a release is deployed to a stage, by default Azure Pipelines automatically downloads all the artifacts in that release to the agent where the deployment job runs. The procedure to download artifacts depends on the type of artifact. For example, Azure Pipelines artifacts are downloaded using an algorithm that downloads multiple files in parallel. Git artifacts are downloaded using Git library functionality. For more details, see Artifact download.

Artifact sources

There are several types of tools you might use in your application lifecycle process to produce or store artifacts. For example, you might use continuous integration systems such as Azure Pipelines, Jenkins, or TeamCity to produce artifacts. You might also use version control systems such as Git or TFVC to store your artifacts. Or you can use repositories such as Package Management in Visual Studio Team Services or a NuGet repository to store your artifacts. You can configure Azure Pipelines to deploy artifacts from all these sources.

By default, a release created from the release pipeline will use the latest version of the artifacts. At the time of linking an artifact source to a release pipeline, you can change this behavior by selecting one of the options to use the latest build from a specific branch by specifying the tags, a specific version, or allow the user to specify the version when the release is created from the pipeline.

Adding an artifact

If you link more than one set of artifacts, you can specify which is the primary (default).

Selecting a default version option

The following sections describe how to work with the different types of artifact sources.


Azure Pipelines

You can link a release pipeline to any of the build pipelines in Azure Pipelines or TFS project collection.

Note

You must include a Publish Artifacts task in your build pipeline. For XAML build pipelines, an artifact with the name drop is published implicitly.

Some of the differences in capabilities between different versions of TFS and Azure Pipelines are:

  • TFS 2015: You can link build pipelines only from the same project of your collection. You can link multiple definitions, but you cannot specify default versions. You can set up a continuous deployment trigger on only one of the definitions. When multiple build pipelines are linked, the latest builds of all the other definitions are used, along with the build that triggered the release creation.
  • TFS 2017 and newer and Azure Pipelines: You can link build pipelines from any of the projects in Azure Pipelines or TFS. You can link multiple build pipelines and specify default values for each of them. You can set up continuous deployment triggers on multiple build sources. When any of the builds completes, it will trigger the creation of a release.

The following features are available when using Azure Pipelines sources:

Feature Behavior with Azure Pipelines sources
Auto-trigger releases New releases can be created automatically when new builds (including XAML builds) are produced. See Continuous Deployment for details. You do not need to configure anything within the build pipeline. See the notes above for differences between version of TFS.
Artifact variables A number of artifact variables are supported for builds from Azure Pipelines.
Work items and commits Azure Pipelines integrates with work items in TFS and Azure Pipelines. These work items are also shown in the details of releases. Azure Pipelines integrates with a number of version control systems such as TFVC and Git, GitHub, Subversion, and external Git repositories. Azure Pipelines shows the commits only when the build is produced from source code in TFVC or Git.
Artifact download By default, build artifacts are downloaded to the agent. You can configure an option in the stage to skip the download of artifacts.
Deployment section in build The build summary includes a Deployment section, which lists all the stages to which the build was deployed.

TFVC, Git, and GitHub

There are scenarios in which you may want to consume artifacts stored in a version control system directly, without passing them through a build pipeline. For example:

  • You are developing a PHP or a JavaScript application that does not require an explicit build pipeline.
  • You manage configurations for various stages in different version control repositories, and you want to consume these configuration files directly from version control as part of the deployment pipeline.
  • You manage your infrastructure and configuration as code (such as Azure Resource Manager templates) and you want to manage these files in a version control repository.

Because you can configure multiple artifact sources in a single release pipeline, you can link both a build pipeline that produces the binaries of the application as well as a version control repository that stores the configuration files into the same pipeline, and use the two sets of artifacts together while deploying.

Azure Pipelines integrates with Team Foundation Version Control (TFVC) repositories, Git repositories, and GitHub repositories.

You can link a release pipeline to any of the Git or TFVC repositories in any of the projects in your collection (you will need read access to these repositories). No additional setup is required when deploying version control artifacts within the same collection.

When you link a Git or GitHub repository and select a branch, you can edit the default properties of the artifact types after the artifact has been saved. This is particularly useful in scenarios where the branch for the stable version of the artifact changes, and continuous delivery releases should use this branch to obtain newer versions of the artifact. You can also specify details of the checkout, such as whether check out submodules and LFS-tracked files, and the shallow fetch depth.

When you link a TFVC branch, you can specify the changeset to be deployed when creating a release.

The following features are available when using TFVC, Git, and GitHub sources:

Feature Behavior with TFVC, Git, and GitHub sources
Auto-trigger releases You can configure a continuous deployment trigger for pushes into the repository in a release pipeline. This can automatically trigger a release when a new commit is made to a repository. See Triggers.
Artifact variables A number of artifact variables are supported for version control sources.
Work items and commits Azure Pipelines cannot show work items or commits associated with releases when using version control artifacts.
Artifact download By default, version control artifacts are downloaded to the agent. You can configure an option in the stage to skip the download of artifacts.

Jenkins

To consume Jenkins artifacts, you must create a service connection with credentials to connect to your Jenkins server. For more details, see service connections and Jenkins service connection. You can then link a Jenkins project to a release pipeline. The Jenkins project must be configured with a post build action to publish the artifacts.

The following features are available when using Jenkins sources:

Feature Behavior with Jenkins sources
Auto-trigger releases You can configure a continuous deployment trigger for pushes into the repository in a release pipeline. This can automatically trigger a release when a new commit is made to a repository. See Triggers.
Artifact variables A number of artifact variables are supported for builds from Jenkins.
Work items and commits Azure Pipelines cannot show work items or commits for Jenkins builds.
Artifact download By default, Jenkins builds are downloaded to the agent. You can configure an option in the stage to skip the download of artifacts.

Artifacts generated by Jenkins builds are typically propagated to storage repositories for archiving and sharing. Azure blob storage is one of the supported repositories, allowing you to consume Jenkins projects that publish to Azure storage as artifact sources in a release pipeline. Deployments download the artifacts automatically from Azure to the agents. In this configuration, connectivity between the agent and the Jenkins server is not required. Microsoft-hosted agents can be used without exposing the server to internet.

Note

Azure Pipelines may not be able to contact your Jenkins server if, for example, it is within your enterprise network. In this case you can integrate Azure Pipelines with Jenkins by setting up an on-premises agent that can access the Jenkins server. You will not be able to see the name of your Jenkins projects when linking to a build, but you can type this into the link dialog field.

For more information about Jenkins integration capabilities, see Azure Pipelines Integration with Jenkins Jobs, Pipelines, and Artifacts.


Azure Container Registry, Docker, Kubernetes

When deploying containerized apps, the container image is first pushed to a container registry. After the push is complete, the container image can be deployed to the Web App for Containers service or a Docker/Kubernetes cluster. You must create a service connection with credentials to connect to your service to deploy images located there, or to Azure. For more details, see service connections.

The following features are available when using Azure Container Registry, Docker, Kubernetes sources:

Feature Behavior with Docker sources
Auto-trigger releases You can configure a continuous deployment trigger for images. This can automatically trigger a release when a new commit is made to a repository. See Triggers.
Artifact variables A number of artifact variables are supported for builds.
Work items and commits Azure Pipelines cannot show work items or commits.
Artifact download By default, builds are downloaded to the agent. You can configure an option in the stage to skip the download of artifacts.

NuGet and npm packages from Package Management

To integrate with NuGet, or npm (Maven is not currently supported), you must first assign licenses for the Package Management extension from the Marketplace. For more information, see the Package Management Overview.

Scenarios where you may want to consume Package Management artifacts are:

  1. You have your application build (such as TFS, Azure Pipelines, TeamCity, Jenkins) published as a package (NuGet or npm) to Package Management and you want to consume the artifact in a release.
  2. As part of your application deployment, you need additional packages stored in Package Management.

When you link a Package Management artifact to your release pipeline, you must select the Feed, Package, and the Default version for the package. You can choose to pick up the latest version of the package, use a specific version, or select the version at the time of release creation. During deployment, the package is downloaded to the agent folder and the contents are extracted as part of the job execution.

The following features are available when using Package Management sources:

Feature Behavior with Package Management sources
Auto-trigger releases You can configure a continuous deployment trigger for packages. This can automatically trigger a release when a package is updated. See Triggers.
Artifact variables A number of artifact variables are supported for packages.
Work items and commits Azure Pipelines cannot show work items or commits.
Artifact download By default, packages are downloaded to the agent. You can configure an option in the stage to skip the download of artifacts.

External or on-premises TFS

You can use Azure Pipelines to deploy artifacts published by an on-premises TFS server. You don’t need to make the TFS server visible on the Internet; you just set up an on-premises automation agent. Builds from an on-premises TFS server are downloaded directly into the on-premises agent, and then deployed to the specified target servers. They will not leave your enterprise network. This allows you to leverage all of your investments in your on-premises TFS server, and take advantage of the release capabilities in Azure Pipelines.

Using this mechanism, you can also deploy artifacts published in one Azure Pipelines subscription in another Azure Pipelines, or deploy artifacts published in one Team Foundation Server from another Team Foundation Server.

To enable these scenarios, you must install the TFS artifacts for Azure Pipelines extension from Visual Studio Marketplace. Then create a service connection with credentials to connect to your TFS server (see service connections for details).

You can then link a TFS build pipeline to your release pipeline. Choose External TFS Build in the Type list.

The following features are available when using external TFS sources:

Feature Behavior with external TFS sources
Auto-trigger releases You cannot configure a continuous deployment trigger for external TFS sources in a release pipeline. To automatically create a new release when a build is complete, you would need to add a script to your build pipeline in the external TFS server to invoke Azure Pipelines REST APIs and to create a new release.
Artifact variables A number of artifact variables are supported for external TFS sources.
Work items and commits Azure Pipelines cannot show work items or commits for external TFS sources.
Artifact download By default, External TFS artifacts are downloaded to the agent. You can configure an option in the stage to skip the download of artifacts.

Note

Azure Pipelines may not be able to contact an on-premises TFS server if, for example, it is within your enterprise network. In this case you can integrate Azure Pipelines with TFS by setting up an on-premises agent that can access the TFS server. You will not be able to see the name of your TFS projects or build pipelines when linking to a build, but you can type these into the link dialog fields. In addition, when you create a release, Azure Pipelines may not be able to query the TFS server for the build numbers. Instead, type the Build ID (not the build number) of the desired build into the appropriate field, or select the Latest build.


TeamCity

To integrate with TeamCity, you must first install the TeamCity artifacts for Azure Pipelines extension from Marketplace.

To consume TeamCity artifacts, start by creating a service connection with credentials to connect to your TeamCity server (see service connections for details).

You can then link a TeamCity build configuration to a release pipeline. The TeamCity build configuration must be configured with an action to publish the artifacts.

The following features are available when using TeamCity sources:

Feature Behavior with TeamCity sources
Auto-trigger releases You cannot configure a continuous deployment trigger for TeamCity sources in a release pipeline. To create a new release automatically when a build is complete, add a script to your TeamCity project that invokes the Azure Pipelines REST APIs to create a new release.
Artifact variables A number of artifact variables are supported for builds from TeamCity.
Work items and commits Azure Pipelines cannot show work items or commits for TeamCity builds.
Artifact download By default, TeamCity builds are downloaded to the agent. You can configure an option in the stage to skip the download of artifacts.

Note

Azure Pipelines may not be able to contact your TeamCity server if, for example, it is within your enterprise network. In this case you can integrate Azure Pipelines with TeamCity by setting up an on-premises agent that can access the TeamCity server. You will not be able to see the name of your TeamCity projects when linking to a build, but you can type this into the link dialog field.


Other sources

Your artifacts may be created and exposed by other types of sources such as a NuGet repository. While we continue to expand the types of artifact sources supported in Azure Pipelines, you can start using it without waiting for support for a specific source type. Simply skip the linking of artifact sources in a release pipeline, and add custom tasks to your stages that download the artifacts directly from your source.


Artifact download

When you deploy a release to a stage, the versioned artifacts from each of the sources are, by default, downloaded to the automation agent so that tasks running within that stage can deploy these artifacts. The artifacts downloaded to the agent are not deleted when a release is completed. However, when you initiate the next release, the downloaded artifacts are deleted and replaced with the new set of artifacts.

A new unique folder in the agent is created for every release pipeline when you initiate a release, and the artifacts are downloaded into that folder. The $(System.DefaultWorkingDirectory) variable maps to this folder.

Note that, at present, Azure Pipelines does not perform any optimization to avoid downloading the unchanged artifacts if the same release is deployed again. In addition, because the previously downloaded contents are always deleted when you initiate a new release, Azure Pipelines cannot perform incremental downloads to the agent.

You can, however, instruct Azure Pipelines to skip the automatic downloadof artifacts to the agent for a specific job and stage of the deployment if you wish. Typically, you will do this when the tasks in that job do not require any artifacts, or if you implement custom code in a task to download the artifacts you require.

In Azure Pipelines, you can, however, select which artifacts you want to download to the agent for a specific job and stage of the deployment. Typically, you will do this to improve the efficiency of the deployment pipeline when the tasks in that job do not require all or any of the artifacts, or if you implement custom code in a task to download the artifacts you require.

Selecting the artifacts to download

Artifact source alias

To ensure the uniqueness of every artifact download, each artifact source linked to a release pipeline is automatically provided with a specific download location known as the source alias. This location can be accessed through the variable:

$(System.DefaultWorkingDirectory)\[source alias]

This uniqueness also ensures that, if you later rename a linked artifact source in its original location (for example, rename a build pipeline in Azure Pipelines or a project in Jenkins), you don’t need to edit the task properties because the download location defined in the agent does not change.

The source alias is, by default, the name of the source selected when you linked the artifact source, prefixed with an underscore; depending on the type of the artifact source this will be the name of the build pipeline, job, project, or repository. You can edit the source alias from the artifacts tab of a release pipeline; for example, when you change the name of the build pipeline and you want to use a source alias that reflects the name of the build pipeline.

The source alias can contain only alphanumeric characters and underscores, and must start with a letter or an underscore

Primary source

When you link multiple artifact sources to a release pipeline, one of them is designated as the primary artifact source. The primary artifact source is used to set a number of pre-defined variables. It can also be used in naming releases.

Artifact variables

Azure Pipelines exposes a set of pre-defined variables that you can access and use in tasks and scripts; for example, when executing PowerShell scripts in deployment jobs. When there are multiple artifact sources linked to a release pipeline, you can access information about each of these. For a list of all pre-defined artifact variables, see variables.

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