Roslyn Feature Feeds

In order to allow streamlined dogfooding of upcoming Roslyn features, we provide two mechanisms that are used in conjuntion and are automatically available for all feature branches:

1. A CI nuget feed at https://roslyn.blob.core.windows.net/nuget/index.json
2. A VSIX gallery feed at https://roslyn.blob.core.windows.net/vsix/[feature]/atom.xml

To get both a feature branch's IDE as well as compiler support, you need to install a matching IDE extension as well as configure and install the specific version of the compilers compiled for that same feature, as explained in the docs on contributing.

The feeds allow you to consume the CI produced artifacts from a feature branch without having to clone and build locally.

In addition, a permalink is also provided to the latest VSIX from the currently branch or alternatively from any branch by using https://roslyn.azurewebsites.net/latest?FEATURE (such as https://roslyn.azurewebsites.net/latest?records).

NuGet Feed

To consume the compiler (and any other packages you might depend on), add the following package source to your NuGet.Config:

<add key="roslyn" value="https://roslyn.blob.core.windows.net/nuget/index.json" />

To always reference the latest compiler toolset for a feature branch named features/records, for example, you can use a wildcard like:

<PackageReference Include="Microsoft.Net.Compilers.Toolset" Version="3.7.0-ci.records.*" />

The label suffix after -ci. will match the branch name after features/ in the repository.

The wildcard can be replaced with a particular build version if you want an exact match (i.e. to be tied to the installed VSIX too).

VSIX Feed

Visual Studio makes it easy to add custom gallery feeds for installing and updating extensions outside of the marketplace.

Unlike the nuget packages where you can easily pick which feature you want to install by appending the right label suffix after -ci., the Extension Manager does not allow selection of different versions of the same extension from a feed. So you need different feeds for each.

You pick the feature feed you want by replacing FEATURE with the name of the feature branch (after features/ in the branch name) in the URL
https://roslyn.blob.core.windows.net/vsix/FEATURE/atom.xml

Setting Up your own CI/Azure

This section documents how to set up the DevOps and Azure resources in order to self-host the feeds and nuget packages.

Prepare Azure Resources

1. Optionally (but recommended) create a separate Resource Group to contain all resources that will handle the feeds (i.e. Azure Function and Blob Storage)
2. Create an empty Azure Functions App, choose .NET Core runtime
3. Create a new storage account (either StorageV2 or BlobStorage) and create three new containers with public read access for blobs access policy: vsix, nuget and latest.

Azure KeyVault

Both the function app and the build pipelines need access to the storage account, via a FeedStorageConnectionString setting. You can copy/paste the connection string directly as a setting for both, or you can use Azure KeyVault. This is the recommended approach for maximum security and policy compliance, and it also facilitates changing that value later on in a single place.

If you decide to use KeyVault:

1. Create a new Azure KeyVault in the same resource group as the rest
2. Create a new Secret and set it to the connection string for the storage account, name it FeedStorageConnectionString. Copy the Secret Identifier URI.
3. In the function app, select the Identity pane and set Status = On for the System assigned identity. This will allow adding read permissions to the function app on the key vault.
4. In the Access policies pane of the key vault, click Add Access Policy and create a new policy with Get (key and secret) permissions for the function app principal (search for its app name in the Principal selector)
5. In the function app, add a new app setting with the following format: @Microsoft.KeyVault(SecretUri=SECRET_URI). Replace SECRET_URI with the value copied in step 2.

If the value was properly read by the function app, a green checkmark will appear next to Key vault Reference in the Source column for the setting.

Azure DevOps

1. Create a new Service connection (in your DevOps project settings), selecting Azure Resource Manager and Service principal (automatic) and select the subscription and resource group. Name it roslyn-Azure.

   The pipelines use roslyn-Azure as the service connection name. You can use a different name, by providing the value via the AzureSubscription variable.

2. After saving the connection, click on it to see the Overview/Details pane. Click on Manage Service Principal, which takes you to Azure AD app registration. Copy the Display name

3. In the Azure portal, navigate to the storage account, and under the Access control IAM section, add a new role assignement. Select Storage Blob Data Contributor role, and paste the app registration display name copied above to search for the identity and save.

Azure DevOps Pipelines

There are two separate pipelines to set up:

1. Uploading to Blob Storage on CI builds
2. Deploying Function App

Storage Upload Pipeline

If you're using Azure KeyVault to keep the storage connection string:

• Open the Library section and create a new variable group
• Select Link secrets from an Azure key vault as variables and link the FeedStorageConnectionString

Steps for setting up the CI pipeline that publishes blobs to storage (both VSIX payloads as well as a serverless nuget feed):

1. Create a new YAML-based pipeline, point it to the roslyn repo/fork and let it pick the default yaml from the repo and save it (don't queue a build)
2. Click Edit, then the vertical dots button next to Save and select Triggers. This allows non-yaml aspects of the pipeline.
3. In the YAML tab, enter src/Tools/FeatureFeed/azure-pipelines-function.yml as the YAML file path and Azure Pipelines as the default agent pool. Optionally give the pipeline a friendly name.
4. If you're not using Azure keyvault, create a FeedStorageConnectionString variable and set its value to the storage account connection string. Also set the variable as a secret. If you're using Azure key vault, just link the previously created variable group instead.
5. Optionally set the value of the AzureSubscription variable if your service connection name is not roslyn-Azure.

Function Deploy Pipeline

Steps for setting up the CI pipeline that publishes and updates the Azure function app that updates the VSIX feed:

1. Create a new YAML-based pipeline, point it to the roslyn repo/fork and let it pick the default yaml from the repo and save it (don't queue a build)
2. Click Edit, then the vertical dots button next to Save and select Triggers. This allows non-yaml aspects of the pipeline.
3. In the YAML tab, enter src/Tools/FeatureFeed/azure-pipelines-function.yml as the YAML file path and Azure Pipelines as the default agent pool. Optionally give the pipeline a friendly name.
4. In the Variables tab, add a new FunctionAppName and set the value to the name of the function app you created earlier.
5. Optionally set the value of the AzureSubscription variable if your service connection name is not roslyn-Azure.