Todd Treece
80 lines
3.6 KiB
Markdown
80 lines
3.6 KiB
Markdown
# AppInstaller
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An `AppInstaller` (`appsdkapiserver.AppInstaller`) is a new concept introduced in v0.40.0 of the Grafana App SDK. It is an interface responsible for installing an app into the Grafana API server. Each app provides an `AppInstaller` implementation, which is then used by the API server to manage the app.
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## Architectural Changes
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### New App Installer Framework
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A new framework for installing and managing apps has been introduced in `pkg/services/apiserver/appinstaller`. This framework is responsible for:
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- **Schema Registration:** Registering the Kubernetes-style API schemas defined by an app.
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- **Admission Plugins:** Registering admission plugins for apps.
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- **OpenAPI Definitions:** Aggregating OpenAPI definitions from all installed apps.
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- **API Installation:** Installing the API groups and resources defined by an app.
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- **Lifecycle Management:** Managing the lifecycle of an app, including initialization and startup.
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### API Server Integration
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Grafana's core API server (`pkg/services/apiserver/service.go`) has been significantly updated to integrate with the new app installer framework. During startup, the API server now performs the following steps:
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1. Collects all `AppInstaller` instances provided by the apps.
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2. Uses the `appinstaller` framework to register schemas, admission plugins, and OpenAPI definitions.
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3. Installs the APIs for each app.
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4. Initializes and starts each app.
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This ensures that apps are seamlessly integrated into Grafana's API server and that their resources are available through the Grafana API.
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### App Registration
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The method for registering apps has been updated:
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- The old way of registering apps using `ProvideBuilderRunners` in `pkg/registry/apps/apps.go` is now deprecated.
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- The new, preferred way is to use the `ProvideAppInstallers` function, which returns a list of `AppInstaller` instances.
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This change streamlines the app registration process and makes it more consistent.
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## Migration Guide
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To migrate an existing app to the new SDK, you need to:
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1. Implement the `appsdkapiserver.AppInstaller` interface for your app.
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2. Update your app's registration to use the `ProvideAppInstallers` function.
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### Example: Playlist App
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The Playlist app has been migrated to the new App SDK. Let's look at how it was done.
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Previously, the Playlist app was registered using `ProvideBuilderRunners`:
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```go
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// pkg/registry/apps/apps.go (before)
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func ProvideBuilderRunners(
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// ...
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playlistAppProvider *playlist.PlaylistAppProvider,
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// ...
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) (*Service, error) {
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// ...
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providers := []app.Provider{playlistAppProvider}
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// ...
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}
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```
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Now, the Playlist app provides an `AppInstaller` and is registered through `ProvideAppInstallers`:
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```go
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// pkg/registry/apps/apps.go (after)
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func ProvideAppInstallers(
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playlistAppInstaller *playlist.PlaylistAppInstaller,
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) []appsdkapiserver.AppInstaller {
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return []appsdkapiserver.AppInstaller{playlistAppInstaller}
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}
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```
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The implementation of the `PlaylistAppInstaller` can be found in `pkg/registry/apps/playlist/register.go`. This file is a good reference for how to implement an `AppInstaller` for your own app.
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The `pkg/registry/apps/playlist/register.go` file does the following:
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- It defines `PlaylistAppInstaller`, which embeds `appsdkapiserver.AppInstaller`.
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- It implements `appinstaller.LegacyStorageProvider` to bridge with Grafana's existing playlist service.
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- The `RegisterAppInstaller` function initializes the installer, providing the app's manifest, specific configuration, and associating Go types with API kinds.
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- It shows how to provide a custom table converter for `kubectl get` style output. |