Documentation
¶
Overview ¶
Package datasource provides utilities for creating and serving a data source plugin over gRPC.
Example ¶
package main
import (
"context"
"net/http"
"os"
"github.com/grafana/grafana-plugin-sdk-go/backend"
"github.com/grafana/grafana-plugin-sdk-go/backend/datasource"
"github.com/grafana/grafana-plugin-sdk-go/backend/instancemgmt"
"github.com/grafana/grafana-plugin-sdk-go/backend/resource/httpadapter"
)
type testDataSourceInstanceSettings struct {
httpClient *http.Client
}
func newDataSourceInstance(setting backend.DataSourceInstanceSettings) (instancemgmt.Instance, error) {
return &testDataSourceInstanceSettings{
httpClient: &http.Client{},
}, nil
}
func (s *testDataSourceInstanceSettings) Dispose() {
// Cleanup
}
type testDataSource struct {
im instancemgmt.InstanceManager
}
func newDataSource() datasource.ServeOpts {
im := datasource.NewInstanceManager(newDataSourceInstance)
ds := &testDataSource{
im: im,
}
mux := http.NewServeMux()
mux.HandleFunc("/test", ds.handleTest)
return datasource.ServeOpts{
CheckHealthHandler: ds,
CallResourceHandler: httpadapter.New(mux),
QueryDataHandler: ds,
}
}
func (ds *testDataSource) getSettings(pluginContext backend.PluginContext) (*testDataSourceInstanceSettings, error) {
iface, err := ds.im.Get(pluginContext)
if err != nil {
return nil, err
}
return iface.(*testDataSourceInstanceSettings), nil
}
func (ds *testDataSource) CheckHealth(ctx context.Context, req *backend.CheckHealthRequest) (*backend.CheckHealthResult, error) {
settings, err := ds.getSettings(req.PluginContext)
if err != nil {
return nil, err
}
// Handle request
resp, err := settings.httpClient.Get("http://")
if err != nil {
return nil, err
}
resp.Body.Close()
return nil, nil
}
func (ds *testDataSource) QueryData(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
var resp *backend.QueryDataResponse
err := ds.im.Do(req.PluginContext, func(settings *testDataSourceInstanceSettings) error {
// Handle request
resp, err := settings.httpClient.Get("http://")
if err != nil {
return err
}
resp.Body.Close()
return nil
})
return resp, err
}
func (ds *testDataSource) handleTest(rw http.ResponseWriter, req *http.Request) {
pluginContext := httpadapter.PluginConfigFromContext(req.Context())
settings, err := ds.getSettings(pluginContext)
if err != nil {
rw.WriteHeader(500)
return
}
// Handle request
resp, err := settings.httpClient.Get("http://")
if err != nil {
rw.WriteHeader(500)
return
}
resp.Body.Close()
}
func main() {
err := datasource.Serve(newDataSource())
if err != nil {
backend.Logger.Error(err.Error())
os.Exit(1)
}
}
Output:
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func NewInstanceManager ¶ added in v0.61.0
func NewInstanceManager(fn InstanceFactoryFunc) instancemgmt.InstanceManager
NewInstanceManager creates a new data source instance manager,
This is a helper method for calling NewInstanceProvider and creating a new instancemgmt.InstanceProvider, and providing that to instancemgmt.New.
func NewInstanceProvider ¶ added in v0.61.0
func NewInstanceProvider(fn InstanceFactoryFunc) instancemgmt.InstanceProvider
NewInstanceProvider create a new data source instance provuder,
The instance provider is responsible for providing cache keys for data source instances, creating new instances when needed and invalidating cached instances when they have been updated in Grafana. Cache key is based on the numerical data source identifier. If fn is nil, NewInstanceProvider panics.
Types ¶
type InstanceFactoryFunc ¶ added in v0.61.0
type InstanceFactoryFunc func(settings backend.DataSourceInstanceSettings) (instancemgmt.Instance, error)
InstanceFactoryFunc factory method for creating data source instances.
type QueryTypeMux ¶
type QueryTypeMux struct {
// contains filtered or unexported fields
}
QueryTypeMux is a query type multiplexer.
Example ¶
package main
import (
"context"
"github.com/grafana/grafana-plugin-sdk-go/backend"
"github.com/grafana/grafana-plugin-sdk-go/backend/datasource"
)
func main() {
mux := datasource.NewQueryTypeMux()
mux.HandleFunc("queryTypeA", func(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
// handle queryTypeA
return nil, nil
})
mux.HandleFunc("queryTypeB", func(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
// handle queryTypeB
return nil, nil
})
_ = datasource.ServeOpts{
QueryDataHandler: mux,
}
}
Output:
func NewQueryTypeMux ¶
func NewQueryTypeMux() *QueryTypeMux
NewQueryTypeMux allocates and returns a new QueryTypeMux.
func (*QueryTypeMux) Handle ¶
func (mux *QueryTypeMux) Handle(queryType string, handler backend.QueryDataHandler)
Handle registers the handler for the given query type.
Providing an empty queryType registers the handler as a fallback handler that will be called when query type doesn't match any registered handlers. If handler is nil, Handle panics. If a handler already exists for queryType, Handle panics.
func (*QueryTypeMux) HandleFunc ¶
func (mux *QueryTypeMux) HandleFunc(queryType string, handler func(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error))
HandleFunc registers the handler function for the given query type.
Providing an empty queryType registers the handler as a fallback handler that will be called when query type doesn't match any registered handlers. If handler is nil, Handle panics. If a handler already exists for queryType, Handle panics.
func (*QueryTypeMux) QueryData ¶
func (mux *QueryTypeMux) QueryData(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error)
QueryData dispatches the request to the handler(s) whose query type matches the request queries query type.
type ServeOpts ¶ added in v0.61.0
type ServeOpts struct {
// CheckHealthHandler handler for health checks.
// Optional to implement.
backend.CheckHealthHandler
// CallResourceHandler handler for resource calls.
// Optional to implement.
backend.CallResourceHandler
// QueryDataHandler handler for data queries.
// Required to implement.
backend.QueryDataHandler
// GRPCSettings settings for gPRC.
GRPCSettings backend.GRPCSettings
}
ServeOpts options for serving a data source plugin.
Source Files