59 lines
1.8 KiB
Go
59 lines
1.8 KiB
Go
package clientmiddleware
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import (
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"context"
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"fmt"
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"github.com/grafana/grafana-plugin-sdk-go/backend"
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"github.com/grafana/grafana/pkg/plugins/pluginrequestmeta"
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)
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// NewStatusSourceMiddleware returns a new backend.HandlerMiddleware that sets the status source in the
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// plugin request meta stored in the context.Context, according to the query data responses returned by QueryError.
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// If at least one query data response has a "downstream" status source and there isn't one with a "plugin" status source,
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// the plugin request meta in the context is set to "downstream".
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func NewStatusSourceMiddleware() backend.HandlerMiddleware {
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return backend.HandlerMiddlewareFunc(func(next backend.Handler) backend.Handler {
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return &StatusSourceMiddleware{
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BaseHandler: backend.NewBaseHandler(next),
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}
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})
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}
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type StatusSourceMiddleware struct {
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backend.BaseHandler
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}
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func (m *StatusSourceMiddleware) QueryData(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
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resp, err := m.BaseHandler.QueryData(ctx, req)
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if resp == nil || len(resp.Responses) == 0 {
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return resp, err
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}
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// Set downstream status source in the context if there's at least one response with downstream status source,
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// and if there's no plugin error
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var hasPluginError bool
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var hasDownstreamError bool
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for _, r := range resp.Responses {
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if r.Error == nil {
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continue
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}
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if r.ErrorSource == backend.ErrorSourceDownstream {
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hasDownstreamError = true
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} else {
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hasPluginError = true
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}
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}
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// A plugin error has higher priority than a downstream error,
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// so set to downstream only if there's no plugin error
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if hasDownstreamError && !hasPluginError {
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if err := pluginrequestmeta.WithDownstreamStatusSource(ctx); err != nil {
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return resp, fmt.Errorf("failed to set downstream status source: %w", err)
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}
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}
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return resp, err
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}
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