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88eea5f62e
Introduces a single-flight call to a function's health endpoint to verify that it is registered with an Istio sidecar (Envoy) before letting the invocation through. Results are cached for 5 seconds, before a probe is required again. Tested without Istio, with probe_functions environment variable set to true, I saw a probe execute in the logs. Fixes: #1721 for Istio users. Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alex@openfaas.com>
54 lines
1.6 KiB
Go
54 lines
1.6 KiB
Go
// Copyright (c) OpenFaaS Author(s). All rights reserved.
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// Licensed under the MIT license. See LICENSE file in the project root for full license information.
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package handlers
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import (
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"fmt"
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"log"
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"net/http"
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"github.com/openfaas/faas/gateway/pkg/middleware"
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"github.com/openfaas/faas/gateway/scaling"
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)
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// MakeScalingHandler creates handler which can scale a function from
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// zero to N replica(s). After scaling the next http.HandlerFunc will
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// be called. If the function is not ready after the configured
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// amount of attempts / queries then next will not be invoked and a status
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// will be returned to the client.
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func MakeScalingHandler(next http.HandlerFunc, scaler scaling.FunctionScaler, config scaling.ScalingConfig, defaultNamespace string) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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functionName, namespace := middleware.GetNamespace(defaultNamespace, middleware.GetServiceName(r.URL.String()))
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res := scaler.Scale(functionName, namespace)
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if !res.Found {
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errStr := fmt.Sprintf("error finding function %s.%s: %s", functionName, namespace, res.Error.Error())
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log.Printf("Scaling: %s\n", errStr)
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w.WriteHeader(http.StatusNotFound)
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w.Write([]byte(errStr))
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return
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}
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if res.Error != nil {
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errStr := fmt.Sprintf("error finding function %s.%s: %s", functionName, namespace, res.Error.Error())
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log.Printf("Scaling: %s\n", errStr)
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w.WriteHeader(http.StatusInternalServerError)
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w.Write([]byte(errStr))
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return
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}
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if res.Available {
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next.ServeHTTP(w, r)
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return
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}
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log.Printf("[Scale] function=%s.%s 0=>N timed-out after %fs\n", functionName, namespace, res.Duration.Seconds())
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}
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}
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