faas/gateway/server.go
2017-01-22 10:45:42 +00:00

110 lines
3.0 KiB
Go

package main
import (
"context"
"encoding/json"
"fmt"
"io/ioutil"
"log"
"net/http"
"time"
"github.com/alexellis/faas/gateway/metrics"
"github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/filters"
"github.com/docker/docker/client"
"github.com/gorilla/mux"
io_prometheus_client "github.com/prometheus/client_model/go"
)
func makeAlertHandler() http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
fmt.Println("Alert received.")
body, _ := ioutil.ReadAll(r.Body)
fmt.Println(string(body))
// Todo: parse alert, validate alert and scale up or down function
w.WriteHeader(http.StatusOK)
}
}
// Function exported for system/functions endpoint
type Function struct {
Name string `json:"name"`
Image string `json:"image"`
InvocationCount float64 `json:"invocationCount"`
Replicas uint64 `json:"replicas"`
}
func makeFunctionReader(metricsOptions metrics.MetricOptions, c *client.Client) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
serviceFilter := filters.NewArgs()
options := types.ServiceListOptions{
Filters: serviceFilter,
}
services, err := c.ServiceList(context.Background(), options)
if err != nil {
fmt.Println(err)
}
// TODO: Filter only "faas" functions (via metadata?)
functions := make([]Function, 0)
for _, service := range services {
counter, _ := metricsOptions.GatewayFunctionInvocation.GetMetricWithLabelValues(service.Spec.Name)
var pbmetric io_prometheus_client.Metric
counter.Write(&pbmetric)
invocations := pbmetric.GetCounter().GetValue()
f := Function{
Name: service.Spec.Name,
Image: service.Spec.TaskTemplate.ContainerSpec.Image,
InvocationCount: invocations,
Replicas: *service.Spec.Mode.Replicated.Replicas,
}
functions = append(functions, f)
}
functionBytes, _ := json.Marshal(functions)
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(200)
w.Write(functionBytes)
}
}
func main() {
var dockerClient *client.Client
var err error
dockerClient, err = client.NewEnvClient()
if err != nil {
log.Fatal("Error with Docker client.")
}
metricsOptions := metrics.BuildMetricsOptions()
metrics.RegisterMetrics(metricsOptions)
r := mux.NewRouter()
r.HandleFunc("/function/{name:[a-zA-Z_]+}", MakeProxy(metricsOptions, true, dockerClient))
r.HandleFunc("/system/alert", makeAlertHandler())
r.HandleFunc("/system/functions", makeFunctionReader(metricsOptions, dockerClient)).Methods("GET")
r.HandleFunc("/", MakeProxy(metricsOptions, false, dockerClient)).Methods("POST")
metricsHandler := metrics.PrometheusHandler()
r.Handle("/metrics", metricsHandler)
r.PathPrefix("/").Handler(http.FileServer(http.Dir("./assets/"))).Methods("GET")
s := &http.Server{
Addr: ":8080",
ReadTimeout: 8 * time.Second,
WriteTimeout: 8 * time.Second,
MaxHeaderBytes: 1 << 20,
Handler: r,
}
log.Fatal(s.ListenAndServe())
}