/
main.go
151 lines (124 loc) · 3.89 KB
/
main.go
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package main
import (
"context"
"encoding/json"
"flag"
"net/http"
"os"
stdprometheus "github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/go-kit/kit/log"
kitprometheus "github.com/go-kit/kit/metrics/prometheus"
httptransport "github.com/go-kit/kit/transport/http"
"github.com/go-kit/kit/endpoint"
)
func main() {
port := flag.String("p", "8080", "Port")
headlessURL := flag.String("-c", "http://localhost:9222/json", "Chrome headless url")
queueSize := flag.Int("-s", 100, "Queue size")
flag.Parse()
jobQueue := make(chan job, *queueSize)
worker := newWorker(*headlessURL, jobQueue)
worker.start()
//logger
logger := log.NewLogfmtLogger(os.Stderr)
//instru
fieldKeys := []string{"method", "error"}
requestCount := kitprometheus.NewCounterFrom(stdprometheus.CounterOpts{
Namespace: "default",
Subsystem: "go_pdf_bot",
Name: "request_count",
Help: "Number of requests received.",
}, fieldKeys)
requestLatency := kitprometheus.NewSummaryFrom(stdprometheus.SummaryOpts{
Namespace: "default",
Subsystem: "go_pdf_bot",
Name: "request_latency_microseconds",
Help: "Total duration of requests in microseconds.",
}, fieldKeys)
countResult := kitprometheus.NewSummaryFrom(stdprometheus.SummaryOpts{
Namespace: "default",
Subsystem: "go_pdf_bot",
Name: "count_result",
Help: "The result of each count method.",
}, []string{}) // no fields here
//router
var router Router
router = jsonrpcRouter{
map[string]controller{
"job/create": jobCreateController{worker},
},
}
router = loggingMiddleware{logger, router}
router = instrumentingMiddleware{requestCount, requestLatency, countResult, router}
handler := httptransport.NewServer(
rpcEndpoint(router),
decodeRequest,
encodeResponse,
)
http.Handle("/rpc", handler)
http.Handle("/metrics", promhttp.Handler())
logger.Log(http.ListenAndServe(":"+*port, nil))
}
// JsonRpcRuter router
type jsonrpcRequest struct {
Jsonrpc string `json:"jsonrpc"`
Method string `json:"method"`
Params map[string]string `json:"params"`
ID string `json:"id"`
}
type jsonrpcErrorResponse struct {
Code int `json:"code,omitempty"`
Message string `json:"message,omitempty"`
Data map[string]string `json:"data,omitempty"`
}
type jsonrpcResponse struct {
Jsonrpc string `json:"jsonrpc"`
Result map[string]string `json:"result"`
Error jsonrpcErrorResponse `json:"error"`
ID string `json:"id"`
}
//Router interface
type Router interface {
route(ctx context.Context, request jsonrpcRequest) (jsonrpcResponse, error)
}
type jsonrpcRouter struct {
routes map[string]controller
}
type controller interface {
action(params map[string]string) map[string]string
}
func (j jsonrpcRouter) route(ctx context.Context, request jsonrpcRequest) (jsonrpcResponse, error) {
response := jsonrpcResponse{
"2.0",
map[string]string{},
jsonrpcErrorResponse{},
request.ID,
}
if j.routes[request.Method] == nil {
response.Error.Code = -32601
response.Error.Message = "Method not found"
return response, nil
}
response.Result = j.routes[request.Method].action(request.Params)
return response, nil
}
func rpcEndpoint(router Router) endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (interface{}, error) {
req := request.(jsonrpcRequest)
response, error := router.route(ctx, req)
return response, error
}
}
func decodeRequest(_ context.Context, r *http.Request) (interface{}, error) {
var req jsonrpcRequest
if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
return nil, err
}
return req, nil
}
func encodeResponse(_ context.Context, w http.ResponseWriter, response interface{}) error {
w.Header().Set("Content-Type", "application/json")
resp := response.(jsonrpcResponse)
return json.NewEncoder(w).Encode(resp)
}