exchanges: Initial context propagation (#744)

* gct: phase one context awareness pass

* exchanges: context propagation pass

* common/requester: force context requirement

* gctcli/exchanges: linter fix

* rpcserver: fix test using dummy rpc server

* backtester: fix comments

* grpc: add correct cancel and timeout for commands

* rpcserver_test: add comment on dummy server

* common: deprecated SendHTTPGetRequest

* linter: fix

* linter: turn on no context check

* apichecker: fix context linter issue

* binance: use param context

* common: remove checks as this gets executed before main

* common: change mutex to RW as clients can be used by multiple go routines.

* common: remove init and JIT default client. Unexport global variables and add protection.

* common: Add comments

* bithumb: after dinner mints fix

communications/slack/slack.go

@@ -4,6 +4,7 @@
 package slack
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -151,7 +152,17 @@ func (s *Slack) GetUsersInGroup(group string) []string {
 // token and a channel
 func (s *Slack) NewConnection() error {
 	if !s.Connected {
-		err := common.SendHTTPGetRequest(s.BuildURL(s.VerificationToken), true, s.Verbose, &s.Details)
+		contents, err := common.SendHTTPRequest(context.TODO(),
+			http.MethodGet,
+			s.BuildURL(s.VerificationToken),
+			nil,
+			nil,
+			s.Verbose)
+		if err != nil {
+			return err
+		}
+
+		err = json.Unmarshal(contents, &s.Details)
 		if err != nil {
 			return err
 		}

communications/smsglobal/smsglobal.go

@@ -2,6 +2,7 @@
 package smsglobal
 
 import (
+	"context"
 	"errors"
 	"flag"
 	"net/http"
@@ -179,15 +180,17 @@ func (s *SMSGlobal) SendMessage(to, message string) error {
 	headers := make(map[string]string)
 	headers["Content-Type"] = "application/x-www-form-urlencoded"
 
-	resp, err := common.SendHTTPRequest(http.MethodPost,
+	resp, err := common.SendHTTPRequest(context.TODO(),
+		http.MethodPost,
 		smsGlobalAPIURL,
 		headers,
-		strings.NewReader(values.Encode()))
+		strings.NewReader(values.Encode()),
+		s.Verbose)
 	if err != nil {
 		return err
 	}
 
-	if !strings.Contains(resp, "OK: 0; Sent queued message") {
+	if !strings.Contains(string(resp), "OK: 0; Sent queued message") {
 		return errSMSNotSent
 	}
 	return nil

communications/telegram/telegram.go

@@ -5,6 +5,7 @@ package telegram
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -245,13 +246,15 @@ func (t *Telegram) SendHTTPRequest(path string, data []byte, result interface{})
 	headers := make(map[string]string)
 	headers["content-type"] = "application/json"
 
-	resp, err := common.SendHTTPRequest(http.MethodPost,
+	resp, err := common.SendHTTPRequest(context.TODO(),
+		http.MethodPost,
 		path,
 		headers,
-		bytes.NewBuffer(data))
+		bytes.NewBuffer(data),
+		t.Verbose)
 	if err != nil {
 		return err
 	}
 
-	return json.Unmarshal([]byte(resp), result)
+	return json.Unmarshal(resp, result)
 }