apollo-backend/cmd/apollo-worker/main.go
2021-07-07 22:59:19 -04:00

230 lines
6.2 KiB
Go

package main
import (
"database/sql"
"fmt"
"log"
"os"
"os/signal"
"runtime"
"syscall"
"time"
"github.com/DataDog/datadog-go/statsd"
_ "github.com/heroku/x/hmetrics/onload"
"github.com/joho/godotenv"
_ "github.com/lib/pq"
"github.com/sideshow/apns2"
"github.com/sideshow/apns2/payload"
"github.com/sideshow/apns2/token"
"github.com/christianselig/apollo-backend/internal/data"
"github.com/christianselig/apollo-backend/internal/reddit"
)
type application struct {
logger *log.Logger
db *sql.DB
models *data.Models
client *reddit.Client
}
var (
workers int = runtime.NumCPU() * 4
rate float64 = 0.1
backoff int = 5
)
func accountWorker(id int, rc *reddit.Client, db *sql.DB, logger *log.Logger, statsd *statsd.Client, quit chan bool) {
authKey, err := token.AuthKeyFromBytes([]byte(os.Getenv("APPLE_KEY_PKEY")))
token := &token.Token{
AuthKey: authKey,
KeyID: os.Getenv("APPLE_KEY_ID"),
TeamID: os.Getenv("APPLE_TEAM_ID"),
}
if err != nil {
log.Fatal("token error:", err)
}
sandboxClient := apns2.NewTokenClient(token)
productionClient := apns2.NewTokenClient(token).Production()
for {
select {
case <-quit:
return
default:
now := float64(time.Now().UTC().UnixNano()/int64(time.Millisecond)) / 1000
tx, err := db.Begin()
if err != nil {
log.Fatal(err)
continue
}
t1 := time.Now()
query := `
SELECT id, username, access_token, refresh_token, expires_at, last_message_id, last_checked_at FROM accounts
WHERE last_checked_at + 5 <= $1::float
ORDER BY last_checked_at
LIMIT 1
FOR UPDATE SKIP LOCKED`
args := []interface{}{now}
account := &data.Account{}
err = tx.QueryRow(query, args...).Scan(&account.ID, &account.Username, &account.AccessToken, &account.RefreshToken, &account.ExpiresAt, &account.LastMessageID, &account.LastCheckedAt)
t2 := time.Now()
statsd.Histogram("apollo.dequeue.latency", float64(t2.Sub(t1).Milliseconds()), []string{}, rate)
if account.ID == 0 {
tx.Commit()
time.Sleep(10 * time.Millisecond)
continue
}
if account.LastCheckedAt > 0 {
latency := now - account.LastCheckedAt - float64(backoff)
statsd.Histogram("apollo.queue.delay", latency, []string{}, rate)
}
_, err = tx.Exec(`UPDATE accounts SET last_checked_at = $1 WHERE id = $2`, now, account.ID)
rac := rc.NewAuthenticatedClient(account.RefreshToken, account.AccessToken)
if account.ExpiresAt < int64(now) {
tokens, _ := rac.RefreshTokens()
tx.Exec(`UPDATE accounts SET access_token = $1, refresh_token = $2, expires_at = $3 WHERE id = $4`,
tokens.AccessToken, tokens.RefreshToken, int64(now+3500), account.ID)
}
t1 = time.Now()
msgs, err := rac.MessageInbox(account.LastMessageID)
t2 = time.Now()
statsd.Histogram("reddit.api.latency", float64(t2.Sub(t1).Milliseconds()), []string{}, rate)
if err != nil {
log.Fatal(err)
}
if len(msgs.MessageListing.Messages) == 0 {
tx.Commit()
continue
}
// Set latest message we alerted on
latestMsg := msgs.MessageListing.Messages[0]
latency := now - latestMsg.CreatedAt
statsd.Histogram("apollo.notification.latency", latency, []string{}, rate)
_, err = tx.Exec(`UPDATE accounts SET last_message_id = $1 WHERE id = $2`, latestMsg.FullName(), account.ID)
if err != nil {
log.Fatal(err)
}
// If no latest message recorded, we're not going to notify on every message. Remember that and move on.
if account.LastMessageID == "" {
tx.Commit()
continue
}
query = `
SELECT apns_token, sandbox FROM devices
LEFT JOIN devices_accounts ON devices.id = devices_accounts.device_id
WHERE devices_accounts.account_id = $1`
rows, err := tx.Query(query, account.ID)
if err != nil {
logger.Fatal(err)
}
defer rows.Close()
devices := []data.Device{}
for rows.Next() {
device := data.Device{}
rows.Scan(&device.APNSToken, &device.Sandbox)
devices = append(devices, device)
}
for _, msg := range msgs.MessageListing.Messages {
for _, device := range devices {
notification := &apns2.Notification{}
notification.DeviceToken = device.APNSToken
notification.Topic = "com.christianselig.Apollo"
notification.Payload = payload.NewPayload().AlertTitle(msg.Subject).AlertBody(msg.Body)
client := productionClient
if device.Sandbox {
client = sandboxClient
}
t1 := time.Now()
res, err := client.Push(notification)
t2 := time.Now()
statsd.Histogram("apns.notification.latency", float64(t2.Sub(t1).Milliseconds()), []string{}, float64(1))
if err != nil {
statsd.Incr("apns.notification.errors", []string{}, float64(1))
logger.Printf("apns error account=%s token=%s err=%s status=%d reason=%q", account.Username, device.APNSToken, err, res.StatusCode, res.Reason)
} else {
statsd.Incr("apns.notification.sent", []string{}, float64(1))
logger.Printf("apns success account=%s token=%s", account.Username, device.APNSToken)
}
}
}
tx.Commit()
}
}
}
func main() {
logger := log.New(os.Stdout, "", log.Ldate|log.Ltime)
if err := godotenv.Load(); err != nil {
logger.Printf("Couldn't find .env so I will read from existing ENV.")
}
dburl, ok := os.LookupEnv("DATABASE_CONNECTION_POOL_URL")
if !ok {
dburl = os.Getenv("DATABASE_URL")
}
db, err := sql.Open("postgres", fmt.Sprintf("%s?binary_parameters=yes", dburl))
if err != nil {
log.Fatal(err)
}
defer db.Close()
logger.Printf("Starting with %d workers.", workers)
db.SetMaxOpenConns(workers * 2)
db.SetMaxIdleConns(workers)
db.SetConnMaxLifetime(time.Hour)
statsd, err := statsd.New("127.0.0.1:8125")
if err != nil {
log.Fatal(err)
}
rc := reddit.NewClient(
os.Getenv("REDDIT_CLIENT_ID"),
os.Getenv("REDDIT_CLIENT_SECRET"),
statsd,
)
// This is a very conservative value -- seen as most of the work that is done in these jobs is
// waiting around for IO.
runtime.GOMAXPROCS(workers + 2) // + 2 for main thread and GC.
quitCh := make(chan bool, workers)
for i := 0; i < workers; i++ {
go accountWorker(i, rc, db, logger, statsd, quitCh)
}
sigs := make(chan os.Signal, 1)
signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
<-sigs
for i := 0; i < workers; i++ {
quitCh <- true
}
os.Exit(0)
}