Telegram stops sending webhook updates

Question

I have my Telegram bot deployed to GCP cloud run. It works fine even when instances get scaled to 0 - when Telegram calls, the instance starts and the bot receives the updates.

But sometimes, in unknown circumstances:

• I send a message to the bot
• No requests I have in GCP
• The instances don't scale

What's interesting is that if I call the getWebhookInfo method:

{
  "ok": true,
  "result": {
    "url": "https://my-host/telegram/webhook",
    "has_custom_certificate": false,
    "pending_update_count": 0,
    "max_connections": 40,
    "ip_address": "35.000.00.000",
    "allowed_updates": [
      "message"
    ]
  }
}

Then Telegram does send updates right after my call, kinda when I remind about myself. Imagine the case:

• No pending updates
• Write a message to the bot
• No requests, no logs, no events in GCP
• Wait a long period of N hours
• call getWebhookInfo
• it returns pending update 1 and calls me

Update:

• the app when it starts upon request calls setWebhookMethod and in most cases, it returns Webhook is already set but sometimes it returns Webhook was set which means

• Telegram forgets about my webhook in unknown circumstances. Though my bot doesn't call the deleteWebhook endpoint

---

What can be wrong?

I don't have any firewall rule other than default.

The certificate is okay as it's managed by Google.

I tried with a static IP (load balancer) and w/o - same case.

I thought it's about "allowed_updates": [ "message" ] but no - it's set now always and no updates.

---

Answer 1

I couldn't figure out the exact reason. I tried using static IP too but it didn't help either.

The closet assumption is that my bot, given the framework I use - kotlin-telegram, sets the webhook during the actual webhook request from Telegram (it does it during the application startup and I have it serverless, it starts e).

I did the following workaround:

• I stopped setting the webhook during the application startup
• I started setting the webhook outside in a scheduled job (GCP Scheduling + GCP cloud functions)