Checking uptime-kuma itself in a docker container and receiving connect ECONNREFUSED

[instantdreams]

⚠️ Please verify that this question has NOT been raised before.

• I checked and didn't find similar issue

🛡️ Security Policy

• I agree to have read this project Security Policy

📝 Describe your problem

I have two monitors for uptime-kuma:

1. Direct
   Friendly Name: services.uptime-kuma
   URL: http://192.168.1.93:3001

2. Reverse Proxy
   Friendly Name: com.example.uptime-kuma
   URL: https://uptime-kuma.example.com

The direct monitor succeeds. The Reverse Proxy monitor fails with error connect ECONNREFUSED 192.168.93.123:443.

For all my servers I create external docker networks and assign each container an ip address within the compose file. I do this for GitOps purposes. For the uptime-kuma container I specifically expose port 3001 on the host ip address of 192.168.1.93. I also define the docker dns settings to my two piholes for the uptime-kuma service.

Here's my compose file configuration:

$ docker compose config
name: uptime-kuma
services:
  uptime-kuma:
    container_name: uptime-kuma
    dns:
      - 192.168.1.91
      - 192.168.1.92
    domainname: example.com
    environment:
      DIRECTORY_APPDATA: /srv/uptime-kuma/data
      PGID: "1000"
      PUID: "1000"
      TZ: America/Edmonton
      UPTIME_KUMA_HIDE_LOG: debug_monitor,info_monitor,debug_cert,info_cert,debug_auth,info_auth,debug_server,info_server,debug_db,info_db,debug_notification,info_notification,debug_socket,info_socket,debug_maintenance,info_maintenance,debug_services,info_services,debug_ratelimit,info_ratelimit
    hostname: uptime-kuma
    image: louislam/uptime-kuma:latest
    networks:
      example-net:
        ipv4_address: 192.168.93.123
    ports:
      - mode: ingress
        host_ip: 192.168.1.93
        target: 3001
        published: "3001"
        protocol: tcp
    restart: unless-stopped
    volumes:
      - type: bind
        source: /srv/uptime-kuma/data
        target: /app/data
        bind:
          create_host_path: true
      - type: bind
        source: /etc/localtime
        target: /etc/localtime
        read_only: true
        bind:
          create_host_path: true
networks:
  example-net:
    name: services
    external: true

How do I configure docker - or the monitor - to use my network DNS rather than the container DNS? I don't think this should require a local proxy.

📝 Error Message(s) or Log

I've reviewed the Troubleshooting guide and searched the issues for any leads.

Here is an example of curl from inside and outside the container:

$ curl https://uptime-kuma.example.com
Found. Redirecting to /dashboard

$ docker exec -it uptime-kuma bash
root@uptime-kuma:/app# curl https://uptime-kuma.example.com --verbose
*   Trying 192.168.93.123...
* TCP_NODELAY set
* connect to 192.168.93.123 port 443 failed: Connection refused
* Failed to connect to uptime-kuma.example.com port 443: Connection refused
* Closing connection 0
curl: (7) Failed to connect to uptime-kuma.example.com port 443: Connection refused

Here's the resolv.conf settings:

$ cat /etc/resolv.conf
nameserver 192.168.1.1

$ docker exec uptime-kuma cat /etc/resolv.conf
# Generated by Docker Engine.
# This file can be edited; Docker Engine will not make further changes once it
# has been modified.

nameserver 127.0.0.11
options ndots:0

# Based on host file: '/etc/resolv.conf' (internal resolver)
# ExtServers: [192.168.1.91 192.168.1.92]
# Overrides: [nameservers]
# Option ndots from: internal

Here's what dig reports:

$ dig

; <<>> DiG 9.18.28-1~deb12u2-Debian <<>>
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11292
;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 1

;; Query time: 20 msec
;; SERVER: 192.168.1.1#53(192.168.1.1) (UDP)
;; WHEN: Wed Feb 05 15:32:11 MST 2025
;; MSG SIZE  rcvd: 239

$ docker exec -it uptime-kuma bash
root@uptime-kuma:/app# apt update && apt --yes install dnsutils
root@uptime-kuma:/app# dig

; <<>> DiG 9.11.5-P4-5.1+deb10u11-Debian <<>>
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56396
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 1

;; Query time: 28 msec
;; SERVER: 127.0.0.11#53(127.0.0.11)
;; WHEN: Wed Feb 05 15:34:58 MST 2025
;; MSG SIZE  rcvd: 239

Same again but with traceroute:

$ traceroute pihole-1.example.com
traceroute to pihole-1.example.com (192.168.1.91), 30 hops max, 60 byte packets
 1  id-edge1.example.com (192.168.1.91)  0.246 ms  0.320 ms  0.327 ms

$ traceroute uptime-kuma.example.com
traceroute to uptime-kuma.example.com (192.168.1.91), 30 hops max, 60 byte packets
 1  id-edge1.example.com (192.168.1.91)  0.228 ms  0.295 ms  0.282 ms

$ docker exec -it uptime-kuma bash
root@uptime-kuma:/app# apt update && apt --yes install traceroute

root@uptime-kuma:/app# traceroute pihole-1.example.com
traceroute to pihole-1.example.com (192.168.1.91), 30 hops max, 60 byte packets
 1  192.168.93.1 (192.168.93.1)  0.037 ms  0.018 ms  0.016 ms
 2  id-edge1.example.com (192.168.1.91)  0.273 ms  0.298 ms  0.266 ms

root@uptime-kuma:/app# traceroute uptime-kuma.example.com
traceroute to uptime-kuma.example.com (192.168.93.123), 30 hops max, 60 byte packets
 1  uptime-kuma.example.com (192.168.93.123)  0.039 ms  0.018 ms  0.015 ms

🐻 Uptime-Kuma Version

1.23.16

💻 Operating System and Arch

Debian 6.1.112-1 (2024-09-30) x86_64 GNU/Linux

🌐 Browser

Firefox 135.0

🖥️ Deployment Environment

• Runtime: Docker 27.3.1 Docker Compose 2.29.7
• Database: sqlite/embedded
• Filesystem used to store the database on: ext4 SSD
• number of monitors: 104

[instantdreams]

I just found #2991 which suggests using { "HOST": "pihole-1.example.com" }, I have changed the monitor and will see.

ETA: Nope, that didn't work.