starred/uptime-kuma

Fork 0

mirror of https://github.com/louislam/uptime-kuma.git synced 2026-03-02 22:57:00 -05:00

[Bug] Cannot read properties of null (reading '_dockerType') #2665

New issue

Closed

opened 2026-02-28 03:02:48 -05:00 by deekerman · 3 comments

deekerman commented

2026-02-28 03:02:48 -05:00

Owner

Originally created by @jamess60 on GitHub (Oct 9, 2023).

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

I checked and didn't find similar issue

🛡️ Security Policy

I agree to have read this project Security Policy

Description

When creating a monitor with type docker container (polls the docker.sock file) and entering the container name, the monitor turns from green to yellow and this notification is sent via telegram:

Cannot read properties of null (reading '_dockerType')

This is in the uptimekuma container log
2023-10-09T15:21:57+02:00 [MONITOR] WARN: Monitor #30 'Overseer (Plex requests)': Failing: Cannot read properties of null (reading '_dockerType') | Interval: 60 seconds | Type: docker | Down Count: 0 | Resend Interval: 0

The only reference I can find is in #2141 but this was linked to a deprecated feature and marked wontfix.

👟 Reproduction steps

Start an uptimekuma:latest container with the docker.sock volume mapped
create a monitor for a container on that host using container name instead of ID

👀 Expected behavior

Monitor should be green as the service is up

😓 Actual Behavior

Service is yellow and error is sent to log

🐻 Uptime-Kuma Version

1.21.3

💻 Operating System and Arch

Debian 12 x64

🌐 Browser

Firefox NA

🐋 Docker Version

Docker 24.0.5

🟩 NodeJS Version

No response

📝 Relevant log output

No response

Originally created by @jamess60 on GitHub (Oct 9, 2023). ### ⚠️ Please verify that this bug has NOT been raised before. - [X] I checked and didn't find similar issue ### 🛡️ Security Policy - [X] I agree to have read this project [Security Policy](https://github.com/louislam/uptime-kuma/security/policy) ### Description When creating a monitor with type docker container (polls the docker.sock file) and entering the container name, the monitor turns from green to yellow and this notification is sent via telegram: Cannot read properties of null (reading '_dockerType') This is in the uptimekuma container log 2023-10-09T15:21:57+02:00 [MONITOR] WARN: Monitor #30 'Overseer (Plex requests)': Failing: Cannot read properties of null (reading '_dockerType') | Interval: 60 seconds | Type: docker | Down Count: 0 | Resend Interval: 0 The only reference I can find is in #2141 but this was linked to a deprecated feature and marked wontfix. ### 👟 Reproduction steps 1) Start an uptimekuma:latest container with the docker.sock volume mapped 2) create a monitor for a container on that host using container name instead of ID ### 👀 Expected behavior Monitor should be green as the service is up ### 😓 Actual Behavior Service is yellow and error is sent to log ### 🐻 Uptime-Kuma Version 1.21.3 ### 💻 Operating System and Arch Debian 12 x64 ### 🌐 Browser Firefox NA ### 🐋 Docker Version Docker 24.0.5 ### 🟩 NodeJS Version _No response_ ### 📝 Relevant log output _No response_

deekerman

2026-02-28 03:02:48 -05:00

closed this issue
added the
bug
label

deekerman commented

2026-02-28 03:02:52 -05:00

Author

Owner

@chakflying commented on GitHub (Oct 9, 2023):

For the "Docker Host" option in the monitor settings, can you try to select the host again and test that it is working?

Test available when you click on "Edit" under the "Docker Host" option:

@chakflying commented on GitHub (Oct 9, 2023): For the "Docker Host" option in the monitor settings, can you try to select the host again and test that it is working? ![image](https://github.com/louislam/uptime-kuma/assets/3271800/cbf62624-ebcb-46f6-977f-05cdcafd0d4c) Test available when you click on "Edit" under the "Docker Host" option: ![image](https://github.com/louislam/uptime-kuma/assets/3271800/99773994-237e-42bc-9def-dc4c9d4ae5fe)

deekerman commented

2026-02-28 03:02:53 -05:00

Author

Owner

@jamess60 commented on GitHub (Oct 9, 2023):

Testing the host works but the issue persists

@jamess60 commented on GitHub (Oct 9, 2023): Testing the host works but the issue persists

deekerman commented

2026-02-28 03:02:53 -05:00

Author

Owner

@chakflying commented on GitHub (Oct 9, 2023):

You can try to delete and recreate the monitor, which should fix the issue.

The bug here seems to be that the "Docker Host" option is not marked as required, and the data is somehow missing in the monitor config after changes.

@chakflying commented on GitHub (Oct 9, 2023): You can try to delete and recreate the monitor, which should fix the issue. The bug here seems to be that the "Docker Host" option is not marked as required, and the data is somehow missing in the monitor config after changes.