MIME type ('text/html') is not executable, and strict MIME type checking is enabled


I have deployed the temporal-web in Kubernetes with more than 2 pods getting this issue with Load Balanced URL. for 2 pods no issues.

Refused to execute script from ‘https://dashboard-asyncworkflow-poc.apps.mt-d2.carl.gkp.net/temporal.bac1f33393b0b0ea4ff3.js’ because its MIME type (‘text/html’) is not executable, and strict MIME type checking is enabled.

Please let me know what is causing the issue?

what do you see as a response to fetching the .js file in your browser’s network tab?

it should be a js file, like the below. Though seems you are getting some error and the response might have some details

HI @Ruslan,

As highlighted resources I am getting the below response in Network tab with different temporal.[hash-code].js in the body section.
It doesn’t show up the script as you mentioned in the screenshot.

Temporal Web v1.13.0

for pod size <= 2

I am getting the below errors on console.

This is a bit tricky to answer as this seems to be an issue with the Load balancer setup. For some reason it redirects all requests to the host base URL and removes the rest of the path

I’ve asked few people who might have an idea about such load balancer issues, though for efficiency the resources on LB configurations and such issues may have more data

@Ruslan - did you find any solution on this?

as this seems to relate to the Load Balancer configuration and not the UI directly, it’s hard to tell what’s wrong with the configuration. What particular load balancer do you use?

@Ruslan, Currently I am not using Load Balancer, Its one of the cluster in Kubernetes.

what does the response Headers tab show here?

Any indication which server responded?

could you clarify about the LB, in the original question you’ve mentioned that URLs were load balanced. However later also said that now you don’t use LB?

Asked few people from our infra team, do you use a reverse proxy when hosting several (3+) instances of Web UI?
assuming aws: elastic load balancer → nginx → 3 web instances ?

do you also use the official Web UI Docker image or you build on your own?

Hey @Ruslan - I’m not aware of the original poster’s situation, but we saw the same issue with our temporal/web setup. We’re running the docker image, version 1.15. We run in Kubernetes, with istio service mesh. Running a single pod of web works well, but if we deploy more than one we saw the same issues.

Is there a chance you could also run the UI v2 beta in a similar setup?

Configuration options for UI v2 can be passed as docker env variables, ui-server/docker at main · temporalio/ui-server · GitHub

Full list of variables is available here ui-server/config_template.yaml at main · temporalio/ui-server · GitHub

Would like to be sure and understand where the issue is coming from, the Web UI or the setup