Cloudflare Developers•4mo ago

Not working... :/ It looks like the build args not passed to the Docker build...

Ankan Saha•9/16/25, 2:11 PM

I found a issue in the container project

Uudidu Not working... :/ It looks like the build args not passed to the Docker build...

kian•9/16/25, 2:51 PM

What version of Wrangler are you using?

Kkian What version of Wrangler are you using?

udiduOP•9/16/25, 2:51 PM

4.33.1

kian•9/16/25, 2:52 PM

"image_vars": {
  "FOO": "BAR"
}

"image_vars": {
  "FOO": "BAR"
}

ARG FOO
RUN echo $FOO

ARG FOO
RUN echo $FOO

=> [build 3/8] RUN echo BAR

=> [build 3/8] RUN echo BAR

kian•9/16/25, 2:53 PM

It seems to work fine for me

udiduOP•9/16/25, 2:56 PM

Wow, it was my mistake, I had the "containers" set twice on my wrangler.jsonc (one for production env) and I forgot to set the image_vars on the production containers...
Anyway now it works, sorry

Is there any way I can pass the image_vars from env? since I don't want to push to my repo the secrets for the build command

kian•9/16/25, 3:37 PM

Not currently but I think secret mounts (https://docs.docker.com/build/building/secrets/#secret-mounts) would be the best method here - we don't currently expose a way to use those either.

kian•9/16/25, 3:37 PM

I'll take it back to the team & see what we can do.

Kkian Not currently but I think secret mounts (<https://docs.docker.com/build/building...

udiduOP•9/16/25, 4:55 PM

I've ended up changing the wrangler.jsonc file inside my github action where I replace the env params placeholders inside the image_vars with secrets from Github :/
I'm not proud of it, but it works

Steps•9/16/25, 5:02 PM

I'm puzzled why nobody fixes the broken getting started docs. :/

kian•9/16/25, 5:34 PM

There’s a docs rework already in flight that fixes up & reorganises the whole /containers/ area

Steps•9/16/25, 7:37 PM

Ah, that’s good to know.

Steps•9/16/25, 7:37 PM

I really want to give containers a shot, but can’t find a working simple sample

julian7797•9/16/25, 8:28 PM

When running locally, I'm not seeing any of my container logs, is there a way to view them?

julian7797•9/16/25, 8:29 PM

Also, my container isn't able to access local databases I'm running, is there a way to enable this with wrangler?

SSteps I really want to give containers a shot, but can’t find a working simple sample

kian•9/16/25, 8:47 PM

https://github.com/cloudflare/templates/tree/main/containers-template is probably the most simple example right now

Steps•9/16/25, 9:01 PM

Yeah, I saw that, but TypeScript and JSONC are more complex than JavaScript and wrangler.TOML

There is a sample in the docs, but it's outdated and non-functional.

Steps•9/16/25, 9:02 PM

JSONC is barely human readable. TOML is way cleaner and easier to grasp.

TypeScript requires tsconfig.json and other stuff.
I'd like a minimal JavaScript standalone file that does the forwarding to the container.

Steps•9/16/25, 9:04 PM

I understand the TS move, but why would you migrate to jsonc?

James•9/16/25, 9:21 PM

fwiw I entirely agree with you and think cf pushing json(c) as config by default was a mistake. I was outspoken against this from the start, but they're all in on it now sadly, despite it being imo measurably worse than toml in so many ways.

James•9/16/25, 9:23 PM

other than that though, I would definitely grab that template from the repo kian linked. It's a good starter, and you can always convert the jsonc to toml (even though I agree you shouldn't have to). I still use toml in all of my projects

(and cloudflare does for lots too: https://github.com/cloudflare/cloudflare-docs/blob/production/wrangler.toml)

julian7797•9/16/25, 9:30 PM

Need a way to access local host ports when running in dev

Jjulian7797 Need a way to access local host ports when running in dev

kian•9/16/25, 9:32 PM

Use

host.docker.internal

host.docker.internal

localhost

localhost

to a container is just itself rather than your host machine.

julian7797•9/16/25, 9:32 PM

thx

julian7797•9/16/25, 9:32 PM

Skill issue on my part

julian7797•9/16/25, 9:32 PM

appreciate the assist

kian•9/16/25, 9:32 PM

I think there is some Docker network modes where you can use

localhost

localhost

but for the default

host.docker.internal

host.docker.internal

is the way

julian7797•9/16/25, 9:34 PM

Cool, also would love to see Hyperdrive support inside the containers

julian7797•9/16/25, 9:34 PM

I think it might already be in a feature request

kian•9/16/25, 9:39 PM

It's on our radar but no ETA - you can follow this GitHub issue for updates: https://github.com/cloudflare/workers-sdk/issues/10320

GitHub

feature: connect to hyperdrive from inside a container · Issue #10...

What versions & operating system are you using? System: OS: macOS 15.5 CPU: (8) arm64 Apple M3 Memory: 120.78 MB / 16.00 GB Shell: 5.9 - /bin/zsh Binaries: Node: 24.2.0 - /opt/homebrew/bin/node...

julian7797•9/16/25, 11:53 PM

Probably missing a config option or something but i have zero logs showing up for my container, and its definitely getting hit bc i see memory, cpu, etc increasing for requests

Jjulian7797 Probably missing a config option or something but i have zero logs showing up fo...

julian7797•9/17/25, 12:00 AM

deleted and recreated, logs showing up now

TangoBee•9/17/25, 12:13 PM

Hi,
I'm using containers locally with npx wrangler dev, but I don't see any logs that I have added in my container code in the terminal.

China•9/17/25, 6:08 PM

Hi everyone,

I'm using Wrangler to deploy a project that's currently configured with a container. The issue is that even when there are no code changes in the container, every time I run wrangler deploy, it rebuilds the container image and pushes it, which takes a lot of time and resources.

Does anyone know if it's possible to use wrangler deploy to update the worker without rebuilding and pushing the container every time?

julian7797•9/17/25, 8:26 PM

Are custom container instance types still up to date in docs? Tried setting according to here: https://developers.cloudflare.com/workers/wrangler/configuration/#custom-instance-types but getting a validate input error while deploying (have an enterprise account)

Cloudflare Docs

Configuration

Use a configuration file to customize the development and deployment setup for your Worker project and other Developer Platform products.

bro14•9/18/25, 1:08 PM

hello does anyone knows how to fix this X [ERROR] You don't have 'containers:write' in your list of scopes i've already added permission on my API TOKEN to edit containers(i don't think there's write option)

updating to latest wrangler works

blyedev•9/19/25, 2:39 AM

Hi everyone quick question. Would it be possible to use hyperdrive with containers?

zerozerozeroone•9/19/25, 3:37 AM

Do or can containers run in a single location?
If containers are idle are they stopped?
Are idle containers that still run but aren’t serving anything still consuming cpu resources?

Bblyedev Hi everyone quick question. Would it be possible to use hyperdrive with containe...

Chaika•9/19/25, 3:44 AM

it's on the roadmap but not yet containers-beta

blyedev•9/19/25, 3:45 AM

It really is great to see that everything I ever need consistently is one the roadmap haha

Chaika•9/19/25, 3:45 AM

soon^tm

Zzerozerozeroone Do or can containers run in a single location? If containers are idle are they s...

Chaika•9/19/25, 3:50 AM

The docs answer those well:
https://developers.cloudflare.com/containers/pricing/
https://developers.cloudflare.com/containers/faq/

Location selection in the faq, if you're just asking about placement
idle is handled by the containers library, the sleepAfter setting which defaults to 10m without any activity/requests

You only pay for what you use — charges start when a request is sent to the container or when it is manually started. Charges stop after the container instance goes to sleep, which can happen automatically after a timeout. This makes it easy to scale to zero, and allows you to get high utilization even with bursty traffic.

TangoBee•9/19/25, 5:56 AM

Hi,
Can we run apache kafka in cloudflare containers?

TangoBee•9/19/25, 5:59 AM

So, I'll be having 3 services. One service will push data to Kafka, and another service will consume that data from Kafka. Is it possible to deploy all three services in one Cloudflare container?

bro14•9/19/25, 8:59 AM

Hello anyone who have tried pulling image from external registry like gcp artifac registry is this possible in cf container?
wrangler.toml
[[containers]]
class_name = "sample"
image = "europe-west-docker.pkg.dev/...."

Bbro14 Hello anyone who have tried pulling image from external registry like gcp artifa...

mcanaleta•9/19/25, 1:19 PM

By the documentation "Currently, all images must use registry.cloudflare.com, which is the default registry for Wrangler." (https://developers.cloudflare.com/containers/image-management/#using-existing-images) so you have to pull & push to cloudflare registry

Cloudflare Docs

Image Management

When running wrangler deploy, if you set the image attribute in you Wrangler configuration
file to a path, wrangler will build your container image locally using Docker, then push it to a registry run by Cloudflare.
This registry is integrated with your Cloudflare account and is backed by R2. All authentication is handled automatically by
Cloudf...

Mmcanaleta By the documentation "Currently, all images must use registry.cloudflare.com, wh...

bro14•9/19/25, 1:21 PM

ahh i see, thank you for responding

kian•9/19/25, 1:24 PM

Yeah - currently pull it locally and push it up to our registry.

kian•9/19/25, 1:24 PM

External registry support is being worked on as mentioned in the docs aside - basically pullthrough so we do the pull + push for you.

Kkian <https://github.com/cloudflare/templates/tree/main/containers-template> is proba...

Steps•9/19/25, 6:22 PM

That is the "most simple"? It's pretty complex.

To be honest, it looks more like a testbed than a minimalistic "get you started" template.

Not working... :/ It looks like the build args not passed to the Docker build...

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