So R2 bandwidth to/from containers is still billed right? - Cloudflare Developers

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dave

Ddave So R2 bandwidth to/from containers is still billed right?

Hard@Work

H

Hard@Work•7/16/25, 5:41 PM

Correct

Elliot Hesp

E

Elliot Hesp•7/16/25, 6:47 PM

Ok I'm 90% sure that reading a ReadableStream from container inside of the DO just doesn't work consistently

Elliot Hesp

E

Elliot Hesp•7/16/25, 7:17 PM

Going to setup a reproduction, but I'm sure something is messed up

rye

R

rye•7/16/25, 7:18 PM

Is there an ideal workflow to get containers working on "Workers for platforms"?

skifimba

S

skifimba•7/16/25, 10:01 PM

Guys is this only me? Container is unable to start

CleanShot_2025-07-17_at_00.01.032x.png

skifimba

Sskifimba Guys is this only me? Container is unable to start

John Spurlock

J

John Spurlock•7/16/25, 10:04 PM

might be https://www.cloudflarestatus.com/incidents/dg4khdw4n3nx

Container applications are unable to start

skifimba

S

skifimba•7/16/25, 10:05 PM

Ah i see thanks @John Spurlock didn't notice that on status page

Elliot Hesp

E

Elliot Hesp•7/17/25, 9:22 AM

Just filed an issue - readable streams out of a container are super inconsistent for me https://github.com/cloudflare/containers/issues/53

GitHub

Unable to proxy ReadableStream to client · Issue #53 · cloudflare...

Hey all, I'm experiencing an issue streaming results from a container to a client. I have a reproduction of the following issue with instructions: https://github.com/Ehesp/cf-containers-repro M...

karimulm

K

karimulm•7/17/25, 7:29 PM

Is hyperdrive accessible from cloudflare container?

karimulm

Kkarimulm Is hyperdrive accessible from cloudflare container?

John Spurlock

J

John Spurlock•7/17/25, 7:39 PM

can we connect to the hyperdrive using

Carl Peaslee

C

Carl Peaslee•7/17/25, 9:32 PM

Hey does anyone have an example that works locally? I cannot get to "container images ready"

つんでれd

つ

つんでれd•7/17/25, 10:25 PM

I ran into the same issue on localhost and was able to resolve it by explicitly setting the port using switchPortswitchPort, rather than downgrading or using containerFetch()containerFetch(). However, it does seem like a design inconsistency that the port must always be specified in local environments but not in production.

I see that these changes were introduced because Durable Objects currently don’t support WebSockets from non-default JSRPC methods. I was thinking it might be cleaner to handle this by overriding the fetch()fetch() method using a helper from @cloudflare/containers@cloudflare/containers, like this:

import { extractPort } from '@cloudflare/containers';

override async fetch(request: Request): Promise<Response> {
  return this.containerFetch(request, extractPort(request));
}

import { extractPort } from '@cloudflare/containers';

override async fetch(request: Request): Promise<Response> {
  return this.containerFetch(request, extractPort(request));
}

FrozenFire

F

FrozenFire•7/18/25, 12:57 AM

Do containers run as close to the edge as workers? I'm trying to figure out if I'm actually getting as close to minimal latency as possible with containers, which use an intermediate DO.

FrozenFire

F

FrozenFire•7/18/25, 12:58 AM

I managed to get my latency-bound workload running in a container, and its performance is about the same as we get in AWS Fargate. Still better than Fargate since we could conceivably get better geoavailability with less lift.

But, I'm considering now whether doing the work to compile to a WASM target might be worth the few ms of latency we shave off.

FrozenFire

FFrozenFire Do containers run as close to the edge as workers? I'm trying to figure out if I...

Elliot Hesp

E

Elliot Hesp•7/18/25, 8:58 AM

I don't think so - workers are edge, DOs themselves are not (still global, but not as "edge" as workers), and I'm not sure containers run in the same location as the DO (at the moment) either

Elliot Hesp

E

Elliot Hesp•7/18/25, 8:58 AM

Thats my take from the docs

flof.fly

F

flof.fly•7/18/25, 9:57 AM

Once in a while, I cannot deploy container changes with Wrangler because: Authentication error [code: 10000]

✘ [ERROR] A request to the Cloudflare API

Am i the only one experiencing this?

I try to deploy again, and it works, is non-deterministic

FrozenFire

FFrozenFire I managed to get my latency-bound workload running in a container, and its perfo...

つんでれd

つ

つんでれd•7/18/25, 10:21 AM

Durable Objects is only deployed to some data centers and may not be the same from Workers. You can see them at https://where.durableobjects.live/

I'm not sure about if Containers or WebAssembly is fast, but if your application is lightweight as enough to not exceed the bundle size limit, it can be worth trying for compiling into WebAssembly.

Tracking where Durable Objects are created, wherever you are in the world.

StoicGameDev#290

SStoicGameDev#290 Is it possible to run a node.js runtime (backend with logic) on Cloudflare?

Hard@Work

H

Hard@Work•7/18/25, 5:03 PM

With containers, yeah. For some Node applications, you can get them to run on Workers

yeahmatt

Y

yeahmatt•7/19/25, 2:08 AM

How do containers know when they are idle and start the sleepAfter countdown? The docs mention that sleepAfter stops the instance if requests not sent for X minutes, does a request include the full request-response cycle? For example, if sleepAfter="5m", and one request is made that takes up to 15m to respond (triggers a long-running task in the container), will the container go to sleep before it returns the response?

yeahmatt

Yyeahmatt How do containers know when they are idle and start the sleepAfter countdown? Th...

Chaika

C

Chaika•7/19/25, 2:29 AM

this is part of the open source container lib
https://github.com/cloudflare/containers/blob/185903e33472aa93a6e11aff2cefb6c62c13d67b/src/lib/container.ts#L717
It's called on receiving a request, and a few spots on container startup, but not after the request.

X

xz•7/19/25, 10:41 PM

hm

FrozenFire

F

FrozenFire•7/21/25, 4:42 PM

Is WebTransport possible with containers, since persistent connections are?

peterp

P

peterp•7/21/25, 9:21 PM

During development has anyone been able to get EXPOSEEXPOSE working for multiple ports?

Aster

A

Aster•7/21/25, 11:18 PM

Hey hey, I am trying to run k3 in a container, with the following:

# syntax=docker/dockerfile:1
FROM rancher/k3s:latest

# Expose the required ports for K3s
EXPOSE 6443
EXPOSE 443
EXPOSE 80

# Set the default command to run K3s server
CMD ["server", "--disable", "traefik"]

# syntax=docker/dockerfile:1
FROM rancher/k3s:latest

# Expose the required ports for K3s
EXPOSE 6443
EXPOSE 443
EXPOSE 80

# Set the default command to run K3s server
CMD ["server", "--disable", "traefik"]

And this is my code:

export class MyContainer extends Container {
  defaultPort = 6443;
  requiredPorts = [6443, 443, 80];
  // ...
}

app.get("/readyz", async (c) => {
  const container = getContainer(c.env.MY_CONTAINER);
  return await container.fetch(c.req.raw);
});
// ...

export class MyContainer extends Container {
  defaultPort = 6443;
  requiredPorts = [6443, 443, 80];
  // ...
}

app.get("/readyz", async (c) => {
  const container = getContainer(c.env.MY_CONTAINER);
  return await container.fetch(c.req.raw);
});
// ...

I get the following:

⎔ Container image(s) ready
⎔ Starting local server...
✘ [ERROR] Error checking if container is ready: connect(): Connection refused: container port not found. Make sure you exposed the port in your container definition.
✘ [ERROR] Error checking if container is ready: internal error; reference = r48029i07cer86vit2h90t6i
✘ [ERROR] Error checking if container is ready: internal error; reference = df2ceaqdffenqqhpp6ka9igg
✘ [ERROR] Error checking if container is ready: internal error; reference = gist59tegar22c3tp1iaj7ac
✘ [ERROR] Error checking if container is ready: connect(): Connection refused: container port not found. Make sure you exposed the port in your container definition.
Container error: [Error: Container exited with unexpected exit code: 1] { exitCode: 1 }
▲ [WARNING] workerd/io/actor-sqlite.c++:647: warning: NOSENTRY SQLite alarm handler canceled with requestScheduledAlarm.; scheduledTime = 1753139731.815s; localAlarmState.orDefault(kj::UNIX_EPOCH) = 1753139733.074s; actorId = b60d370ee54d17e273624ceb809e666d47bc8cb445b274c648f7e06520b5a613
[wrangler:info] GET /readyz 500 Internal Server Error

⎔ Container image(s) ready
⎔ Starting local server...
✘ [ERROR] Error checking if container is ready: connect(): Connection refused: container port not found. Make sure you exposed the port in your container definition.
✘ [ERROR] Error checking if container is ready: internal error; reference = r48029i07cer86vit2h90t6i
✘ [ERROR] Error checking if container is ready: internal error; reference = df2ceaqdffenqqhpp6ka9igg
✘ [ERROR] Error checking if container is ready: internal error; reference = gist59tegar22c3tp1iaj7ac
✘ [ERROR] Error checking if container is ready: connect(): Connection refused: container port not found. Make sure you exposed the port in your container definition.
Container error: [Error: Container exited with unexpected exit code: 1] { exitCode: 1 }
▲ [WARNING] workerd/io/actor-sqlite.c++:647: warning: NOSENTRY SQLite alarm handler canceled with requestScheduledAlarm.; scheduledTime = 1753139731.815s; localAlarmState.orDefault(kj::UNIX_EPOCH) = 1753139733.074s; actorId = b60d370ee54d17e273624ceb809e666d47bc8cb445b274c648f7e06520b5a613
[wrangler:info] GET /readyz 500 Internal Server Error

Any idea what could be the issue?

Manuel Ogomigo

M

Manuel Ogomigo•7/22/25, 9:21 AM

Hi is it possible to connect wrangler binding like R2 into the cotainer?

I have a ffmpeg running with rust, and I want to connect my R2 to it, so I can just add it once it's done but doesn't seem to work.

Is there any way to make it work?

Manuel Ogomigo

MManuel Ogomigo Hi is it possible to connect wrangler binding like R2 into the cotainer? I have...

1984 Ford Laser

1

1984 Ford Laser•7/22/25, 9:43 AM

Maybe do a fetch to a Worker from within the container to retrieve the files from R2? Also apparently rclone can mount R2 via S3 API but haven't tried it myself

Manuel Ogomigo

M

Manuel Ogomigo•7/22/25, 9:52 AM

Okay somehow env doesn't work there the wrangler doesn't send the env in the container

Screenshot_2025-07-22_at_10.52.35.png

Manuel Ogomigo

M

Manuel Ogomigo•7/22/25, 10:04 AM

2 warnings found (use docker --debug to expand):

SecretsUsedInArgOrEnv: Do not use ARG or ENV instructions for sensitive data (ENV "R2_ACCESS_KEY_ID") (line 37)
SecretsUsedInArgOrEnv: Do not use ARG or ENV instructions for sensitive data (ENV "R2_ACCESS_SECRET_KEY") (line 38)

Getting this warning when using env in Dockerfile, if there's anyway to do this correctly, I'll really appreciate

Maurice

M

Maurice•7/22/25, 4:14 PM

Any idea on how to get hot reload working on a containerized deno app?

"You may prefer to set up your own code watchers and reloading mechanisms, or mount a local directory into the local container images to sync code changes. This can be done, but there is no built-in mechanism for doing so in Wrangler, and best-practices will depend on the languages and frameworks you are using in your container code."

https://developers.cloudflare.com/containers/local-dev/

Cloudflare Docs

Local Development

You can run both your container and your Worker locally, without additional configuration, by running npx wrangler dev in your project's directory.

Maurice

M

Maurice•7/22/25, 4:14 PM

In a multi-container setup

Usman

U

Usman•7/22/25, 4:32 PM

Folks, does hyperdrive work with containers? I passed this.env.HYPERDRIVE.connectionStringthis.env.HYPERDRIVE.connectionString from my worker to container. But my Python code inside the container is not able to reach the host. Works fine if I use my origin database connection string inside Python. Also worker can connect to db with hyperdrive connection string. Only container can't. Any ideas?

could not translate host name "3d9c675c6d0235ddd9a54021ff8d1c14.hyperdrive.local" to address: Name or service not known

could not translate host name "3d9c675c6d0235ddd9a54021ff8d1c14.hyperdrive.local" to address: Name or service not known

Usman

UUsman Folks, does hyperdrive work with containers? I passed `this.env.HYPERDRIVE.conne...

Usman

U

Usman•7/22/25, 4:36 PM

Okay, found this. So basically there's no reliable way to connect to a native or low latency database yet, not even D1.

can we connect to the hyperdrive using

Manuel Ogomigo

MManuel Ogomigo Hi is it possible to connect wrangler binding like R2 into the cotainer? I have...

Brett (Fiberplane)

B

Brett (Fiberplane)•7/22/25, 7:37 PM

i just built R2 support into our container last night. i have the access key id and secret key in the env of the worker, and i set the environment variables when i invoke the container itself.

this.container.start({
  // Need egress
  enableInternet: true,
  // Set env vars for R2 access in the container
  env: {
    R2_ENDPOINT_URL: `https://${this.env.CLOUDFLARE_ACCOUNT_ID}.r2.cloudflarestorage.com`,
    R2_ACCESS_KEY_ID: this.env.R2_ACCESS_KEY_ID,
    R2_SECRET_ACCESS_KEY: this.env.R2_SECRET_ACCESS_KEY,
    R2_BUCKET_NAME: this.env.BUNDLE_R2_BUCKET_NAME,
  },
});

this.container.start({
  // Need egress
  enableInternet: true,
  // Set env vars for R2 access in the container
  env: {
    R2_ENDPOINT_URL: `https://${this.env.CLOUDFLARE_ACCOUNT_ID}.r2.cloudflarestorage.com`,
    R2_ACCESS_KEY_ID: this.env.R2_ACCESS_KEY_ID,
    R2_SECRET_ACCESS_KEY: this.env.R2_SECRET_ACCESS_KEY,
    R2_BUCKET_NAME: this.env.BUNDLE_R2_BUCKET_NAME,
  },
});

no need to use ENV commands in the Dockerfile!

Brett (Fiberplane)

B

Brett (Fiberplane)•7/22/25, 7:40 PM

******

btw for the containers team: i have a small feature request for the dashboard!

if there is any way to provide metrics on when containers are killed for exceeding memory, that'd be awesome to surface in the dashboard. right now you have to cross-reference the P99 of memory usage with the instance sizee

Brett (Fiberplane)

BBrett (Fiberplane)i just built R2 support into our container last night. i have the access key id ...

Manuel Ogomigo

M

Manuel Ogomigo•7/22/25, 7:53 PM

Thank you for this, this worked, how do you send the reqeusts, you use it's api right?

Brett (Fiberplane)

B

Brett (Fiberplane)•7/22/25, 7:56 PM

yeah so i'm using a bun/hono api and just load in the aws s3 sdk to upload the file

also btw, where did you find the r2 access key id? i resorted to looking up the id of my api key in my browser inspector network tab from inside the dashboard

Manuel Ogomigo

M

Manuel Ogomigo•7/22/25, 8:00 PM

I got it from the API.

I'm using rust to run ffmpeg, I think that's the problem, it's not working proeprly. I'll check again.
Thank you for the tip!

Ricardo Gonçalves

R

Ricardo Gonçalves•7/22/25, 8:02 PM

Just for confirmation, is it possible to run docker-in-docker with Cloudflare Worker Containers? (I guess the answer is "no")

brainstorm

Bbrainstorm Do you have your code publicly available? I'd love to take a peek at how you str...

Brett (Fiberplane)

B

Brett (Fiberplane)•7/23/25, 10:34 PM

So the code is on a private repo but we just finally got around to refactoring to use the new Container class so we’re setting the env vars on the class itself per the docs — so it looks slightly different than what I posted (though that was working)

Brett (Fiberplane)

B

Brett (Fiberplane)•7/23/25, 10:34 PM

Pretty sure cf bindings in the container are an inevitability though

ralphjsmit

R

ralphjsmit•7/24/25, 11:01 AM

Hey guys, I am getting the following error all the time when making requests from local:

There is no Container instance available at this time.  This is likely because you have reached your max concurrent instance count (set in wrangler config) or are you currently provisioning the Container. If you are deploying your Container for the first time, check your dashboard to see provisioning status, this may take a few minutes.

There is no Container instance available at this time.  This is likely because you have reached your max concurrent instance count (set in wrangler config) or are you currently provisioning the Container. If you are deploying your Container for the first time, check your dashboard to see provisioning status, this may take a few minutes.

However, live usage appears pretty normal with just 4 live instances and all way below the concurrency limits.

CleanShot_2025-07-24_at_13.01.322x.png

⎔ Container image(s) ready
⎔ Starting local server...
✘ [ERROR] Error checking if container is ready: connect(): Connection refused: container port not found. Make sure you exposed the port in your container definition.
✘ [ERROR] Error checking if container is ready: internal error; reference = r48029i07cer86vit2h90t6i
✘ [ERROR] Error checking if container is ready: internal error; reference = df2ceaqdffenqqhpp6ka9igg
✘ [ERROR] Error checking if container is ready: internal error; reference = gist59tegar22c3tp1iaj7ac
✘ [ERROR] Error checking if container is ready: connect(): Connection refused: container port not found. Make sure you exposed the port in your container definition.
Container error: [Error: Container exited with unexpected exit code: 1] { exitCode: 1 }
▲ [WARNING] workerd/io/actor-sqlite.c++:647: warning: NOSENTRY SQLite alarm handler canceled with requestScheduledAlarm.; scheduledTime = 1753139731.815s; localAlarmState.orDefault(kj::UNIX_EPOCH) = 1753139733.074s; actorId = b60d370ee54d17e273624ceb809e666d47bc8cb445b274c648f7e06520b5a613
[wrangler:info] GET /readyz 500 Internal Server Error

⎔ Container image(s) ready
⎔ Starting local server...
✘ [ERROR] Error checking if container is ready: connect(): Connection refused: container port not found. Make sure you exposed the port in your container definition.
✘ [ERROR] Error checking if container is ready: internal error; reference = r48029i07cer86vit2h90t6i
✘ [ERROR] Error checking if container is ready: internal error; reference = df2ceaqdffenqqhpp6ka9igg
✘ [ERROR] Error checking if container is ready: internal error; reference = gist59tegar22c3tp1iaj7ac
✘ [ERROR] Error checking if container is ready: connect(): Connection refused: container port not found. Make sure you exposed the port in your container definition.
Container error: [Error: Container exited with unexpected exit code: 1] { exitCode: 1 }
▲ [WARNING] workerd/io/actor-sqlite.c++:647: warning: NOSENTRY SQLite alarm handler canceled with requestScheduledAlarm.; scheduledTime = 1753139731.815s; localAlarmState.orDefault(kj::UNIX_EPOCH) = 1753139733.074s; actorId = b60d370ee54d17e273624ceb809e666d47bc8cb445b274c648f7e06520b5a613
[wrangler:info] GET /readyz 500 Internal Server Error

There is no Container instance available at this time.  This is likely because you have reached your max concurrent instance count (set in wrangler config) or are you currently provisioning the Container. If you are deploying your Container for the first time, check your dashboard to see provisioning status, this may take a few minutes.

There is no Container instance available at this time.  This is likely because you have reached your max concurrent instance count (set in wrangler config) or are you currently provisioning the Container. If you are deploying your Container for the first time, check your dashboard to see provisioning status, this may take a few minutes.

export class MyContainer extends Container {
  defaultPort = 6443;
  requiredPorts = [6443, 443, 80];
  // ...
}

app.get("/readyz", async (c) => {
  const container = getContainer(c.env.MY_CONTAINER);
  return await container.fetch(c.req.raw);
});
// ...

export class MyContainer extends Container {
  defaultPort = 6443;
  requiredPorts = [6443, 443, 80];
  // ...
}

app.get("/readyz", async (c) => {
  const container = getContainer(c.env.MY_CONTAINER);
  return await container.fetch(c.req.raw);
});
// ...

this.container.start({
  // Need egress
  enableInternet: true,
  // Set env vars for R2 access in the container
  env: {
    R2_ENDPOINT_URL: `https://${this.env.CLOUDFLARE_ACCOUNT_ID}.r2.cloudflarestorage.com`,
    R2_ACCESS_KEY_ID: this.env.R2_ACCESS_KEY_ID,
    R2_SECRET_ACCESS_KEY: this.env.R2_SECRET_ACCESS_KEY,
    R2_BUCKET_NAME: this.env.BUNDLE_R2_BUCKET_NAME,
  },
});

this.container.start({
  // Need egress
  enableInternet: true,
  // Set env vars for R2 access in the container
  env: {
    R2_ENDPOINT_URL: `https://${this.env.CLOUDFLARE_ACCOUNT_ID}.r2.cloudflarestorage.com`,
    R2_ACCESS_KEY_ID: this.env.R2_ACCESS_KEY_ID,
    R2_SECRET_ACCESS_KEY: this.env.R2_SECRET_ACCESS_KEY,
    R2_BUCKET_NAME: this.env.BUNDLE_R2_BUCKET_NAME,
  },
});

# syntax=docker/dockerfile:1
FROM rancher/k3s:latest

# Expose the required ports for K3s
EXPOSE 6443
EXPOSE 443
EXPOSE 80

# Set the default command to run K3s server
CMD ["server", "--disable", "traefik"]

# syntax=docker/dockerfile:1
FROM rancher/k3s:latest

# Expose the required ports for K3s
EXPOSE 6443
EXPOSE 443
EXPOSE 80

# Set the default command to run K3s server
CMD ["server", "--disable", "traefik"]