CMD and EXPOSE and WORKDIR

[near steppe]

Hi everyone,

We are enjoying the dagger experience so far but i'm struggling with specifying a CMD and an EXPOSE.

I have something like: PythonSDK

container = container.with_workdir('/widgets')
container = container.with_exposed_port(80)
container = container.with_entrypoint(["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "80"])

And then it gets published to a private ECR with no problems.

When we inspect the image no CMD, no WORKDIR, no EXPOSE and NO ENTRYPOINT are added.

When we try to docker run it fails.

Are we missing something?
Thanks in advance

[split flint]

Hi! Normally there should be an entrypoint... If you want to set CMD, that's with container.with_default_args.

But your understanding of with_entrypoint is correct. Assuming you're pushing the result of that pipeline, the image should have an ENTRYPOINT

same with EXPOSE, but it's possible that it's not implemented yet

[near steppe]

Thanks @split flint ill give it a try with default args

with the EXPOSE and ENTRYPOINT, is there any workaround for that?

and with WORKDIR

this container = container.with_default_args(["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "80"]) worked

[near steppe]

even though im not being able to make it work, the with_default_args added the CMD properly, but it seems the WORKDIR instruction it is being ignored

CMD and EXPOSE and WORKDIR

[split flint]

To summarize my understanding:

• with_default_args correctly sets CMD in the image ✅
• withExec should use the content of CMD from an image, but doesn't ❌
• with_entrypoint should set ENTRYPOINT in the image, but doesn't ❌
• with_exposed_port should set EXPOSE in the image, but doesn't ❌
• with_workdir should set WORKDIR in the image, but doesn't ❌

Is that right?
(EDIT: add workdir)

[near steppe]

yes, and also i dont see the WORKDIR instruction, therefore the container can't start properly

[split flint]

I guess I should make this a table... One column for image push, one column for image pull

[near steppe]

so when docker run the CMD command runs from a different location

[split flint]

ah ok

Let me open an issue to track all this

[near steppe]

good, i can provide more details if needed

at this moment im blocked with this, im trying to make it run somehow, basically im replicating this Dockerfile

FROM python:3.10.10-alpine3.17
WORKDIR /bookingservice
COPY ./requirements.txt  /bookingservice/requirements.txt
RUN pip install --no-cache-dir --upgrade -r /bookingservice/requirements.txt
COPY app /bookingservice/app
CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "80"]

everything looks great up until i run it

[near steppe]

Hello there, any suggestions on how to work around this? I'm using version Python SDK 0.4.2

Maybe if I just start from a Dockerfile containing this instructions, then do the dagger magic and then publish

I wonder how people is using it

[maiden tendon]

👋 will try to help async, maybe others can step in too

do you have a full code snippet that reproduces this issue? I think everything but EXPOSE should work. (WithExposedPort doesn't actually set that value atm - an oversight.)

[novel cove]

@near steppe this should do the trick

package main

import (
    "context"
    "os"

    "dagger.io/dagger"
)

func main() {
    ctx := context.Background()

    // create Dagger client
    client, err := dagger.Connect(ctx, dagger.WithLogOutput(os.Stderr))
    if err != nil {
        panic(err)
    }
    defer client.Close()

    client.Container().
        Build(client.Directory().WithNewFile("Dockerfile", `
FROM alpine
EXPOSE 8080
ENTRYPOINT foo
    `)).
        Export(ctx, "./export.tar")
    // create Redis service container
    if err != nil {
        panic(err)
    }
}

@maiden tendon ref: https://github.com/dagger/dagger/issues/3886

basically as Solomon mentioned, seems like the only thing that can be currently set is CMD through DefaultArgs and LABELS. ENTRYPOINT and EXPOSE can't seem to be set otherwise.

[maiden tendon]

all of those things should be setting the OCI config though, just not EXPOSE (that's a trivial fix). entrypoint for example should work: https://github.com/dagger/dagger/blob/0fdbf271e316dade21a4e99c1be4f12e272673e0/core/schema/container.go#L182-L187 - and works in the exact same way as withDefaultArgs, so that's why I'm confused

[near steppe]

thanks for the help guys! i'll try this approaches, also the WORKDIR instruction is not being added and that's being the main problem for myself, because the CMD command runs in a different location than intended

[novel cove]

@maiden tendon you're correct. ENTRYOPOINT is set correctly

@near steppeworkingdir should be also working as Alex mentions

package main

import (
    "context"
    "os"

    "dagger.io/dagger"
)

func main() {
    ctx := context.Background()

    // create Dagger client
    client, err := dagger.Connect(ctx, dagger.WithLogOutput(os.Stderr))
    if err != nil {
        panic(err)
    }
    defer client.Close()

    client.Container().From("alpine").WithWorkdir("/test").
        Export(ctx, "./export.tar")
    // create Redis service container
    if err != nil {
        panic(err)
    }
}

^ that produces a tarball with the correct WorkingDir

[novel cove]

so yep, seems like the only missing image config is EXPOSE

[near steppe]

i'll give this a try and get back to you, gracias guys

one more thing, im not familiar with that tarball export, that will give me the Dockerfile?

[novel cove]

nope, it gives you the OCI tarball. Inside that tarball you'll find all the OCI image layers as well as the metadata files that describe the image

[near steppe]

oh i see! i can use that to verify if its built properly

[novel cove]

with that tar you can do docker load -i <export.tar> to load the image in your local docker daemon

[novel cove]

yep

[oblique rivet]

with_default_args is still not documented in dagger docs, should i create an issue?

[oblique rivet]

@novel cove @split flint