How to expose ports for go_image?

[chaitanya9186]

#305

[mattmoor]

You can compose go_image with container_image, e.g.

go_image(
    name = "foo",
    ...
)

container_image(
    name = "bar",
    base = ":foo",
    ports = [...],
)

[chaitanya9186]

But bazel run :bar target not running the container.

[mattmoor]

This was harder to make the default for container_image (really: docker_build) which has been around for years. You can enable that for that rule with: legacy_run_behavior = False.

You can also invert the layer ordering to get this, e.g.:

load("@io_bazel_rules_docker//go:image.bzl", GO_DEFAULT_BASE="DEFAULT_BASE")

container_image(
    name = "bar",
    base = GO_DEFAULT_BASE,
    ports = [...],
)

go_image(
    name = "foo",
    base = ":bar",
    ...
)

[chaitanya9186]

I have tried the invertion approach too. If I run docker run -d -p 8888:8888 <image> I able to query with localhost:8888, but if I run bazel run :foo I am unable to query localhost:8888.

I referred the generated config file, it has the ExposedPorts: {"8888:8888/tcp": {}} filed.

And I also checked docker ps -a list, with manual docker run I see 40ef854fdb77 <image> "/app/server/serve..." 20 seconds ago Up 19 seconds 0.0.0.0:8888->8888/tcp.

with bazel run :foo I see 8fcc1ca061f0 <image> "/app/server/serve..." 6 seconds ago Up 5 seconds 8888/tcp

I am not sure, what's happening, but I get a feeling that I miss some other setting.

[mattmoor]

We don't expose network on the Docker daemon by default when a lang_image is run (except war_image).

I feel like this is a mistake, particularly since you can't override it. We should be doing what we do for war_image for all lang_image. I'll just fix this.

Another thing to beware of is that ctrl+C of the container run by bazel won't kill it. This is a longstanding Bazel bug, that I'll dig up and ping.

[mattmoor]

here's the thread: bazelbuild/bazel#3519

[wkiser]

I was running into similar problems as @chaitanya9186 when trying to run a flask app in a container locally. Now that #312 is merged, can the lang_image binaries be updated to accept a docker_run_flags argument (and pass it to the app_layer)? Based off of my brief local testing that would make the docker pick up the run flags when running `bazel run :lang_image' locally.

[alsutton]

I've put a PR up to add the ports option to the go_image; #462

[nlopezgi]

lang_images have the same arguments as their corresponding lang_binary rules. The recommended way to get these additional properties is still to compose the lang_image with a container_image as indicated in the comment above.

[alsutton]

Given _binary and _image tackle two different types of problem (the need for a locally executable binary -v- the need to compose a container image) it seems a little odd to try and keep their parameters in absolute sync, but hey, your repo, your rules :)

[nlopezgi]

is this still an issue? please reopen if so.