How can I add a file to the docker context that is located in the root of my repo, e.g.

entrypoint.sh
pants.toml
/serviceA
    Dockerfile
    BUILD

And the COPY in the Dockerfile looks like this:

COPY entrypoint.sh /

What needs to be added to the BUILD file? It is always complaining that the file cannot be found.

See https://www.pantsbuild.org/docs/docker#build-docker-image-example. Add a

BUILD

in root of your repo and add a

file

target for it. Then depend on that

file

target in your

docker_image

target.

serviceA

BUILD

file:

docker_image(
    name="service-runtime",
    source="runtime.Dockerfile",
    dependencies = ["//:entrypoint"],
)

root

BUILD

file:

file(
    name='entrypoint',
    source="lambda_entrypoint.sh",
)

Result:

#9 [4/5] COPY lambda_entrypoint.sh /
#9 sha256:4262b25edb23c1b1e7dd5b18cf34f449f18864e45c0ce62ee4fa0b0b2329e8b2
#9 ERROR: "/lambda_entrypoint.sh" not found: not found

What am I missing?

time to debug then: pass

--no-process-cleanup

to your Pants invocation. The log will print out the directory where the execution sandbox has been preserved. Let’s see if the file made it into the execution sandbox. (There will also be a

__run.sh

script with the

docker build

invocation.)

In order to include files in your docker build context from “outside” your subtree where your

docker_image

target is defined, you need to adjust the

context_root

(see

./pants docker_image --help

)

15:35:00.22 [INFO] Preserving local process execution dir /tmp/pants-sandbox-Kugjdt for "Building docker image service-runtime:latest"

...

vscode ➜ /nefino_li (feature/DEV-2928-add-all-services ✗) $ ls -la /tmp/pants-sandbox-Kugjdt
total 20
drwxr-xr-x 3 vscode vscode 4096 Jun 29 15:35 .
drwxrwxrwt 1 root   root   4096 Jun 29 15:35 ..
-rwxr-xr-x 1 vscode vscode  378 Jun 29 15:35 __run.sh
-rw-r--r-- 1 vscode vscode  185 Jun 29 15:35 lambda_entrypoint.sh
drwxr-xr-x 2 vscode vscode 4096 Jun 29 15:35 services
vscode ➜ /nefino_li (feature/DEV-2928-add-all-services ✗) $

Here services=serviceA directory

in your

__run.sh

I would expect to see a docker invocation, that uses a subdirectory of your sandbox as build context.

__run.sh

content:

#!/bin/bash
# This command line should execute the same process as pants did internally.
export FUNCTION_DIR=/function PACKAGE_DOWNLOAD_PATH=/packages VARIANT=3.8-bullseye
cd /tmp/pants-sandbox-Kugjdt
/usr/bin/docker build --tag $'service-runtime:latest' --build-arg FUNCTION_DIR --build-arg PACKAGE_DOWNLOAD_PATH --build-arg VARIANT --file services/runtime.Dockerfile services

yep, indeed. the final

services

on the docker build line there is the context root.

context_root=""

did the trick. Thank you! Learned something new again!

(thanks for jumping in to assist @fast-nail-55400)