My BUILD file to the service looks like below :

python_sources(
    name="app",
    sources=["app.py"],
)

docker_image(
    name="book-creator",
    source="Dockerfile",
    dependencies=[
        "src/services/utils:utils",
        "src/pants_poc/db:db",
        ":app"
    ]
)

python_tests(
    name="tests",
    dependencies=[
        ":app",
        "//:tests"
    ]
)

However the problem is for some reason the dependencies are not found in the docker build context. Below is the output when i run the command :

pants run src/services/book_creator/Dockerfile

:

19:51:33.51 [INFO] Completed: Building docker image book-creator:latest
19:51:33.51 [WARN] Docker build failed for `docker_image` src/services/book_creator:book-creator. The src/services/book_creator/Dockerfile has `COPY` instructions for source files that may not have been found in the Docker build context.

The following files were not found in the Docker build context:

  * .
  * src/services/book_creator
  * src/services/utils


19:51:33.52 [ERROR] 1 Exception encountered:

Engine traceback:
  in `run` goal

ProcessExecutionFailure: Process 'Building docker image book-creator:latest' failed with exit code 1.
stdout:

stderr:
#0 building with "default" instance using docker driver

#1 [internal] load build definition from Dockerfile
#1 transferring dockerfile: 1.15kB done
#1 DONE 0.0s

#2 [auth] elevait/python-deployment-base:pull token for <http://harbor.elevait.io|harbor.elevait.io>
#2 DONE 0.0s

#3 [internal] load metadata for <http://harbor.elevait.io/elevait/python-deployment-base:v3.12|harbor.elevait.io/elevait/python-deployment-base:v3.12>
#3 DONE 0.3s

#4 [internal] load .dockerignore
#4 transferring context: 2B done
#4 DONE 0.0s

#5 [build 1/3] FROM <http://harbor.elevait.io/elevait/python-deployment-base:v3.12@sha256:ae335c36461032f6d557c95af16d3af8301d7ec4c13e7c7dc3316ec6b3f2fd20|harbor.elevait.io/elevait/python-deployment-base:v3.12@sha256:ae335c36461032f6d557c95af16d3af8301d7ec4c13e7c7dc3316ec6b3f2fd20>
#5 DONE 0.0s

#6 [internal] load build context
#6 transferring context: 1.28kB done
#6 DONE 0.0s

#5 [build 1/3] FROM <http://harbor.elevait.io/elevait/python-deployment-base:v3.12@sha256:ae335c36461032f6d557c95af16d3af8301d7ec4c13e7c7dc3316ec6b3f2fd20|harbor.elevait.io/elevait/python-deployment-base:v3.12@sha256:ae335c36461032f6d557c95af16d3af8301d7ec4c13e7c7dc3316ec6b3f2fd20>
#5 CACHED

#7 [build 3/3] RUN --mount=type=cache,sharing=locked,id=pants_poc-pip-cache,target=~/.cache/pip                                                      pip install --target /service/site-packages .[service] --constraint requirements.txt
#7 CACHED

#8 [stage-1 2/4] COPY --from=build /service/site-packages /home/elevait/.local/lib/sitepackages
#8 CACHED

#9 [stage-1 3/4] COPY src/services/utils /home/elevait/.local/lib/sitepackages/utils
#9 ERROR: failed to calculate checksum of ref SYJ3:OJS6:3SFC:5MHZ:E3AE:MBNF:XA26:QHF7:4UJD:G7MW:45EC:DJUI::lnqiea0yfwuq5ux0udfzmj8lk: "/src/services/utils": not found

#10 [build 2/3] COPY --chown=1000 . .
#10 CANCELED
------
 > [stage-1 3/4] COPY src/services/utils /home/elevait/.local/lib/sitepackages/utils:
------
Dockerfile:25
--------------------
  23 |     COPY --from=build /service/site-packages ${TARGET_DIR}
  24 |     
  25 | >>> COPY src/services/utils ${TARGET_DIR}/utils
  26 |     
  27 |     COPY src/services/book_creator .
--------------------
ERROR: failed to solve: failed to compute cache key: failed to calculate checksum of ref SYJ3:OJS6:3SFC:5MHZ:E3AE:MBNF:XA26:QHF7:4UJD:G7MW:45EC:DJUI::lnqiea0yfwuq5ux0udfzmj8lk: "/src/services/utils": not found



Use `--keep-sandboxes=on_failure` to preserve the process chroot for inspection.

However when i do a

peek

into the dockerfile i can see the dependencies, so ideally i would assume that pants would copy them over in the context:

> pants peek src/services/book_creator/Dockerfile
[
  {
    "address": "src/services/book_creator:book-creator",
    "target_type": "docker_image",
    "build_network": null,
    "build_platform": null,
    "cache_from": null,
    "cache_to": null,
    "context_root": null,
    "dependencies": [
      "src/pants_poc/db/__init__.py",
      "src/pants_poc/db/books_model.py",
      "src/services/book_creator/app.py:app",
      "src/services/utils/__init__.py",
      "src/services/utils/common.py"
    ],
    "dependencies_raw": [
      "src/services/utils:utils",
      "src/pants_poc/db:db",
      ":app"
    ],
    "description": null,
    "extra_build_args": [],
    "extra_build_hosts": null,
    "extra_run_args": [],
    "goals": [
      "package",
      "publish",
      "run"
    ],
    "image_labels": null,
    "image_tags": [
      "latest"
    ],
    "instructions": null,
    "output": {
      "type": "docker"
    },
    "output_path": "${spec_path_normalized}/${target_name_normalized}${file_suffix}",
    "pull": false,
    "registries": [
      "<all default registries>"
    ],
    "repository": null,
    "restartable": false,
    "secrets": null,
    "skip_push": false,
    "source_raw": "Dockerfile",
    "sources": [
      "src/services/book_creator/Dockerfile"
    ],
    "sources_fingerprint": "55bbea08a13b77e619eb0b8582aa5ec3525ff228b7b01165c88561bd9b0b9edc",
    "squash": false,
    "ssh": [],
    "tags": null,
    "target_stage": null
  }
]

I vaguely recall having seen some issues like this where the dependencies don't seem to appear correctly in later stages of a multi-stage docker build. I don't have enough information to write an issue though. One thing to try: Run

pants --keep-sandboxes=always package ::

and check your logs for something like

Preserving sandbox dir /tmp/<somethingsomething> for: Build docker image

and then you can

cd

into that directory. There should be a file called

__run.sh

which is the exact command pants runs to build your docker image. You can inspect/modify/re-run for debugging purposes to see if you can see what the issue is. (Translating these fixes back into your build files is an exercise for the reader). The rest of this sandbox dir will be a subset of your repo/filesystem, so you can check to make sure all the expected files are there (ie. if dependencies were brought in correctly)