Skip to content

Add discussion of build context dir for Dockerfile builds #221

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Nov 10, 2023
Merged

Add discussion of build context dir for Dockerfile builds #221

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
67 changes: 63 additions & 4 deletions build_a_container.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -288,7 +288,7 @@ creating images that can be run using {Singularity}'s :ref:`OCI mode

$ singularity build --oci ./debian.oci.sif ./Dockerfile
INFO: Did not find usable running buildkitd daemon; spawning our own.
INFO: cfg.Root for buildkitd: /home/omer/.local/share/buildkit
INFO: cfg.Root for buildkitd: /home/myuser/.local/share/buildkit
INFO: Using crun runtime for buildkitd daemon.
INFO: running buildkitd server on /run/user/1000/buildkit/buildkitd-0179484509442521.sock
[+] Building 4.3s (5/5)
Expand Down Expand Up @@ -378,7 +378,7 @@ that is piped through ``stdin``. The following example demonstrates both:

$ singularity build --oci ./lolcow.oci.sif ./Dockerfile
INFO: Did not find usable running buildkitd daemon; spawning our own.
INFO: cfg.Root for buildkitd: /home/omer/.local/share/buildkit
INFO: cfg.Root for buildkitd: /home/myuser/.local/share/buildkit
INFO: Using crun runtime for buildkitd daemon.
INFO: running buildkitd server on /run/user/1000/buildkit/buildkitd-8961170237105250.sock
[+] Building 15.1s (9/9)
Expand Down Expand Up @@ -445,13 +445,72 @@ complete. This ephemeral build daemon is based on `moby/buildkit

.. note::

Launching the ephemeral ``buildkitd`` daemon requires a system with
Launching the ephemeral build daemon requires a system with
:ref:`user namespace support <setuid_and_userns>` as well as ``crun`` /
``runc`` installed. These are independently required for using
{Singularity}'s :ref:`OCI mode <oci_sysreq>`. See the `Admin Guide
<https://sylabs.io/guides/{adminversion}/admin-guide/>`__ for more
information on these system requirements.

The `build context <https://docs.docker.com/build/building/context/>`__ for
Dockerfile builds using {Singularity} is always the current working directory.
Therefore, if you want to have the build context set to a different directory
than the one your Dockerfile is in, all you have to do is run {Singularity}
*from the desired context dir*, and provide a relative or absolute path to the
Dockerfile:

.. code:: console

$ pwd
/home/myuser/tmp/my_context_dir

$ ls
some_file

$ cat some_file
Some text.

$ cat ../Dockerfile
From alpine
ADD some_file /
CMD cat /some_file

$ singularity build --oci ./container.oci.sif ../Dockerfile
INFO: Did not find usable running buildkitd daemon; spawning our own.
INFO: cfg.Root for buildkitd: /home/myuser/.local/share/buildkit
INFO: Using "crun" runtime for buildkitd daemon.
INFO: running buildkitd server on /run/user/1000/buildkit/buildkitd-8519770128063388.sock
[+] Building 1.3s (6/7)
[+] Building 1.4s (7/7) FINISHED
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 143B 0.0s
=> [internal] load metadata for docker.io/library/alpine:latest 1.3s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 88B 0.0s
=> [1/2] FROM docker.io/library/alpine:latest@sha256:eece025e432 0.0s
=> => resolve docker.io/library/alpine:latest@sha256:eece025e432 0.0s
=> CACHED [2/2] ADD some_file / 0.0s
=> exporting to docker image format 0.0s
=> => exporting layers 0.0s
=> => exporting manifest sha256:78c2cbf8ea2441c7a3d75f80bd0660ef 0.0s
=> => exporting config sha256:58e9a24e9242901475f317e201185cbf10 0.0s
=> => sending tarball 0.0s
Getting image source signatures
Copying blob 96526aa774ef done |
Copying blob 15061a177792 done |
Copying config 3d12fd8035 done |
Writing manifest to image destination
INFO: Converting OCI image to OCI-SIF format
INFO: Squashing image to single layer
INFO: Writing OCI-SIF image
INFO: Cleaning up.
INFO: Build complete: ./container.oci.sif

$ singularity run --oci ./container.oci.sif
Some text.

Additional features
===================

Expand All @@ -476,7 +535,7 @@ following to build a container image for the 64-bit ARM architecure:

$ singularity build --arch arm64 --oci ./alpine.oci.sif ./Dockerfile.alpine
INFO: Did not find usable running buildkitd daemon; spawning our own.
INFO: cfg.Root for buildkitd: /home/omer/.local/share/buildkit
INFO: cfg.Root for buildkitd: /home/myuser/.local/share/buildkit
INFO: Using "crun" runtime for buildkitd daemon.
INFO: running buildkitd server on /run/user/1000/buildkit/buildkitd-4747966236261602.sock
[+] Building 0.6s (1/2)
Expand Down