Initial commit

.gitignore

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+/_build/

README.md

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+# Minimal Base Python Container Image
+
+The *pythonctnr* image contains ONLY the Python runtime, and nothing else.  It
+is suitable for deploying applications written in pure Python, without any
+external library dependencies.  No shell or other OS utilities are included.
+Just `/usr/bin/python3` and the libraries it needs to run.
+
+
+## Building
+
+The contents of the container image are built with [buildroot][0].
+
+```sh
+make -C ~/src/buildroot O=${PWD}/_build pythonctnr_defconfig
+make -C _build
+```
+
+This will produce a `rootfs.tar` tarball in `_build/images`, which is then
+converted to a container image using `buildah`.
+
+```sh
+ctnr=$(buildah from scratch)
+buildah add ${ctnr} _build/images/rootfs.tar /
+buildah commit ${ctnr} pythonctnr:latest
+```
+
+[0]: https://buildroot.org/
+
+
+## Usage
+
+The container image can be used like any other image, e.g. in a `Dockerfile`.
+*pip* is included, to allow installing Python distribution packages.
+
+```Dockerfile
+FROM pythonctnr
+
+RUN ["/usr/bin/python3", "-m", "pip", "install", "mypkg"]
+```
+
+**NOTE**: Because there is no shell, the default string form of the `RUN`
+instruction does not work.  You must use the *exec* form.

configs/pythonctnr_defconfig

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+BR2_x86_64=y
+BR2_TOOLCHAIN_BUILDROOT_GLIBC=y
+BR2_TARGET_GENERIC_HOSTNAME="pythonctnr"
+BR2_TARGET_GENERIC_ISSUE=""
+BR2_INIT_NONE=y
+BR2_ROOTFS_MERGED_USR=y
+# BR2_TARGET_ENABLE_ROOT_LOGIN is not set
+BR2_SYSTEM_BIN_SH_NONE=y
+# BR2_TARGET_GENERIC_GETTY is not set
+# BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW is not set
+BR2_SYSTEM_DEFAULT_PATH="/bin:/sbin:/usr/bin:/usr/sbin"
+# BR2_PACKAGE_BUSYBOX is not set
+BR2_PACKAGE_PYTHON3=y
+BR2_PACKAGE_PYTHON_PIP=y

external.desc

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+name: pythonctnr
+desc: Python container image