From ce3c7ee17307776f393b8f7fd6c8cb0221719264 Mon Sep 17 00:00:00 2001
From: Ed Morley <501702+edmorley@users.noreply.github.com>
Date: Tue, 21 May 2024 23:49:55 +0100
Subject: [PATCH] Heroku-24: Add `binutils` to the run image (#306)

Python's `ctypes.util.find_library` is used to find libraries at
runtime. `find_library()` calls out to various external programs to help
with this task, initially trying `ldconfig`, and then falling back to
`gcc` and `ld` if needed - as documented here:
https://docs.python.org/3/library/ctypes.html#finding-shared-libraries

Even after the removal of compilation tools from the run image in #273,
`ldconfig` still exists in the run image, so libraries can still be
found by `ctypes.util.find_library` in the base image.

However, whilst the `find_library()` docs say that it supports
`LD_LIBRARY_PATH`, the docs fail to mention that the env var is only
honoured when `ld` can be found:
https://github.com/python/cpython/blob/e870c852c0ea96fa4e4569e9c39c7ceb80ce858d/Lib/ctypes/util.py#L315-L320

As such, when only `ldconfig` is available, `find_library()` only
returns libraries from the base image, and not any installed via eg the
APT or other buildpacks (which rely upon `LD_LIBRARY_PATH` since they
have to do userland "installs" of libraries due to not having root
permissions).

One such popular use of `ctypes.util.find_library` is in Django's GIS
feature, which uses it to locate the GDAL library at runtime:
https://github.com/django/django/blob/4971a9afe5642569f3dcfcd3972ebb39e88dd457/django/contrib/gis/gdal/libgdal.py#L53-L66

Therefore, we sadly have to include `binutils` in the run image after
all - though thankfully doing so only forgoes 19 MB of the original
203 MB run image size reduction from removing `gcc`, `make` and
`libc6-dev`.

GUS-W-15821115.
---
 heroku-24/installed-packages-amd64.txt | 9 +++++++++
 heroku-24/installed-packages-arm64.txt | 9 +++++++++
 heroku-24/setup.sh                     | 1 +
 3 files changed, 19 insertions(+)

diff --git a/heroku-24/installed-packages-amd64.txt b/heroku-24/installed-packages-amd64.txt
index bde28d72..fa6e2b3d 100644
--- a/heroku-24/installed-packages-amd64.txt
+++ b/heroku-24/installed-packages-amd64.txt
@@ -7,6 +7,9 @@ bash
 bind9-dnsutils
 bind9-host
 bind9-libs
+binutils
+binutils-common
+binutils-x86-64-linux-gnu
 bsdutils
 bzip2
 ca-certificates
@@ -62,6 +65,7 @@ libassuan0
 libattr1
 libaudit-common
 libaudit1
+libbinutils
 libblkid1
 libbpf1
 libbrotli1
@@ -80,6 +84,8 @@ libcfitsio10t64
 libcgif0
 libcom-err2
 libcrypt1
+libctf-nobfd0
+libctf0
 libcurl3t64-gnutls
 libcurl4t64
 libdatrie1
@@ -120,6 +126,7 @@ libgnutls-openssl27t64
 libgnutls30t64
 libgomp1
 libgpg-error0
+libgprofng0
 libgraphite2-3
 libgssapi-krb5-2
 libharfbuzz-gobject0
@@ -136,6 +143,7 @@ libicu74
 libidn2-0
 libimagequant0
 libimath-3-1-29t64
+libjansson4
 libjbig0
 libjpeg-turbo8
 libjpeg8
@@ -216,6 +224,7 @@ libselinux1
 libsemanage-common
 libsemanage2
 libsepol2
+libsframe1
 libsharpyuv0
 libsmartcols1
 libsodium23
diff --git a/heroku-24/installed-packages-arm64.txt b/heroku-24/installed-packages-arm64.txt
index bde28d72..3029a59b 100644
--- a/heroku-24/installed-packages-arm64.txt
+++ b/heroku-24/installed-packages-arm64.txt
@@ -7,6 +7,9 @@ bash
 bind9-dnsutils
 bind9-host
 bind9-libs
+binutils
+binutils-aarch64-linux-gnu
+binutils-common
 bsdutils
 bzip2
 ca-certificates
@@ -62,6 +65,7 @@ libassuan0
 libattr1
 libaudit-common
 libaudit1
+libbinutils
 libblkid1
 libbpf1
 libbrotli1
@@ -80,6 +84,8 @@ libcfitsio10t64
 libcgif0
 libcom-err2
 libcrypt1
+libctf-nobfd0
+libctf0
 libcurl3t64-gnutls
 libcurl4t64
 libdatrie1
@@ -120,6 +126,7 @@ libgnutls-openssl27t64
 libgnutls30t64
 libgomp1
 libgpg-error0
+libgprofng0
 libgraphite2-3
 libgssapi-krb5-2
 libharfbuzz-gobject0
@@ -136,6 +143,7 @@ libicu74
 libidn2-0
 libimagequant0
 libimath-3-1-29t64
+libjansson4
 libjbig0
 libjpeg-turbo8
 libjpeg8
@@ -216,6 +224,7 @@ libselinux1
 libsemanage-common
 libsemanage2
 libsepol2
+libsframe1
 libsharpyuv0
 libsmartcols1
 libsodium23
diff --git a/heroku-24/setup.sh b/heroku-24/setup.sh
index e768ed3a..8dc161de 100755
--- a/heroku-24/setup.sh
+++ b/heroku-24/setup.sh
@@ -39,6 +39,7 @@ apt-get upgrade -y --no-install-recommends
 
 packages=(
   bind9-dnsutils # For `dig`, `host` and `nslookup`.
+  binutils # Python's `ctypes.util.find_library` requires `ld` to find libraries specified via `LD_LIBRARY_PATH`.
   bzip2
   curl
   file