ci: macos: use cached macports install

A significant chunk of the time on the macos CI task is spent installing
packages using homebrew. The downloads of the packages are cached, but the
installation needs to happen every time. We can't cache the whole homebrew
installation, because it is too large due to pre-installed packages.

Speed this up by installing packages using macports and caching the
installation as .dmg. That's a lot faster than unpacking a tarball.

In addition, don't install llvm - it wasn't enabled when building, so it's
just a waste of time/space.

This substantially speeds up the mac CI time, both in the cold cache and in
the warm cache case (the latter from ~1m20s to ~5s).

It doesn't seem great to have diverging sources of packages for CI between
branches, so backpatch to 15 (where CI was added).

Discussion: https://postgr.es/m/20230805202539.r3umyamsnctysdc7@awork3.anarazel.de
Backpatch: 15-, where CI was added

.cirrus.yml

@@ -435,8 +435,7 @@ task:
 
     CIRRUS_WORKING_DIR: ${HOME}/pgsql/
     CCACHE_DIR: ${HOME}/ccache
-    HOMEBREW_CACHE: ${HOME}/homebrew-cache
-    PERL5LIB: ${HOME}/perl5/lib/perl5
+    MACPORTS_CACHE: ${HOME}/macports-cache
 
     CC: ccache cc
     CXX: ccache c++
@@ -459,55 +458,43 @@ task:
     - mkdir ${HOME}/cores
     - sudo sysctl kern.corefile="${HOME}/cores/core.%P"
 
-  perl_cache:
-    folder: ~/perl5
-  cpan_install_script:
-    - perl -mIPC::Run -e 1 || cpan -T IPC::Run
-    - perl -mIO::Pty -e 1 || cpan -T IO::Pty
-  upload_caches: perl
-
-
-  # XXX: Could we instead install homebrew into a cached directory? The
-  # homebrew installation takes a good bit of time every time, even if the
-  # packages do not need to be downloaded.
-  homebrew_cache:
-    folder: $HOMEBREW_CACHE
+  # Use macports, even though homebrew is installed. The installation
+  # of the additional packages we need would take quite a while with
+  # homebrew, even if we cache the downloads. We can't cache all of
+  # homebrew, because it's already large. So we use macports. To cache
+  # the installation we create a .dmg file that we mount if it already
+  # exists.
+  # XXX: The reason for the direct p5.34* references is that we'd need
+  # the large macport tree around to figure out that p5-io-tty is
+  # actually p5.34-io-tty. Using the unversioned name works, but
+  # updates macports every time.
+  macports_cache:
+    folder: ${MACPORTS_CACHE}
   setup_additional_packages_script: |
-    brew install \
+    sh src/tools/ci/ci_macports_packages.sh \
       ccache \
-      icu4c \
-      krb5 \
-      llvm \
+      icu \
+      kerberos5 \
       lz4 \
-      make \
       meson \
       openldap \
       openssl \
-      python \
-      tcl-tk \
+      p5.34-io-tty \
+      p5.34-ipc-run \
+      tcl \
       zstd
-
-    brew cleanup -s # to reduce cache size
-  upload_caches: homebrew
+    # Make macports install visible for subsequent steps
+    echo PATH=/opt/local/sbin/:/opt/local/bin/:$PATH >> $CIRRUS_ENV
+  upload_caches: macports
 
   ccache_cache:
     folder: $CCACHE_DIR
   configure_script: |
-    brewpath="/opt/homebrew"
-    PKG_CONFIG_PATH="${brewpath}/lib/pkgconfig:${PKG_CONFIG_PATH}"
-
-    for pkg in icu4c krb5 openldap openssl zstd ; do
-      pkgpath="${brewpath}/opt/${pkg}"
-      PKG_CONFIG_PATH="${pkgpath}/lib/pkgconfig:${PKG_CONFIG_PATH}"
-      PATH="${pkgpath}/bin:${pkgpath}/sbin:$PATH"
-    done
-
-    export PKG_CONFIG_PATH PATH
-
+    export PKG_CONFIG_PATH="/opt/local/lib/pkgconfig/"
     meson setup \
       --buildtype=debug \
-      -Dextra_include_dirs=${brewpath}/include \
-      -Dextra_lib_dirs=${brewpath}/lib \
+      -Dextra_include_dirs=/opt/local/include \
+      -Dextra_lib_dirs=/opt/local/lib \
       -Dcassert=true \
       -Duuid=e2fs -Ddtrace=auto \
       -DPG_TEST_EXTRA="$PG_TEST_EXTRA" \

src/tools/ci/ci_macports_packages.sh

@@ -0,0 +1,97 @@
+#!/bin/sh
+
+# Installs the passed in packages via macports. To make it fast enough
+# for CI, cache the installation as a .dmg file.  To avoid
+# unnecessarily updating the cache, the cached image is only modified
+# when packages are installed or removed.  Any package this script is
+# not instructed to install, will be removed again.
+#
+# This currently expects to be run in a macos cirrus-ci environment.
+
+set -e
+# set -x
+
+packages="$@"
+
+macports_url="https://github.com/macports/macports-base/releases/download/v2.8.1/MacPorts-2.8.1-13-Ventura.pkg"
+cache_dmg="macports.hfs.dmg"
+
+if [ "$CIRRUS_CI" != "true" ]; then
+    echo "expect to be called within cirrus-ci" 1>2
+    exit 1
+fi
+
+sudo mkdir -p /opt/local
+mkdir -p ${MACPORTS_CACHE}/
+
+# If we are starting from clean cache, perform a fresh macports
+# install. Otherwise decompress the .dmg we created previously.
+#
+# After this we have a working macports installation, with an unknown set of
+# packages installed.
+new_install=0
+update_cached_image=0
+if [ -e ${MACPORTS_CACHE}/${cache_dmg}.zstd ]; then
+    time zstd -T0 -d ${MACPORTS_CACHE}/${cache_dmg}.zstd -o ${cache_dmg}
+    time sudo hdiutil attach -kernel ${cache_dmg} -owners on -shadow ${cache_dmg}.shadow -mountpoint /opt/local
+else
+    new_install=1
+    curl -fsSL -o macports.pkg "$macports_url"
+    time sudo installer -pkg macports.pkg -target /
+    # this is a throwaway environment, and it'd be a few lines to gin
+    # up a correct user / group when using the cache.
+    echo macportsuser root | sudo tee -a /opt/local/etc/macports/macports.conf
+fi
+export PATH=/opt/local/sbin/:/opt/local/bin/:$PATH
+
+# mark all installed packages unrequested, that allows us to detect
+# packages that aren't needed anymore
+if [ -n "$(port -q installed installed)" ] ; then
+    sudo port unsetrequested installed
+fi
+
+# if setting all the required packages as requested fails, we need
+# to install at least one of them
+if ! sudo port setrequested $packages > /dev/null 2>&1 ; then
+    echo not all required packages installed, doing so now
+    update_cached_image=1
+    # to keep the image small, we deleted the ports tree from the image...
+    sudo port selfupdate
+    # XXX likely we'll need some other way to force an upgrade at some
+    # point...
+    sudo port upgrade outdated
+    sudo port install -N $packages
+    sudo port setrequested $packages
+fi
+
+# check if any ports should be uninstalled
+if [ -n "$(port -q installed rleaves)" ] ; then
+    echo superflous packages installed
+    update_cached_image=1
+    sudo port uninstall --follow-dependencies rleaves
+
+    # remove prior cache contents, don't want to increase size
+    rm -f ${MACPORTS_CACHE}/*
+fi
+
+# Shrink installation if we created / modified it
+if [ "$new_install" -eq 1 -o "$update_cached_image" -eq 1 ]; then
+    sudo /opt/local/bin/port clean --all installed
+    sudo rm -rf /opt/local/var/macports/{software,sources}/*
+fi
+
+# If we're starting from a clean cache, start a new image. If we have
+# an image, but the contents changed, update the image in the cache
+# location.
+if [ "$new_install" -eq 1 ]; then
+    # use a generous size, so additional software can be installed later
+    time sudo hdiutil create -fs HFS+ -format UDRO -size 10g -layout NONE -srcfolder /opt/local/ ${cache_dmg}
+    time zstd -T -10 -z ${cache_dmg} -o ${MACPORTS_CACHE}/${cache_dmg}.zstd
+elif [ "$update_cached_image" -eq 1 ]; then
+    sudo hdiutil detach /opt/local/
+    time hdiutil convert -format UDRO ${cache_dmg} -shadow ${cache_dmg}.shadow -o updated.hfs.dmg
+    rm ${cache_dmg}.shadow
+    mv updated.hfs.dmg ${cache_dmg}
+    time zstd --force -T -10 -z ${cache_dmg} -o ${MACPORTS_CACHE}/${cache_dmg}.zstd
+    time sudo hdiutil attach -kernel ${cache_dmg} -owners on -shadow ${cache_dmg}.shadow -mountpoint /opt/local
+fi