func InstallLocalPkg()

in targets/linux/deb/distro/install.go [58:128]

• 46 lines of code
• 5 McCabe index (conditional complexity)

func InstallLocalPkg(pkg llb.State, upgrade bool, opts ...llb.ConstraintsOpt) llb.RunOption {
	return dalec.RunOptFunc(func(ei *llb.ExecInfo) {
		// The apt solver always tries to select the latest package version even
		// when constraints specify that an older version should be installed and
		// that older version is available in a repo. This leads the solver to
		// simply refuse to install our target package if the latest version of ANY
		// dependency package is incompatible with the constraints. To work around
		// this we first install the .deb for the package with dpkg, specifically
		// ignoring any dependencies so that we can avoid the constraints issue.
		// We then use aptitude to fix the (possibly broken) install of the
		// package, and we pass the aptitude solver a hint to REJECT any solution
		// that involves uninstalling the package. This forces aptitude to find a
		// solution that will respect the constraints even if the solution involves
		// pinning dependency packages to older versions.
		const installScript = `#!/usr/bin/env sh
set -ex

# Make sure any cached data from local repos is purged since this should not
# be shared between builds.
rm -f /var/lib/apt/lists/_*
apt autoclean -y

# Remove any previously failed attempts to get repo data
rm -rf /var/lib/apt/lists/partial/*
apt update

if [ "${DALEC_UPGRADE}" = "true" ]; then
	apt dist-upgrade -y
fi

if apt install -y ${1}; then
	exit 0
fi

if ! command -v aptitude > /dev/null; then
	needs_cleanup=1
	apt install -y aptitude
fi

cleanup() {
	if [ "${needs_cleanup}" = "1" ]; then
		apt remove -y aptitude
	fi
}

trap cleanup EXIT

dpkg -i --force-depends ${1}

pkg_name="$(dpkg-deb -f ${1} | grep 'Package:' | awk -F': ' '{ print $2 }')"
aptitude install -y -f -o "Aptitude::ProblemResolver::Hints::=reject ${pkg_name} :UNINST"
`

		script := llb.Scratch().File(
			llb.Mkfile("install.sh", 0o755, []byte(installScript)),
			dalec.WithConstraint(&ei.Constraints),
			dalec.WithConstraints(opts...),
		)

		p := "/tmp/dalec/internal/deb/install-with-constraints.sh"
		debPath := "/tmp/dalec/internal/debs"

		llb.AddMount(p, script, llb.SourcePath("install.sh")).SetRunOption(ei)
		llb.AddMount(debPath, pkg, llb.Readonly).SetRunOption(ei)
		llb.AddEnv("DEBIAN_FRONTEND", "noninteractive").SetRunOption(ei)
		llb.AddEnv("DALEC_UPGRADE", strconv.FormatBool(upgrade)).SetRunOption(ei)

		args := []string{p, filepath.Join(debPath, "*.deb")}
		llb.Args(args).SetRunOption(ei)
	})
}