3 files changed, 137 insertions, 0 deletions
diff --git a/archinstall/lib/pacman/__init__.py b/archinstall/lib/pacman/__init__.py
new file mode 100644
index 00000000..6478f0cc
--- /dev/null
+++ b/archinstall/lib/pacman/__init__.py
@@ -0,0 +1,88 @@
+from pathlib import Path
+import time
+import re
+from typing import TYPE_CHECKING, Any, List, Callable, Union
+from shutil import copy2
+
+from ..general import SysCommand
+from ..output import warn, error, info
+from .repo import Repo
+from .config import Config
+from ..exceptions import RequirementError
+from ..plugins import plugins
+
+if TYPE_CHECKING:
+	_: Any
+
+
+class Pacman:
+
+	def __init__(self, target: Path, silent: bool = False):
+		self.synced = False
+		self.silent = silent
+		self.target = target
+
+	@staticmethod
+	def run(args :str, default_cmd :str = 'pacman') -> SysCommand:
+		"""
+		A centralized function to call `pacman` from.
+		It also protects us from colliding with other running pacman sessions (if used locally).
+		The grace period is set to 10 minutes before exiting hard if another pacman instance is running.
+		"""
+		pacman_db_lock = Path('/var/lib/pacman/db.lck')
+
+		if pacman_db_lock.exists():
+			warn(_('Pacman is already running, waiting maximum 10 minutes for it to terminate.'))
+
+		started = time.time()
+		while pacman_db_lock.exists():
+			time.sleep(0.25)
+
+			if time.time() - started > (60 * 10):
+				error(_('Pre-existing pacman lock never exited. Please clean up any existing pacman sessions before using archinstall.'))
+				exit(1)
+
+		return SysCommand(f'{default_cmd} {args}')
+
+	def ask(self, error_message: str, bail_message: str, func: Callable, *args, **kwargs):
+		while True:
+			try:
+				func(*args, **kwargs)
+				break
+			except Exception as err:
+				error(f'{error_message}: {err}')
+				if not self.silent and input('Would you like to re-try this download? (Y/n): ').lower().strip() in 'y':
+					continue
+				raise RequirementError(f'{bail_message}: {err}')
+
+	def sync(self):
+		if self.synced:
+			return
+		self.ask(
+			'Could not sync a new package database',
+			'Could not sync mirrors',
+			self.run,
+			'-Syy',
+			default_cmd='/usr/bin/pacman'
+		)
+		self.synced = True
+
+	def strap(self, packages: Union[str, List[str]]):
+		self.sync()
+		if isinstance(packages, str):
+			packages = [packages]
+
+		for plugin in plugins.values():
+			if hasattr(plugin, 'on_pacstrap'):
+				if (result := plugin.on_pacstrap(packages)):
+					packages = result
+
+		info(f'Installing packages: {packages}')
+
+		self.ask(
+			'Could not strap in packages',
+			'Pacstrap failed. See /var/log/archinstall/install.log or above message for error details',
+			SysCommand,
+			f'/usr/bin/pacstrap -C /etc/pacman.conf -K {self.target} {" ".join(packages)} --noconfirm',
+			peek_output=True
+		)
diff --git a/archinstall/lib/pacman/config.py b/archinstall/lib/pacman/config.py
new file mode 100644
index 00000000..6686f4a9
--- /dev/null
+++ b/archinstall/lib/pacman/config.py
@@ -0,0 +1,44 @@
+import re
+from pathlib import Path
+from shutil import copy2
+from typing import List
+
+from .repo import Repo
+
+
+class Config:
+	def __init__(self, target: Path):
+		self.path = Path("/etc") / "pacman.conf"
+		self.chroot_path = target / "etc" / "pacman.conf"
+		self.repos: List[Repo] = []
+
+	def enable(self, repo: Repo):
+		self.repos.append(repo)
+
+	def apply(self):
+		if not self.repos:
+			return
+
+		if Repo.Testing in self.repos:
+			if Repo.Multilib in self.repos:
+				repos_pattern = f'({Repo.Multilib.value}|.+-{Repo.Testing.value})'
+			else:
+				repos_pattern = f'(?!{Repo.Multilib.value}).+-{Repo.Testing.value}'
+		else:
+			repos_pattern = Repo.Multilib.value
+
+		pattern = re.compile(rf"^#\s*\[{repos_pattern}\]$")
+
+		lines = iter(self.path.read_text().splitlines(keepends=True))
+		with open(self.path, 'w') as f:
+			for line in lines:
+				if pattern.match(line):
+					# Uncomment this line and the next.
+					f.write(line.lstrip('#'))
+					f.write(next(lines).lstrip('#'))
+				else:
+					f.write(line)
+
+	def persist(self):
+		if self.repos:
+			copy2(self.path, self.chroot_path)
diff --git a/archinstall/lib/pacman/repo.py b/archinstall/lib/pacman/repo.py
new file mode 100644
index 00000000..7a461431
--- /dev/null
+++ b/archinstall/lib/pacman/repo.py
@@ -0,0 +1,5 @@
+from enum import Enum
+
+class Repo(Enum):
+	Multilib = "multilib"
+	Testing = "testing"