Improve handling of paths

Variables ending in _path contain a Path, those ending in _dir are
strings.

etc/shipcat.toml

@@ -3,5 +3,8 @@
 # Where to find container configuration files
 container_config_dir = "/etc/shipcat/containers"
 
+# Where to find container roots (can be overridden by container's config)
+container_root_dir = "/aux/containers"
+
 # Overall verbosity
 verbosity = 0

shipcat/config.py

@@ -16,7 +16,8 @@ class ConfigError(RuntimeError):
 
 
 class GlobalConfig:
-    container_config_dir: Path
+    container_config_path: Path
+    container_root_path: Path
     verbosity: int
 
     @classmethod
@@ -39,16 +40,19 @@ class GlobalConfig:
 
     def parse(self, walker: Walker) -> None:
         with walker.enter_object() as w:
-            self.container_config_dir = Path(w['container_config_dir'].as_str())
+            self.container_config_path = Path(w['container_config_dir'].as_str())
+            self.container_root_path = Path(w['container_root_dir'].as_str())
             self.verbosity = w['verbosity'].as_int(0)
 
 
 class ContainerConfig:
-    container: str
-    root_dir: str
+    name: str
+    root_path: Path
+    data_path: Path
     image: str
     allowed_users: Set[int]
     allowed_groups: Set[int]
+    global_config: GlobalConfig
 
     # Automatically generated
     pid_file: str
@@ -59,7 +63,7 @@ class ContainerConfig:
         if not re.fullmatch(r'[0-9A-Za-z_-]+', name):
             raise ConfigError(f'Invalid container name {name}')
 
-        path = global_config.container_config_dir / (name + '.toml')
+        path = global_config.container_config_path / (name + '.toml')
         try:
             with open(path, 'rb') as f:
                 root = tomllib.load(f)
@@ -69,7 +73,8 @@ class ContainerConfig:
             raise ConfigError(f'Cannot parse container configuration {path}: {e}')
 
         cc = ContainerConfig()
-        cc.container = name
+        cc.name = name
+        cc.global_config = global_config
         try:
             cc.parse(Walker(root))
         except WalkerError as e:
@@ -79,6 +84,13 @@ class ContainerConfig:
 
     def parse(self, walker: Walker) -> None:
         with walker.enter_object() as w:
+            rd = w['root_dir']
+            if rd.is_present():
+                self.root_path = Path(rd.as_str())
+            else:
+                self.root_path = self.global_config.container_root_path / self.name
+            self.data_path = self.root_path / 'data'
+
             self.root_dir = w['root_dir'].as_str()
             self.image = w['image'].as_str()
 
@@ -100,5 +112,5 @@ class ContainerConfig:
                     wu.raise_error(f'Unknown group {name}')
                 self.allowed_groups.add(grp.gr_gid)
 
-        self.pid_file = f'/run/shc/{self.container}.pid'
-        self.user_name = self.container
+        self.pid_file = f'/run/shc/{self.name}.pid'
+        self.user_name = self.name

shipcat/main.py

@@ -145,7 +145,7 @@ def cmd_init(args: argparse.Namespace) -> None:
 
     progress(f'Using user {cc.user_name}, uid {uid}, subuids {sur.first}+{sur.count}, subgids {sgr.first}+{sgr.count}\n')
 
-    root_path = Path(cc.root_dir)
+    root_path = cc.root_path
     progress(f'Container directory {root_path}: ')
     if root_path.is_dir():
         progress('already exists\n')
@@ -154,7 +154,7 @@ def cmd_init(args: argparse.Namespace) -> None:
         os.chown(root_path, 0, sgr.first)
         progress('created\n')
 
-    data_path = root_path / 'data'
+    data_path = cc.data_path
     progress(f'Data directory {data_path}: ')
     if data_path.is_dir():
         progress('already exists\n')
@@ -173,35 +173,36 @@ def cmd_init(args: argparse.Namespace) -> None:
 
 def service_action(cc: ContainerConfig, action: str) -> None:
     run_command(
-        ['systemctl', action, f'shc@{cc.container}.service']
+        ['systemctl', action, f'shc@{cc.name}.service']
     )
 
 
 def cmd_create(args: argparse.Namespace) -> None:
-    name = args.name
     cc = setup_container(args, False)
 
-    data_dir = Path(cc.root_dir) / 'data'
-    ip = socket.gethostbyname(name)
-
     run_command(
         ['podman', 'pull', cc.image]
     )
 
     service_action(cc, 'stop')
+    create_container(cc)
+
+
+def create_container(cc: ContainerConfig) -> None:
+    ip = socket.gethostbyname(cc.name)
 
     run_command(
-        ['podman', 'rm', '-if', name]
+        ['podman', 'rm', '-if', cc.name]
     )
 
     run_command(
         [
             'podman', 'create',
-            '--name', name,
+            '--name', cc.name,
             '--conmon-pidfile', cc.pid_file,
             '--log-driver', 'journald',
-            '--hostname', name,
-            '--volume', f'{data_dir}:/data',
+            '--hostname', cc.name,
+            '--volume', f'{cc.data_path}:/data',
             '--network', 'static',
             '--ip', ip,
             '--subuidname', cc.user_name,
@@ -240,7 +241,7 @@ def cmd_shell(args: argparse.Namespace) -> None:
     cc = setup_container(args, False)
 
     run_command(
-        ['podman', 'exec', '-it', cc.container, '/bin/bash']
+        ['podman', 'exec', '-it', cc.name, '/bin/bash']
     )
 
 
@@ -252,7 +253,7 @@ def cmd_exec(args: argparse.Namespace) -> None:
         cmd.append('--tty')
     if args.user is not None:
         cmd.extend(['--user', args.user])
-    cmd.append(cc.container)
+    cmd.append(cc.name)
     cmd.extend(args.arg)
 
     run_command(cmd)
@@ -282,33 +283,36 @@ def cmd_rsync(args: argparse.Namespace) -> None:
     cmd = ['podman', 'exec', '-i']
     if user is not None:
         cmd.extend(['--user', user])
-    cmd.append(cc.container)
+    cmd.append(cc.name)
     cmd.extend(rsync)
 
     run_command(cmd)
 
 
 def cmd_list(args: argparse.Namespace) -> None:
-    for conf in Path(config.container_config_dir).iterdir():
+    for conf in config.container_config_path.iterdir():
         if conf.suffix == '.toml':
             cc = ContainerConfig.load(config, conf.stem)
             if args.all or check_rights(cc, args.as_user, args.as_groups):
-                print(cc.container)
+                print(cc.name)
 
 
 def main_service_start():
     # Service helper for service start, called by root
 
     if len(sys.argv) != 2:
-        die("Expected arguments: container")
+        die("Expected arguments: name")
 
     config = load_config()
     cc = ContainerConfig.load(config, sys.argv[1])
 
-    pid_file = f'/run/shc/{cc.container}.pid'
+    # Just to be sure
+    run_command(['podman', 'stop', '--ignore', cc.name])
+
+    pid_file = f'/run/shc/{cc.name}.pid'
     Path(pid_file).unlink(missing_ok=True)
 
-    run_command(['podman', 'start', cc.container])
+    run_command(['podman', 'start', cc.name])
 
 
 def main_service_stop():
@@ -320,7 +324,7 @@ def main_service_stop():
     config = load_config()
     cc = ContainerConfig.load(config, sys.argv[1])
 
-    run_command(['podman', 'stop', '--ignore', cc.container])
+    run_command(['podman', 'stop', '--ignore', cc.name])
 
 
 def parse_int_list(s: str) -> List[int]: