Improve exception handling

shlax/actions/copy.py

@@ -3,6 +3,8 @@ import binascii
 import glob
 import os
 
+from ..exceptions import ShlaxException
+
 
 class Copy:
     def __init__(self, *args):
@@ -15,12 +17,16 @@ class Copy:
             else:
                 self.src.append(src)
 
-    def listfiles(self):
+    async def listfiles(self, target):
         if getattr(self, '_listfiles', None):
             return self._listfiles
 
         result = []
         for src in self.src:
+            if not await target.parent.exists(src):
+                target.output.fail(self)
+                raise ShlaxException(f'File not found {src}')
+
             if os.path.isfile(src):
                 result.append(src)
                 continue
@@ -39,7 +45,7 @@ class Copy:
     async def __call__(self, target):
         await target.mkdir(self.dst)
 
-        for path in self.listfiles():
+        for path in await self.listfiles(target):
             if os.path.isdir(path):
                 await target.mkdir(os.path.join(self.dst, path))
             elif '/' in path:
@@ -55,9 +61,11 @@ class Copy:
     def __str__(self):
         return f'Copy({", ".join(self.src)}, {self.dst})'
 
-    async def cachekey(self):
+    async def cachekey(self, target):
         async def chksum(path):
             with open(path, 'rb') as f:
                 return (path, str(binascii.crc32(f.read())))
-        results = await asyncio.gather(*[chksum(f) for f in self.listfiles()])
+        results = await asyncio.gather(
+            *[chksum(f) for f in await self.listfiles(target)]
+        )
         return {path: chks for path, chks in results}

shlax/actions/packages.py

@@ -27,28 +27,33 @@ class Packages:
             update='apk update',
             upgrade='apk upgrade',
             install='apk add',
+            host=None,
         ),
         apt=dict(
             update='apt-get -y update',
             upgrade='apt-get -y upgrade',
             install='apt-get -y --no-install-recommends install',
+            host=None,
         ),
         pacman=dict(
             update='pacman -Sy',
             upgrade='pacman -Su --noconfirm',
             install='pacman -S --noconfirm',
             lastupdate='stat -c %Y /var/lib/pacman/sync/core.db',
+            host='/var/lib/pacman',
         ),
         dnf=dict(
             update='dnf makecache --assumeyes',
             upgrade='dnf upgrade --best --assumeyes --skip-broken',  # noqa
             install='dnf install --setopt=install_weak_deps=False --best --assumeyes',  # noqa
             lastupdate='stat -c %Y /var/cache/dnf/* | head -n1',
+            host=None,
         ),
         yum=dict(
             update='yum update',
             upgrade='yum upgrade',
             install='yum install',
+            host=None,
         ),
     )
 
@@ -62,6 +67,12 @@ class Packages:
             self.packages += line.split(' ')
 
     async def cache_setup(self, target):
+        # Try to use the host cache directory if present rather than home
+        # directory, in cases where host and guest are the same distros
+        hostpath = self.mgrs[self.mgr]['host']
+        if target.exists(hostpath):
+            self.cache_root = hostpath
+
         if 'CACHE_DIR' in os.environ:
             self.cache_root = os.path.join(os.getenv('CACHE_DIR'))
         else:

shlax/cli.py

@@ -13,7 +13,7 @@ import importlib
 import os
 import sys
 
-from .proc import ProcFailure
+from .exceptions import ShlaxException
 
 
 class Group(cli2.Group):
@@ -57,10 +57,11 @@ class Command(cli2.Command):
 
         try:
             result = super().__call__(*argv)
-        except ProcFailure:
+        except ShlaxException as exc:
             # just output the failure without TB, as command was already
             # printed anyway
-            pass
+            self.exit_code = 1
+            self['target'].value.output.fail(exc)
 
         if self['target'].value.results:
             if self['target'].value.results[-1].status == 'failure':

shlax/proc.py

@@ -7,10 +7,11 @@ import os
 import shlex
 import sys
 
+from .exceptions import ShlaxException
 from .output import Output
 
 
-class ProcFailure(Exception):
+class ProcFailure(ShlaxException):
     def __init__(self, proc):
         self.proc = proc
 

shlax/targets/buildah.py

@@ -88,7 +88,7 @@ class Buildah(Target):
                 prefix = tag
                 break
         if hasattr(action, 'cachekey'):
-            action_key = action.cachekey()
+            action_key = action.cachekey(self)
             if asyncio.iscoroutine(action_key):
                 action_key = str(await action_key)
         else: