Reduce unnecessary file downloading in archive/file states

salt/fileclient.py

@@ -185,12 +185,13 @@ def file_list_emptydirs(self, saltenv=u'base', prefix=u''):
         '''
         raise NotImplementedError
 
-    def cache_file(self, path, saltenv=u'base', cachedir=None):
+    def cache_file(self, path, saltenv=u'base', cachedir=None, source_hash=None):
         '''
         Pull a file down from the file server and store it in the minion
         file cache
         '''
-        return self.get_url(path, u'', True, saltenv, cachedir=cachedir)
+        return self.get_url(
+            path, u'', True, saltenv, cachedir=cachedir, source_hash=source_hash)
 
     def cache_files(self, paths, saltenv=u'base', cachedir=None):
         '''
@@ -470,7 +471,7 @@ def get_dir(self, path, dest=u'', saltenv=u'base', gzip=None,
         return ret
 
     def get_url(self, url, dest, makedirs=False, saltenv=u'base',
-                no_cache=False, cachedir=None):
+                no_cache=False, cachedir=None, source_hash=None):
         '''
         Get a single file from a URL.
         '''
@@ -525,14 +526,28 @@ def get_url(self, url, dest, makedirs=False, saltenv=u'base',
                     return u''
         elif not no_cache:
             dest = self._extrn_path(url, saltenv, cachedir=cachedir)
+            if source_hash is not None:
+                try:
+                    source_hash = source_hash.split('=')[-1]
+                    form = salt.utils.files.HASHES_REVMAP[len(source_hash)]
+                    if salt.utils.get_hash(dest, form) == source_hash:
+                        log.debug(
+                            'Cached copy of %s (%s) matches source_hash %s, '
+                            'skipping download', url, dest, source_hash
+                        )
+                        return dest
+                except (AttributeError, KeyError, IOError, OSError):
+                    pass
             destdir = os.path.dirname(dest)
             if not os.path.isdir(destdir):
                 os.makedirs(destdir)
 
         if url_data.scheme == u's3':
             try:
                 def s3_opt(key, default=None):
-                    u'''Get value of s3.<key> from Minion config or from Pillar'''
+                    '''
+                    Get value of s3.<key> from Minion config or from Pillar
+                    '''
                     if u's3.' + key in self.opts:
                         return self.opts[u's3.' + key]
                     try:
@@ -785,7 +800,7 @@ def get_template(
 
     def _extrn_path(self, url, saltenv, cachedir=None):
         '''
-        Return the extn_filepath for a given url
+        Return the extrn_filepath for a given url
         '''
         url_data = urlparse(url)
         if salt.utils.platform.is_windows():

salt/modules/archive.py

@@ -60,7 +60,8 @@ def list_(name,
           strip_components=None,
           clean=False,
           verbose=False,
-          saltenv='base'):
+          saltenv='base',
+          source_hash=None):
     '''
     .. versionadded:: 2016.11.0
     .. versionchanged:: 2016.11.2
@@ -149,6 +150,14 @@ def list_(name,
         ``archive``. This is only applicable when ``archive`` is a file from
         the ``salt://`` fileserver.
 
+    source_hash
+        If ``name`` is an http(s)/ftp URL and the file exists in the minion's
+        file cache, this option can be passed to keep the minion from
+        re-downloading the archive if the cached copy matches the specified
+        hash.
+
+        .. versionadded:: Oxygen
+
     .. _tarfile: https://docs.python.org/2/library/tarfile.html
     .. _xz: http://tukaani.org/xz/
 
@@ -160,6 +169,7 @@ def list_(name,
             salt '*' archive.list /path/to/myfile.tar.gz strip_components=1
             salt '*' archive.list salt://foo.tar.gz
             salt '*' archive.list https://domain.tld/myfile.zip
+            salt '*' archive.list https://domain.tld/myfile.zip source_hash=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15
             salt '*' archive.list ftp://10.1.2.3/foo.rar
     '''
     def _list_tar(name, cached, decompress_cmd, failhard=False):
@@ -309,7 +319,7 @@ def _list_rar(name, cached):
                 )
         return dirs, files, []
 
-    cached = __salt__['cp.cache_file'](name, saltenv)
+    cached = __salt__['cp.cache_file'](name, saltenv, source_hash=source_hash)
     if not cached:
         raise CommandExecutionError('Failed to cache {0}'.format(name))
 
@@ -1094,7 +1104,7 @@ def unzip(zip_file,
     return _trim_files(cleaned_files, trim_output)
 
 
-def is_encrypted(name, clean=False, saltenv='base'):
+def is_encrypted(name, clean=False, saltenv='base', source_hash=None):
     '''
     .. versionadded:: 2016.11.0
 
@@ -1113,6 +1123,18 @@ def is_encrypted(name, clean=False, saltenv='base'):
             If there is an error listing the archive's contents, the cached
             file will not be removed, to allow for troubleshooting.
 
+    saltenv : base
+        Specifies the fileserver environment from which to retrieve
+        ``archive``. This is only applicable when ``archive`` is a file from
+        the ``salt://`` fileserver.
+
+    source_hash
+        If ``name`` is an http(s)/ftp URL and the file exists in the minion's
+        file cache, this option can be passed to keep the minion from
+        re-downloading the archive if the cached copy matches the specified
+        hash.
+
+        .. versionadded:: Oxygen
 
     CLI Examples:
 
@@ -1122,9 +1144,10 @@ def is_encrypted(name, clean=False, saltenv='base'):
             salt '*' archive.is_encrypted salt://foo.zip
             salt '*' archive.is_encrypted salt://foo.zip saltenv=dev
             salt '*' archive.is_encrypted https://domain.tld/myfile.zip clean=True
+            salt '*' archive.is_encrypted https://domain.tld/myfile.zip source_hash=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15
             salt '*' archive.is_encrypted ftp://10.1.2.3/foo.zip
     '''
-    cached = __salt__['cp.cache_file'](name, saltenv)
+    cached = __salt__['cp.cache_file'](name, saltenv, source_hash=source_hash)
     if not cached:
         raise CommandExecutionError('Failed to cache {0}'.format(name))
 

salt/modules/cp.py

@@ -352,7 +352,7 @@ def get_dir(path, dest, saltenv='base', template=None, gzip=None, **kwargs):
     return _client().get_dir(path, dest, saltenv, gzip)
 
 
-def get_url(path, dest='', saltenv='base', makedirs=False):
+def get_url(path, dest='', saltenv='base', makedirs=False, source_hash=None):
     '''
     .. versionchanged:: Oxygen
         ``dest`` can now be a directory
@@ -386,6 +386,13 @@ def get_url(path, dest='', saltenv='base', makedirs=False):
         Salt fileserver envrionment from which to retrieve the file. Ignored if
         ``path`` is not a ``salt://`` URL.
 
+    source_hash
+        If ``path`` is an http(s) or ftp URL and the file exists in the
+        minion's file cache, this option can be passed to keep the minion from
+        re-downloading the file if the cached copy matches the specified hash.
+
+        .. versionadded:: Oxygen
+
     CLI Example:
 
     .. code-block:: bash
@@ -394,9 +401,11 @@ def get_url(path, dest='', saltenv='base', makedirs=False):
         salt '*' cp.get_url http://www.slashdot.org /tmp/index.html
     '''
     if isinstance(dest, six.string_types):
-        result = _client().get_url(path, dest, makedirs, saltenv)
+        result = _client().get_url(
+            path, dest, makedirs, saltenv, source_hash=source_hash)
     else:
-        result = _client().get_url(path, None, makedirs, saltenv, no_cache=True)
+        result = _client().get_url(
+            path, None, makedirs, saltenv, no_cache=True, source_hash=source_hash)
     if not result:
         log.error(
             'Unable to fetch file {0} from saltenv {1}.'.format(
@@ -429,11 +438,18 @@ def get_file_str(path, saltenv='base'):
     return fn_
 
 
-def cache_file(path, saltenv='base'):
+def cache_file(path, saltenv='base', source_hash=None):
     '''
     Used to cache a single file on the Minion
 
-    Returns the location of the new cached file on the Minion.
+    Returns the location of the new cached file on the Minion
+
+    source_hash
+        If ``name`` is an http(s) or ftp URL and the file exists in the
+        minion's file cache, this option can be passed to keep the minion from
+        re-downloading the file if the cached copy matches the specified hash.
+
+        .. versionadded:: Oxygen
 
     CLI Example:
 
@@ -485,7 +501,7 @@ def cache_file(path, saltenv='base'):
     if senv:
         saltenv = senv
 
-    result = _client().cache_file(path, saltenv)
+    result = _client().cache_file(path, saltenv, source_hash=source_hash)
     if not result:
         log.error(
             u'Unable to cache file \'%s\' from saltenv \'%s\'.',

salt/modules/file.py

@@ -60,23 +60,14 @@
 import salt.utils.templates
 import salt.utils.url
 from salt.exceptions import CommandExecutionError, MinionError, SaltInvocationError, get_error_message as _get_error_message
+from salt.utils.files import HASHES, HASHES_REVMAP
 
 log = logging.getLogger(__name__)
 
 __func_alias__ = {
     'makedirs_': 'makedirs'
 }
 
-HASHES = {
-    'sha512': 128,
-    'sha384': 96,
-    'sha256': 64,
-    'sha224': 56,
-    'sha1': 40,
-    'md5': 32,
-}
-HASHES_REVMAP = dict([(y, x) for x, y in six.iteritems(HASHES)])
-
 
 def __virtual__():
     '''
@@ -3767,14 +3758,8 @@ def source_list(source, source_hash, saltenv):
                         ret = (single_src, single_hash)
                         break
                 elif proto.startswith('http') or proto == 'ftp':
-                    try:
-                        if __salt__['cp.cache_file'](single_src):
-                            ret = (single_src, single_hash)
-                            break
-                    except MinionError as exc:
-                        # Error downloading file. Log the caught exception and
-                        # continue on to the next source.
-                        log.exception(exc)
+                    ret = (single_src, single_hash)
+                    break
                 elif proto == 'file' and os.path.exists(urlparsed_single_src.path):
                     ret = (single_src, single_hash)
                     break
@@ -3794,9 +3779,8 @@ def source_list(source, source_hash, saltenv):
                     ret = (single, source_hash)
                     break
                 elif proto.startswith('http') or proto == 'ftp':
-                    if __salt__['cp.cache_file'](single):
-                        ret = (single, source_hash)
-                        break
+                    ret = (single, source_hash)
+                    break
                 elif single.startswith('/') and os.path.exists(single):
                     ret = (single, source_hash)
                     break
@@ -4007,11 +3991,14 @@ def _get_local_file_source_sum(path):
             else:
                 sfn = cached_dest
 
-        # If we didn't have the template or remote file, let's get it
-        # Similarly when the file has been updated and the cache has to be refreshed
+        # If we didn't have the template or remote file, or the file has been
+        # updated and the cache has to be refreshed, download the file.
         if not sfn or cache_refetch:
             try:
-                sfn = __salt__['cp.cache_file'](source, saltenv)
+                sfn = __salt__['cp.cache_file'](
+                    source,
+                    saltenv,
+                    source_hash=source_sum.get('hsum'))
             except Exception as exc:
                 # A 404 or other error code may raise an exception, catch it
                 # and return a comment that will fail the calling state.
@@ -4675,15 +4662,18 @@ def check_file_meta(
     '''
     changes = {}
     if not source_sum:
-        source_sum = dict()
+        source_sum = {}
     lstats = stats(name, hash_type=source_sum.get('hash_type', None), follow_symlinks=False)
     if not lstats:
         changes['newfile'] = name
         return changes
     if 'hsum' in source_sum:
         if source_sum['hsum'] != lstats['sum']:
             if not sfn and source:
-                sfn = __salt__['cp.cache_file'](source, saltenv)
+                sfn = __salt__['cp.cache_file'](
+                    source,
+                    saltenv,
+                    source_hash=source_sum['hsum'])
             if sfn:
                 try:
                     changes['diff'] = get_diff(
@@ -4750,7 +4740,9 @@ def get_diff(file1,
              saltenv='base',
              show_filenames=True,
              show_changes=True,
-             template=False):
+             template=False,
+             source_hash_file1=None,
+             source_hash_file2=None):
     '''
     Return unified diff of two files
 
@@ -4785,6 +4777,22 @@ def get_diff(file1,
 
         .. versionadded:: Oxygen
 
+    source_hash_file1
+        If ``file1`` is an http(s)/ftp URL and the file exists in the minion's
+        file cache, this option can be passed to keep the minion from
+        re-downloading the archive if the cached copy matches the specified
+        hash.
+
+        .. versionadded:: Oxygen
+
+    source_hash_file2
+        If ``file2`` is an http(s)/ftp URL and the file exists in the minion's
+        file cache, this option can be passed to keep the minion from
+        re-downloading the archive if the cached copy matches the specified
+        hash.
+
+        .. versionadded:: Oxygen
+
     CLI Examples:
 
     .. code-block:: bash
@@ -4793,14 +4801,17 @@ def get_diff(file1,
         salt '*' file.get_diff /tmp/foo.txt /tmp/bar.txt
     '''
     files = (file1, file2)
+    source_hashes = (source_hash_file1, source_hash_file2)
     paths = []
     errors = []
 
-    for filename in files:
+    for filename, source_hash in zip(files, source_hashes):
         try:
             # Local file paths will just return the same path back when passed
             # to cp.cache_file.
-            cached_path = __salt__['cp.cache_file'](filename, saltenv)
+            cached_path = __salt__['cp.cache_file'](filename,
+                                                    saltenv,
+                                                    source_hash=source_hash)
             if cached_path is False:
                 errors.append(
                     u'File {0} not found'.format(