add a path_join filter which joins path components (#62713)

changelogs/fragments/62713-add-path_join-filter.yaml

@@ -0,0 +1,2 @@
+minor_changes:
+    - core filters - Adding ``path_join`` filter to the core filters list

docs/docsite/rst/user_guide/playbooks_filters.rst

@@ -1308,6 +1308,12 @@ To get the root and extension of a path or filename (new in version 2.0)::
     # with path == 'nginx.conf' the return would be ('nginx', '.conf')
     {{ path | splitext }}
 
+To join one or more path components::
+
+    {{ ('/etc', path, 'subdir', file) | path_join }}
+
+.. versionadded:: 2.10
+
 String filters
 ==============
 

lib/ansible/plugins/filter/core.py

@@ -581,6 +581,17 @@ def random_mac(value, seed=None):
     return value + re.sub(r'(..)', r':\1', rnd)
 
 
+def path_join(paths):
+    ''' takes a sequence or a string, and return a concatenation
+        of the different members '''
+    if isinstance(paths, string_types):
+        return os.path.join(paths)
+    elif is_sequence(paths):
+        return os.path.join(*paths)
+    else:
+        raise AnsibleFilterError("|path_join expects string or sequence, got %s instead." % type(paths))
+
+
 class FilterModule(object):
     ''' Ansible core jinja2 filters '''
 
@@ -612,6 +623,7 @@ class FilterModule(object):
             'dirname': partial(unicode_wrap, os.path.dirname),
             'expanduser': partial(unicode_wrap, os.path.expanduser),
             'expandvars': partial(unicode_wrap, os.path.expandvars),
+            'path_join': path_join,
             'realpath': partial(unicode_wrap, os.path.realpath),
             'relpath': partial(unicode_wrap, os.path.relpath),
             'splitext': partial(unicode_wrap, os.path.splitext),

test/integration/targets/filters/files/foo.txt

@@ -52,6 +52,10 @@ files to exist and are passthrus to the python os.path functions
 /etc/motd with basename = motd
 /etc/motd with dirname  = /etc
 
+path_join_simple = /etc/subdir/test
+path_join_with_slash = /test
+path_join_relative = etc/subdir/test
+
 TODO: realpath follows symlinks.  There isn't a test for this just now.
 
 TODO: add tests for set theory operations like union

test/integration/targets/filters/templates/foo.j2

@@ -46,6 +46,10 @@ files to exist and are passthrus to the python os.path functions
 /etc/motd with basename = {{ '/etc/motd' | basename }}
 /etc/motd with dirname  = {{ '/etc/motd' | dirname }}
 
+path_join_simple = {{ ('/etc', 'subdir', 'test') | path_join }}
+path_join_with_slash = {{ ('/etc', 'subdir', '/test') | path_join }}
+path_join_relative = {{ ('etc', 'subdir', 'test') | path_join }}
+
 TODO: realpath follows symlinks.  There isn't a test for this just now.
 
 TODO: add tests for set theory operations like union