[fix] The deployer runtime_deploy should preserve symlinks (#17824)

* Validate runtime deploy with symlinks

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Preserve previous method structure

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Use fnmatch for preserve symlinks

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Do not copy symlinks when not requested

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Add comment about testing in Windows

Co-authored-by: James <memsharded@gmail.com>

* Validate links

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Skip symlink check on Windows

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Validate when not using synlink

Signed-off-by: Uilian Ries <uilianries@gmail.com>

---------

Signed-off-by: Uilian Ries <uilianries@gmail.com>
Co-authored-by: James <memsharded@gmail.com>

Author: uilianries

conan/internal/deploy.py

@@ -1,6 +1,7 @@
 import filecmp
 import os
 import shutil
+import fnmatch
 
 from conan.internal.cache.home_paths import HomePaths
 from conan.api.output import ConanOutput
@@ -99,6 +100,8 @@ def full_deploy(graph, output_folder):
 def runtime_deploy(graph, output_folder):
     """
     Deploy all the shared libraries and the executables of the dependencies in a flat directory.
+
+    It preserves symlinks in case the configuration tools.deployer:symlinks is True.
     """
     conanfile = graph.root.conanfile
     output = ConanOutput(scope="runtime_deploy")
@@ -125,7 +128,7 @@ def runtime_deploy(graph, output_folder):
             if not os.path.isdir(libdir):
                 output.warning(f"{dep.ref} {libdir} does not exist")
                 continue
-            count += _flatten_directory(dep, libdir, output_folder, symlinks, [".dylib", ".so"])
+            count += _flatten_directory(dep, libdir, output_folder, symlinks, [".dylib*", ".so*"])
 
         output.info(f"Copied {count} files from {dep.ref}")
     conanfile.output.success(f"Runtime deployed to folder: {output_folder}")
@@ -142,11 +145,15 @@ def _flatten_directory(dep, src_dir, output_dir, symlinks, extension_filter=None
     output = ConanOutput(scope="runtime_deploy")
     for src_dirpath, _, src_filenames in os.walk(src_dir, followlinks=symlinks):
         for src_filename in src_filenames:
-            if extension_filter and not any(src_filename.endswith(ext) for ext in extension_filter):
+            if extension_filter and not any(fnmatch.fnmatch(src_filename, f'*{ext}') for ext in extension_filter):
                 continue
 
             src_filepath = os.path.join(src_dirpath, src_filename)
             dest_filepath = os.path.join(output_dir, src_filename)
+
+            if not symlinks and os.path.islink(src_filepath):
+                continue
+
             if os.path.exists(dest_filepath):
                 if filecmp.cmp(src_filepath, dest_filepath):  # Be efficient, do not copy
                     output.verbose(f"{dest_filepath} exists with same contents, skipping copy")
@@ -156,7 +163,9 @@ def _flatten_directory(dep, src_dir, output_dir, symlinks, extension_filter=None
 
             try:
                 file_count += 1
-                shutil.copy2(src_filepath, dest_filepath, follow_symlinks=symlinks)
+                # INFO: When follow_symlinks is false, and src is a symbolic link, it tries to
+                # copy all metadata from the src symbolic link to the newly created dst link
+                shutil.copy2(src_filepath, dest_filepath, follow_symlinks=not symlinks)
                 output.verbose(f"Copied {src_filepath} into {output_dir}")
             except Exception as e:
                 if "WinError 1314" in str(e):

test/functional/command/test_install_deploy.py

@@ -511,6 +511,47 @@ def package_info(self):
         expected = sorted(["pkga.so", "pkgb.so", "pkga.dll"])
         assert sorted(os.listdir(os.path.join(c.current_folder, "myruntime"))) == expected
 
+@pytest.mark.parametrize("symlink, expected",
+                         [(True, ["libfoo.so.0.1.0", "libfoo.so.0", "libfoo.so"]),
+                          (False, ["libfoo.so.0.1.0",])])
+def test_runtime_deploy_symlinks(symlink, expected):
+    """ The deployer runtime_deploy should preserve symlinks when deploying shared libraries
+    """
+    c = TestClient()
+    conanfile = textwrap.dedent("""
+           from conan import ConanFile
+           from conan.tools.files import copy, chdir
+           import os
+           class Pkg(ConanFile):
+               package_type = "shared-library"
+               def package(self):
+                   copy(self, "*.so*", src=self.build_folder, dst=self.package_folder)
+                   with chdir(self, os.path.join(self.package_folder, "lib")):
+                       os.symlink(src="libfoo.so.0.1.0", dst="libfoo.so.0")
+                       os.symlink(src="libfoo.so.0", dst="libfoo.so")
+           """)
+    c.save({"foo/conanfile.py": conanfile,
+            "foo/lib/libfoo.so.0.1.0": "",})
+    c.run("export-pkg foo/ --name=foo --version=0.1.0")
+    c.run(f"install --requires=foo/0.1.0 --deployer=runtime_deploy --deployer-folder=output -c:a tools.deployer:symlinks={symlink}")
+
+    sorted_expected = sorted(expected)
+    assert sorted(os.listdir(os.path.join(c.current_folder, "output"))) == sorted_expected
+    link_so_0 = os.path.join(c.current_folder, "output", "libfoo.so.0")
+    link_so = os.path.join(c.current_folder, "output", "libfoo.so")
+    lib = os.path.join(c.current_folder, "output", "libfoo.so.0.1.0")
+    # INFO: This test requires in Windows to have symlinks enabled, otherwise it will fail
+    if symlink and platform.system() != "Windows":
+        assert os.path.islink(link_so_0)
+        assert os.path.islink(link_so)
+        assert not os.path.isabs(os.readlink(link_so_0))
+        assert not os.path.isabs(os.readlink(os.path.join(link_so)))
+        assert os.path.realpath(link_so) == os.path.realpath(link_so_0)
+        assert os.path.realpath(link_so_0) == os.path.realpath(lib)
+        assert not os.path.islink(lib)
+    else:
+        assert not os.path.islink(lib)
+
 
 def test_deployer_errors():
     c = TestClient()