Add config for yadm to create read-only template output

test/conftest.py

@@ -157,6 +157,7 @@ def supported_configs():
         "yadm.openssl-old",
         "yadm.openssl-program",
         "yadm.ssh-perms",
+        "yadm.template-read-only",
     ]
 
 

test/test_alt.py

@@ -292,6 +292,28 @@ def test_ensure_alt_path(runner, paths, style):
     assert run.out == ""
     assert paths.work.join(filename).read().strip() == "test-data"
 
+@pytest.mark.usefixtures("ds1_repo_copy")
+@pytest.mark.parametrize("readonly", [None, "true", "false"])
+def test_template_readonly(runner, yadm_cmd, paths, tst_sys, readonly):
+    """Remove write permission for template result file.
+
+    If the `yadm.template-read-only` configuration is not set to false,
+    the resulting file from processing a template should has no write permission.
+    """
+    # set the value of template read-only
+    if readonly:
+        runner(yadm_cmd("config", "yadm.template-read-only", readonly))
+
+    utils.create_alt_files(paths, f"##template.default")
+    run = runner(yadm_cmd("alt"))
+
+    for stale_path in [utils.ALT_FILE1, utils.ALT_FILE2]:
+        write_perm_mask = os.stat(paths.work.join(stale_path)).st_mode & 0o222
+        if readonly == "false":
+            assert write_perm_mask > 0
+        else:
+            assert write_perm_mask == 0
+
 
 def setup_standard_yadm_dir(paths):
     """Configure a yadm home within the work tree"""

yadm

@@ -540,6 +540,7 @@ function move_file() {
 
   mv -f "$temp_file" "$output"
   copy_perms "$input" "$output"
+  [ "$(config --bool yadm.template-read-only)" != "false" ] && chmod a-w "$output"
 }
 
 # ****** yadm Commands ******
@@ -1266,6 +1267,7 @@ yadm.openssl-ciphername
 yadm.openssl-old
 yadm.openssl-program
 yadm.ssh-perms
+yadm.template-read-only
 EOF
   printf '%s' "$msg"
 }

yadm.1

@@ -108,6 +108,9 @@ unnecessary to run this command, as yadm automatically processes alternates by
 default. This automatic behavior can be disabled by setting the configuration
 .I yadm.auto-alt
 to "false".
+The resulting file's write permission can be controlled with the
+.I yadm.template-read-only
+configuration.
 .TP
 .B bootstrap
 Execute
@@ -425,6 +428,10 @@ By default, the first "openssl" found in $PATH is used.
 Disable the permission changes to
 .IR $HOME/.ssh/* .
 This feature is enabled by default.
+.TP
+.B yadm.template-read-only
+Remove write permissions from the resulting template file.
+This feature is enabled by default.
 
 .RE
 The following five "local" configurations are not stored in the

yadm.md

@@ -67,7 +67,9 @@
               TEMPLATES sections. It is usually unnecessary to run  this  com‐
               mand,  as  yadm  automatically  processes alternates by default.
               This automatic behavior can be disabled by setting the  configu‐
-              ration yadm.auto-alt to "false".
+              ration  yadm.auto-alt  to  "false".   The resulting file's write
+              permission can be controlled  with  the  yadm.template-read-only
+              configuration.
 
        bootstrap
               Execute $HOME/.config/yadm/bootstrap if it exists.