postprocess: Allow add-files into /etc

Even though it's really `/usr/etc`. This is for greater consistency with
`postprocess-script` where it appears as `/etc`.

Closes: #997
Approved by: jlebon

src/libpriv/rpmostree-postprocess.c

@@ -1273,6 +1273,17 @@ rpmostree_copy_additional_files (int            rootfs_dfd,
       dest += strspn (dest, "/");
       if (!*dest)
         return glnx_throw (error, "Invalid destination in add-files");
+      /* At this point on the filesystem level, the /etc content is already in
+       * /usr/etc. But let's be nice and allow people to use add-files into /etc
+       * and have it appear in /usr/etc; in most cases we want /usr/etc to just
+       * be a libostree implementation detail.
+       */
+      g_autofree char *dest_owned = NULL;
+      if (g_str_has_prefix (dest, "etc/"))
+        {
+          dest_owned = g_strconcat ("usr/", dest, NULL);
+          dest = dest_owned;
+        }
 
       g_print ("Adding file '%s'\n", dest);
 

tests/compose-tests/test-misc-tweaks.sh

@@ -13,11 +13,15 @@ pysetjsonmember "default_target" '"multi-user.target"'
 pyappendjsonmember "packages" '["tuned"]'
 pysetjsonmember "units" '["tuned.service"]'
 # And test adding/removing files
-pysetjsonmember "add-files" '[["foo.txt", "/usr/etc/foo.txt"]]'
+pysetjsonmember "add-files" '[["foo.txt", "/usr/etc/foo.txt"],
+                              ["baz.txt", "/usr/share/baz.txt"],
+                              ["bar.txt", "/etc/bar.txt"]]'
 pysetjsonmember "remove-files" '["etc/hosts"]'
 pysetjsonmember "remove-from-packages" '[["setup", "/etc/hosts\..*"]]'
 rnd=$RANDOM
 echo $rnd > composedata/foo.txt
+echo bar > composedata/bar.txt
+echo baz > composedata/baz.txt
 # Test tmp-is-dir
 pysetjsonmember "tmp-is-dir" 'True'
 
@@ -44,6 +48,10 @@ echo "ok enable units"
 # Tests for files
 ostree --repo=${repobuild} cat ${treeref} /usr/etc/foo.txt > out.txt
 assert_file_has_content out.txt $rnd
+ostree --repo=${repobuild} cat ${treeref} /usr/etc/bar.txt > out.txt
+assert_file_has_content out.txt bar
+ostree --repo=${repobuild} cat ${treeref} /usr/share/baz.txt > out.txt
+assert_file_has_content out.txt baz
 echo "ok add-files"
 
 ostree --repo=${repobuild} ls ${treeref} /usr/etc > out.txt