[pve-devel] [RFC PATCH container] setup: ability to ignore files

[Wolfgang Bumiller]

Make the ct_* file wrapper functions ignore files for which
a file named .pve-ignore.$name exists.
---

This uses a .pve-ignore prefix. Another option would be a suffix. I'm
not sure which is better, but personally I like to keep annoying files
like that "hidden" from my standard view.

 src/PVE/LXC/Setup/Base.pm                      | 22 ++++++++++++++++++++++
 src/test/test-debian-012/etc/.pve-ignore.hosts |  0
 src/test/test-debian-012/etc/hosts             |  2 ++
 src/test/test-debian-012/etc/hosts.exp         |  2 ++
 4 files changed, 26 insertions(+)
 create mode 100644 src/test/test-debian-012/etc/.pve-ignore.hosts
 create mode 100644 src/test/test-debian-012/etc/hosts
 create mode 100644 src/test/test-debian-012/etc/hosts.exp

diff --git a/src/PVE/LXC/Setup/Base.pm b/src/PVE/LXC/Setup/Base.pm
index 1490578..83bad3e 100644
--- a/src/PVE/LXC/Setup/Base.pm
+++ b/src/PVE/LXC/Setup/Base.pm
@@ -10,6 +10,7 @@ use Encode;
 use Fcntl;
 use File::Path;
 use File::Spec;
+use File::Basename;
 
 use PVE::INotify;
 use PVE::Tools;
@@ -446,10 +447,25 @@ sub post_create_hook {
 # File access wrappers for container setup code.
 # For user-namespace support these might need to take uid and gid maps into account.
 
+sub ct_is_file_ignored {
+    my ($self, $file) = @_;
+    my ($name, $path) = fileparse($file);
+    return -f "$path/.pve-ignore.$name";
+}
+
+sub ct_filter_ignored_files {
+    my $self = shift;
+    grep { !$self->ct_is_file_ignored($_) } @_;
+}
+
 sub ct_reset_ownership {
     my ($self, @files) = @_;
     my $conf = $self->{conf};
     return if !$self->{id_map};
+
+    @files = $self->ct_filter_ignored_files(@files);
+    return if !@files;
+
     my $uid = $self->{rootuid};
     my $gid = $self->{rootgid};
     chown($uid, $gid, @files);
@@ -468,12 +484,14 @@ sub ct_mkdir {
 sub ct_unlink {
     my ($self, @files) = @_;
     foreach my $file (@files) {
+	next if $self->ct_is_file_ignored($file);
 	CORE::unlink($file);
     }
 }
 
 sub ct_rename {
     my ($self, $old, $new) = @_;
+    return if $self->ct_is_file_ignored($new);
     CORE::rename($old, $new);
 }
 
@@ -486,6 +504,7 @@ sub ct_open_file_read {
 sub ct_open_file_write {
     my $self = shift;
     my $file = shift;
+    $file = '/dev/null' if $self->ct_is_file_ignored($file);
     my $fh = IO::File->new($file, O_WRONLY | O_CREAT, @_);
     $self->ct_reset_ownership($fh);
     return $fh;
@@ -507,6 +526,7 @@ sub ct_make_path {
 
 sub ct_symlink {
     my ($self, $old, $new) = @_;
+    return if $self->ct_is_file_ignored($new);
     return CORE::symlink($old, $new);
 }
 
@@ -552,6 +572,7 @@ sub ct_file_get_contents {
 
 sub ct_file_set_contents {
     my ($self, $file, $data, $perms) = @_;
+    return if $self->ct_is_file_ignored($file);
     PVE::Tools::file_set_contents($file, $data, $perms);
     $self->ct_reset_ownership($file);
 }
@@ -560,6 +581,7 @@ sub ct_file_set_contents {
 # Optionally if the file becomes empty it will be deleted.
 sub ct_modify_file {
     my ($self, $file, $data, %options) = @_;
+    return if $self->ct_is_file_ignored($file);
 
     my $head = "# --- BEGIN PVE ---\n";
     my $tail = "# --- END PVE ---\n";
diff --git a/src/test/test-debian-012/etc/.pve-ignore.hosts b/src/test/test-debian-012/etc/.pve-ignore.hosts
new file mode 100644
index 0000000..e69de29
diff --git a/src/test/test-debian-012/etc/hosts b/src/test/test-debian-012/etc/hosts
new file mode 100644
index 0000000..6e62c35
--- /dev/null
+++ b/src/test/test-debian-012/etc/hosts
@@ -0,0 +1,2 @@
+This is my hosts file.
+And you're not allowed to change it!
diff --git a/src/test/test-debian-012/etc/hosts.exp b/src/test/test-debian-012/etc/hosts.exp
new file mode 100644
index 0000000..6e62c35
--- /dev/null
+++ b/src/test/test-debian-012/etc/hosts.exp
@@ -0,0 +1,2 @@
+This is my hosts file.
+And you're not allowed to change it!
-- 
2.1.4