[pve-devel] [PATCH v1 pve-storage 0/2] SSHFS Example Storage Plugin

[pve-devel] [PATCH v1 pve-storage 0/2] SSHFS Example Storage Plugin

[Max Carrara]

SSHFS Example Storage Plugin - v1
=================================

Add a custom storage plugin based on SSHFS [0] to serve as an example
for an upcoming storage plugin development guide. This plugin should
also be ready for production usage, though it would be nice to get some
more testing (and potentially performance-tuning) done.

The plugin demonstrates how the following things should be handled:
- handling sensitive properties (shout-out to Fiona [1])
  - the private key is copied to /etc/pve/priv/storage/${PRIV_KEY}.key
    instead of being put into /etc/pve/storage.cfg
  - on removal of the storage, the private key is also removed 
  - though not really that nicely supported via the CLI, updating the
    private key file is also handled
- making use of /etc/pve/priv/known_hosts for easy setup on a cluster
  and marking the storage as shared automatically
- connection checking (since it's a network storage)
- conditionally creating the mountpoint and mounting the storage if not
  already mounted
- unmounting the storage on removal (not deactivation!)
- handling "notes" and "protected" attributes for backups

Furthermore, the plugin lives in its own subdir inside `pve-storage`,
complete with its own `debian/` dir and `Makefile` in order to
demonstrate how to package a plugin for Debian.

NOTE: The plugin is *not* built via the top-level `Makefile` at the
moment.

How to Use & Test
-----------------

You'll need some kind guest you can SSH into with pubkey auth.
On that host, it's best to create some directory for SSHFS, e.g.:

    mkdir -p /srv/sshfs && chmod 750 /srv/sshfs

The plugin can easily be built via `make deb` inside
`example/sshfs-plugin`. Once built and installed on a different PVE host
of your choice, you should first deploy a private key for SSHFS, e.g.:

  ssh-copy-id -i ~/.ssh/id_my_private_key \
    -o UserKnownHostsFile=/etc/pve/priv/known_hosts [USER]@[HOST]

Then, using the deployed key, the storage can be added as follows:

  pvesm add sshfs [STOREID] \
    --username [USER] \
    --server [HOST] \
    --sshfs-remote-path /srv/sshfs \
    --path /mnt/path/to/storage \
    --sshfs-private-key ~/.ssh/id_my_private_key

The storage should then pop up in the UI. It should be functionally
equivalent to most other dir-based network storages, except that imports
aren't supported in order to keep the example from becoming too complex.

Would be nice if somebody could give this a spin! I think there's
definitely room for some performance improvements, but so far the
storage was doing *alright*. IOPS are terrible, though.

References
----------

[0]: https://github.com/libfuse/sshfs
[1]: https://lore.proxmox.com/pve-devel/20250404133204.239783-6-f.ebner@proxmox.com/

Older Versions
--------------

rfc-v1: https://lore.proxmox.com/pve-devel/20250328171209.503132-1-m.carrara@proxmox.com/

Summary of Changes
------------------

Max Carrara (2):
  example: sshfs plugin: add custom storage plugin for SSHFS
  example: sshfs plugin: package SSHFSPlugin.pm

 example/sshfs-plugin/Makefile                 |  71 ++++
 example/sshfs-plugin/debian/changelog         |   5 +
 example/sshfs-plugin/debian/control           |  22 +
 example/sshfs-plugin/debian/copyright         |  21 +
 example/sshfs-plugin/debian/rules             |  26 ++
 example/sshfs-plugin/debian/source/format     |   1 +
 example/sshfs-plugin/debian/triggers          |   1 +
 .../lib/PVE/Storage/Custom/SSHFSPlugin.pm     | 398 ++++++++++++++++++
 8 files changed, 545 insertions(+)
 create mode 100644 example/sshfs-plugin/Makefile
 create mode 100644 example/sshfs-plugin/debian/changelog
 create mode 100644 example/sshfs-plugin/debian/control
 create mode 100644 example/sshfs-plugin/debian/copyright
 create mode 100755 example/sshfs-plugin/debian/rules
 create mode 100644 example/sshfs-plugin/debian/source/format
 create mode 100644 example/sshfs-plugin/debian/triggers
 create mode 100644 example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm

-- 
2.39.5



_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel

[pve-devel] [PATCH v1 pve-storage 1/2] example: sshfs plugin: add custom storage plugin for SSHFS

[Max Carrara]

This commit adds an example implementation of a custom storage plugin
that uses SSHFS [0] as the underlying filesystem.

The implementation is very similar to that of the NFS plugin; as a
prerequisite, it is currently necessary to use pubkey auth and have
the host's root user's public key deployed to the remote host like so:

  ssh-copy-id -i ~/.ssh/id_my_private_key \
    -o UserKnownHostsFile=/etc/pve/priv/known_hosts [USER]@[HOST]

Then, the storage can be added as follows:

  pvesm add sshfs [STOREID] \
    --username [USER] \
    --server [HOST] \
    --sshfs-remote-path [ABS PATH ON REMOTE] \
    --path /mnt/path/to/storage \
    --sshfs-private-key ~/.ssh/id_my_private_key

If the host is part of a cluster, other nodes may connect to the
remote without any additional setup required. This is because we copy
the private key to `/etc/pve/priv/storage/$KEYNAME.key` and use the
cluster-wide `/etc/pve/priv/known_hosts` file. Also mark each SSHFS
storage as `shared` by default in order to make use of this.

Note: Because there's currently no way to officially and permanently
mark a storage as shared (like some built-in plugins [1]) set
`$scfg->{shared} = 1;` in `on_add_hook`. This has almost the same
effect as modifying `@PVE::Storage::Plugin::SHARED_STORAGE` directly,
except that the `shared` is written to `/etc/pve/storage.cfg`.

[0]: https://github.com/libfuse/sshfs
[1]: https://git.proxmox.com/?p=pve-storage.git;a=blob;f=src/PVE/Storage/Plugin.pm;h=4e16420f667f196e8eb99ae7c9f3f1d3e13791fb;hb=refs/heads/master#l37

Signed-off-by: Max Carrara <m.carrara@proxmox.com>
---
Changes rfc-v1 --> v1:
  * rework most of the plugin
  * cease to call methods of DirPlugin (plugins should be isolated;
    we don't want to encourage third-party devs to do that)
  * handle SSH private key as sensitive property and place it on pmxcfs
  * make storage shared
  * manually implement attribute handling ("notes", "protected" for
    backups)

 .../lib/PVE/Storage/Custom/SSHFSPlugin.pm     | 398 ++++++++++++++++++
 1 file changed, 398 insertions(+)
 create mode 100644 example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm

diff --git a/example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm b/example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm
new file mode 100644
index 0000000..75b29c1
--- /dev/null
+++ b/example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm
@@ -0,0 +1,398 @@
+package PVE::Storage::Custom::SSHFSPlugin;
+
+use strict;
+use warnings;
+
+use feature 'signatures';
+
+use Cwd qw();
+use Encode qw(decode encode);
+use File::Path qw(make_path);
+use File::Basename qw(dirname);
+use IO::File;
+use POSIX;
+
+use PVE::ProcFSTools;
+use PVE::Tools qw(
+    file_copy
+    file_get_contents
+    file_set_contents
+    run_command
+);
+
+use base qw(PVE::Storage::Plugin);
+
+my $CLUSTER_KNOWN_HOSTS = "/etc/pve/priv/known_hosts";
+
+# Plugin Definition
+
+sub api {
+    return 11;
+}
+
+sub type {
+    return 'sshfs';
+}
+
+sub plugindata {
+    return {
+	content => [
+	    {
+		images => 1,
+		rootdir => 1,
+		vztmpl => 1,
+		iso => 1,
+		backup => 1,
+		snippets => 1,
+		none => 1,
+	    },
+	    {
+		images => 1,
+		rootdir => 1,
+	    },
+	],
+	format => [
+	    {
+		raw => 1,
+		qcow2 => 1,
+		vmdk => 1,
+	    },
+	    'qcow2',
+	],
+	'sensitive-properties' => {
+	    'sshfs-private-key' => 1,
+	},
+    };
+}
+
+sub properties {
+    return {
+	'sshfs-remote-path' => {
+	    description => "Path on the remote filesystem used for SSHFS. Must be absolute.",
+	    type => 'string',
+	    format => 'pve-storage-path',
+	},
+	'sshfs-private-key' => {
+	    description => "Path to the private key to use for SSHFS.",
+	    type => 'string',
+	    format => 'pve-storage-path',
+	}
+    };
+}
+
+sub options {
+    return {
+	disable => { optional => 1 },
+	path => { fixed => 1 },
+	'create-base-path' => { optional => 1 },
+	content => { optional => 1 },
+	'create-subdirs' => { optional => 1 },
+	'content-dirs' => { optional => 1 },
+	'prune-backups' => { optional => 1 },
+	'max-protected-backups' => { optional => 1 },
+	format => { optional => 1 },
+	bwlimit => { optional => 1 },
+	preallocation => { optional => 1 },
+	nodes => { optional => 1 },
+	shared => { optional => 1 },
+
+	# SSHFS Options
+	username => {},
+	server => {},
+	'sshfs-remote-path' => {},
+	port => { optional => 1 },
+	'sshfs-private-key' => { optional => 1 },
+   };
+}
+
+# SSHFS Helpers
+
+my sub sshfs_remote_from_config: prototype($) ($scfg) {
+    my ($user, $host, $remote_path) = $scfg->@{qw(username server sshfs-remote-path)};
+    return "${user}\@${host}:${remote_path}";
+}
+
+my sub sshfs_private_key_path: prototype($) ($storeid) {
+    return "/etc/pve/priv/storage/$storeid.key";
+}
+
+my sub sshfs_common_ssh_opts: prototype($) ($storeid) {
+    my $private_key_path = sshfs_private_key_path($storeid);
+
+    my @common_opts = (
+	'-o', "UserKnownHostsFile=${CLUSTER_KNOWN_HOSTS}",
+	'-o', 'GlobalKnownHostsFile=none',
+	'-o', "IdentityFile=${private_key_path}",
+    );
+
+    return @common_opts;
+}
+
+my sub sshfs_set_private_key: prototype($$) ($storeid, $src_key_path) {
+    die "path of private key file not specified" if !defined($src_key_path);
+    die "path of private key file does not exist" if ! -e $src_key_path;
+    die "path of private key file does not point to a file" if ! -f $src_key_path;
+
+    my $dest_key_path = sshfs_private_key_path($storeid);
+
+    my $dest_key_parent_dir = dirname($dest_key_path);
+    if (! -e $dest_key_parent_dir) {
+	make_path($dest_key_parent_dir, { chmod => 0700 });
+    } else {
+	die "'$dest_key_path' already exists" if -e $dest_key_path;
+    }
+
+    file_copy($src_key_path, $dest_key_path, undef, 600);
+
+    return undef;
+}
+
+my sub sshfs_remove_private_key: prototype($) ($storeid) {
+    my $key_path = sshfs_private_key_path($storeid);
+    unlink($key_path) or $! == ENOENT or die "failed to remove private key '$key_path' - $!\n";
+
+    return undef;
+}
+
+my sub sshfs_is_mounted: prototype($) ($scfg) {
+    my $remote = sshfs_remote_from_config($scfg);
+
+    my $mountpoint = Cwd::realpath($scfg->{path}); # Resolve symlinks
+    return 0 if !defined($mountpoint);
+
+    my $mountdata = PVE::ProcFSTools::parse_proc_mounts();
+
+    my $has_found_mountpoint = grep {
+	$_->[0] =~ m|^\Q${remote}\E$|
+	&& $_->[1] eq $mountpoint
+	&& $_->[2] eq 'fuse.sshfs'
+    } $mountdata->@*;
+
+    return $has_found_mountpoint != 0;
+}
+
+my sub sshfs_mount: prototype($$) ($scfg, $storeid) {
+    my $remote = sshfs_remote_from_config($scfg);
+    my ($port, $mountpoint) = $scfg->@{qw(port path)};
+
+    my @common_opts = sshfs_common_ssh_opts($storeid);
+    my $cmd = [
+	'/usr/bin/sshfs', @common_opts,
+	'-o', 'noatime',
+    ];
+
+    push($cmd->@*, '-p', $port) if $port;
+    push($cmd->@*, $remote, $mountpoint);
+
+    eval {
+	run_command(
+	    $cmd,
+	    timeout => 10,
+	    errfunc => sub { warn "$_[0]\n"; },
+	);
+    };
+    if (my $err = $@) {
+	die "failed to mount SSHFS storage '$remote' at '$mountpoint': $@\n";
+    }
+
+    die "SSHFS storage '$remote' not mounted at '$mountpoint' despite reported success\n"
+	if ! sshfs_is_mounted($scfg);
+
+    return;
+}
+
+my sub sshfs_umount: prototype($) ($scfg) {
+    my $mountpoint = $scfg->{path};
+
+    my $cmd = ['/usr/bin/umount', $mountpoint];
+
+    eval {
+	run_command(
+	    $cmd,
+	    timeout => 10,
+	    errfunc => sub { warn "$_[0]\n"; },
+	);
+    };
+    if (my $err = $@) {
+	die "failed to unmount SSHFS at '$mountpoint': $err\n";
+    }
+
+    return;
+}
+
+# Storage Implementation
+
+sub on_add_hook ($class, $storeid, $scfg, %sensitive) {
+    $scfg->{shared} = 1; # mark SSHFS storages as shared by default
+
+    eval {
+	my $src_key_path = $sensitive{'sshfs-private-key'};
+	sshfs_set_private_key($storeid, $src_key_path);
+    };
+    die "error while adding SSHFS storage '${storeid}': $@\n" if $@;
+
+    return undef;
+}
+
+sub on_update_hook ($class, $storeid, $scfg, %sensitive) {
+    return undef if !exists($sensitive{'sshfs-private-key'});
+
+    my $src_key_path = $sensitive{'sshfs-private-key'};
+
+    if (!defined($src_key_path)) {
+	warn "removing private key for SSHFS storage '${storeid}'";
+	warn "the storage might not be mountable without a private key!";
+
+	eval { sshfs_remove_private_key($storeid); };
+	die $@ if $@;
+
+	return undef;
+    }
+
+    my $dest_key_path = sshfs_private_key_path($storeid);
+    my $dest_key_path_tmp = "${dest_key_path}.old";
+
+    file_copy($dest_key_path, $dest_key_path_tmp) if -e $dest_key_path;
+
+    eval { file_copy($src_key_path, $dest_key_path, undef, 600); };
+
+    if (my $err = $@) {
+	if (-e $dest_key_path_tmp) {
+	    warn "attempting to restore previous private key for storage '${storeid}'\n";
+	    eval { file_copy($dest_key_path_tmp, $dest_key_path, undef, 600); };
+	    warn "$@\n" if $@;
+
+	    unlink $dest_key_path_tmp;
+	}
+
+	die "failed to set private key for SSHFS storage '${storeid}': $err\n";
+    }
+
+    unlink $dest_key_path_tmp;
+
+    return undef;
+}
+
+sub on_delete_hook ($class, $storeid, $scfg) {
+    eval { sshfs_remove_private_key($storeid); };
+    warn $@ if $@;
+
+    eval { sshfs_umount($scfg) if sshfs_is_mounted($scfg); };
+    warn $@ if $@;
+
+    return undef;
+}
+
+sub check_connection ($class, $storeid, $scfg) {
+    my ($user, $host, $port) = $scfg->@{qw(username server port)};
+
+    my @common_opts = sshfs_common_ssh_opts($storeid);
+    my $cmd = [
+	'/usr/bin/ssh',
+	'-T',
+	@common_opts,
+	'-o', 'BatchMode=yes',
+	'-o', 'ConnectTimeout=5',
+    ];
+
+    push($cmd->@*, "-p", $port) if $port;
+    push($cmd->@*, "${user}\@${host}", 'exit 0');
+
+    eval {
+	run_command(
+	    $cmd,
+	    timeout => 10,
+	    errfunc => sub { warn "$_[0]\n"; },
+	);
+    };
+    if (my $err = $@) {
+	warn "$err";
+	return 0;
+    }
+
+    return 1;
+}
+
+sub activate_storage ($class, $storeid, $scfg, $cache) {
+    my $mountpoint = $scfg->{path};
+
+    if (!sshfs_is_mounted($scfg)) {
+	if ($scfg->{'create-base-path'} // 1) {
+	    make_path($mountpoint);
+	}
+
+	die "unable to activate storage '$storeid' - directory '$mountpoint' does not exist\n"
+	    if ! -d $mountpoint;
+
+	sshfs_mount($scfg, $storeid);
+    }
+
+    $class->SUPER::activate_storage($storeid, $scfg, $cache);
+    return;
+}
+
+sub get_volume_attribute ($class, $scfg, $storeid, $volname, $attribute) {
+    my ($vtype) = $class->parse_volname($volname);
+    return if $vtype ne 'backup';
+
+    my $volume_path = PVE::Storage::Plugin->filesystem_path($scfg, $volname);
+
+    if ($attribute eq 'notes') {
+	my $notes_path = $volume_path . $class->SUPER::NOTES_EXT;
+
+	if (-f $notes_path) {
+	    my $notes = file_get_contents($notes_path);
+	    return eval { decode('UTF-8', $notes, 1) } // $notes;
+	}
+
+	return "";
+    }
+
+    if ($attribute eq 'protected') {
+	return -e PVE::Storage::protection_file_path($volume_path) ? 1 : 0;
+    }
+
+    return;
+}
+
+sub update_volume_attribute ($class, $scfg, $storeid, $volname, $attribute, $value) {
+    my ($vtype, $name) = $class->parse_volname($volname);
+    die "only backups support attribute '$attribute'\n" if $vtype ne 'backup';
+
+    my $volume_path = PVE::Storage::Plugin->filesystem_path($scfg, $volname);
+
+    if ($attribute eq 'notes') {
+	my $notes_path = $volume_path . $class->SUPER::NOTES_EXT;
+
+	if (defined($value)) {
+	    my $encoded_notes = encode('UTF-8', $value);
+	    file_set_contents($notes_path, $encoded_notes);
+	} else {
+	    unlink $notes_path or $! == ENOENT or die "could not delete notes - $!\n";
+	}
+
+	return;
+    }
+
+    if ($attribute eq 'protected') {
+	my $protection_path = PVE::Storage::protection_file_path($volume_path);
+
+	# Protection already set or unset
+	return if !((-e $protection_path) xor $value);
+
+	if ($value) {
+	    my $fh = IO::File->new($protection_path, O_CREAT, 0644)
+		or die "unable to create protection file '$protection_path' - $!\n";
+	    close($fh);
+	} else {
+	    unlink $protection_path or $! == ENOENT
+		or die "could not delete protection file '$protection_path' - $!\n";
+	}
+
+	return;
+    }
+
+    die "attribute '$attribute' is not supported for storage type '$scfg->{type}'\n";
+}
+
+1;
-- 
2.39.5



_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel

[pve-devel] [PATCH v1 pve-storage 2/2] example: sshfs plugin: package SSHFSPlugin.pm

[Max Carrara]

Package the new SSHFS plugin separately from the libpve-storage-perl
source. This avoids mixing up the example packaging code with the
pre-existing one.

Note that the Makefile this commit adds currently isn't being called
by the top-level one in the repository root.

Signed-off-by: Max Carrara <m.carrara@proxmox.com>
---
Changes rfc-v1 --> v1:
  * none

 example/sshfs-plugin/Makefile             | 71 +++++++++++++++++++++++
 example/sshfs-plugin/debian/changelog     |  5 ++
 example/sshfs-plugin/debian/control       | 22 +++++++
 example/sshfs-plugin/debian/copyright     | 21 +++++++
 example/sshfs-plugin/debian/rules         | 26 +++++++++
 example/sshfs-plugin/debian/source/format |  1 +
 example/sshfs-plugin/debian/triggers      |  1 +
 7 files changed, 147 insertions(+)
 create mode 100644 example/sshfs-plugin/Makefile
 create mode 100644 example/sshfs-plugin/debian/changelog
 create mode 100644 example/sshfs-plugin/debian/control
 create mode 100644 example/sshfs-plugin/debian/copyright
 create mode 100755 example/sshfs-plugin/debian/rules
 create mode 100644 example/sshfs-plugin/debian/source/format
 create mode 100644 example/sshfs-plugin/debian/triggers

diff --git a/example/sshfs-plugin/Makefile b/example/sshfs-plugin/Makefile
new file mode 100644
index 0000000..cbd0691
--- /dev/null
+++ b/example/sshfs-plugin/Makefile
@@ -0,0 +1,71 @@
+# Makes useful Debian-specific variables available
+include /usr/share/dpkg/default.mk
+
+# --- Useful variables for convenience
+
+# Note that variables can be overridden, e.g. `make install DESTDIR='./foo'`
+DESTDIR=
+PACKAGE=pve-storage-sshfs-plugin
+
+BINDIR=${DESTDIR}/usr/bin
+PERLLIBDIR=${DESTDIR}/usr/share/perl5
+MAN1DIR=${DESTDIR}/usr/share/man/man1
+MAN8DIR=${DESTDIR}/usr/share/man/man8
+CRONDAILYDIR=${DESTDIR}/etc/cron.daily
+INITDBINDIR=${DESTDIR}/etc/init.d
+SERVICEDIR=${DESTDIR}/lib/systemd/system
+BASHCOMPLDIR=${DESTDIR}/usr/share/bash-completion/completions/
+ZSHCOMPLDIR=${DESTDIR}/usr/share/zsh/vendor-completions/
+HARADIR=${DESTDIR}/usr/share/cluster
+DOCDIR=${DESTDIR}/usr/share/doc/${PACKAGE}
+PODDIR=${DESTDIR}/usr/share/doc/${PACKAGE}/pod
+USRSHARE=${DESTDIR}/usr/share/${PACKAGE}
+
+# Directory where our custom plugin has to go
+PLUGINDIR=${PERLLIBDIR}/PVE/Storage/Custom
+
+export VERSION = $(DEB_VERSION_UPSTREAM_REVISION)
+
+BUILDDIR = $(PACKAGE)-$(DEB_VERSION_UPSTREAM)
+
+DSC=$(PACKAGE)_$(DEB_VERSION).dsc
+DEB=$(PACKAGE)_$(DEB_VERSION)_$(DEB_HOST_ARCH).deb
+
+# --- Targets
+
+$(BUILDDIR):
+	rm -rf $@ $@.tmp
+	mkdir $@.tmp
+	rsync -a * $@.tmp
+	# You can add additional commands instead of this comment if you need to
+	# e.g. create additional files inside the build directory etc.
+	mv $@.tmp $@
+
+# Creates a .deb package for installation
+.PHONY: deb
+deb: $(DEB)
+$(DEB): $(BUILDDIR)
+	cd $(BUILDDIR); dpkg-buildpackage -b -us -uc
+	lintian $(DEB)
+
+# Creates a .dsc (Debian source) package
+.PHONY: dsc
+dsc:
+	rm -rf $(BUILDDIR) $(DSC)
+	$(MAKE) $(DSC)
+	lintian $(DSC)
+
+$(DSC): $(BUILDDIR)
+	cd $(BUILDDIR); dpkg-buildpackage -S -us -uc -d
+
+# Target used to place files and directories at expected locations, with expected permissions
+.PHONY: install
+install:
+	install -D -m 0644 lib/PVE/Storage/Custom/SSHFSPlugin.pm $(PLUGINDIR)/SSHFSPlugin.pm
+
+# Used to clean up your builds
+.PHONY: clean
+clean:
+	rm -f $(PACKAGE)*.tar* *.deb *.dsc *.build *.buildinfo *.changes
+	rm -rf dest $(PACKAGE)-[0-9]*/
+
diff --git a/example/sshfs-plugin/debian/changelog b/example/sshfs-plugin/debian/changelog
new file mode 100644
index 0000000..7372095
--- /dev/null
+++ b/example/sshfs-plugin/debian/changelog
@@ -0,0 +1,5 @@
+pve-storage-sshfs-plugin (1.0.0) UNRELEASED; urgency=medium
+
+  * Initial release.
+
+ -- Proxmox Support Team <support@proxmox.com>  Wed, 09 Apr 2025 16:13:26 +0200
diff --git a/example/sshfs-plugin/debian/control b/example/sshfs-plugin/debian/control
new file mode 100644
index 0000000..5732cd6
--- /dev/null
+++ b/example/sshfs-plugin/debian/control
@@ -0,0 +1,22 @@
+Source: pve-storage-sshfs-plugin
+Section: perl
+Priority: optional
+Maintainer: Proxmox Support Team <support@proxmox.com>
+Rules-Requires-Root: no
+Build-Depends:
+ debhelper-compat (= 13),
+ libpve-storage-perl (>= 8.3.3),
+ lintian,
+ perl,
+ rsync,
+Standards-Version: 4.6.2
+
+Package: pve-storage-sshfs-plugin
+Architecture: any
+Depends:
+ ${misc:Depends},
+ ${perl:Depends},
+ libpve-storage-perl (>= 8.3.3),
+ sshfs (>= 3.7.3),
+Description: SSHFS storage plugin for Proxmox Virtual Environment.
+ Used to demonstrate plugin development.
diff --git a/example/sshfs-plugin/debian/copyright b/example/sshfs-plugin/debian/copyright
new file mode 100644
index 0000000..c26ed02
--- /dev/null
+++ b/example/sshfs-plugin/debian/copyright
@@ -0,0 +1,21 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Source: https://git.proxmox.com/?p=pve-storage.git
+
+Files:
+ *
+Copyright:
+ 2025 Proxmox Server Solutions GmbH <support@proxmox.com>
+License: AGPL-3.0+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Affero General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
diff --git a/example/sshfs-plugin/debian/rules b/example/sshfs-plugin/debian/rules
new file mode 100755
index 0000000..f1d1d25
--- /dev/null
+++ b/example/sshfs-plugin/debian/rules
@@ -0,0 +1,26 @@
+#!/usr/bin/make -f
+
+# See debhelper(7) (uncomment to enable).
+# Output every command that modifies files on the build system.
+#export DH_VERBOSE = 1
+
+
+# See FEATURE AREAS in dpkg-buildflags(1).
+#export DEB_BUILD_MAINT_OPTIONS = hardening=+all
+
+# See ENVIRONMENT in dpkg-buildflags(1).
+# Package maintainers to append CFLAGS.
+#export DEB_CFLAGS_MAINT_APPEND  = -Wall -pedantic
+# Package maintainers to append LDFLAGS.
+#export DEB_LDFLAGS_MAINT_APPEND = -Wl,--as-needed
+
+
+%:
+	dh $@
+
+
+# dh_make generated override targets.
+# This is an example for Cmake (see <https://bugs.debian.org/641051>).
+#override_dh_auto_configure:
+#	dh_auto_configure -- \
+#	-DCMAKE_LIBRARY_PATH=$(DEB_HOST_MULTIARCH)
diff --git a/example/sshfs-plugin/debian/source/format b/example/sshfs-plugin/debian/source/format
new file mode 100644
index 0000000..89ae9db
--- /dev/null
+++ b/example/sshfs-plugin/debian/source/format
@@ -0,0 +1 @@
+3.0 (native)
diff --git a/example/sshfs-plugin/debian/triggers b/example/sshfs-plugin/debian/triggers
new file mode 100644
index 0000000..59dd688
--- /dev/null
+++ b/example/sshfs-plugin/debian/triggers
@@ -0,0 +1 @@
+activate-noawait pve-api-updates
-- 
2.39.5



_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel

Re: [pve-devel] [PATCH v1 pve-storage 1/2] example: sshfs plugin: add custom storage plugin for SSHFS

[Max Carrara]

On Wed Apr 16, 2025 at 2:47 PM CEST, Max Carrara wrote:
> This commit adds an example implementation of a custom storage plugin
> that uses SSHFS [0] as the underlying filesystem.
>
> The implementation is very similar to that of the NFS plugin; as a
> prerequisite, it is currently necessary to use pubkey auth and have
> the host's root user's public key deployed to the remote host like so:
>
>   ssh-copy-id -i ~/.ssh/id_my_private_key \
>     -o UserKnownHostsFile=/etc/pve/priv/known_hosts [USER]@[HOST]
>
> Then, the storage can be added as follows:
>
>   pvesm add sshfs [STOREID] \
>     --username [USER] \
>     --server [HOST] \
>     --sshfs-remote-path [ABS PATH ON REMOTE] \
>     --path /mnt/path/to/storage \
>     --sshfs-private-key ~/.ssh/id_my_private_key
>
> If the host is part of a cluster, other nodes may connect to the
> remote without any additional setup required. This is because we copy
> the private key to `/etc/pve/priv/storage/$KEYNAME.key` and use the
> cluster-wide `/etc/pve/priv/known_hosts` file. Also mark each SSHFS
> storage as `shared` by default in order to make use of this.
>
> Note: Because there's currently no way to officially and permanently
> mark a storage as shared (like some built-in plugins [1]) set
> `$scfg->{shared} = 1;` in `on_add_hook`. This has almost the same
> effect as modifying `@PVE::Storage::Plugin::SHARED_STORAGE` directly,
> except that the `shared` is written to `/etc/pve/storage.cfg`.
>
> [0]: https://github.com/libfuse/sshfs
> [1]: https://git.proxmox.com/?p=pve-storage.git;a=blob;f=src/PVE/Storage/Plugin.pm;h=4e16420f667f196e8eb99ae7c9f3f1d3e13791fb;hb=refs/heads/master#l37
>
> Signed-off-by: Max Carrara <m.carrara@proxmox.com>
> ---
> Changes rfc-v1 --> v1:
>   * rework most of the plugin
>   * cease to call methods of DirPlugin (plugins should be isolated;
>     we don't want to encourage third-party devs to do that)
>   * handle SSH private key as sensitive property and place it on pmxcfs
>   * make storage shared
>   * manually implement attribute handling ("notes", "protected" for
>     backups)
>
>  .../lib/PVE/Storage/Custom/SSHFSPlugin.pm     | 398 ++++++++++++++++++
>  1 file changed, 398 insertions(+)
>  create mode 100644 example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm
>
> diff --git a/example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm b/example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm
> new file mode 100644
> index 0000000..75b29c1
> --- /dev/null
> +++ b/example/sshfs-plugin/lib/PVE/Storage/Custom/SSHFSPlugin.pm
> @@ -0,0 +1,398 @@
> +package PVE::Storage::Custom::SSHFSPlugin;
> +
> +use strict;
> +use warnings;
> +
> +use feature 'signatures';
> +
> +use Cwd qw();
> +use Encode qw(decode encode);
> +use File::Path qw(make_path);
> +use File::Basename qw(dirname);
> +use IO::File;
> +use POSIX;
> +
> +use PVE::ProcFSTools;
> +use PVE::Tools qw(
> +    file_copy
> +    file_get_contents
> +    file_set_contents
> +    run_command
> +);
> +
> +use base qw(PVE::Storage::Plugin);
> +
> +my $CLUSTER_KNOWN_HOSTS = "/etc/pve/priv/known_hosts";
> +
> +# Plugin Definition
> +
> +sub api {
> +    return 11;
> +}
> +
> +sub type {
> +    return 'sshfs';
> +}
> +
> +sub plugindata {
> +    return {
> +	content => [
> +	    {
> +		images => 1,
> +		rootdir => 1,
> +		vztmpl => 1,
> +		iso => 1,
> +		backup => 1,
> +		snippets => 1,
> +		none => 1,

Argh, there's one thing I just noticed: The `none` content type above
should not be declared here and needs to be removed, because it's for
internal use only (for now, at least).

Even though we'll ship this example ourselves, it should of course still
adhere to what third-party plugin devs should do. >.>

For now it doesn't hurt if it's here and can just be removed in a
follow-up, but I'll already intentionally exclude it from the upcoming
plugin dev guide.

> +	    },
> +	    {
> +		images => 1,
> +		rootdir => 1,
> +	    },
> +	],
> +	format => [
> +	    {
> +		raw => 1,
> +		qcow2 => 1,
> +		vmdk => 1,
> +	    },
> +	    'qcow2',
> +	],
> +	'sensitive-properties' => {
> +	    'sshfs-private-key' => 1,
> +	},
> +    };
> +}
> +
> +sub properties {
> +    return {
> +	'sshfs-remote-path' => {
> +	    description => "Path on the remote filesystem used for SSHFS. Must be absolute.",
> +	    type => 'string',
> +	    format => 'pve-storage-path',
> +	},
> +	'sshfs-private-key' => {
> +	    description => "Path to the private key to use for SSHFS.",
> +	    type => 'string',
> +	    format => 'pve-storage-path',
> +	}
> +    };
> +}
> +
> +sub options {
> +    return {
> +	disable => { optional => 1 },
> +	path => { fixed => 1 },
> +	'create-base-path' => { optional => 1 },
> +	content => { optional => 1 },
> +	'create-subdirs' => { optional => 1 },
> +	'content-dirs' => { optional => 1 },
> +	'prune-backups' => { optional => 1 },
> +	'max-protected-backups' => { optional => 1 },
> +	format => { optional => 1 },
> +	bwlimit => { optional => 1 },
> +	preallocation => { optional => 1 },
> +	nodes => { optional => 1 },
> +	shared => { optional => 1 },
> +
> +	# SSHFS Options
> +	username => {},
> +	server => {},
> +	'sshfs-remote-path' => {},
> +	port => { optional => 1 },
> +	'sshfs-private-key' => { optional => 1 },
> +   };
> +}
> +
> +# SSHFS Helpers
> +
> +my sub sshfs_remote_from_config: prototype($) ($scfg) {
> +    my ($user, $host, $remote_path) = $scfg->@{qw(username server sshfs-remote-path)};
> +    return "${user}\@${host}:${remote_path}";
> +}
> +
> +my sub sshfs_private_key_path: prototype($) ($storeid) {
> +    return "/etc/pve/priv/storage/$storeid.key";
> +}
> +
> +my sub sshfs_common_ssh_opts: prototype($) ($storeid) {
> +    my $private_key_path = sshfs_private_key_path($storeid);
> +
> +    my @common_opts = (
> +	'-o', "UserKnownHostsFile=${CLUSTER_KNOWN_HOSTS}",
> +	'-o', 'GlobalKnownHostsFile=none',
> +	'-o', "IdentityFile=${private_key_path}",
> +    );
> +
> +    return @common_opts;
> +}
> +
> +my sub sshfs_set_private_key: prototype($$) ($storeid, $src_key_path) {
> +    die "path of private key file not specified" if !defined($src_key_path);
> +    die "path of private key file does not exist" if ! -e $src_key_path;
> +    die "path of private key file does not point to a file" if ! -f $src_key_path;
> +
> +    my $dest_key_path = sshfs_private_key_path($storeid);
> +
> +    my $dest_key_parent_dir = dirname($dest_key_path);
> +    if (! -e $dest_key_parent_dir) {
> +	make_path($dest_key_parent_dir, { chmod => 0700 });
> +    } else {
> +	die "'$dest_key_path' already exists" if -e $dest_key_path;
> +    }
> +
> +    file_copy($src_key_path, $dest_key_path, undef, 600);
> +
> +    return undef;
> +}
> +
> +my sub sshfs_remove_private_key: prototype($) ($storeid) {
> +    my $key_path = sshfs_private_key_path($storeid);
> +    unlink($key_path) or $! == ENOENT or die "failed to remove private key '$key_path' - $!\n";
> +
> +    return undef;
> +}
> +
> +my sub sshfs_is_mounted: prototype($) ($scfg) {
> +    my $remote = sshfs_remote_from_config($scfg);
> +
> +    my $mountpoint = Cwd::realpath($scfg->{path}); # Resolve symlinks
> +    return 0 if !defined($mountpoint);
> +
> +    my $mountdata = PVE::ProcFSTools::parse_proc_mounts();
> +
> +    my $has_found_mountpoint = grep {
> +	$_->[0] =~ m|^\Q${remote}\E$|
> +	&& $_->[1] eq $mountpoint
> +	&& $_->[2] eq 'fuse.sshfs'
> +    } $mountdata->@*;
> +
> +    return $has_found_mountpoint != 0;
> +}
> +
> +my sub sshfs_mount: prototype($$) ($scfg, $storeid) {
> +    my $remote = sshfs_remote_from_config($scfg);
> +    my ($port, $mountpoint) = $scfg->@{qw(port path)};
> +
> +    my @common_opts = sshfs_common_ssh_opts($storeid);
> +    my $cmd = [
> +	'/usr/bin/sshfs', @common_opts,
> +	'-o', 'noatime',
> +    ];
> +
> +    push($cmd->@*, '-p', $port) if $port;
> +    push($cmd->@*, $remote, $mountpoint);
> +
> +    eval {
> +	run_command(
> +	    $cmd,
> +	    timeout => 10,
> +	    errfunc => sub { warn "$_[0]\n"; },
> +	);
> +    };
> +    if (my $err = $@) {
> +	die "failed to mount SSHFS storage '$remote' at '$mountpoint': $@\n";
> +    }
> +
> +    die "SSHFS storage '$remote' not mounted at '$mountpoint' despite reported success\n"
> +	if ! sshfs_is_mounted($scfg);
> +
> +    return;
> +}
> +
> +my sub sshfs_umount: prototype($) ($scfg) {
> +    my $mountpoint = $scfg->{path};
> +
> +    my $cmd = ['/usr/bin/umount', $mountpoint];
> +
> +    eval {
> +	run_command(
> +	    $cmd,
> +	    timeout => 10,
> +	    errfunc => sub { warn "$_[0]\n"; },
> +	);
> +    };
> +    if (my $err = $@) {
> +	die "failed to unmount SSHFS at '$mountpoint': $err\n";
> +    }
> +
> +    return;
> +}
> +
> +# Storage Implementation
> +
> +sub on_add_hook ($class, $storeid, $scfg, %sensitive) {
> +    $scfg->{shared} = 1; # mark SSHFS storages as shared by default
> +
> +    eval {
> +	my $src_key_path = $sensitive{'sshfs-private-key'};
> +	sshfs_set_private_key($storeid, $src_key_path);
> +    };
> +    die "error while adding SSHFS storage '${storeid}': $@\n" if $@;
> +
> +    return undef;
> +}
> +
> +sub on_update_hook ($class, $storeid, $scfg, %sensitive) {
> +    return undef if !exists($sensitive{'sshfs-private-key'});
> +
> +    my $src_key_path = $sensitive{'sshfs-private-key'};
> +
> +    if (!defined($src_key_path)) {
> +	warn "removing private key for SSHFS storage '${storeid}'";
> +	warn "the storage might not be mountable without a private key!";
> +
> +	eval { sshfs_remove_private_key($storeid); };
> +	die $@ if $@;
> +
> +	return undef;
> +    }
> +
> +    my $dest_key_path = sshfs_private_key_path($storeid);
> +    my $dest_key_path_tmp = "${dest_key_path}.old";
> +
> +    file_copy($dest_key_path, $dest_key_path_tmp) if -e $dest_key_path;
> +
> +    eval { file_copy($src_key_path, $dest_key_path, undef, 600); };
> +
> +    if (my $err = $@) {
> +	if (-e $dest_key_path_tmp) {
> +	    warn "attempting to restore previous private key for storage '${storeid}'\n";
> +	    eval { file_copy($dest_key_path_tmp, $dest_key_path, undef, 600); };
> +	    warn "$@\n" if $@;
> +
> +	    unlink $dest_key_path_tmp;
> +	}
> +
> +	die "failed to set private key for SSHFS storage '${storeid}': $err\n";
> +    }
> +
> +    unlink $dest_key_path_tmp;
> +
> +    return undef;
> +}
> +
> +sub on_delete_hook ($class, $storeid, $scfg) {
> +    eval { sshfs_remove_private_key($storeid); };
> +    warn $@ if $@;
> +
> +    eval { sshfs_umount($scfg) if sshfs_is_mounted($scfg); };
> +    warn $@ if $@;
> +
> +    return undef;
> +}
> +
> +sub check_connection ($class, $storeid, $scfg) {
> +    my ($user, $host, $port) = $scfg->@{qw(username server port)};
> +
> +    my @common_opts = sshfs_common_ssh_opts($storeid);
> +    my $cmd = [
> +	'/usr/bin/ssh',
> +	'-T',
> +	@common_opts,
> +	'-o', 'BatchMode=yes',
> +	'-o', 'ConnectTimeout=5',
> +    ];
> +
> +    push($cmd->@*, "-p", $port) if $port;
> +    push($cmd->@*, "${user}\@${host}", 'exit 0');
> +
> +    eval {
> +	run_command(
> +	    $cmd,
> +	    timeout => 10,
> +	    errfunc => sub { warn "$_[0]\n"; },
> +	);
> +    };
> +    if (my $err = $@) {
> +	warn "$err";
> +	return 0;
> +    }
> +
> +    return 1;
> +}
> +
> +sub activate_storage ($class, $storeid, $scfg, $cache) {
> +    my $mountpoint = $scfg->{path};
> +
> +    if (!sshfs_is_mounted($scfg)) {
> +	if ($scfg->{'create-base-path'} // 1) {
> +	    make_path($mountpoint);
> +	}
> +
> +	die "unable to activate storage '$storeid' - directory '$mountpoint' does not exist\n"
> +	    if ! -d $mountpoint;
> +
> +	sshfs_mount($scfg, $storeid);
> +    }
> +
> +    $class->SUPER::activate_storage($storeid, $scfg, $cache);
> +    return;
> +}
> +
> +sub get_volume_attribute ($class, $scfg, $storeid, $volname, $attribute) {
> +    my ($vtype) = $class->parse_volname($volname);
> +    return if $vtype ne 'backup';
> +
> +    my $volume_path = PVE::Storage::Plugin->filesystem_path($scfg, $volname);
> +
> +    if ($attribute eq 'notes') {
> +	my $notes_path = $volume_path . $class->SUPER::NOTES_EXT;
> +
> +	if (-f $notes_path) {
> +	    my $notes = file_get_contents($notes_path);
> +	    return eval { decode('UTF-8', $notes, 1) } // $notes;
> +	}
> +
> +	return "";
> +    }
> +
> +    if ($attribute eq 'protected') {
> +	return -e PVE::Storage::protection_file_path($volume_path) ? 1 : 0;
> +    }
> +
> +    return;
> +}
> +
> +sub update_volume_attribute ($class, $scfg, $storeid, $volname, $attribute, $value) {
> +    my ($vtype, $name) = $class->parse_volname($volname);
> +    die "only backups support attribute '$attribute'\n" if $vtype ne 'backup';
> +
> +    my $volume_path = PVE::Storage::Plugin->filesystem_path($scfg, $volname);
> +
> +    if ($attribute eq 'notes') {
> +	my $notes_path = $volume_path . $class->SUPER::NOTES_EXT;
> +
> +	if (defined($value)) {
> +	    my $encoded_notes = encode('UTF-8', $value);
> +	    file_set_contents($notes_path, $encoded_notes);
> +	} else {
> +	    unlink $notes_path or $! == ENOENT or die "could not delete notes - $!\n";
> +	}
> +
> +	return;
> +    }
> +
> +    if ($attribute eq 'protected') {
> +	my $protection_path = PVE::Storage::protection_file_path($volume_path);
> +
> +	# Protection already set or unset
> +	return if !((-e $protection_path) xor $value);
> +
> +	if ($value) {
> +	    my $fh = IO::File->new($protection_path, O_CREAT, 0644)
> +		or die "unable to create protection file '$protection_path' - $!\n";
> +	    close($fh);
> +	} else {
> +	    unlink $protection_path or $! == ENOENT
> +		or die "could not delete protection file '$protection_path' - $!\n";
> +	}
> +
> +	return;
> +    }
> +
> +    die "attribute '$attribute' is not supported for storage type '$scfg->{type}'\n";
> +}
> +
> +1;



_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel