add support for owner, group, and mount_options

There are some toplevel options that can be provided
to synced_folders plugins that include `owner`, `group`
and `mount_options` [1] . Let's try to add support for
them here.

The owner/group settings haven't really been an issue
for us I think because we pass in `-o allow_other` to
sshfs, but we had a request for support so let's try
to comply.

Closes #127

[1] https://github.com/hashicorp/vagrant/blob/2c3397c46851ef29a3589bf3214a3eee12da8484/website/content/docs/synced-folders/basic_usage.mdx#options

lib/vagrant-sshfs/cap/guest/linux/sshfs_forward_mount.rb

@@ -2,6 +2,7 @@
 require "vagrant/util/retryable"
 require "vagrant/util/platform"
 require "tempfile"
+require Vagrant.source_root.join("plugins/synced_folders/unix_mount_helpers")
 
 # This is already done for us in lib/vagrant-sshfs.rb. We needed to
 # do it there before Process.uid is called the first time by Vagrant
@@ -15,6 +16,7 @@ module GuestLinux
     module Cap
       class MountSSHFS
         extend Vagrant::Util::Retryable
+        extend VagrantPlugins::SyncedFolder::UnixMountHelpers
         @@logger = Log4r::Logger.new("vagrant::synced_folders::sshfs_mount")
 
         def self.list_mounts_command
@@ -80,7 +82,25 @@ def self.sshfs_forward_mount_folder(machine, opts)
               hostpath = File.expand_path(opts[:hostpath], machine.env.root_path)
               hostpath  = Vagrant::Util::Platform.fs_real_path(hostpath).to_s
           end
-
+
+          # Support for user provided mount_options, owner, group
+          # https://github.com/hashicorp/vagrant/blob/2c3397c46851ef29a3589bf3214a3eee12da8484/website/content/docs/synced-folders/basic_usage.mdx#options
+          mount_options = opts.fetch(:mount_options, [])
+          # Determine owner/group info to use
+          if (opts.has_key?(:owner) and opts[:owner]) or
+             (opts.has_key?(:group) and opts[:group])
+            detected_ids = detect_owner_group_ids(
+                machine, expanded_guest_path, mount_options, opts)
+            mount_uid = detected_ids[:uid]
+            mount_gid = detected_ids[:gid]
+            mount_options.append("uid=#{mount_uid}")
+            mount_options.append("gid=#{mount_gid}")
+          end
+          # Combine mount_options into sshfs_opts_append (also user provided)
+          if not mount_options.empty?()
+            opts[:sshfs_opts_append] =
+              opts[:sshfs_opts_append].to_s + ' -o ' + mount_options.join(',') + ' '
+          end
 
           # Add in some sshfs/fuse options that are common to both mount methods
           opts[:sshfs_opts] = ' -o allow_other ' # allow non-root users to access

lib/vagrant-sshfs/cap/host/linux/sshfs_reverse_mount.rb

@@ -81,9 +81,50 @@ def self.sshfs_mount(machine, opts)
 
           ssh_opts_append = opts[:ssh_opts_append].to_s # provided by user
 
+          # Support for user provided mount_options, owner, group
+          # https://github.com/hashicorp/vagrant/blob/2c3397c46851ef29a3589bf3214a3eee12da8484/website/content/docs/synced-folders/basic_usage.mdx#options
+          mount_options = opts.fetch(:mount_options, [])
+          if (opts.has_key?(:owner) and opts[:owner]) or
+             (opts.has_key?(:group) and opts[:group])
+            # Find the `id` command on the system and set the error class
+            id_command = Vagrant::Util::Which.which('id')
+            getent_command = Vagrant::Util::Which.which('getent')
+            error_class = VagrantPlugins::SyncedFolderSSHFS::Errors::SSHFSFindUIDGIDFailed
+            # Identify the uid
+            cmd = "#{id_command} -u #{opts[:owner]}"
+            result = Vagrant::Util::Subprocess.execute(*cmd.split())
+            if result.exit_code != 0
+              raise error_class, command: cmd, stdout: result.stdout, stderr: result.stderr
+            end
+            mount_uid = result.stdout.chomp
+            # Identify the gid. If a group was provided use that otherwise use
+            # the group detected with the detected user id.
+            if opts.has_key?(:group) and opts[:group]
+              cmd = "#{getent_command} group #{opts[:group]}"
+              result = Vagrant::Util::Subprocess.execute(*cmd.split())
+              if result.exit_code != 0
+                raise error_class, command: cmd, stdout: result.stdout, stderr: result.stderr
+              end
+              mount_gid = result.stdout.split(':').at(2).to_s.chomp
+            else
+              cmd = "#{id_command} -g #{mount_uid}"
+              result = Vagrant::Util::Subprocess.execute(*cmd.split())
+              if result.exit_code != 0
+                raise error_class, command: cmd, stdout: result.stdout, stderr: result.stderr
+              end
+              mount_gid = result.stdout.chomp
+            end
+            # Add them to the mount options
+            mount_options.append("uid=#{mount_uid}")
+            mount_options.append("gid=#{mount_gid}")
+          end
+
           # SSHFS executable options
           sshfs_opts = opts[:sshfs_opts]
           sshfs_opts_append = opts[:sshfs_opts_append].to_s # provided by user
+          if not mount_options.empty?()
+            sshfs_opts_append+= ' -o ' + mount_options.join(',') + ' '
+          end
 
           username = machine.ssh_info[:username]
           host = machine.ssh_info[:host]

lib/vagrant-sshfs/errors.rb

@@ -37,6 +37,10 @@ class SSHFSExeNotAvailable < SSHFSError
       class SSHFSGetAbsolutePathFailed < SSHFSError
         error_key(:get_absolute_path_failed)
       end
+
+      class SSHFSFindUIDGIDFailed < SSHFSError
+        error_key(:find_uid_gid_failed)
+      end
     end
   end
 end

locales/synced_folder_sshfs.yml

@@ -92,4 +92,18 @@ en:
 
           Stderr from the command:
 
+          %{stderr}
+        find_uid_gid_failed: |-
+          Attempting to find the UID/GID failed.
+
+          The command and output are:
+
+          %{command}
+
+          Stdout from the command:
+
+          %{stdout}
+
+          Stderr from the command:
+
           %{stderr}

test/misc/README.txt

@@ -5,40 +5,46 @@
 # To test we will first create the directory on the machine where
 # we will mount the guest /etc/ into the host (the reverse mount).
 
-mkdir /tmp/reverse_mount_etc
+mkdir /tmp/reverse_mount_etc_uid_gid/
 
 # Next we will define where our 3rd party host is (the normal mount).
 # This can be another vagrant box or whatever machine you want.
-export THIRD_PARTY_HOST='192.168.121.73'                                                                                                                                               
-export THIRD_PARTY_HOST_USER='vagrant'                                                                                                                                                 
+export THIRD_PARTY_HOST='192.168.121.73'
+export THIRD_PARTY_HOST_USER='vagrant'
 export THIRD_PARTY_HOST_PASS='vagrant'
 
 # Open an extra file descriptor to test it is not passed onto child processes
 # https://github.com/dustymabe/vagrant-sshfs/issues/120
 tmpfile=$(mktemp)
 exec {extra_fd}<> "$tmpfile"
 
-# Next vagrant up - will do 4 mounts
+# Next vagrant up - will do 5 mounts
 #  - slave
+#  - slave with owner/group
 #  - slave with sym link
-#  - normal
-#  - reverse
+#  - normal (from 3rd party host)
+#  - reverse with owner/group
 vagrant up
 
 # Next run the script to test the mounts:
 $ bash dotests.sh 
 Testing slave forward mount!
-        d635332fe7aa4d4fb48e5cb9357bdedf
+        1358d4a18a2d4ba7be380b991e899952
+Testing slave forward mount with owner/group!
+        root:wheel
+        1358d4a18a2d4ba7be380b991e899952
 Testing slave forward mount with a symlink!
-        d635332fe7aa4d4fb48e5cb9357bdedf
+        1358d4a18a2d4ba7be380b991e899952
 Testing normal forward mount!
-        6ccc3034df924bd289dd16205bf3d629
-Testing reverse mount!
-        508619e7e68e446c84d1fcdf7e0dc577
-
-# We are printing out the machine-id under each mount. The first two
-should be the same, because they are from the same machine. The last
-two should be different.
+        ef56862ae88f43c0a81962ba6f68a668
+Testing reverse mount with owner/group!
+        root:wheel
+        ef4f3b50e2034b3593a9eb8b71350abe
+
+# We are printing out the machine-id under each mount. The first three
+should be the same, because they are from the same machine (the host).
+The last two should be different; one from 3rd party machine and one
+from the test VM itself (read from the host).
 
 # Close our file descriptor. No other process should be using it
 exec {extra_fd}>&-

test/misc/Vagrantfile

@@ -4,22 +4,41 @@ Vagrant.configure(2) do |config|
 
     # Test a forward slave mount:
     #   mounting /etc/ from the vagrant host into the guest
-    config.vm.synced_folder "/etc/", "/tmp/forward_slave_mount_etc/", type: "sshfs"
+    config.vm.synced_folder "/etc/", "/tmp/forward_slave_mount_etc/",
+        type: "sshfs",
+        mount_options: ['ro']
+
+    # Test a forward slave with owner/group info:
+    #   mounting /etc/ from the vagrant host into the guest
+    config.vm.synced_folder "/etc/", "/tmp/forward_slave_mount_etc_uid_gid/",
+        type: "sshfs",
+        mount_options: ['ro', 'default_permissions'],
+        owner: "root",
+        group: "wheel"
 
     # Test a forward mount to a location that is a symbolic link
     # https://github.com/dustymabe/vagrant-sshfs/issues/44
-    config.vm.synced_folder "/etc/", "/var/run/forward_slave_mount_sym_link_test/", type: "sshfs"
+    config.vm.synced_folder "/etc/", "/var/run/forward_slave_mount_sym_link_test/",
+        type: "sshfs",
+        mount_options: ['ro']
 
     # Test a forward normal mount:
     #     mounting a folder from a 3rd party host into guest
-    config.vm.synced_folder "/etc/", "/tmp/forward_normal_mount_etc/", type: "sshfs",
+    config.vm.synced_folder "/etc/", "/tmp/forward_normal_mount_etc/",
+        type: "sshfs",
         ssh_host: ENV['THIRD_PARTY_HOST'],
         ssh_username: ENV['THIRD_PARTY_HOST_USER'],
-        ssh_password: ENV['THIRD_PARTY_HOST_PASS']
+        ssh_password: ENV['THIRD_PARTY_HOST_PASS'],
+        mount_options: ['ro']
 
-    # Test a reverse mount:
+    # Test a reverse mount with owner/group
     # mounting /etc/ from vagrant guest into vagrant host
-    config.vm.synced_folder "/tmp/reverse_mount_etc/", "/etc", type: "sshfs", reverse: true
+    config.vm.synced_folder "/tmp/reverse_mount_etc_uid_gid/", "/etc",
+        type: "sshfs",
+        reverse: true,
+        owner: "root",
+        group: "wheel",
+        mount_options: ['ro']
 
     host = 'sshfs-tests'
     box  = 'fedora/34-cloud-base'

test/misc/dotests.sh

@@ -6,12 +6,19 @@ set -eu
 echo -en "Testing slave forward mount!\n\t"
 vagrant ssh -- cat /tmp/forward_slave_mount_etc/machine-id
 
+echo -en "Testing slave forward mount with owner/group!\n\t"
+vagrant ssh -- stat --printf '%U:%G' /tmp/forward_slave_mount_etc_uid_gid
+echo -en "\n\t"
+vagrant ssh -- cat /tmp/forward_slave_mount_etc_uid_gid/machine-id
+
 # https://github.com/dustymabe/vagrant-sshfs/issues/44
 echo -en "Testing slave forward mount with a symlink!\n\t"
 vagrant ssh -- cat /run/forward_slave_mount_sym_link_test/machine-id
 
 echo -en "Testing normal forward mount!\n\t"
 vagrant ssh -- cat /tmp/forward_normal_mount_etc/machine-id
 
-echo -en "Testing reverse mount!\n\t"
-cat /tmp/reverse_mount_etc/machine-id
+echo -en "Testing reverse mount with owner/group!\n\t"
+stat --printf '%U:%G' /tmp/reverse_mount_etc_uid_gid/
+echo -en "\n\t"
+cat /tmp/reverse_mount_etc_uid_gid/machine-id