[pve-devel] [PATCH cluster] pvecm add: require user to navigate out of /etc/pve

[Friedrich Weber <f.weber@proxmox.com>]

If `pvecm add` is issued from /etc/pve (or any subdirectory), it
prints some errors:

    [...]
    shell-init: error retrieving current directory: getcwd: cannot
    access parent directories: Transport endpoint is not connected
    [...]
    successfully added node 'pve-c2' to cluster.
    cannot fetch initial working directory: Transport endpoint is not
    connected at /usr/share/perl5/PVE/CLI/pvecm.pm line 446.

The reason is that `pvecm add` restarts pmxcfs, which re-mounts the
fuse mount at /etc/pve, invalidating pvecm's working directory.

The error messages give the impression that something went wrong.
Indeed, the second error indicates the temporary directory is not
cleaned up. The cluster join itself actually works, though.

The issue could be fixed by chdir'ing to / in `pvecm add`. However,
the user's shell would still remain in the now-invalid /etc/pve,
potentially leading to confusing "transport endpoint not connected"
messages in future interactions.

To avoid this, require the user to chdir out of /etc/pve before
running `pvecm add`.

Signed-off-by: Friedrich Weber <f.weber@proxmox.com>
---
 data/PVE/CLI/pvecm.pm | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/data/PVE/CLI/pvecm.pm b/data/PVE/CLI/pvecm.pm
index 5ac9ed3..b0b5931 100755
--- a/data/PVE/CLI/pvecm.pm
+++ b/data/PVE/CLI/pvecm.pm
@@ -3,6 +3,7 @@ package PVE::CLI::pvecm;
 use strict;
 use warnings;
 
+use Cwd qw(getcwd);
 use File::Path;
 use File::Basename;
 use PVE::Tools qw(run_command);
@@ -348,6 +349,11 @@ __PACKAGE__->register_method ({
     code => sub {
 	my ($param) = @_;
 
+	# avoid "transport endpoint not connected" errors that occur if
+	# restarting pmxcfs while in fuse-mounted /etc/pve
+	die "Navigate out of $basedir before running 'pvecm add', for example by running 'cd'.\n"
+	    if getcwd() =~ m!^$basedir(/.*)?$!;
+
 	my $nodename = PVE::INotify::nodename();
 	my $host = $param->{hostname};
 
-- 
2.30.2