pbot-vm: massive refactor

* replace heartbeat with health-check
  * instead of steady stream of newlines every 5s, now awaits input
    and responds with `vmstat` output

* more reliably use host/config/vm-exec.json to get libvirt domain name
  for snapshot-revert, server address, serial ports, vagrant setting, etc

* use iptables/nftables to disable networking
  * added guest/bin/disable-network-[iptables,nftables]
  * added guest/bin/enable-network-[iptables,nftables]

* replace ugly ___OUTPUT___ texts in sh, bash, ksh, zsh languages

* documentation updates and tweaks

applets/pbot-vm/guest/bin/disable-network-iptables

@@ -0,0 +1,9 @@
+#!/bin/sh
+# disables all incoming, outgoing and forwarded traffic except incoming/established SSH
+iptables -F
+iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
+iptables -A INPUT -p tcp --dport 22 -j ACCEPT
+iptables -P INPUT DROP
+iptables -P FORWARD DROP
+iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
+iptables -P OUTPUT DROP

applets/pbot-vm/guest/bin/disable-network-nftables

@@ -0,0 +1,8 @@
+#!/bin/sh
+# disables all incoming, outgoing and forwarded traffic except incoming/established SSH
+nft add table ip filter
+nft add chain ip filter INPUT '{ type filter hook input priority 0; policy drop; }'
+nft add chain ip filter OUTPUT '{ type filter hook output priority 0; policy drop; }'
+nft 'add rule ip filter INPUT ct state related,established counter accept'
+nft 'add rule ip filter INPUT tcp dport 22 counter accept'
+nft 'add rule ip filter OUTPUT ct state related,established counter accept'

applets/pbot-vm/guest/bin/enable-network-iptables

@@ -0,0 +1,3 @@
+#!/bin/sh
+# removes all iptables rules to re-enable networking
+iptables -F

applets/pbot-vm/guest/bin/enable-network-nftables

@@ -0,0 +1,3 @@
+#!/bin/sh
+# deletes filter table to re-enable networking
+nft delete table ip filter

applets/pbot-vm/guest/bin/guest-server

@@ -5,7 +5,7 @@
 # Purpose: PBot VM Guest server. Runs inside PBot VM Guest and processes
 # incoming VM commands from vm-exec.
 
-# SPDX-FileCopyrightText: 2022 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2022-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 use 5.020;
@@ -20,7 +20,7 @@ use constant {
     USERNAME  => 'vm',
     MOD_DIR   => '/usr/local/share/pbot-vm/',
     SERIAL    => '/dev/ttyS2',
-    HEARTBEAT => '/dev/ttyS3',
+    HEALTH    => '/dev/ttyS3',
     VPORT     => $ENV{PBOTVM_VPORT} // 5555,
 };
 
@@ -30,7 +30,6 @@ use lib MOD_DIR . "Languages";
 use Guest;
 
 use File::Basename;
-use IPC::Shareable;
 
 my %languages;
 
@@ -68,11 +67,9 @@ sub serial_server() {
     open(my $input,  '<', SERIAL) or die $!;
     open(my $output, '>', SERIAL) or die $!;
 
-    tie my $running, 'IPC::Shareable', { key => 'running' };
-
     my $buffer = '';
 
-    while ($running) {
+    while (1) {
         my $command = Guest::read_input($input, \$buffer, 'Serial');
 
         if (not defined $command) {
@@ -119,19 +116,20 @@ sub do_server() {
     }
 }
 
-sub do_heartbeat() {
+sub do_healthcheck() {
-    open(my $heartbeat, '>', HEARTBEAT) or die $!;
+    open(my $health_in,  '<', HEALTH) or die $!;
+    open(my $health_out, '>', HEALTH) or die $!;
 
-    tie my $running, 'IPC::Shareable', { key => 'running' };
+    print "Healthcheck listening on PID $$...\n";
 
-    print "Heart beating on PID $$...\n";
+    while (1) {
-
+        my $input = <$health_in>;
-    while ($running) {
+        my $vmstat = `vmstat`;
-        print $heartbeat "\n";
+        print $health_out "$vmstat\n";
-        sleep 5;
+        print $health_out ":END\n";
     }
 
-    print "Heart beat stopped.\n";
+    print "Healthcheck stopped.\n";
     exit; # exit child process
 }
 
@@ -160,14 +158,10 @@ sub main() {
 
     install_signal_handlers();
 
-    tie my $running, 'IPC::Shareable', { key => 'running', create => 1, destroy => 1 };
-
-    $running = 1;
-
     my $pid = fork // die "Fork failed: $!";
 
     if ($pid == 0) {
-        do_heartbeat();
+        do_healthcheck();
     } else {
         do_server();
     }

applets/pbot-vm/guest/bin/setup-guest

@@ -1,11 +1,11 @@
-#!/bin/sh
+#!/bin/bash
 
 # File: setup-guest
 #
 # Purpose: Sets up PBot VM Guest. Copies necessary files to the appropriate
 # location, sets up environment variables and various configuration details.
 
-# SPDX-FileCopyrightText: 2022 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2022-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 # determine OS/distribution
@@ -56,9 +56,6 @@ cp guest/include/prelude.h /usr/include
 # require root password for polkit actions
 cp guest/polkit/* /etc/polkit-1/rules.d/
 
-# disable networking
-nmcli networking off
-
 # set environment variables
 if ! grep -qF "pbot-vm" /root/.bashrc; then
   echo '# pbot-vm' >> /root/.bashrc
@@ -66,8 +63,12 @@ if ! grep -qF "pbot-vm" /root/.bashrc; then
   echo export ASAN_OPTIONS=detect_leaks=0 >> /root/.bashrc
 fi
 
-echo PBot Guest VM is now set up.
+export DEBUGINFOD_URLS
+export ASAN_OPTIONS=detect_leaks=0
+
+echo PBot Guest VM is set up.
 echo
-echo !! Networking is now disabled. To re-enable networking run: nmcli networking on
+echo To start PBot Guest Server: guest-server
-echo
+
-echo For changes to take effect, run this command now: source /root/.bashrc
+# make environment variables take effect
+exec /bin/bash

applets/pbot-vm/guest/lib/Guest.pm

@@ -5,7 +5,7 @@
 # Purpose: Collection of functions to interface with the PBot VM Guest and
 # execute VM commands.
 
-# SPDX-FileCopyrightText: 2022 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2022-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 package Guest;
@@ -22,7 +22,6 @@ use English;
 use Encode;
 use File::Basename;
 use JSON::XS;
-use IPC::Shareable;
 use Data::Dumper;
 
 sub read_input($input, $buffer, $tag) {
@@ -59,7 +58,13 @@ sub read_input($input, $buffer, $tag) {
     print STDERR "-" x 40, "\n";
     print STDERR "$tag got [$line]\n";
 
-    my $command = decode_json($line);
+    my $command = eval { decode_json($line) };
+
+    if ($@) {
+        print STDERR "Failed to decode JSON: $@\n";
+        return undef;
+    }
+
     $command->{arguments} //= '';
     $command->{input}     //= '';
 

applets/pbot-vm/guest/provision/debian-trixie

@@ -16,10 +16,17 @@ apt install -y socat
 # for `cc` C language support
 apt install -y libubsan1 libasan8 gdb gcc gcc-multilib clang
 
-# for pbot-vm guest-server support
-apt install -y --no-install-recommends libipc-shareable-perl libipc-run-perl libjson-xs-perl
-
 # for `cc` additional languages
 apt install -y ksh zsh tcl lua5.4 php8.2-cli nodejs guile3.0 beef bc g++
 apt install -y clisp golang-go
 apt install -y --no-install-recommends default-jre default-jdk
+
+# for pbot-vm guest-server support
+apt install -y --no-install-recommends libipc-run-perl libjson-xs-perl
+
+# disable networking
+./guest/bin/disable-network-iptables
+
+echo 'Networking disabled.'
+echo 'To re-enable, run ./guest/bin/enable-networking-iptables'
+echo 'To disable again, run ./guest/bin/disable-network-iptables'

applets/pbot-vm/guest/provision/tumbleweed

@@ -14,10 +14,16 @@ zypper -n in socat
 # for `cc` C language support
 zypper -n in libubsan1 libasan8 gdb gcc gcc-32bit glibc-32bit clang
 
-# for pbot-vm guest-server support
-zypper -n in perl-IPC-Run perl-JSON-XS make cpanm
-cpanm -n IPC::Shareable
-
 # for `cc` additional languages
 zypper -n in ksh zsh tcl lua php8-cli nodejs-common guile bff bc gcc-c++
 zypper -n in --no-recommends clisp gcc-go java java-devel
+
+# for pbot-vm guest-server support
+zypper -n in perl-IPC-Run perl-JSON-XS
+
+# disable networking
+./guest/bin/disable-network-nftables
+
+echo 'Networking disabled.'
+echo 'To re-enable, run ./guest/bin/enable-networking-nftables'
+echo 'To disable again, run ./guest/bin/disable-network-nftables'

applets/pbot-vm/host/bin/vm-exec

@@ -2,15 +2,18 @@
 
 # File: vm-exec
 #
-# Purpose: Process and send commands to the PBot Guest server (guest-server) on
+# Purpose: Process and send commands to the PBot Guest server (guest-server)
-# the default VM socket CID/port (7/5555) or the default serial TCP port (5555).
+# using the details from the config/vm-exec.json configuration file.
+#
+# Additionally, takes `-revert` and `-health` options to revert VM or check
+# VM's health.
 #
 # Use the PBOTVM_CID, PBOTVM_VPORT and/or PBOTVM_SERIAL environment variables to
-# override these defaults. E.g.:
+# override the config/vm-exec.json values. E.g.:
 #
 # $ PBOTVM_CID=42 PBOTVM_SERIAL=7777 vm-exec -lang=sh echo test
 
-# SPDX-FileCopyrightText: 2021 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2021-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 use 5.020;
@@ -22,9 +25,13 @@ use feature qw(signatures);
 no warnings qw(experimental::signatures);
 
 use constant {
-    SERIAL => $ENV{PBOTVM_SERIAL} // 5555,
+    DOMAIN  => $ENV{PBOTVM_DOMAIN} // 'pbot-vm',
-    CID    => $ENV{PBOTVM_CID}    // 7,
+    ADDR    => $ENV{PBOTVM_ADDR}   // '127.0.0.1',
-    VPORT  => $ENV{PBOTVM_VPORT}  // 5555,
+    SERIAL  => $ENV{PBOTVM_SERIAL} // 5555,
+    HEALTH  => $ENV{PBOTVM_HEALTH} // 5556,
+    CID     => $ENV{PBOTVM_CID}    // 7,
+    VPORT   => $ENV{PBOTVM_VPORT}  // 5555,
+    VAGRANT => $ENV{PBOTVM_VAGRANT} // 0,
 };
 
 use File::Basename;
@@ -64,7 +71,7 @@ sub connect_serial($context) {
     print STDERR "Connecting to remote VM serial port $context->{'vm-serial'}\n";
 
     my $vm = IO::Socket::INET->new(
-        PeerAddr => '127.0.0.1',
+        PeerAddr => $context->{'vm-addr'},
         PeerPort => $context->{'vm-serial'},
         Proto => 'tcp',
         Type => SOCK_STREAM
@@ -96,6 +103,12 @@ sub connect_vm($context) {
 sub make_context_from_args(@args_in) {
     my $args = join ' ', @args_in;
 
+    # extract leading options
+    my %opts;
+    while ($args =~ s/^-(revert|health)\s+//) {
+        $opts{$1} = 1;
+    }
+
     my $context = eval { decode_json $args };
 
     if ($@) {
@@ -108,8 +121,14 @@ sub make_context_from_args(@args_in) {
         }
     }
 
+    # set extracted leading options
+    foreach my $opt (keys %opts) {
+        print STDERR "Setting option `$opt`.\n";
+        $context->{$opt} = 1;
+    }
+
     # parse options specific to vm-exec
-    while ($context->{code} =~ s/^-(lang|vm-cid|vm-vport|vm-serial|vm)=([^ ]+)\s*//) {
+    while ($context->{code} =~ s/^-(lang|revert|health|vm-domain|vm-health|vm-cid|vm-vport|vm-serial|vm)=([^ ]+)\s*//) {
         my ($option, $value) = ($1, $2);
         print STDERR "Overriding `$option` to `$value`.\n";
         $context->{$option} = lc $value;
@@ -190,13 +209,17 @@ sub configure_context($context, $config) {
         if (not defined $entry) {
             my $machines = list_machines($config);
             print "Unknown machine '$machine'; available machines are: $machines\n";
-            exit 1;
+            exit 3;
         }
 
         # override values
-        $context->{'vm-serial'} = $entry->{'serial'};
+        $context->{'vm-domain'}  = $machine;
-        $context->{'vm-cid'}    = $entry->{'cid'};
+        $context->{'vm-addr'}    = $entry->{'addr'};
-        $context->{'vm-vport'}  = $entry->{'vport'};
+        $context->{'vm-health'}  = $entry->{'health'};
+        $context->{'vm-serial'}  = $entry->{'serial'};
+        $context->{'vm-cid'}     = $entry->{'cid'};
+        $context->{'vm-vport'}   = $entry->{'vport'};
+        $context->{'vm-vagrant'} = $entry->{'vagrant'};
     } else {
         # otherwise configure any undefined values as default machine
         my $machine = $config->{'default-machine'};
@@ -207,22 +230,30 @@ sub configure_context($context, $config) {
         if (not defined $entry) {
             my $machines = list_machines($config);
             print "Unknown machine '$machine'; available machines are: $machines\n";
-            exit 1;
+            exit 3;
         }
 
         # update any undefined values, preserving any existing values
-        $context->{'vm-serial'} //= $entry->{'serial'};
+        $context->{'vm-domain'}  //= $machine;
-        $context->{'vm-cid'}    //= $entry->{'cid'};
+        $context->{'vm-addr'}    //= $entry->{'addr'};
-        $context->{'vm-vport'}  //= $entry->{'vport'};
+        $context->{'vm-health'}  //= $entry->{'health'};
+        $context->{'vm-serial'}  //= $entry->{'serial'};
+        $context->{'vm-cid'}     //= $entry->{'cid'};
+        $context->{'vm-vport'}   //= $entry->{'vport'};
+        $context->{'vm-vagrant'} //= $entry->{'vagrant'};
     }
 
     # set any undefined values to default values
-    $context->{nick}        //= 'vm';
+    $context->{nick}         //= 'vm';
-    $context->{channel}     //= 'vm';
+    $context->{channel}      //= 'vm';
-    $context->{lang}        //= 'c2x';
+    $context->{lang}         //= 'c2x';
-    $context->{'vm-serial'} //= SERIAL;
+    $context->{'vm-domain'}  //= DOMAIN;
-    $context->{'vm-cid'}    //= CID;
+    $context->{'vm-addr'}    //= ADDR;
-    $context->{'vm-vport'}  //= VPORT;
+    $context->{'vm-health'}  //= HEALTH;
+    $context->{'vm-serial'}  //= SERIAL;
+    $context->{'vm-cid'}     //= CID;
+    $context->{'vm-vport'}   //= VPORT;
+    $context->{'vm-vagrant'} //= VAGRANT;
 }
 
 sub main() {
@@ -232,6 +263,59 @@ sub main() {
 
     configure_context($context, $config);
 
+    # instructed to revert machine
+    if ($context->{revert}) {
+        if (exists $config->{aliases}->{$context->{'vm-domain'}}) {
+            $context->{'vm-domain'} = $config->{aliases}->{$context->{'vm-domain'}};
+        }
+
+        print STDERR "REVERT $context->{'vm-domain'}\n";
+
+        if ($context->{'vm-vagrant'}) {
+            system("virsh -c qemu:///system snapshot-revert $context->{'vm-domain'} 1");
+        } else {
+            system("virsh snapshot-revert $context->{'vm-domain'} 1");
+        }
+
+        exit 0;
+    }
+
+    # instructed to check health
+    if ($context->{health}) {
+        my $health = IO::Socket::INET->new(
+            PeerAddr => $context->{'vm-addr'},
+            PeerPort => $context->{'vm-health'},
+            Proto => 'tcp',
+            Type => SOCK_STREAM
+        );
+
+        if (not defined $health) {
+            print STDERR "Unable to connect to health $context->{'vm-addr'} $context->{'vm-health'}\n";
+            exit 2;
+        }
+
+        print $health "\n";
+
+
+        eval {
+            alarm 2;
+            local $SIG{ALRM} = sub { die "Health timed-out\n"; };
+
+            while (my $output = <$health>) {
+                last if $output eq ":END\r\n";
+                print $output;
+            }
+            close $health;
+        };
+
+        if ($@) {
+            print STDERR "Failed to get health: $@\n";
+            exit 1;
+        }
+
+        exit 0;
+    }
+
     # load language before checking usage in order to handle -lang=? flag
     # to list languages instead of showing a usage message
     my $lang = load_language($context);

applets/pbot-vm/host/bin/vm-server

@@ -6,7 +6,7 @@
 # listens for incoming commands from vm-client. Invokes vm-exec to send
 # commands to the PBot Guest Server (guest-server).
 
-# SPDX-FileCopyrightText: 2021 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2021-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 use 5.020;
@@ -25,19 +25,24 @@ use Encode;
 
 use constant {
     SERVER_PORT     => $ENV{PBOTVM_PORT}    // 9000,
-    HEARTBEAT_PORT  => $ENV{PBOTVM_HEART}   // 5556,
-    DOMAIN_NAME     => $ENV{PBOTVM_DOMAIN}  // 'pbot-vm',
     COMPILE_TIMEOUT => $ENV{PBOTVM_TIMEOUT} // 10,
 };
 
-sub vm_revert() {
+sub vm_revert($input) {
     return if $ENV{PBOTVM_NOREVERT};
     print "Reverting vm...\n";
-    system('time virsh snapshot-revert '.DOMAIN_NAME.' 1');
+    execute("perl vm-exec -revert $input", 1000);
     print "Reverted.\n";
 }
 
-sub execute($command) {
+sub vm_check_health($input) {
+    print "Checking health...\n";
+    my ($ret, $result) = execute("perl vm-exec -health $input", 2);
+    print "$result\n" if length $result;
+    return ($ret, $result);
+}
+
+sub execute($command, $timeout = COMPILE_TIMEOUT) {
     print "execute ($command)\n";
 
     # to get $? from pipe
@@ -53,7 +58,7 @@ sub execute($command) {
     my $result = eval {
         my $output = '';
         local $SIG{ALRM} = sub { kill 9, $pid; die "Timed-out: $output\n"; };
-        alarm(COMPILE_TIMEOUT);
+        alarm($timeout);
 
         while (my $line = decode('UTF-8', <$fh>)) {
             $output .= $line;
@@ -80,47 +85,6 @@ sub execute($command) {
     return ($ret, $result);
 }
 
-sub connect_to_heartbeat() {
-    my $heartbeat;
-    my $attempts = 15;
-
-    while (!$heartbeat && $attempts > 0) {
-        print "Connecting to heartbeat on port ".HEARTBEAT_PORT." ... ";
-
-        $heartbeat = IO::Socket::INET->new (
-            PeerAddr => '127.0.0.1',
-            PeerPort => HEARTBEAT_PORT,
-            Proto    => 'tcp',
-            Type     => SOCK_STREAM,
-        );
-
-        if (!$heartbeat) {
-            print "failed.\n";
-            --$attempts;
-            print "Trying again in 2 seconds ($attempts attempts remaining) ...\n" if $attempts > 0;
-            sleep 2;
-        } else {
-            print "success!\n";
-        }
-    }
-
-    return $heartbeat;
-}
-
-sub do_heartbeat() {
-    tie my $heartbeat, 'IPC::Shareable', { key => 'heartbeat' };
-    tie my $running,   'IPC::Shareable', { key => 'running'   };
-
-    while ($running) {
-        my $heartbeat_monitor = connect_to_heartbeat();
-
-        while ($running and <$heartbeat_monitor>) {
-            $heartbeat = time;
-        }
-    }
-    exit;
-}
-
 sub server_listen($port) {
     my $server = IO::Socket::INET->new (
         Proto     => 'tcp',
@@ -135,29 +99,25 @@ sub server_listen($port) {
 }
 
 sub do_server() {
-    tie my $heartbeat, 'IPC::Shareable', { key => 'heartbeat' };
-    tie my $running,   'IPC::Shareable', { key => 'running'   };
-
     print "Starting PBot VM Server on port " . SERVER_PORT . "\n";
     my $server = eval { server_listen(SERVER_PORT) };
 
     if ($@) {
         print STDERR $@;
-        $running = 0;
         return;
     }
 
-    while ($running and my $client = $server->accept) {
+    while (my $client = $server->accept) {
         print '-' x 20, "\n";
         my $hostinfo = gethostbyaddr($client->peeraddr);
         print "Connect from ", $client->peerhost, " at ", scalar localtime, "\n";
-        handle_client($client, $heartbeat);
+        handle_client($client);
     }
 
     print "Shutting down server.\n";
 }
 
-sub handle_client($client, $heartbeat) {
+sub handle_client($client) {
     my ($timed_out, $killed) = (0, 0);
 
     my $r = fork;
@@ -177,30 +137,50 @@ sub handle_client($client, $heartbeat) {
 
     $client->autoflush(1);
 
-    eval {
+    my $input = eval {
         # give client 5 seconds to send a line
         local $SIG{ALRM} = sub { die "Client I/O timed-out\n"; };
         alarm 5;
 
-        while (my $line = decode('UTF-8', <$client>)) {
+        my $input;
-            $line =~ s/[\r\n]+$//;
+
-            next if $line =~ m/^\s*$/;
+        while ($input = decode('UTF-8', <$client>)) {
+            $input =~ s/[\r\n]+$//;
+            next if $input =~ m/^\s*$/;
 
             # give client 5 more seconds
             alarm 5;
 
-            print "[$$] Read [$line]\n";
+            print "[$$] Read [$input]\n";
 
-            if (time - $heartbeat > 5) {
+            # check health
-                print "[$$] Lost heartbeat, ignoring compile attempt.\n";
+            my ($health, $health_message) = vm_check_health($input);
-                print $client "Virtual machine is resetting, try again soon.\n";
+
+            if ($health == 2) {
+                print "[$$] Unable to connect to VM health check, ignoring compile attempt.\n";
+                print $client "Virtual machine is offline.\n";
+                last;
+            }
+
+            if ($health == 1 || $health == -13) {
+                print "[$$] VM not responding to health check, ignoring compile attempt.\n";
+                print $client "Virtual machine is temporarily unavailable, try again soon.\n";
+                last;
+            }
+
+            if ($health != 0) {
+                if (length $health_message) {
+                    print $client $health_message;
+                } else {
+                    print $client "Virtual machine is misbehaving, try again soon.\n";
+                }
                 last;
             }
 
             # disable client time-out
             alarm 0;
 
-            my ($ret, $result) = execute("perl vm-exec $line");
+            my ($ret, $result) = execute("perl vm-exec $input");
 
             $result =~ s/\s+$//;
             print "Ret: $ret; result: [$result]\n";
@@ -217,6 +197,8 @@ sub handle_client($client, $heartbeat) {
             print $client encode('UTF-8', $result . "\n");
             last;
         }
+
+        return $input;
     };
 
     # print client time-out exception
@@ -228,11 +210,11 @@ sub handle_client($client, $heartbeat) {
     print "[$$] timed out: $timed_out; killed: $killed\n";
 
     if ($timed_out || $killed) {
-        vm_revert();
+        vm_revert($input);
     }
 
     # child done
-    print "[$$] client exiting\n";
+    print "[$$] client exit\n";
     print "=" x 20, "\n";
     exit;
 }
@@ -244,23 +226,8 @@ sub main() {
     # let OS clean-up child exits
     $SIG{CHLD} = 'IGNORE';
 
-    tie my $heartbeat, 'IPC::Shareable', { key => 'heartbeat', create => 1, destroy => 1 };
+    # start server
-    tie my $running,   'IPC::Shareable', { key => 'running',   create => 1, destroy => 1 };
+    do_server();
-
-    $running   = 1;
-    $heartbeat = 0;
-
-    my $heartbeat_pid = fork // die "Heartbeat fork failed: $!";
-
-    if ($heartbeat_pid == 0) {
-        do_heartbeat();
-    } else {
-        do_server();
-    }
-
-    print "Waiting for heart to stop...\n";
-    waitpid($heartbeat_pid, 0);
-    print "Heart stopped.\n";
 }
 
 main();

applets/pbot-vm/host/config/vm-exec.json

@@ -1,21 +1,25 @@
 {
    "machines" : {
       "pbot-vm" : {
+         "addr" : "127.0.0.1",
          "serial" : 5555,
-         "heart" : 5556,
+         "health" : 5556,
          "cid" : 7,
-         "vport" : 5555
+         "vport" : 5555,
+         "vagrant" : 0
       },
       "pbot-test-vm" : {
+         "addr" : "127.0.0.1",
          "serial" : 7777,
-         "heart" : 7778,
+         "health" : 7778,
          "cid" : 42,
-         "vport" : 5555
+         "vport" : 5555,
+         "vagrant" : 1
       }
    },
    "aliases" : {
-      "openSUSE" : "pbot-vm",
+      "main" : "pbot-vm",
       "test" : "pbot-test-vm"
    },
-   "default-machine" : "openSUSE"
+   "default-machine" : "main"
 }

applets/pbot-vm/host/devices/add-serials

@@ -2,7 +2,7 @@
 
 DOMAIN="${PBOTVM_DOMAIN:-pbot-vm}"
 SERIAL="${PBOTVM_SERIAL:-5555}"
-HEART="${PBOTVM_HEART:-5556}"
+HEALTH="${PBOTVM_HEALTH:-5556}"
 
 cat > serial-2.xml <<EOF
 <serial type='tcp'>
@@ -14,7 +14,7 @@ EOF
 
 cat > serial-3.xml <<EOF
 <serial type='tcp'>
-    <source mode='bind' host='127.0.0.1' service='$HEART' tls='no'/>
+    <source mode='bind' host='127.0.0.1' service='$HEALTH' tls='no'/>
     <protocol type='raw'/>
     <target port='3'/>
 </serial>

applets/pbot-vm/host/lib/Languages/bash.pm

@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 
-# SPDX-FileCopyrightText: 2021 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2021-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 use warnings;
@@ -17,11 +17,11 @@ sub initialize {
   $self->{default_options} = '';
   $self->{cmdline}         = 'bash $options $sourcefile';
 
-  $self->{cmdline_opening_comment} = ": <<'____CMDLINE____'\n";
+  $self->{cmdline_opening_comment} = ": <<'CMDLINE'\n";
-  $self->{cmdline_closing_comment} = "____CMDLINE____\n";
+  $self->{cmdline_closing_comment} = "CMDLINE\n";
 
-  $self->{output_opening_comment} = ": << '____OUTPUT____'\n";
+  $self->{output_opening_comment} = ": << 'OUTPUT'\n";
-  $self->{output_closing_comment} = "____OUTPUT____\n";
+  $self->{output_closing_comment} = "OUTPUT\n";
 }
 
 1;

applets/pbot-vm/host/lib/Languages/ksh.pm

@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 
-# SPDX-FileCopyrightText: 2021 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2021-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 use warnings;
@@ -17,11 +17,11 @@ sub initialize {
   $self->{default_options} = '';
   $self->{cmdline}         = 'ksh $options $sourcefile';
 
-  $self->{cmdline_opening_comment} = ": <<'____CMDLINE____'\n";
+  $self->{cmdline_opening_comment} = ": <<'CMDLINE'\n";
-  $self->{cmdline_closing_comment} = "____CMDLINE____\n";
+  $self->{cmdline_closing_comment} = "CMDLINE\n";
 
-  $self->{output_opening_comment} = ": << '____OUTPUT____'\n";
+  $self->{output_opening_comment} = ": << 'OUTPUT'\n";
-  $self->{output_closing_comment} = "____OUTPUT____\n";
+  $self->{output_closing_comment} = "OUTPUT\n";
 }
 
 1;

applets/pbot-vm/host/lib/Languages/sh.pm

@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 
-# SPDX-FileCopyrightText: 2021 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2021-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 use warnings;
@@ -17,11 +17,11 @@ sub initialize {
   $self->{default_options} = '';
   $self->{cmdline}         = 'sh $options $sourcefile';
 
-  $self->{cmdline_opening_comment} = ": <<'____CMDLINE____'\n";
+  $self->{cmdline_opening_comment} = ": <<'CMDLINE'\n";
-  $self->{cmdline_closing_comment} = "____CMDLINE____\n";
+  $self->{cmdline_closing_comment} = "CMDLINE\n";
 
-  $self->{output_opening_comment} = ": << '____OUTPUT____'\n";
+  $self->{output_opening_comment} = ": << 'OUTPUT'\n";
-  $self->{output_closing_comment} = "____OUTPUT____\n";
+  $self->{output_closing_comment} = "OUTPUT\n";
 }
 
 1;

applets/pbot-vm/host/lib/Languages/zsh.pm

@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 
-# SPDX-FileCopyrightText: 2021 Pragmatic Software <pragma78@gmail.com>
+# SPDX-FileCopyrightText: 2021-2024 Pragmatic Software <pragma78@gmail.com>
 # SPDX-License-Identifier: MIT
 
 use warnings;
@@ -17,11 +17,11 @@ sub initialize {
   $self->{default_options} = '';
   $self->{cmdline}         = 'zsh $options $sourcefile';
 
-  $self->{cmdline_opening_comment} = ": <<'____CMDLINE____'\n";
+  $self->{cmdline_opening_comment} = ": <<'CMDLINE'\n";
-  $self->{cmdline_closing_comment} = "____CMDLINE____\n";
+  $self->{cmdline_closing_comment} = "CMDLINE\n";
 
-  $self->{output_opening_comment} = ": << '____OUTPUT____'\n";
+  $self->{output_opening_comment} = ": << 'OUTPUT'\n";
-  $self->{output_closing_comment} = "____OUTPUT____\n";
+  $self->{output_closing_comment} = "OUTPUT\n";
 }
 
 1;

applets/pbot-vm/vagrant/Debian-testing64/Vagrantfile

@@ -4,8 +4,8 @@
 ENV['VAGRANT_DEFAULT_PROVIDER'] = 'libvirt'
 
 PBOTVM_SERIAL = ENV['PBOTVM_SERIAL'] || 5555
-PBOTVM_HEART  = ENV['PBOTVM_HEART']  || 5556
+PBOTVM_HEALTH = ENV['PBOTVM_HEALTH'] || 5556
-PBOTVM_NAME   = ENV['PBOTVM_NAME']   || 'pbot-vagrant-vm'
+PBOTVM_DOMAIN = ENV['PBOTVM_DOMAIN'] || 'pbot-vm'
 
 Vagrant.configure("2") do |config|
   # Every Vagrant development environment requires a box. You can search for

applets/pbot-vm/vagrant/README.md

@@ -9,47 +9,73 @@ section, then return to this guide.
 
 To install vagrant on openSUSE, use:
 
-    zypper install --no-recommends vagrant vagrant-libvirt
+    zypper install --no-recommends vagrant
 
 Otherwise see https://vagrant-libvirt.github.io/vagrant-libvirt/installation.html for installation instructions for your platform.
 
 ### Install vagrant-libvirt
 
-If your distribution does not have a `vagrant-libvirt` package or if you need an up-to-date version use Vagrant's plugin manager:
-
     vagrant plugin install vagrant-libvirt
 
 ### Start Vagrant Box
 
 To start a virtual machine, `cd` into one of the PBot-VM Vagrant sub-directories and run the following command. This will download
-the appropriate virtual machine image and automatically configure it as a PBot VM Guest.
+the appropriate virtual machine image and automatically configure it as the default PBot VM Guest, `pbot-vm` described by
+[`host/config/vm-exec.json`](../host/config/vm-exec.json):
 
     vagrant up
 
-You may pass optional environment variables to override pbot-vm default configuration (see [PBot VM Environment Variables](../../../doc/VirtualMachine.md#environment-variables)):
+You may pass optional environment variables to override pbot-vm default configuration (see [PBot VM Environment Variables](../../../doc/VirtualMachine.md#environment-variables)).
+For example, to create `pbot-test-vm` described by [`host/config/vm-exec.json`](../host/config/vm-exec.json):
 
-    PBOTVM_SERIAL=7777 PBOTVM_HEART=7778 vagrant up
+    PBOTVM_DOMAIN=pbot-test-vm PBOTVM_SERIAL=7777 PBOTVM_HEALTH=7778 vagrant up
 
 ### Connect to Vagrant Box
 
+Use SSH to connect to the PBot VM Guest:
+
     vagrant ssh
 
+If you specified a `PBOTVM_DOMAIN`, e.g. `pbot-test-vm`, you must specify it:
+
+    PBOTVM_DOMAIN=pbot-test-vm vagrant ssh
+
 ### Start PBot VM Guest Server
 
-    sudo guest-server
+Once connected to the PBot VM Guest via SSH, start `guest-server` in the background:
+
+    sudo nohup guest-server &> log &
 
 Some distributions may require you to specify the full path:
 
-    sudo /usr/local/bin/guest-server
+    sudo nohup /usr/local/bin/guest-server &> log &
+
+### Disconnect from Vagrant Box
+
+Now you can type `logout` to exit the PBot VM Guest.
+
+### Create snapshot of PBot VM Guest
+
+After you've logged out of the PBot VM Guest with `guest-server` running in the background, create a snapshot. This allows PBot to revert to a known good state when a command times out.
+If a `PBOTVM_DOMAIN` was defined, replace `pbot-vm` with that name.
+
+    virsh -c qemu:///system snapshot-create-as pbot-vm 1
+
+### Edit vm-exec.json
+
+If you used `vagrant up` without specifying a `PBOTVM_DOMAIN`, you must edit the [`../host/config/vm-exec.json`](../host/config/vm-exec.json)
+configuration file to set the `vagrant` value to `1` for the `pbot-vm` machine.
+
+If you have specified a `PBOTVM_DOMAIN`, ensure the appropriate entries exist in the `vm-exec.json` configuration file.
+
+By default, `pbot-test-vm` already has `vagrant` set to `1`.
 
 ### Start PBot VM Host Server
 
-After starting the guest-server, you must now start the host server.
+    cd ../host/bin/
-
+    ./vm-server
-    ../host/bin/vm-server
 
 ### Test PBot VM
-
 In your instance of PBot, the `sh` and `cc`, etc, commands should now produce output:
 
     <pragma-> sh echo Hello world!

applets/pbot-vm/vagrant/common/Vagrantfile.common

@@ -4,15 +4,18 @@
 Vagrant.configure("2") do |config|
   config.vm.box_check_update = false
 
-  config.vm.hostname = PBOTVM_NAME
+  config.vm.define PBOTVM_DOMAIN
+  config.vm.hostname = PBOTVM_DOMAIN
 
   config.vm.provider :libvirt do |libvirt|
+    libvirt.title = PBOTVM_DOMAIN
+    libvirt.default_prefix = ""
     libvirt.qemuargs :value => "-chardev"
     libvirt.qemuargs :value => "socket,id=charserial1,host=127.0.0.1,port=#{PBOTVM_SERIAL},server=on,wait=off"
     libvirt.qemuargs :value => "-device"
     libvirt.qemuargs :value => '{"driver":"isa-serial","chardev":"charserial1","id":"serial1","index":2}'
     libvirt.qemuargs :value => "-chardev"
-    libvirt.qemuargs :value => "socket,id=charserial2,host=127.0.0.1,port=#{PBOTVM_HEART},server=on,wait=off"
+    libvirt.qemuargs :value => "socket,id=charserial2,host=127.0.0.1,port=#{PBOTVM_HEALTH},server=on,wait=off"
     libvirt.qemuargs :value => "-device"
     libvirt.qemuargs :value => '{"driver":"isa-serial","chardev":"charserial2","id":"serial2","index":3}'
   end

applets/pbot-vm/vagrant/openSUSE-Tumbleweed/Vagrantfile

@@ -4,8 +4,8 @@
 ENV['VAGRANT_DEFAULT_PROVIDER'] = 'libvirt'
 
 PBOTVM_SERIAL = ENV['PBOTVM_SERIAL'] || 5555
-PBOTVM_HEART  = ENV['PBOTVM_HEART']  || 5556
+PBOTVM_HEALTH = ENV['PBOTVM_HEALTH'] || 5556
-PBOTVM_NAME   = ENV['PBOTVM_NAME']   || 'pbot-vagrant-vm'
+PBOTVM_DOMAIN = ENV['PBOTVM_DOMAIN'] || 'pbot-vm'
 
 Vagrant.configure("2") do |config|
   # Every Vagrant development environment requires a box. You can search for

doc/README.md

@@ -353,7 +353,8 @@
   * [Initial virtual machine set-up complete](VirtualMachine.md#initial-virtual-machine-set-up-complete)
 * [Start PBot VM Host](VirtualMachine.md#start-pbot-vm-host)
   * [Test PBot](VirtualMachine.md#test-pbot)
-* [QEMU command from libvirt](VirtualMachine.md#qemu-command-from-libvirt)
+  * [Adding additional VMs](VirtualMachine.md#adding-additional-vms)
+  * [QEMU command from libvirt](VirtualMachine.md#qemu-command-from-libvirt)
 <!-- md-toc-end -->
 <!-- md-toc-begin -->
 * [Frequently Asked Questions](FAQ.md#frequently-asked-questions)

lib/PBot/VERSION.pm

@@ -25,8 +25,8 @@ use PBot::Imports;
 # These are set by the /misc/update_version script
 use constant {
     BUILD_NAME     => "PBot",
-    BUILD_REVISION => 4740,
+    BUILD_REVISION => 4741,
-    BUILD_DATE     => "2024-04-07",
+    BUILD_DATE     => "2024-04-10",
 };
 
 sub initialize {}