245 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			Perl
		
	
	
	
	
	
			
		
		
	
	
			245 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			Perl
		
	
	
	
	
	
| #! @perl@
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| 
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| use strict;
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| use POSIX;
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| use File::Path;
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| use File::Slurp;
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| use Fcntl ':flock';
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| use Getopt::Long qw(:config gnu_getopt);
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| 
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| my $socat = '@socat@/bin/socat';
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| 
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| # Ensure a consistent umask.
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| umask 0022;
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| 
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| # Parse the command line.
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| 
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| sub showHelp {
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|     print <<EOF;
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| Usage: nixos-container list
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|        nixos-container create <container-name> [--config <string>] [--ensure-unique-name]
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|        nixos-container destroy <container-name>
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|        nixos-container start <container-name>
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|        nixos-container stop <container-name>
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|        nixos-container login <container-name>
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|        nixos-container root-login <container-name>
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|        nixos-container run <container-name> -- args...
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|        nixos-container set-root-password <container-name> <password>
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|        nixos-container show-ip <container-name>
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| EOF
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|     exit 0;
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| }
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| 
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| my $ensureUniqueName = 0;
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| my $extraConfig;
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| 
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| GetOptions(
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|     "help" => sub { showHelp() },
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|     "ensure-unique-name" => \$ensureUniqueName,
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|     "config=s" => \$extraConfig
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|     ) or exit 1;
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| 
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| my $action = $ARGV[0] or die "$0: no action specified\n";
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| 
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| 
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| # Execute the selected action.
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| 
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| mkpath("/etc/containers", 0, 0755);
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| mkpath("/var/lib/containers", 0, 0700);
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| 
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| if ($action eq "list") {
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|     foreach my $confFile (glob "/etc/containers/*.conf") {
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|         $confFile =~ /\/([^\/]+).conf$/ or next;
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|         print "$1\n";
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|     }
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|     exit 0;
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| }
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| 
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| my $containerName = $ARGV[1] or die "$0: no container name specified\n";
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| $containerName =~ /^[a-zA-Z0-9\-]+$/ or die "$0: invalid container name\n";
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| 
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| sub writeNixOSConfig {
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|     my ($nixosConfigFile) = @_;
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| 
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|     my $nixosConfig = <<EOF;
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| { config, lib, pkgs, ... }:
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| 
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| with lib;
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| 
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| { boot.isContainer = true;
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|   networking.hostName = mkDefault "$containerName";
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|   networking.useDHCP = false;
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|   $extraConfig
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| }
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| EOF
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| 
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|     write_file($nixosConfigFile, $nixosConfig);
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| }
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| 
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| if ($action eq "create") {
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|     # Acquire an exclusive lock to prevent races with other
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|     # invocations of ‘nixos-container create’.
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|     my $lockFN = "/run/lock/nixos-container";
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|     open(my $lock, '>>', $lockFN) or die "$0: opening $lockFN: $!";
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|     flock($lock, LOCK_EX) or die "$0: could not lock $lockFN: $!";
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| 
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|     my $confFile = "/etc/containers/$containerName.conf";
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|     my $root = "/var/lib/containers/$containerName";
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| 
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|     # Maybe generate a unique name.
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|     if ($ensureUniqueName) {
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|         my $base = $containerName;
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|         for (my $nr = 0; ; $nr++) {
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|             $containerName = "$base-$nr";
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|             $confFile = "/etc/containers/$containerName.conf";
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|             $root = "/var/lib/containers/$containerName";
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|             last unless -e $confFile || -e $root;
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|         }
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|     }
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| 
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|     die "$0: container ‘$containerName’ already exists\n" if -e $confFile;
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| 
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|     # Get an unused IP address.
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|     my %usedIPs;
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|     foreach my $confFile2 (glob "/etc/containers/*.conf") {
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|         my $s = read_file($confFile2) or die;
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|         $usedIPs{$1} = 1 if $s =~ /^HOST_ADDRESS=([0-9\.]+)$/m;
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|         $usedIPs{$1} = 1 if $s =~ /^LOCAL_ADDRESS=([0-9\.]+)$/m;
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|     }
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| 
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|     my ($ipPrefix, $hostAddress, $localAddress);
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|     for (my $nr = 1; $nr < 255; $nr++) {
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|         $ipPrefix = "10.233.$nr";
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|         $hostAddress = "$ipPrefix.1";
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|         $localAddress = "$ipPrefix.2";
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|         last unless $usedIPs{$hostAddress} || $usedIPs{$localAddress};
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|         $ipPrefix = undef;
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|     }
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| 
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|     die "$0: out of IP addresses\n" unless defined $ipPrefix;
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| 
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|     my @conf;
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|     push @conf, "PRIVATE_NETWORK=1\n";
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|     push @conf, "HOST_ADDRESS=$hostAddress\n";
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|     push @conf, "LOCAL_ADDRESS=$localAddress\n";
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|     write_file($confFile, \@conf);
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| 
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|     close($lock);
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| 
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|     print STDERR "host IP is $hostAddress, container IP is $localAddress\n";
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| 
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|     mkpath("$root/etc/nixos", 0, 0755);
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| 
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|     my $nixosConfigFile = "$root/etc/nixos/configuration.nix";
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|     writeNixOSConfig $nixosConfigFile;
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| 
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|     # The per-container directory is restricted to prevent users on
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|     # the host from messing with guest users who happen to have the
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|     # same uid.
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|     my $profileDir = "/nix/var/nix/profiles/per-container";
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|     mkpath($profileDir, 0, 0700);
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|     $profileDir = "$profileDir/$containerName";
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|     mkpath($profileDir, 0, 0755);
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| 
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|     system("nix-env", "-p", "$profileDir/system",
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|            "-I", "nixos-config=$nixosConfigFile", "-f", "<nixpkgs/nixos>",
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|            "--set", "-A", "system") == 0
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|         or die "$0: failed to build initial container configuration\n";
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| 
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|     print "$containerName\n" if $ensureUniqueName;
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|     exit 0;
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| }
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| 
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| my $root = "/var/lib/containers/$containerName";
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| my $profileDir = "/nix/var/nix/profiles/per-container/$containerName";
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| my $confFile = "/etc/containers/$containerName.conf";
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| die "$0: container ‘$containerName’ does not exist\n" if !-e $confFile;
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| 
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| sub isContainerRunning {
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|     my $status = `systemctl show 'container\@$containerName'`;
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|     return $status =~ /ActiveState=active/;
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| }
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| 
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| sub stopContainer {
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|     system("systemctl", "stop", "container\@$containerName") == 0
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|         or die "$0: failed to stop container\n";
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| }
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| 
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| if ($action eq "destroy") {
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|     die "$0: cannot destroy declarative container (remove it from your configuration.nix instead)\n"
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|         unless POSIX::access($confFile, &POSIX::W_OK);
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| 
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|     stopContainer if isContainerRunning;
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| 
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|     rmtree($profileDir) if -e $profileDir;
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|     rmtree($root) if -e $root;
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|     unlink($confFile) or die;
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| }
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| 
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| elsif ($action eq "start") {
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|     system("systemctl", "start", "container\@$containerName") == 0
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|         or die "$0: failed to start container\n";
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| }
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| 
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| elsif ($action eq "stop") {
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|     stopContainer;
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| }
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| 
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| elsif ($action eq "update") {
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|     my $nixosConfigFile = "$root/etc/nixos/configuration.nix";
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| 
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|     # FIXME: may want to be more careful about clobbering the existing
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|     # configuration.nix.
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|     writeNixOSConfig $nixosConfigFile if (defined $extraConfig && $extraConfig ne "");
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| 
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|     system("nix-env", "-p", "$profileDir/system",
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|            "-I", "nixos-config=$nixosConfigFile", "-f", "<nixpkgs/nixos>",
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|            "--set", "-A", "system") == 0
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|         or die "$0: failed to build container configuration\n";
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| 
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|     if (isContainerRunning) {
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|         print STDERR "reloading container...\n";
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|         system("systemctl", "reload", "container\@$containerName") == 0
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|             or die "$0: failed to reload container\n";
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|     }
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| }
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| 
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| elsif ($action eq "login") {
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|     exec("machinectl", "login", "--", $containerName);
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| }
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| 
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| elsif ($action eq "root-login") {
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|     exec($socat, "unix:$root/var/lib/root-login.socket", "-,echo=0,raw");
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| }
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| 
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| elsif ($action eq "run") {
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|     shift @ARGV; shift @ARGV;
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|     my $pid = open(SOCAT, "|-", $socat, "-t0", "-", "unix:$root/var/lib/run-command.socket") or die "$0: cannot start $socat: $!\n";
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|     print SOCAT join(' ', map { "'$_'" } @ARGV), "\n";
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|     flush SOCAT;
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|     waitpid($pid, 0);
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|     close(SOCAT);
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| }
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| 
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| elsif ($action eq "set-root-password") {
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|     # FIXME: don't get password from the command line.
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|     my $password = $ARGV[2] or die "$0: no password given\n";
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|     my $pid = open(SOCAT, "|-", $socat, "-t0", "-", "unix:$root/var/lib/run-command.socket") or die "$0: cannot start $socat: $!\n";
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|     print SOCAT "passwd\n";
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|     print SOCAT "$password\n";
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|     print SOCAT "$password\n";
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|     flush SOCAT;
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|     waitpid($pid, 0);
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|     close(SOCAT);
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| }
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| 
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| elsif ($action eq "show-ip") {
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|     my $s = read_file($confFile) or die;
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|     $s =~ /^LOCAL_ADDRESS=([0-9\.]+)$/m or die "$0: cannot get IP address\n";
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|     print "$1\n";
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| }
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| 
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| else {
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|     die "$0: unknown action ‘$action’\n";
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| }
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