webappusers in new servers

edited 2023/11/24 by pedro

orchestra/contrib/systemusers/admin.py

@@ -9,8 +9,8 @@ from orchestra.contrib.accounts.filters import IsActiveListFilter
 
 from .actions import set_permission, create_link
 from .filters import IsMainListFilter
-from .forms import SystemUserCreationForm, SystemUserChangeForm
+from .forms import SystemUserCreationForm, SystemUserChangeForm, WebappUserChangeForm, WebappUserCreationForm
-from .models import SystemUser
+from .models import SystemUser, WebappUsers
 
 
 class SystemUserAdmin(ChangePasswordAdminMixin, SelectAccountAdminMixin, ExtendedModelAdmin):
@@ -78,4 +78,34 @@ class SystemUserAdmin(ChangePasswordAdminMixin, SelectAccountAdminMixin, Extende
         return super(SystemUserAdmin, self).has_delete_permission(request, obj)
 
 
+
+class WebappUserAdmin(ChangePasswordAdminMixin, SelectAccountAdminMixin, ExtendedModelAdmin):
+    list_display = (
+        'username', 'account_link', 'shell', 'home', 'target_server'
+    )
+    fieldsets = (
+        (None, {
+            'fields': ('account_link', 'username', 'password', )
+        }),
+        (_("System"), {
+            'fields': ('shell', 'home', 'target_server'),
+        }),
+    )
+    add_fieldsets = (
+        (None, {
+            'fields': ('account_link', 'username', 'password1', 'password2')
+        }),
+        (_("System"), {
+            'fields': ('shell', 'home', 'target_server'),
+        }),
+    )
+    search_fields = ('username', 'account__username')
+    readonly_fields = ('account_link',)
+    change_readonly_fields = ('username', 'home', 'target_server')
+    add_form = WebappUserCreationForm
+    form = WebappUserChangeForm
+    ordering = ('-id',)
+    
+
 admin.site.register(SystemUser, SystemUserAdmin)
+admin.site.register(WebappUsers, WebappUserAdmin)

orchestra/contrib/systemusers/apps.py

@@ -2,6 +2,7 @@ import sys
 
 from django.apps import AppConfig
 from django.db.models.signals import post_migrate
+from django.utils.translation import gettext_lazy as _
 
 from orchestra.core import services
 
@@ -11,11 +12,12 @@ class SystemUsersConfig(AppConfig):
     verbose_name = "System users"
     
     def ready(self):
-        from .models import SystemUser
+        from .models import SystemUser, WebappUsers
         services.register(SystemUser, icon='roleplaying.png')
         if 'migrate' in sys.argv and 'accounts' not in sys.argv:
             post_migrate.connect(self.create_initial_systemuser,
                 dispatch_uid="orchestra.contrib.systemusers.apps.create_initial_systemuser")
+        services.register(WebappUsers, icon='roleplaying.png', verbose_name =_('WebApp User'), verbose_name_plural=_("Webapp users"))
     
     def create_initial_systemuser(self, **kwargs):
         from .models import SystemUser

orchestra/contrib/systemusers/backends.py

@@ -554,44 +554,7 @@ class UNIXUserControllerNewServers(ServiceController):
                 done
                 """) % context
             )
-        else:
+            
-            self.append(textwrap.dedent("""
-                check_code=0
-                # Ensure no processes running as user to modify/create
-                if ps -u %(user)s &> /dev/null; then
-                    pkill -u %(user)s; sleep 3;
-                    pkill -9 -u %(user)s; sleep 2;
-                fi
-                                        
-                # Update/create user state for %(user)s
-                if id %(user)s &> /dev/null; then
-                    usermod %(user)s  \\
-                        --password '%(password)s' \\
-                        --shell '%(shell)s' \\
-                        --groups '%(groups)s' || check_code=$?
-                else
-                    useradd %(user)s --home '/%(user)s' \\
-                        --password '%(password)s' \\
-                        --shell '%(shell)s' \\
-                        --groups '%(groups)s' || check_code=$?
-                fi
-                                        
-                if [[ $check_code -ne 0 ]]; then
-                        exit check_code
-                fi
-                
-                # Ensure homedir exists and has correct perms
-                mkdir -p %(home)s 
-                chown %(user)s:%(user)s  %(home)s 
-                chmod 750 %(home)s 
-
-                # Create /chroots/$uid symlink into /home/$user.parent/webapps/
-                uid=$(id -u "%(user)s")
-                ln -n -f -s %(mainuser_home)s/webapps /chroots/$uid 
-            """) % context
-            )
-
-
             for member in settings.SYSTEMUSERS_DEFAULT_GROUP_MEMBERS:
                 context['member'] = member
                 self.append('usermod -a -G %(user)s %(member)s || exit_code=$?' % context)
@@ -739,8 +702,6 @@ class UNIXUserControllerNewServers(ServiceController):
         if user.is_main:
             groups = list(user.account.systemusers.exclude(username=user.username).values_list('username', flat=True))
             groups.append("main-systemusers")
-        # groups = list(user.groups.values_list('username', flat=True))
-        # groups.append("webapp-systemusers")
         return groups 
     
     def get_context(self, user):
@@ -756,5 +717,116 @@ class UNIXUserControllerNewServers(ServiceController):
             'base_home': user.get_base_home(),
             'mainuser_home': user.main.get_home(),
         }
-        # context['deleted_home'] = settings.SYSTEMUSERS_MOVE_ON_DELETE_PATH % context
+        context['deleted_home'] = settings.SYSTEMUSERS_MOVE_ON_DELETE_PATH % context
+        return replace(context, "'", '"')
+
+
+
+
+class WebappUserController(ServiceController):
+    """
+    Basic UNIX system user/group support based on <tt>useradd</tt>, <tt>usermod</tt>, <tt>userdel</tt> and <tt>groupdel</tt>.
+    Autodetects and uses ACL if available, for better permission management.
+    """
+    verbose_name = _("SFTP Webapp user")
+    model = 'systemusers.WebappUsers'
+    actions = ('save', 'delete',)
+    doc_settings = (settings, (
+        'SYSTEMUSERS_DEFAULT_GROUP_MEMBERS',
+        'SYSTEMUSERS_MOVE_ON_DELETE_PATH',
+        'SYSTEMUSERS_FORBIDDEN_PATHS'
+    ))
+    
+    def save(self, user):
+        context = self.get_context(user)
+        if not context['user']:
+            return
+
+        self.append(textwrap.dedent("""
+            # Update/create user state for %(user)s
+            if id %(user)s  &> /dev/null; then
+                usermod %(user)s --home '/%(home)s' \\
+                    --password '%(password)s' \\
+                    --shell '%(shell)s' \\
+                    --groups '%(groups)s'
+            else
+                useradd_code=0
+                useradd %(user)s --home '/%(home)s' \\
+                    --password '%(password)s' \\
+                    --shell '%(shell)s' \\
+                    --groups '%(groups)s' || useradd_code=$?
+                if [[ $useradd_code -eq 8 ]]; then
+                    # User is logged in, kill and retry
+                    pkill -u %(user)s; sleep 2
+                    pkill -9 -u %(user)s; sleep 1
+                    useradd %(user)s --home '/%(home)s' \\
+                        --password '%(password)s' \\
+                        --shell '%(shell)s' \\
+                        --groups '%(groups)s'
+                elif [[ $useradd_code -ne 0 ]]; then
+                    exit $useradd_code
+                fi
+            fi
+            usermod -aG %(user)s %(parent)s
+                                    
+            # Ensure homedir exists and has correct perms
+            mkdir -p '%(webapp_path)s'  || exit_code=1
+            chown %(user)s:%(user)s %(webapp_path)s  || exit_code=1
+            chmod 750 '%(webapp_path)s'  || exit_code=1
+            
+            # Create /chroots/$uid symlink into /home/$user.parent/webapps/
+            uid=$(id -u "%(user)s")
+            ln -n -f -s %(base_home)s/webapps /chroots/$uid  || exit_code=1
+        """) % context
+        )
+
+    
+    def delete(self, user):
+        context = self.get_context(user)
+        if not context['user']:
+            return
+
+        self.append(textwrap.dedent("""\
+            # Delete %(user)s user
+            uid=$(id -u "%(user)s")
+                                    
+            nohup bash -c 'sleep 2 && killall -u %(user)s -s KILL' &> /dev/null &
+            killall -u %(user)s || true
+            userdel %(user)s || exit_code=$?
+            groupdel %(group)s || exit_code=$?
+                                    
+            # Delete /chroots/$uid symlink into /home/$user.parent/webapps/
+            rm /chroots/$uid  
+            """) % context
+        )
+        if context['deleted_home']:
+            self.append(textwrap.dedent("""\
+                # Move home into SYSTEMUSERS_MOVE_ON_DELETE_PATH, nesting if exists.
+                mv '%(webapp_path)s' '%(deleted_home)s' || exit_code=$?
+                """) % context
+            )
+        else:
+            self.append("rm -fr -- '%(webapp_path)s'" % context)
+    
+    
+    def get_groups(self, user):
+        groups = []
+        groups = list(user.account.systemusers.exclude(username=user.username).values_list('username', flat=True))
+        groups.append("webapp-systemusers")
+        return groups 
+    
+    def get_context(self, user):
+        context = {
+            'object_id': user.pk,
+            'user': user.username,
+            'group': user.username,
+            'groups': ','.join(self.get_groups(user)),
+            'password': user.password, #if user.active else '*%s' % user.password,
+            'shell': user.shell,
+            'home': user.home,
+            'base_home': user.get_base_home(),
+            'webapp_path': os.path.normpath(user.get_base_home() + "/webapps/" + user.home),
+            'parent': user.get_parent(), 
+        }
+        context['deleted_home'] = context['webapp_path'] + ".delete"
         return replace(context, "'", '"')

orchestra/contrib/systemusers/forms.py

@@ -6,6 +6,7 @@ from django.core.exceptions import ValidationError
 from django.utils.translation import gettext_lazy as _
 
 from orchestra.forms import UserCreationForm, UserChangeForm
+from orchestra.contrib.webapps.settings import WEBAPP_NEW_SERVERS
 
 from . import settings
 from .models import SystemUser
@@ -162,3 +163,27 @@ class PermissionForm(LinkForm):
             ('r', _("Read only")),
             ('w', _("Write only"))
         ))
+
+# ----------------------------
+
+
+class WebappUserFormMixin(object):
+    
+    def __init__(self, *args, **kwargs):
+        super(WebappUserFormMixin, self).__init__(*args, **kwargs)
+    
+    def clean(self):
+        if not self.instance.pk:
+            server = self.cleaned_data.get('target_server')
+            if server:
+                if server.name not in WEBAPP_NEW_SERVERS:
+                    self.add_error("target_server", _(f"{server} does not belong to the new servers"))
+        return self.cleaned_data
+
+class WebappUserCreationForm(WebappUserFormMixin, UserCreationForm):
+    pass
+
+
+class WebappUserChangeForm(WebappUserFormMixin, UserChangeForm):
+    pass
+

orchestra/contrib/systemusers/migrations/0001_initial.py

@@ -1,30 +1,32 @@
-# -*- coding: utf-8 -*-
+# Generated by Django 2.2.28 on 2023-07-22 08:04
-from __future__ import unicode_literals
 
-from django.db import models, migrations
-import orchestra.core.validators
 from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+import orchestra.core.validators
 
 
 class Migration(migrations.Migration):
 
+    initial = True
+
     dependencies = [
-#        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
     ]
 
     operations = [
         migrations.CreateModel(
             name='SystemUser',
             fields=[
-                ('id', models.AutoField(primary_key=True, serialize=False, auto_created=True, verbose_name='ID')),
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ('username', models.CharField(validators=[orchestra.core.validators.validate_username], unique=True, help_text='Required. 64 characters or fewer. Letters, digits and ./-/_ only.', max_length=32, verbose_name='username')),
+                ('username', models.CharField(help_text='Required. 32 characters or fewer. Letters, digits and ./-/_ only.', max_length=32, unique=True, validators=[orchestra.core.validators.validate_username], verbose_name='username')),
                 ('password', models.CharField(max_length=128, verbose_name='password')),
-                ('home', models.CharField(blank=True, max_length=256, help_text='Starting location when login with this no-shell user.', verbose_name='home')),
+                ('home', models.CharField(blank=True, help_text='Starting location when login with this no-shell user.', max_length=256, verbose_name='home')),
-                ('directory', models.CharField(blank=True, max_length=256, help_text="Optional directory relative to user's home.", verbose_name='directory')),
+                ('directory', models.CharField(blank=True, help_text="Optional directory relative to user's home.", max_length=256, verbose_name='directory')),
-                ('shell', models.CharField(default='/dev/null', max_length=32, choices=[('/dev/null', 'No shell, FTP only'), ('/bin/rssh', 'No shell, SFTP/RSYNC only'), ('/bin/bash', '/bin/bash'), ('/bin/sh', '/bin/sh')], verbose_name='shell')),
+                ('shell', models.CharField(choices=[('/dev/null', 'No shell, FTP only'), ('/bin/rssh', 'No shell, SFTP/RSYNC only'), ('/usr/bin/git-shell', 'No shell, GIT only'), ('/bin/bash', '/bin/bash')], default='/dev/null', max_length=32, verbose_name='shell')),
                 ('is_active', models.BooleanField(default=True, help_text='Designates whether this account should be treated as active. Unselect this instead of deleting accounts.', verbose_name='active')),
-#                ('account', models.ForeignKey(to=settings.AUTH_USER_MODEL, related_name='systemusers', verbose_name='Account')),
+                ('account', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='systemusers', to=settings.AUTH_USER_MODEL, verbose_name='Account')),
-                ('groups', models.ManyToManyField(to='systemusers.SystemUser', blank=True, help_text='A new group will be created for the user. Which additional groups would you like them to be a member of?')),
+                ('groups', models.ManyToManyField(blank=True, help_text='A new group will be created for the user. Which additional groups would you like them to be a member of?', to='systemusers.SystemUser')),
             ],
         ),
     ]

orchestra/contrib/systemusers/migrations/0002_webappusers.py

@@ -0,0 +1,33 @@
+# Generated by Django 2.2.28 on 2023-07-22 08:05
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+import orchestra.core.validators
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('orchestration', '__first__'),
+        ('systemusers', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='WebappUsers',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('username', models.CharField(help_text='Required. 32 characters or fewer. Letters, digits and ./-/_ only.', max_length=32, unique=True, validators=[orchestra.core.validators.validate_username], verbose_name='username')),
+                ('password', models.CharField(max_length=128, verbose_name='password')),
+                ('home', models.CharField(blank=True, help_text='Starting location when login with this no-shell user.', max_length=256, verbose_name='home')),
+                ('shell', models.CharField(choices=[('/dev/null', 'No shell, FTP only'), ('/bin/rssh', 'No shell, SFTP/RSYNC only'), ('/usr/bin/git-shell', 'No shell, GIT only'), ('/bin/bash', '/bin/bash')], default='/dev/null', max_length=32, verbose_name='shell')),
+                ('account', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='accounts', to=settings.AUTH_USER_MODEL, verbose_name='Account')),
+                ('target_server', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='orchestration.Server', verbose_name='Server')),
+            ],
+            options={
+                'unique_together': {('username', 'target_server')},
+            },
+        ),
+    ]

orchestra/contrib/systemusers/models.py

@@ -136,3 +136,43 @@ class SystemUser(models.Model):
 
     def get_home(self):
         return os.path.normpath(os.path.join(self.home, self.directory))
+
+
+
+# ------------------
+
+class WebappUsers(models.Model):
+    """
+    System users for webapp
+    Username max_length determined by LINUX system user/group lentgh: 32
+    """
+    username = models.CharField(_("username"), max_length=32, unique=True,
+        help_text=_("Required. 32 characters or fewer. Letters, digits and ./-/_ only."),
+        validators=[validators.validate_username])
+    password = models.CharField(_("password"), max_length=128)
+    account = models.ForeignKey('accounts.Account', verbose_name=_("Account"),
+        related_name='accounts', on_delete=models.CASCADE)
+    home = models.CharField(_("WebappDir"), max_length=256, blank=True,
+        help_text=_("name dir webapp /home/<main>/webapps/<DirName>"),
+        validators=[validators.validate_string_dir])
+    shell = models.CharField(_("shell"), max_length=32, choices=settings.WEBAPPUSERS_SHELLS,
+        default='/dev/null')
+    target_server = models.ForeignKey('orchestration.Server', on_delete=models.CASCADE,
+        verbose_name=_("Server"))
+
+    class Meta:
+        unique_together = ('username', 'target_server')
+        verbose_name = 'WebAppUser'
+        verbose_name_plural = 'WebappUsers'
+
+    def __str__(self):
+        return self.username
+    
+    def set_password(self, raw_password):
+        self.password = make_password(raw_password)
+    
+    def get_base_home(self):
+        return os.path.normpath(self.account.main_systemuser.home)
+    
+    def get_parent(self):
+        return self.account.main_systemuser

orchestra/contrib/systemusers/settings.py

@@ -7,6 +7,13 @@ _names = ('user', 'username')
 _backend_names = _names + ('group', 'shell', 'mainuser', 'home', 'base_home')
 
 
+WEBAPPUSERS_SHELLS = Setting('SYSTEMUSERS_SHELLS',
+    (
+        ('/dev/null', _("No shell, SFTP only")),
+        ('/bin/bash', "/bin/bash"),
+    ),
+)
+
 SYSTEMUSERS_SHELLS = Setting('SYSTEMUSERS_SHELLS',
     (
         ('/dev/null', _("No shell, FTP only")),

orchestra/contrib/vps/backends.py.new

@@ -0,0 +1,135 @@
+import decimal
+import textwrap
+
+from orchestra.contrib.orchestration import ServiceController
+from orchestra.contrib.resources import ServiceMonitor
+
+from . import settings
+
+
+class ProxmoxOVZ(ServiceController):
+    model = 'vps.VPS'
+    
+    RESOURCES = (
+        ('memory', 'mem'),
+        ('swap', 'swap'),
+        ('disk', 'disk')
+    )
+    GET_PROXMOX_INFO = textwrap.dedent("""
+        function get_vz_info () {
+            hostname=$1
+            version=$(pveversion | cut -d '/' -f2 | cut -d'.' -f1)
+            if [[ $version -lt 2 ]]; then
+                conf=$(grep "CID\\|:$hostname:" /var/lib/pve-manager/vzlist | grep -B1 ":$hostname:")
+                CID=$(echo "$conf" | head -n1 | cut -d':' -f2)
+                CTID=$(echo "$conf" | tail -n1 | cut -d':' -f1)
+                node=$(pveca -l | grep "^\\s*$CID\\s*:" | awk {'print $3'})
+            else
+                conf=$(grep -r "HOSTNAME=\\"$hostname\\"" /etc/pve/nodes/*/openvz/*.conf)
+                node=$(echo "${conf}" | cut -d"/" -f5)
+                CTID=$(echo "${conf}" | cut -d"/" -f7 | cut -d"\\." -f1)
+            fi
+            echo $CTID $node
+        }""")
+    
+    def prepare(self):
+        super(ProxmoxOVZ, self).prepare()
+        self.append(self.GET_PROXMOX_INFO)
+    
+    def get_vzset_args(self, context):
+        args = list(settings.VPS_DEFAULT_VZSET_ARGS)
+        for resource, arg_name in self.RESOURCES:
+            try:
+                allocation = context[resource]
+            except KeyError:
+                pass
+            else:
+                args.append('--%s %i' % (arg_name, allocation))
+        return ' '.join(args)
+    
+    def run_ssh_commands(self, ssh_commands):
+        commands = '\n    '.join(ssh_commands)
+        self.append(textwrap.dedent("""\
+            cat << EOF | ssh root@${info[1]}
+                %s
+            EOF""") % commands
+        )
+    
+    def save(self, vps):
+        # TODO create the container
+        context = self.get_context(vps)
+        self.append(textwrap.dedent("""
+            info=( $(get_vz_info %(hostname)s) )
+            echo "Managing ${info[@]}"\
+            """) % context
+        )
+        ssh_commands = []
+        vzset_args = self.get_vzset_args(context)
+        if vzset_args:
+            context['vzset_args'] = vzset_args
+            ssh_commands.append("pvectl vzset ${info[0]} %(vzset_args)s" % context)
+        if hasattr(vps, 'password'):
+            context['password'] = vps.password.replace('$', '\\$')
+            ssh_commands.append(textwrap.dedent("""\
+                echo 'root:%(password)s' \\
+                    | chroot /var/lib/vz/private/${info[0]} chpasswd -e""") % context
+            )
+        self.run_ssh_commands(ssh_commands)
+    
+    def get_context(self, vps):
+        context = {
+            'hostname': vps.hostname,
+        }
+        for resource, __ in self.RESOURCES:
+            try:
+                allocation = getattr(vps.resources, resource).allocated
+            except AttributeError:
+                pass
+            else:
+                context[resource] = allocation
+        return context
+
+
+class ProxmoxOpenVZTraffic(ServiceMonitor):
+    model = 'vps.VPS'
+    resource = ServiceMonitor.TRAFFIC
+    monthly_sum_old_values = True
+    GET_PROXMOX_INFO = ProxmoxOVZ.GET_PROXMOX_INFO
+
+    def prepare(self):
+        super(ProxmoxOpenVZTraffic, self).prepare()
+        self.append(self.GET_PROXMOX_INFO)
+        self.append(textwrap.dedent("""
+            function monitor () {
+                object_id=$1
+                hostname=$2
+                info=( $(get_vz_info $hostname) )
+                cat << EOF | ssh root@${info[1]}
+                    vzctl exec ${info[0]} cat /proc/net/dev \\
+                        | grep venet0 \\
+                        | tr ':' ' ' \\
+                        | awk '{sum=\\$2+\\$10} END {printf ("$object_id %0.0f\\n", sum)}'
+            EOF
+            }
+            """)
+        )
+    
+    def process(self, line):
+        """ diff with last stored state """
+        object_id, value, state = super(ProxmoxOpenVZTraffic, self).process(line)
+        value = decimal.Decimal(value)
+        last = self.get_last_data(object_id)
+        if not last or last.state > value:
+            return object_id, value, value
+        return object_id, value-last.state, value
+    
+    def monitor(self, vps):
+        """ Get OpenVZ container traffic on a Proxmox cluster """
+        context = self.get_context(vps)
+        self.append('monitor %(object_id)s %(hostname)s' % context)
+    
+    def get_context(self, vps):
+        return {
+            'object_id': vps.id,
+            'hostname': vps.hostname,
+        }

orchestra/contrib/webapps/settings.py

@@ -282,3 +282,11 @@ WEBAPPS_CMS_CACHE_DIR = Setting('WEBAPPS_CMS_CACHE_DIR',
     '/tmp/orchestra_cms_cache',
     help_text="Server-side cache directori for CMS tarballs.",
 )
+
+WEBAPP_NEW_SERVERS = Setting('WEBAPP_NEW_SERVERS',
+    (
+        'bookworm',
+        'web-11.pangea.lan',
+        'web-12.pangea.lan',
+    )
+)

orchestra/core/validators.py

@@ -177,3 +177,10 @@ def validate_phone(value, country):
         raise ValidationError(msg)
     if not phonenumbers.is_valid_number(number):
         raise ValidationError(msg)
+
+def validate_string_dir(value):
+    """
+    A single non-empty line of free-form text with no whitespace.
+    """
+    validators.RegexValidator('^[\_\-0-9a-z]+$',
+        _("Enter a valid name dir (spaceless lowercase text, number and _- )"), 'invalid')(value)

orchestra/utils/html.py.bk

@@ -0,0 +1,37 @@
+import textwrap
+
+from django.templatetags.static import static
+from django.utils.html import format_html
+from django.utils.translation import gettext_lazy as _
+
+from orchestra.utils.sys import run
+
+
+def html_to_pdf(html, pagination=False):
+    """ converts HTL to PDF using wkhtmltopdf """
+    context = {
+        'pagination': textwrap.dedent("""\
+            --footer-center "Page [page] of [topage]" \\
+            --footer-font-name sans \\
+            --footer-font-size 7 \\
+            --footer-spacing 7"""
+        ) if pagination else '',
+    }
+    cmd = textwrap.dedent("""\
+        PATH=$PATH:/usr/local/bin/
+        xvfb-run -a -s "-screen 0 2480x3508x16" wkhtmltopdf -q \\
+            --use-xserver \\
+            %(pagination)s \\
+            --margin-bottom 22 \\
+            --margin-top 20 - - \
+        """) % context
+    return run(cmd, stdin=html.encode('utf-8')).stdout
+
+
+def get_on_site_link(url):
+    context = {
+        'title': _("View on site %s") % url,
+        'url': url,
+        'image': format_html('<img src="{}"></img>', static('orchestra/images/view-on-site.png')),
+    }
+    return format_html('<a href="{url}" title="{title}">{image}</a>', **context)