T6219: Add support for container sysctl parameter (backport #3614) (#3629)

* container: T6219: Add support for container sysctl / kernel parameters

(cherry picked from commit 717ea64e4c54a8be619ffc29c16c6203b29319dd)

* T6219: align with system sysctl and limit parameters to supported

(cherry picked from commit f030464952168b553b5b3e29b461d437c2642a9b)

---------

Co-authored-by: Ben Pilgrim <ben@pilgrim.me.uk>
Co-authored-by: Nicolas Vollmar <nvollmar@gmail.com>

6 files changed, 100 insertions, 15 deletions

diff --git a/interface-definitions/container.xml.in b/interface-definitions/container.xml.in
index 1ad7215e5..6ea44a6d4 100644
--- a/interface-definitions/container.xml.in
+++ b/interface-definitions/container.xml.in
@@ -71,6 +71,35 @@
               <multi/>
             </properties>
           </leafNode>
+          <node name="sysctl">
+            <properties>
+              <help>Configure namespaced kernel parameters of the container</help>
+            </properties>
+            <children>
+              <tagNode name="parameter">
+                <properties>
+                  <help>Sysctl key name</help>
+                  <completionHelp>
+                    <script>${vyos_completion_dir}/list_container_sysctl_parameters.sh</script>
+                  </completionHelp>
+                  <valueHelp>
+                    <format>txt</format>
+                    <description>Sysctl key name</description>
+                  </valueHelp>
+                  <constraint>
+                    <validator name="sysctl"/>
+                  </constraint>
+                </properties>
+                <children>
+                  <leafNode name="value">
+                    <properties>
+                      <help>Sysctl configuration value</help>
+                    </properties>
+                  </leafNode>
+                </children>
+              </tagNode>
+            </children>
+          </node>
           #include <include/generic-description.xml.i>
           <tagNode name="device">
             <properties>
diff --git a/smoketest/config-tests/container-simple b/smoketest/config-tests/container-simple
index cc80ef4cf..5af365cf9 100644
--- a/smoketest/config-tests/container-simple
+++ b/smoketest/config-tests/container-simple
@@ -11,3 +11,4 @@ set container name c02 allow-host-networks
 set container name c02 allow-host-pid
 set container name c02 capability 'sys-time'
 set container name c02 image 'busybox:stable'
+set container name c02 sysctl parameter kernel.msgmax value '8192'
\ No newline at end of file
diff --git a/smoketest/configs/container-simple b/smoketest/configs/container-simple
index 82983afb7..b98a440b5 100644
--- a/smoketest/configs/container-simple
+++ b/smoketest/configs/container-simple
@@ -10,6 +10,11 @@ container {
         allow-host-pid
         cap-add sys-time
         image busybox:stable
+        sysctl {
+            parameter kernel.msgmax {
+                value "8192"
+            }
+        }
     }
 }
 interfaces {
diff --git a/smoketest/scripts/cli/test_container.py b/smoketest/scripts/cli/test_container.py
index 90f821c60..3dd97a175 100755
--- a/smoketest/scripts/cli/test_container.py
+++ b/smoketest/scripts/cli/test_container.py
@@ -80,6 +80,7 @@ class TestContainer(VyOSUnitTestSHIM.TestCase):
 
         self.cli_set(base_path + ['name', cont_name, 'image', cont_image])
         self.cli_set(base_path + ['name', cont_name, 'allow-host-networks'])
+        self.cli_set(base_path + ['name', cont_name, 'sysctl', 'parameter', 'kernel.msgmax', 'value', '4096'])
 
         # commit changes
         self.cli_commit()
@@ -91,6 +92,10 @@ class TestContainer(VyOSUnitTestSHIM.TestCase):
         # Check for running process
         self.assertEqual(process_named_running(PROCESS_NAME), pid)
 
+        # verify
+        tmp = cmd(f'sudo podman exec -it {cont_name} sysctl kernel.msgmax')
+        self.assertEqual(tmp, 'kernel.msgmax = 4096')
+
     def test_cpu_limit(self):
         cont_name = 'c2'
 
diff --git a/src/completion/list_container_sysctl_parameters.sh b/src/completion/list_container_sysctl_parameters.sh
new file mode 100755
index 000000000..cf8d006e5
--- /dev/null
+++ b/src/completion/list_container_sysctl_parameters.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+#
+# Copyright (C) 2024 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+declare -a vals
+eval "vals=($(/sbin/sysctl -N -a|grep -E '^(fs.mqueue|net)\.|^(kernel.msgmax|kernel.msgmnb|kernel.msgmni|kernel.sem|kernel.shmall|kernel.shmmax|kernel.shmmni|kernel.shm_rmid_forced)$'))"
+echo ${vals[@]}
+exit 0
diff --git a/src/conf_mode/container.py b/src/conf_mode/container.py
index 0ce528045..ded370a7a 100755
--- a/src/conf_mode/container.py
+++ b/src/conf_mode/container.py
@@ -43,6 +43,7 @@ from vyos.template import render
 from vyos.xml_ref import default_value
 from vyos import ConfigError
 from vyos import airbag
+
 airbag.enable()
 
 config_containers = '/etc/containers/containers.conf'
@@ -50,16 +51,19 @@ config_registry = '/etc/containers/registries.conf'
 config_storage = '/etc/containers/storage.conf'
 systemd_unit_path = '/run/systemd/system'
 
+
 def _cmd(command):
     if os.path.exists('/tmp/vyos.container.debug'):
         print(command)
     return cmd(command)
 
+
 def network_exists(name):
     # Check explicit name for network, returns True if network exists
     c = _cmd(f'podman network ls --quiet --filter name=^{name}$')
     return bool(c)
 
+
 # Common functions
 def get_config(config=None):
     if config:
@@ -86,21 +90,22 @@ def get_config(config=None):
     # registry is a tagNode with default values - merge the list from
     # default_values['registry'] into the tagNode variables
     if 'registry' not in container:
-        container.update({'registry' : {}})
+        container.update({'registry': {}})
         default_values = default_value(base + ['registry'])
         for registry in default_values:
-            tmp = {registry : {}}
+            tmp = {registry: {}}
             container['registry'] = dict_merge(tmp, container['registry'])
 
     # Delete container network, delete containers
     tmp = node_changed(conf, base + ['network'])
-    if tmp: container.update({'network_remove' : tmp})
+    if tmp: container.update({'network_remove': tmp})
 
     tmp = node_changed(conf, base + ['name'])
-    if tmp: container.update({'container_remove' : tmp})
+    if tmp: container.update({'container_remove': tmp})
 
     return container
 
+
 def verify(container):
     # bail out early - looks like removal from running config
     if not container:
@@ -125,8 +130,8 @@ def verify(container):
             # of image upgrade and deletion.
             image = container_config['image']
             if run(f'podman image exists {image}') != 0:
-                Warning(f'Image "{image}" used in container "{name}" does not exist '\
-                        f'locally. Please use "add container image {image}" to add it '\
+                Warning(f'Image "{image}" used in container "{name}" does not exist ' \
+                        f'locally. Please use "add container image {image}" to add it ' \
                         f'to the system! Container "{name}" will not be started!')
 
             if 'cpu_quota' in container_config:
@@ -167,11 +172,11 @@ def verify(container):
 
                         # We can not use the first IP address of a network prefix as this is used by podman
                         if ip_address(address) == ip_network(network)[1]:
-                            raise ConfigError(f'IP address "{address}" can not be used for a container, '\
+                            raise ConfigError(f'IP address "{address}" can not be used for a container, ' \
                                               'reserved for the container engine!')
 
                     if cnt_ipv4 > 1 or cnt_ipv6 > 1:
-                        raise ConfigError(f'Only one IP address per address family can be used for '\
+                        raise ConfigError(f'Only one IP address per address family can be used for ' \
                                           f'container "{name}". {cnt_ipv4} IPv4 and {cnt_ipv6} IPv6 address(es)!')
 
             if 'device' in container_config:
@@ -186,6 +191,13 @@ def verify(container):
                     if not os.path.exists(source):
                         raise ConfigError(f'Device "{dev}" source path "{source}" does not exist!')
 
+            if 'sysctl' in container_config and 'parameter' in container_config['sysctl']:
+                for var, cfg in container_config['sysctl']['parameter'].items():
+                    if 'value' not in cfg:
+                        raise ConfigError(f'sysctl parameter {var} has no value assigned!')
+                    if var.startswith('net.') and 'allow_host_networks' in container_config:
+                        raise ConfigError(f'sysctl parameter {var} cannot be set when using host networking!')
+
             if 'environment' in container_config:
                 for var, cfg in container_config['environment'].items():
                     if 'value' not in cfg:
@@ -219,7 +231,8 @@ def verify(container):
 
             # Can not set both allow-host-networks and network at the same time
             if {'allow_host_networks', 'network'} <= set(container_config):
-                raise ConfigError(f'"allow-host-networks" and "network" for "{name}" cannot be both configured at the same time!')
+                raise ConfigError(
+                    f'"allow-host-networks" and "network" for "{name}" cannot be both configured at the same time!')
 
             # gid cannot be set without uid
             if 'gid' in container_config and 'uid' not in container_config:
@@ -235,8 +248,10 @@ def verify(container):
                 raise ConfigError(f'prefix for network "{network}" must be defined!')
 
             for prefix in network_config['prefix']:
-                if is_ipv4(prefix): v4_prefix += 1
-                elif is_ipv6(prefix): v6_prefix += 1
+                if is_ipv4(prefix):
+                    v4_prefix += 1
+                elif is_ipv6(prefix):
+                    v6_prefix += 1
 
             if v4_prefix > 1:
                 raise ConfigError(f'Only one IPv4 prefix can be defined for network "{network}"!')
@@ -262,6 +277,7 @@ def verify(container):
 
     return None
 
+
 def generate_run_arguments(name, container_config):
     image = container_config['image']
     cpu_quota = container_config['cpu_quota']
@@ -269,6 +285,12 @@ def generate_run_arguments(name, container_config):
     shared_memory = container_config['shared_memory']
     restart = container_config['restart']
 
+    # Add sysctl options
+    sysctl_opt = ''
+    if 'sysctl' in container_config and 'parameter' in container_config['sysctl']:
+        for k, v in container_config['sysctl']['parameter'].items():
+            sysctl_opt += f" --sysctl {k}={v['value']}"
+
     # Add capability options. Should be in uppercase
     capabilities = ''
     if 'capability' in container_config:
@@ -341,7 +363,7 @@ def generate_run_arguments(name, container_config):
     if 'allow_host_pid' in container_config:
       host_pid = '--pid host'
 
-    container_base_cmd = f'--detach --interactive --tty --replace {capabilities} --cpus {cpu_quota} ' \
+    container_base_cmd = f'--detach --interactive --tty --replace {capabilities} --cpus {cpu_quota} {sysctl_opt} ' \
                          f'--memory {memory}m --shm-size {shared_memory}m --memory-swap 0 --restart {restart} ' \
                          f'--name {name} {hostname} {device} {port} {volume} {env_opt} {label} {uid} {host_pid}'
 
@@ -375,6 +397,7 @@ def generate_run_arguments(name, container_config):
 
     return f'{container_base_cmd} --no-healthcheck --net {networks} {ip_param} {entrypoint} {image} {command} {command_arguments}'.strip()
 
+
 def generate(container):
     # bail out early - looks like removal from running config
     if not container:
@@ -387,7 +410,7 @@ def generate(container):
         for network, network_config in container['network'].items():
             tmp = {
                 'name': network,
-                'id' : sha256(f'{network}'.encode()).hexdigest(),
+                'id': sha256(f'{network}'.encode()).hexdigest(),
                 'driver': 'bridge',
                 'network_interface': f'pod-{network}',
                 'subnets': [],
@@ -399,7 +422,7 @@ def generate(container):
                 }
             }
             for prefix in network_config['prefix']:
-                net = {'subnet' : prefix, 'gateway' : inc_ip(prefix, 1)}
+                net = {'subnet': prefix, 'gateway': inc_ip(prefix, 1)}
                 tmp['subnets'].append(net)
 
                 if is_ipv6(prefix):
@@ -418,11 +441,12 @@ def generate(container):
 
             file_path = os.path.join(systemd_unit_path, f'vyos-container-{name}.service')
             run_args = generate_run_arguments(name, container_config)
-            render(file_path, 'container/systemd-unit.j2', {'name': name, 'run_args': run_args,},
+            render(file_path, 'container/systemd-unit.j2', {'name': name, 'run_args': run_args, },
                    formater=lambda _: _.replace("&quot;", '"').replace("&apos;", "'"))
 
     return None
 
+
 def apply(container):
     # Delete old containers if needed. We can't delete running container
     # Option "--force" allows to delete containers with any status
@@ -485,6 +509,7 @@ def apply(container):
 
     return None
 
+
 if __name__ == '__main__':
     try:
         c = get_config()