<title>Methods</title>
<para><function>GetMachine()</function> may be used to get the machine object path for the machine with
- the specified name. Similarly, <function>GetMachineByPID()</function> get the machine object the
+ the specified name. Similarly, <function>GetMachineByPID()</function> gets the machine object the
specified PID belongs to if there is any.</para>
- <para><function>GetImage()</function> may be used to the the image object path for the image with the
+ <para><function>GetImage()</function> may be used to get the image object path of the image with the
specified name.</para>
- <para><function>ListMachines()</function> returns an array with all currently registered machines. The
+ <para><function>ListMachines()</function> returns an array of all currently registered machines. The
structures in the array consist of the following fields: machine name, machine class, an identifier for
the service that registered the machine and the machine object path.</para>
- <para><function>ListImages()</function> returns an array with all currently known images. The
+ <para><function>ListImages()</function> returns an array of all currently known images. The
structures in the array consist of the following fields: image name, type, read-only flag, creation
- time, modification time, current disk space, image object path.</para>
+ time, modification time, current disk space, and image object path.</para>
<para><function>CreateMachine()</function> may be used to register a new virtual machine or container
- with <command>systemd-machined</command>, creating a scope unit for it. This takes as arguments: a
- machine name chosen by the registrar, an optional UUID as 32 byte array, a string that identifies the
+ with <command>systemd-machined</command>, creating a scope unit for it. It accepts the following arguments: a
+ machine name chosen by the registrar, an optional UUID as a 32 byte array, a string that identifies the
service that registers the machine, a class string, the PID of the leader process of the machine, an
optional root directory of the container, and an array of additional properties to use for the scope
- registration. The virtual machine name must be suitable as hostname, and hence should follow the usual
- DNS hostname rules, as well as Linux hostname restrictions. Specifically: only 7 Bit ASCII is
+ registration. The virtual machine name must be suitable as a hostname, and hence should follow the usual
+ DNS hostname rules, as well as the Linux hostname restrictions. Specifically, only 7 bit ASCII is
permitted, a maximum length of 64 characters is enforced, only characters from the set
<literal>a-zA-Z0-9-_.</literal> are allowed, the name may not begin with a dot, and it may not contain
two dots immediately following each other. Container and VM managers should ideally use the hostname
<citerefentry><refentrytitle>nss-mymachines</refentrytitle><manvolnum>8</manvolnum></citerefentry>. If
a container manager needs to embed characters outside of the indicated range, escaping is required,
possibly using <literal>_</literal> as the escape character. Another (somewhat natural) option would be
- to utilize Internet IDNA encoding. The UUID is passed as 32 byte array, or if no suitable UUID is
- available an empty array (zero length) or zeroed out array shall be passed. The UUID should identify
- the virtual machine/container uniquely, and should ideally be the same one as
+ to utilize Internet IDNA encoding. The UUID is passed as a 32 byte array or, if no suitable UUID is
+ available, an empty array (zero length) or zeroed out array shall be passed. The UUID should identify
+ the virtual machine/container uniquely and should ideally be the same UUID that
<filename>/etc/machine-id</filename> in the VM/container is initialized from. The service string can be
free-form, but it is recommended to pass a short lowercase identifier like
<literal>systemd-nspawn</literal>, <literal>libvirt-lxc</literal> or similar. The class string should
be either <literal>container</literal> or <literal>vm</literal> indicating whether the machine to
register is of the respective class. The leader PID should be the host PID of the init process of the
- container, or the encapsulating process of the VM. If the root directory of the container is known and
- available in the host's hierarchy, it should be passed, otherwise use the empty string. Finally, the
+ container or the encapsulating process of the VM. If the root directory of the container is known and
+ available in the host's hierarchy, it should be passed. Otherwise, pass the empty string instead. Finally, the
scope properties are passed as array in the same way as to PID1's
- <function>StartTransientUnit()</function>. This method call will internally register a transient scope
- unit for the calling client (utilizing the passed scope_properties), and move the leader PID into
- it. The call returns an object path for the registered machine object, implementing the
+ <function>StartTransientUnit()</function> method. Calling this method will internally register a transient scope
+ unit for the calling client (utilizing the passed scope_properties) and move the leader PID into
+ it. The call returns an object path for the registered machine object that implements the
<interfacename>org.freedesktop.machine1.Machine</interfacename> interface (see below). Also see the
<ulink url="https://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/">New Control Group
- Interfaces</ulink> for details about scope units, and how to alter resource control settings on the
+ Interfaces</ulink> for details about scope units and how to alter resource control settings on the
created machine at runtime.</para>
- <para><function>RegisterMachine()</function> is similar to <function>CreateMachine()</function>,
- however only registers a machine, but does not create a scope unit for it. The caller's unit will be
- registered instead. This call is only recommended to be used for container or VM managers that are run
+ <para><function>RegisterMachine()</function> is similar to <function>CreateMachine()</function>.
+ However, it only registers a machine and does not create a scope unit for it. Instead, the caller's unit is
+ registered. We recommend to only use this method for container or VM managers that are run
multiple times, one instance for each container/VM they manage, and are invoked as system
services.</para>
<para><function>CreateMachineWithNetwork()</function> and
<function>RegisterMachineWithNetwork()</function> are similar to <function>CreateMachine()</function>
and <function>RegisterMachine()</function> but take an extra argument: an array of network interface
- indexes that point towards the virtual machine or container. The interface indexes should reference one
- or more network interfaces on the host that can be used to communicate with the guest. Commonly the
- passed interface index refers to the host side of a "veth" link (in case of containers), or a
- "tun"/"tap" link (in case of VMs) or the host side of a bridge interface that bridges access to the
+ indices that point towards the virtual machine or container. The interface indices should reference one
+ or more network interfaces on the host that can be used to communicate with the guest. Commonly, the
+ passed interface index refers to the host side of a "veth" link (in case of containers), a
+ "tun"/"tap" link (in case of VMs), or the host side of a bridge interface that bridges access to the
VM/container interfaces. Specifying this information is useful to enable support for link-local IPv6
- communication to the machines, since the scope field of sockaddr_in6 can be initialized by the
+ communication to the machines since the scope field of sockaddr_in6 can be initialized by the
specified ifindex.
<citerefentry><refentrytitle>nss-mymachines</refentrytitle><manvolnum>8</manvolnum></citerefentry>
makes use of this information.</para>
- <para><function>KillMachine()</function> sends a UNIX signal to the machine's processes. It takes a
+ <para><function>KillMachine()</function> sends a UNIX signal to the machine's processes. As its arguments, it takes a
machine name (as originally passed to <function>CreateMachine()</function> or returned by
- <function>ListMachines()</function>). An identifier what precisely to send the signal to being either
- <literal>leader</literal> or <literal>all</literal>, plus a numeric UNIX signal integer.</para>
+ <function>ListMachines()</function>), an identifier that specifies what precisely to send the signal to (either
+ <literal>leader</literal> or <literal>all</literal>), and a numeric UNIX signal integer.</para>
<para><function>TerminateMachine()</function> terminates a virtual machine, killing its processes. It
- takes a machine name as argument.</para>
+ takes a machine name as its only argument.</para>
<para><function>GetMachineAddresses()</function> retrieves the IP addresses of a container. This call
returns an array of pairs consisting of an address family specifier (<constant>AF_INET</constant> or
containers that make use of network namespacing.</para>
<para><function>GetMachineOSRelease()</function> retrieves the OS release information of a
- container. This call returns an array of key value pairs read from the
+ container. This method returns an array of key value pairs read from the
<citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry> file in
- the container, and is useful to identify the operating system used in a container.</para>
+ the container and is useful to identify the operating system used in a container.</para>
<para><function>OpenMachinePTY()</function> allocates a pseudo TTY in the container and returns a file
descriptor and its path. This is equivalent to transitioning into the container and invoking
<citerefentry><refentrytitle>posix_openpt</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
<para><function>OpenMachineLogin()</function> allocates a pseudo TTY in the container and ensures that
- a getty loging prompt of the container is running on the other end. It returns the file descriptor of
- the PTY plus the PTY path. This is useful for acquiring a pty with a login prompt from the
+ a getty login prompt of the container is running on the other end. It returns the file descriptor of
+ the PTY and the PTY path. This is useful for acquiring a pty with a login prompt from the
container.</para>
<para><function>OpenMachineShell()</function> allocates a pseudo TTY in the container, as the specified
- user, and invokes an executable of the specified path, with a list of arguments (starting from
- argv[0]), and an environment block. It then returns the file descriptor of the PTY plus the PTY
+ user, and invokes the executable at the specified path with a list of arguments (starting from
+ argv[0]) and an environment block. It then returns the file descriptor of the PTY and the PTY
path.</para>
<para><function>BindMountMachine()</function> bind mounts a file or directory from the host into the
- container. Takes a machine name, the source directory on the host, and the destination directory in the
- container as argument. Also takes two booleans, one indicating whether the bind mount shall be
+ container. Its arguments consist of a machine name, the source directory on the host, the destination directory in the
+ container, and two booleans, one indicating whether the bind mount shall be
read-only, the other indicating whether the destination mount point shall be created first, if it is
missing.</para>
<para><function>CopyFromMachine()</function> copies files or directories from a container into the
- host. Takes a container name, a source directory in the container and a destination directory on the
- host as argument. <function>CopyToMachine()</function> does the opposite and copies files from a source
+ host. It takes a container name, a source directory in the container and a destination directory on the
+ host as arguments. <function>CopyToMachine()</function> does the opposite and copies files from a source
directory on the host into a destination directory in the container.</para>
- <para><function>RemoveImage()</function> removes the image by the specified name.</para>
+ <para><function>RemoveImage()</function> removes the image with the specified name.</para>
- <para><function>RenameImage()</function> renames the specified image to a new name.</para>
+ <para><function>RenameImage()</function> renames the specified image.</para>
- <para><function>CloneImage()</function> clones the specified image under a new name. Also takes a
- boolean argument indicating whether the resuling image shall be read-only or not.</para>
+ <para><function>CloneImage()</function> clones the specified image under a new name. It also takes a
+ boolean argument indicating whether the resulting image shall be read-only or not.</para>
<para><function>MarkImageReadOnly()</function> toggles the read-only flag of an image.</para>
<para><function>SetImageLimit()</function> sets a per-image quota limit.</para>
<para><function>MapFromMachineUser()</function>, <function>MapToMachineUser()</function>,
- <function>MapFromMachineGroup()</function>, <function>MapToMachineGroup()</function> may be used to map
- UIDs/GIDs from the host user namespace to a container namespace or back.</para>
+ <function>MapFromMachineGroup()</function>, and <function>MapToMachineGroup()</function> may be used to map
+ UIDs/GIDs from the host user namespace to a container user namespace or vice versa.</para>
</refsect2>
<refsect2>
<title>Signals</title>
<para><function>MachineNew</function> and <function>MachineRemoved</function> are sent whenever a new
- machine is registered or removed. These signals carry the machine name plus the object path to the
+ machine is registered or removed. These signals carry the machine name and the object path to the corresponding
<interfacename>org.freedesktop.machine1.Machine</interfacename> interface (see below).</para>
</refsect2>
<refsect2>
<title>Methods</title>
- <para><function>Terminate()</function> and <function>Kill()</function> terminate/kill the machine, and
+ <para><function>Terminate()</function> and <function>Kill()</function> terminate/kill the machine. These methods
take the same arguments as <function>TerminateMachine()</function> and
- <function>KillMachine()</function> on the Manager interface.</para>
+ <function>KillMachine()</function> on the Manager interface, respectively.</para>
- <para><function>GetAddresses()</function> and <function>GetOSRelease()</function> get IP address and OS
- release information from the machine, and take the same arguments as
+ <para><function>GetAddresses()</function> and <function>GetOSRelease()</function> get the IP address and OS
+ release information from the machine. These methods take the same arguments as
<function>GetMachineAddresses()</function> and <function>GetMachineOSRelease()</function> of the
- Manager interface, described above.</para>
+ Manager interface, respectively.</para>
</refsect2>
<refsect2>
<title>Properties</title>
- <para><varname>Name</varname> is the machine name, as it was passed in during registration with
+ <para><varname>Name</varname> is the machine name as it was passed in during registration with
<function>CreateMachine()</function> on the manager object.</para>
<para><varname>Id</varname> is the machine UUID.</para>
<para><varname>Timestamp</varname> and <varname>TimestampMonotonic</varname> are the realtime and
- monotonic timestamps when the virtual machines where created.</para>
+ monotonic timestamps when the virtual machines where created in microseconds since the epoch.</para>
- <para><varname>Service</varname> contains a short string identifying the registering service, as passed
+ <para><varname>Service</varname> contains a short string identifying the registering service as passed
in during registration of the machine.</para>
<para><varname>Unit</varname> is the systemd scope or service unit name for the machine.</para>
<para><varname>Leader</varname> is the PID of the leader process of the machine.</para>
- <para><varname>Class</varname> is the class of the machine and either the string "vm" (for real VMs
+ <para><varname>Class</varname> is the class of the machine and is either the string "vm" (for real VMs
based on virtualized hardware) or "container" (for light-weight userspace virtualization sharing the
same kernel as the host).</para>
- <para><varname>RootDirectory</varname> is the root directory of the container if that is known and
- applicable, or the empty string.</para>
+ <para><varname>RootDirectory</varname> is the root directory of the container if it is known and
+ applicable or the empty string.</para>
- <para><varname>NetworkInterfaces</varname> contains an array of network interface indexes that point
- towards the container or VM or the host. For details about this information see the description of
+ <para><varname>NetworkInterfaces</varname> contains an array of network interface indices that point
+ towards the container, the VM or the host. For details about this information see the description of
<function>CreateMachineWithNetwork()</function> above.</para>
- <para><varname>State</varname> is the state of the machine, and one of <literal>opening</literal>,
- <literal>running</literal>, <literal>closing</literal>. Note that the state machine is not considered
+ <para><varname>State</varname> is the state of the machine and is one of <literal>opening</literal>,
+ <literal>running</literal>, or <literal>closing</literal>. Note that the state machine is not considered
part of the API and states might be removed or added without this being considered API breakage.
</para>
</refsect2>
projects / thirdparty / systemd.git / blobdiff