module ietf-restconf-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-server";
prefix rcs;
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-x509-cert-to-name {
prefix x509c2n;
reference
"RFC 7407: A YANG Data Model for SNMP Configuration";
}
import ietf-tcp-client {
prefix tcpc;
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-tcp-server {
prefix tcps;
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-tls-server {
prefix tlss;
reference
"RFC FFFF: YANG Groupings for TLS Clients and TLS Servers";
}
import ietf-http-server {
prefix https;
reference
"RFC GGGG: YANG Groupings for HTTP Clients and HTTP Servers";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web:
WG List:
Author: Kent Watsen
Author: Gary Wu
Author: Juergen Schoenwaelder
";
description
"This module contains a collection of YANG definitions
for configuring RESTCONF servers.
Copyright (c) 2021 IETF Trust and the persons identified
as authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with
or without modification, is permitted pursuant to, and
subject to the license terms contained in, the Simplified
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC IIII
(https://www.rfc-editor.org/info/rfcIIII); see the RFC
itself for full legal notices.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL',
'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED',
'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document
are to be interpreted as described in BCP 14 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
revision 2021-05-18 {
description
"Initial version";
reference
"RFC IIII: RESTCONF Client and Server Models";
}
// Features
feature http-listen {
description
"The 'http-listen' feature indicates that the RESTCONF server
supports opening a port to listen for incoming RESTCONF over
TPC client connections, whereby the TLS connections are
terminated by an external system.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature https-listen {
description
"The 'https-listen' feature indicates that the RESTCONF server
supports opening a port to listen for incoming RESTCONF over
TLS client connections, whereby the TLS connections are
terminated by the server itself.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature https-call-home {
description
"The 'https-call-home' feature indicates that the RESTCONF
server supports initiating connections to RESTCONF clients.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
// Groupings
grouping restconf-server-grouping {
description
"A reusable grouping for configuring a RESTCONF server
without any consideration for how underlying transport
sessions are established.
Note that this grouping uses a fairly typical descendant
node name such that a stack of 'uses' statements will
have name conflicts. It is intended that the consuming
data model will resolve the issue by wrapping the 'uses'
statement in a container called, e.g.,
'restconf-server-parameters'. This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
container client-identity-mappings {
description
"Specifies mappings through which RESTCONF client X.509
certificates are used to determine a RESTCONF username.
If no matching and valid cert-to-name list entry can be
found, then the RESTCONF server MUST close the connection,
and MUST NOT accept RESTCONF messages over it.";
reference
"RFC 7407: A YANG Data Model for SNMP Configuration.";
uses x509c2n:cert-to-name {
refine "cert-to-name/fingerprint" {
mandatory false;
description
"A 'fingerprint' value does not need to be specified
when the 'cert-to-name' mapping is independent of
fingerprint matching. A 'cert-to-name' having no
fingerprint value will match any client certificate
and therefore should only be present at the end of
the user-ordered 'cert-to-name' list.";
}
}
}
}
grouping restconf-server-listen-stack-grouping {
description
"A reusable grouping for configuring a RESTCONF server
'listen' protocol stack for a single connection.";
choice transport {
mandatory true;
description
"Selects between available transports. This is a
'choice' statement so as to support additional
transport options to be augmented in.";
case http {
if-feature "http-listen";
container http {
description
"Configures RESTCONF server stack assuming that
TLS-termination is handled externally.";
container external-endpoint {
presence
"Identifies that an external endpoint has been
configured. This statement is present so the
mandatory descendant nodes do not imply that
this node must be configured.";
description
"Identifies contact information for the external
system that terminates connections before passing
them thru to this server (e.g., a network address
translator or a load balancer). These values have
no effect on the local operation of this server,
but may be used by the application when needing to
inform other systems how to contact this server.";
leaf address {
type inet:ip-address;
mandatory true;
description
"The IP address or hostname of the external system
that terminates incoming RESTCONF client
connections before forwarding them to this
server.";
}
leaf port {
type inet:port-number;
default "443";
description
"The port number that the external system listens
on for incoming RESTCONF client connections that
are forwarded to this server. The default HTTPS
port (443) is used, as expected for a RESTCONF
connection.";
}
}
container tcp-server-parameters {
description
"A wrapper around the TCP server parameters
to avoid name collisions.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "80";
description
"The RESTCONF server will listen on the IANA-
assigned well-known port value for 'http'
(80) if no value is specified.";
}
}
}
container http-server-parameters {
description
"A wrapper around the HTTP server parameters
to avoid name collisions.";
uses https:http-server-grouping;
}
container restconf-server-parameters {
description
"A wrapper around the RESTCONF server parameters
to avoid name collisions.";
uses rcs:restconf-server-grouping;
}
}
}
case https {
if-feature "https-listen";
container https {
description
"Configures RESTCONF server stack assuming that
TLS-termination is handled internally.";
container tcp-server-parameters {
description
"A wrapper around the TCP server parameters
to avoid name collisions.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "443";
description
"The RESTCONF server will listen on the IANA-
assigned well-known port value for 'https'
(443) if no value is specified.";
}
}
}
container tls-server-parameters {
description
"A wrapper around the TLS server parameters
to avoid name collisions.";
uses tlss:tls-server-grouping;
}
container http-server-parameters {
description
"A wrapper around the HTTP server parameters
to avoid name collisions.";
uses https:http-server-grouping;
}
container restconf-server-parameters {
description
"A wrapper around the RESTCONF server parameters
to avoid name collisions.";
uses rcs:restconf-server-grouping;
}
}
}
}
}
grouping restconf-server-callhome-stack-grouping {
description
"A reusable grouping for configuring a RESTCONF server
'call-home' protocol stack, for a single connection.";
choice transport {
mandatory true;
description
"Selects between available transports. This is a
'choice' statement so as to support additional
transport options to be augmented in.";
case https {
if-feature "https-listen";
container https {
description
"Configures RESTCONF server stack assuming that
TLS-termination is handled internally.";
container tcp-client-parameters {
description
"A wrapper around the TCP client parameters
to avoid name collisions.";
uses tcpc:tcp-client-grouping {
refine "remote-port" {
default "4336";
description
"The RESTCONF server will attempt to
connect to the IANA-assigned well-known
port for 'restconf-ch-tls' (4336) if no
value is specified.";
}
}
}
container tls-server-parameters {
description
"A wrapper around the TLS server parameters
to avoid name collisions.";
uses tlss:tls-server-grouping;
}
container http-server-parameters {
description
"A wrapper around the HTTP server parameters
to avoid name collisions.";
uses https:http-server-grouping;
}
container restconf-server-parameters {
description
"A wrapper around the RESTCONF server parameters
to avoid name collisions.";
uses rcs:restconf-server-grouping;
}
}
}
}
}
grouping restconf-server-app-grouping {
description
"A reusable grouping for configuring a RESTCONF server
application that supports both 'listen' and 'call-home'
protocol stacks for a multiplicity of connections.";
container listen {
if-feature "http-listen or https-listen";
presence
"Identifies that the server has been configured to
listen for incoming client connections. This statement
is present so the mandatory descendant nodes do not
imply that this node must be configured.";
description
"Configures the RESTCONF server to listen for RESTCONF
client connections.";
list endpoint {
key "name";
min-elements 1;
description
"List of endpoints to listen for RESTCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the RESTCONF listen endpoint.";
}
uses restconf-server-listen-stack-grouping;
}
}
container call-home {
if-feature "https-call-home";
presence
"Identifies that the server has been configured to initiate
call home connections. This statement is present so the
mandatory descendant nodes do not imply that this node
must be configured.";
description
"Configures the RESTCONF server to initiate the underlying
transport connection to RESTCONF clients.";
list restconf-client {
key "name";
min-elements 1;
description
"List of RESTCONF clients the RESTCONF server is to
maintain simultaneous call-home connections with.";
leaf name {
type string;
description
"An arbitrary name for the remote RESTCONF client.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key "name";
min-elements 1;
ordered-by user;
description
"User-ordered list of endpoints for this RESTCONF
client. Defining more than one enables high-
availability.";
leaf name {
type string;
description
"An arbitrary name for this endpoint.";
}
uses restconf-server-callhome-stack-grouping;
}
}
container connection-type {
description
"Indicates the RESTCONF server's preference for how the
RESTCONF connection is maintained.";
choice connection-type {
mandatory true;
description
"Selects between available connection types.";
case persistent-connection {
container persistent {
presence
"Indicates that a persistent connection is to be
maintained.";
description
"Maintain a persistent connection to the RESTCONF
client. If the connection goes down, immediately
start trying to reconnect to the RESTCONF server,
using the reconnection strategy.
This connection type minimizes any RESTCONF
client to RESTCONF server data-transfer delay,
albeit at the expense of holding resources
longer.";
}
}
case periodic-connection {
container periodic {
presence
"Indicates that a periodic connection is to be
maintained.";
description
"Periodically connect to the RESTCONF client.
This connection type increases resource
utilization, albeit with increased delay in
RESTCONF client to RESTCONF client interactions.
The RESTCONF client SHOULD gracefully close
the underlying TLS connection upon completing
planned activities. If the underlying TLS
connection is not closed gracefully, the
RESTCONF server MUST immediately attempt
to reestablish the connection.
In the case that the previous connection is
still active (i.e., the RESTCONF client has not
closed it yet), establishing a new connection
is NOT RECOMMENDED.";
leaf period {
type uint16;
units "minutes";
default "60";
description
"Duration of time between periodic connections.";
}
leaf anchor-time {
type yang:date-and-time {
// constrained to minute-level granularity
pattern '\d{4}-\d{2}-\d{2}T\d{2}:\d{2}'
+ '(Z|[\+\-]\d{2}:\d{2})';
}
description
"Designates a timestamp before or after which a
series of periodic connections are determined.
The periodic connections occur at a whole
multiple interval from the anchor time. For
example, for an anchor time is 15 minutes past
midnight and a period interval of 24 hours, then
a periodic connection will occur 15 minutes past
midnight everyday.";
}
leaf idle-timeout {
type uint16;
units "seconds";
default "120"; // two minutes
description
"Specifies the maximum number of seconds that
the underlying TCP session may remain idle.
A TCP session will be dropped if it is idle
for an interval longer than this number of
seconds. If set to zero, then the server
will never drop a session because it is idle.";
}
}
}
}
}
container reconnect-strategy {
description
"The reconnection strategy directs how a RESTCONF server
reconnects to a RESTCONF client after discovering its
connection to the client has dropped, even if due to a
reboot. The RESTCONF server starts with the specified
endpoint and tries to connect to it max-attempts times
before trying the next endpoint in the list (round
robin).";
leaf start-with {
type enumeration {
enum first-listed {
description
"Indicates that reconnections should start with
the first endpoint listed.";
}
enum last-connected {
description
"Indicates that reconnections should start with
the endpoint last connected to. If no previous
connection has ever been established, then the
first endpoint configured is used. RESTCONF
servers SHOULD be able to remember the last
endpoint connected to across reboots.";
}
enum random-selection {
description
"Indicates that reconnections should start with
a random endpoint.";
}
}
default "first-listed";
description
"Specifies which of the RESTCONF client's endpoints
the RESTCONF server should start with when trying
to connect to the RESTCONF client.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default "3";
description
"Specifies the number times the RESTCONF server tries
to connect to a specific endpoint before moving on to
the next endpoint in the list (round robin).";
}
}
} // restconf-client
} // call-home
} // restconf-server-app-grouping
// Protocol accessible node for servers that implement this module.
container restconf-server {
uses restconf-server-app-grouping;
description
"Top-level container for RESTCONF server configuration.";
}
}