module ietf-restconf-client {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-client";
prefix "rcc";
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-tls-client {
prefix ts;
revision-date 2018-10-22; // stable grouping definitions
reference
"RFC ZZZZ: YANG Groupings for TLS Clients and TLS Servers";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web:
WG List:
Author: Kent Watsen
Author: Gary Wu
";
description
"This module contains a collection of YANG definitions for
configuring RESTCONF clients.
Copyright (c) 2017 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
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision "2018-10-22" {
description
"Initial version";
reference
"RFC XXXX: RESTCONF Client and Server Models";
}
// Features
feature initiate {
description
"The 'initiate' feature indicates that the RESTCONF client
supports initiating RESTCONF connections to RESTCONF servers
using at least one transport (e.g., TLS, etc.).";
}
feature tls-initiate {
if-feature initiate;
description
"The 'tls-initiate' feature indicates that the RESTCONF client
supports initiating TLS connections to RESTCONF servers. This
feature exists as TLS might not be a mandatory to implement
transport in the future.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature listen {
description
"The 'listen' feature indicates that the RESTCONF client
supports opening a port to accept RESTCONF server call
home connections using at least one transport (e.g.,
TLS, etc.).";
}
feature tls-listen {
if-feature listen;
description
"The 'tls-listen' feature indicates that the RESTCONF client
supports opening a port to listen for incoming RESTCONF
server call-home TLS connections. This feature exists as
TLS might not be a mandatory to implement transport in the
future.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
container restconf-client {
uses restconf-client-grouping;
description
"Top-level container for RESTCONF client configuration.";
}
grouping restconf-client-grouping {
description
"Top-level grouping for RESTCONF client configuration.";
container initiate {
if-feature initiate;
presence "Enables client to initiate TCP connections";
description
"Configures client initiating underlying TCP connections.";
list restconf-server {
key name;
min-elements 1;
description
"List of RESTCONF servers the RESTCONF client is to
initiate connections to in parallel.";
leaf name {
type string;
description
"An arbitrary name for the RESTCONF server.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key name;
min-elements 1;
ordered-by user;
description
"A non-empty user-ordered list of endpoints for this
RESTCONF client to try to connect to in sequence.
Defining more than one enables high-availability.";
leaf name {
type string;
description
"An arbitrary name for this endpoint.";
}
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 tls {
if-feature tls-initiate;
container tls {
description
"Specifies TLS-specific transport
configuration.";
leaf address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the endpoint.
If a domain name is configured, then the
DNS resolution should happen on each usage
attempt. If the the DNS resolution results
in multiple IP addresses, the IP addresses
will be tried according to local preference
order until a connection has been established
or until all IP addresses have failed.";
}
leaf port {
type inet:port-number;
default 443;
description
"The IP port for this endpoint. The RESTCONF
client will use the IANA-assigned well-known
port for 'https' (443) if no value is
specified.";
}
uses ts:tls-client-grouping {
refine "client-identity/auth-type" {
mandatory true;
description
"RESTCONF clients MUST pass some
authentication credentials.";
}
}
}
} // end tls
} // end transport
container connection-type {
description
"Indicates the kind of connection to use.";
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 server. If the connection goes down,
immediately start trying to reconnect to it,
using the reconnection strategy. This
connection type minimizes any RESTCONF server
to RESTCONF client data-transfer delay, albeit
at the expense of holding resources longer.";
container keep-alives {
description
"Configures the keep-alive policy, to
proactively test the aliveness of the TLS
server. An unresponsive TLS server will
be dropped after approximately max-attempts
* max-wait seconds.";
leaf max-wait {
type uint16 {
range "1..max";
}
units seconds;
default 30;
description
"Sets the amount of time in seconds after
which if no data has been received from
the TLS server, a TLS-level message will
be sent to test the aliveness of the TLS
server.";
}
leaf max-attempts {
type uint8;
default 3;
description
"Sets the maximum number of sequential
keep-alive messages that can fail to
obtain a response from the TLS server
before assuming the TLS server is no
longer alive.";
}
}
}
}
case periodic-connection {
container periodic {
presence
"Indicates that a periodic connection is to be
maintained.";
description
"Periodically connect to the NETCONF server.
The RESTCONF server should close the underlying
TLS connection upon completing planned
activities.
This connection type increases resource
utilization, albeit with increased delay in
RESTCONF server to RESTCONF client
interactions.";
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 TLS session may remain
idle. A TLS session will be dropped if it
is idle for an interval longer than this
number of seconds If set to zero, then the
RESTCONF client will never drop a session
because it is idle.";
}
}
} // end periodic-connection
} // end connection-type
} // end connection-type
container reconnect-strategy {
description
"The reconnection strategy directs how a RESTCONF
client reconnects to a RESTCONF server, after
discovering its connection to the server has
dropped, even if due to a reboot. The RESTCONF
client 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 clients
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 server's
endpoints the RESTCONF client should start
with when trying to connect to the RESTCONF
server.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default 3;
description
"Specifies the number times the RESTCONF client
tries to connect to a specific endpoint before
moving on to the next endpoint in the list
(round robin).";
}
} // end reconnect-strategy
} // end endpoint
} // end endpoints
} // end restconf-server
} // end initiate
container listen {
if-feature listen;
presence "Enables client to accept call-home connections";
description
"Configures client accepting call-home TCP connections.";
leaf idle-timeout {
type uint16;
units "seconds";
default 3600; // one hour
description
"Specifies the maximum number of seconds that an
underlying TLS session may remain idle. A TLS 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. Sessions that have a notification subscription
active are never dropped.";
}
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.";
}
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 tls {
if-feature tls-listen;
container tls {
description
"TLS-specific listening configuration for inbound
connections.";
leaf address {
type inet:ip-address;
description
"The IP address to listen on for incoming call-
home connections. The RESTCONF client will
listen on all configured interfaces if no
value is specified. INADDR_ANY (0.0.0.0) or
INADDR6_ANY (0:0:0:0:0:0:0:0 a.k.a. ::) MUST
be used when the server is to listen on all
IPv4 or IPv6 addresses, respectively.";
}
leaf port {
type inet:port-number;
default 4336;
description
"The port number to listen on for call-home
connections. The RESTCONF client will listen
on the IANA-assigned well-known port for
'restconf-ch-tls' (4336) if no value is
specified.";
}
uses ts:tls-client-grouping {
refine "client-identity/auth-type" {
mandatory true;
description
"RESTCONF clients MUST pass some authentication
credentials.";
}
}
}
}
} // end transport
} // end endpoint
} // end listen
} // end restconf-client
}