Add load-balancing reverse-proxy documentation and examples

1 files changed, 8 insertions, 311 deletions

diff --git a/docs/configuration/loadbalancing/index.rst b/docs/configuration/loadbalancing/index.rst
index 18f01347..382bd0d7 100644
--- a/docs/configuration/loadbalancing/index.rst
+++ b/docs/configuration/loadbalancing/index.rst
@@ -1,315 +1,12 @@
-:lastproofread: 2023-01-27
-
 .. _load-balancing:
 
-WAN load balancing
-==================
-
-Outbound traffic can be balanced between two or more outbound interfaces.
-If a path fails, traffic is balanced across the remaining healthy paths,
-a recovered path is automatically added back to the routing table and used by 
-the load balancer. The load balancer automatically adds routes for each path to
-the routing table and balances traffic across the configured interfaces,
-determined by interface health and weight.
-
-
-In a minimal configuration, the following must be provided:
-
- * an interface with a nexthop
- * one rule with a LAN (inbound-interface) and the WAN (interface).
-
-Let's assume we have two DHCP WAN interfaces and one LAN (eth2):
-
-.. code-block:: none
-
-    set load-balancing wan interface-health eth0 nexthop 'dhcp'
-    set load-balancing wan interface-health eth1 nexthop 'dhcp'
-    set load-balancing wan rule 1 inbound-interface 'eth2'
-    set load-balancing wan rule 1 interface eth0
-    set load-balancing wan rule 1 interface eth1
-
-.. note::
-
-    WAN Load Balacing should not be used when dynamic routing protocol is
-    used/needed. This feature creates customized routing tables and firewall
-    rules, that makes it incompatible to use with routing protocols.
-
-Balancing Rules
----------------
-
-Interfaces, their weight and the type of traffic to be balanced are defined in
-numbered balancing rule sets. The rule sets are executed in numerical order
-against outgoing packets. In case of a match the packet is sent through an
-interface specified in the matching rule. If a packet doesn't match any rule
-it is sent by using the system routing table. Rule numbers can't be changed.
-
-Create a load balancing rule, it can be a number between 1 and 9999:
-
-.. code-block:: none
-
-    vyos@vyos# set load-balancing wan rule 1
-    Possible completions:
-    description             Description for this rule
-    > destination           Destination
-    exclude                 Exclude packets matching this rule from wan load balance
-    failover                Enable failover for packets matching this rule from wan load balance
-    inbound-interface       Inbound interface name (e.g., "eth0") [REQUIRED]
-    +> interface            Interface name [REQUIRED]
-    > limit                 Enable packet limit for this rule
-    per-packet-balancing    Option to match traffic per-packet instead of the default, per-flow
-    protocol                Protocol to match
-    > source                Source information
-
-Interface weight
-****************
-
-Let's expand the example from above and add weight to the interfaces.
-The bandwidth from eth0 is larger than eth1. Per default, outbound traffic is
-distributed randomly across available interfaces. Weights can be assigned to
-interfaces to influence the balancing.
-
-.. code-block:: none
-
-    set load-balancing wan rule 1 interface eth0 weight 2
-    set load-balancing wan rule 1 interface eth1 weight 1
-
-66% of traffic is routed to eth0, eth1 gets 33% of traffic.
-
-Rate limit
-**********
-
-A packet rate limit can be set for a rule to apply the rule to traffic above or
-below a specified threshold. To configure the rate limiting use:
-
-.. code-block:: none
-
-    set load-balancing wan rule <rule> limit <parameter>
-
-* ``burst``: Number of packets allowed to overshoot the limit within ``period``.
-  Default 5.
-* ``period``: Time window for rate calculation. Possible values:
-  ``second`` (one second), ``minute`` (one minute), ``hour`` (one hour).
-  Default is ``second``.
-* ``rate``: Number of packets. Default 5.
-* ``threshold``: ``below`` or ``above`` the specified rate limit.
-
-Flow and packet-based balancing
-*******************************
-
-Outgoing traffic is balanced in a flow-based manner.
-A connection tracking table is used to track flows by their source address,
-destination address and port. Each flow is assigned to an interface according
-to the defined balancing rules and subsequent packets are sent through the
-same interface. This has the advantage that packets always arrive in order if
-links with different speeds are in use.
-
-Packet-based balancing can lead to a better balance across interfaces when out
-of order packets are no issue. Per-packet-based balancing can be set for a
-balancing rule with:
-
-.. code-block:: none
-
-    set load-balancing wan rule <rule> per-packet-balancing
-
-Exclude traffic
-***************
-
-To exclude traffic from load balancing, traffic matching an exclude rule is not
-balanced but routed through the system routing table instead:
-
-.. code-block:: none
-
-    set load-balancing wan rule <rule> exclude
-
-
-Health checks
--------------
-
-The health of interfaces and paths assigned to the load balancer is
-periodically checked by sending ICMP packets (ping) to remote destinations,
-a TTL test or the execution of a user defined script. If an interface fails the
-health check it is removed from the load balancer's pool of interfaces.
-To enable health checking for an interface:
-
-.. code-block:: none
-
-    vyos@vyos# set load-balancing wan interface-health <interface>
-    Possible completions:
-    failure-count    Failure count
-    nexthop          Outbound interface nexthop address. Can be 'dhcp or ip address' [REQUIRED]
-    success-count    Success count
-    +> test          Rule number
-
-Specify nexthop on the path to the destination, ``ipv4-address`` can be set to
-``dhcp``
-
-.. code-block:: none
-
-    set load-balancing wan interface-health <interface> nexthop <ipv4-address>
-
-Set the number of health check failures before an interface is marked as
-unavailable, range for number is 1 to 10, default 1. Or set the number of
-successful health checks before an interface is added back to the interface
-pool, range for number is 1 to 10, default 1.
-
-.. code-block:: none
-
-    set load-balancing wan interface-health <interface> failure-count <number>
-    set load-balancing wan interface-health <interface> success-count <number>
-
-Each health check is configured in its own test, tests are numbered and
-processed in numeric order. For multi target health checking multiple tests
-can be defined:
-
-.. code-block:: none
-
-    vyos@vyos# set load-balancing wan interface-health eth1 test 0
-    Possible completions:
-    resp-time    Ping response time (seconds)
-    target       Health target address
-    test-script  Path to user defined script
-    ttl-limit    Ttl limit (hop count)
-    type         WLB test type
-
-* ``resp-time``: the maximum response time for ping in seconds.
-  Range 1...30, default 5
-* ``target``: the target to be sent ICMP packets to, address can be an IPv4
-  address or hostname
-* ``test-script``: A user defined script must return 0 to be considered
-  successful and non-zero to fail. Scripts are located in /config/scripts,
-  for different locations the full path needs to be provided
-* ``ttl-limit``: For the UDP TTL limit test the hop count limit must be
-  specified. The limit must be shorter than the path length, an ICMP time
-  expired message is needed to be returned for a successful test. default 1
-* ``type``: Specify the type of test. type can be ping, ttl or a user defined
-  script
-
-Source NAT rules
-----------------
-
-Per default, interfaces used in a load balancing pool replace the source IP
-of each outgoing packet with its own address to ensure that replies arrive on
-the same interface. This works through automatically generated source NAT (SNAT)
-rules, these rules are only applied to balanced traffic. In cases where this
-behaviour is not desired, the automatic generation of SNAT rules can be
-disabled:
-
-.. code-block:: none
-
-    set load-balancing wan disable-source-nat
-
-Sticky Connections
-------------------
-Inbound connections to a WAN interface can be improperly handled when the reply
-is sent back to the client.
-
-.. image:: /_static/images/sticky-connections.jpg
-   :width: 80%
-   :align: center
-
-
-Upon reception of an incoming packet, when a response is sent, it might be
-desired to ensure that it leaves from the same interface as the inbound one.
-This can be achieved by enabling sticky connections in the load balancing:
-
-.. code-block:: none
-
-    set load-balancing wan sticky-connections inbound
-
-Failover
---------
-
-In failover mode, one interface is set to be the primary interface and other
-interfaces are secondary or spare. Instead of balancing traffic across all
-healthy interfaces, only the primary interface is used and in case of failure,
-a secondary interface selected from the pool of available interfaces takes over.
-The primary interface is selected based on its weight and health, others become
-secondary interfaces. Secondary interfaces to take over a failed primary
-interface are chosen from the load balancer's interface pool, depending
-on their weight and health. Interface roles can also be selected based on rule
-order by including interfaces in balancing rules and ordering those rules
-accordingly. To put the load balancer in failover mode, create a failover rule:
-
-.. code-block:: none
-
-    set load-balancing wan rule <number> failover
-
-Because existing sessions do not automatically fail over to a new path,
-the session table can be flushed on each connection state change:
-
-.. code-block:: none
-
-    set load-balancing wan flush-connections
-
-.. warning::
-
-    Flushing the session table will cause other connections to fall back from
-    flow-based to packet-based balancing until each flow is reestablished.
-
-Script execution
-----------------
-
-A script can be run when an interface state change occurs. Scripts are run
-from /config/scripts, for a different location specify the full path:
-
-.. code-block:: none
-
-    set load-balancing wan hook script-name
-
-Two environment variables are available:
-
-* ``WLB_INTERFACE_NAME=[interfacename]``: Interface to be monitored
-* ``WLB_INTERFACE_STATE=[ACTIVE|FAILED]``: Interface state
-
-.. warning::
-
-    Blocking call with no timeout. System will become unresponsive if script
-    does not return!
-
-Handling and monitoring
------------------------
-
-
-Show WAN load balancer information including test types and targets.
-A character at the start of each line depicts the state of the test
-
-* ``+`` successful
-* ``-`` failed
-* a blank indicates that no test has been carried out
-
-.. code-block:: none
-
-    vyos@vyos:~$ show wan-load-balance
-    Interface:  eth0
-    Status:  failed
-    Last Status Change:  Tue Jun 11 20:12:19 2019
-    -Test:  ping  Target:
-        Last Interface Success:  55s
-        Last Interface Failure:  0s
-        # Interface Failure(s):  5
-
-    Interface:  eth1
-    Status:  active
-    Last Status Change:  Tue Jun 11 20:06:42 2019
-    +Test:  ping  Target:
-        Last Interface Success:  0s
-        Last Interface Failure:  6m26s
-        # Interface Failure(s):  0
-
-Show connection data of load balanced traffic:
-
-.. code-block:: none
-
-    vyos@vyos:~$ show wan-load-balance connection
-    conntrack v1.4.2 (conntrack-tools): 3 flow entries have been shown.
-    Type    State           Src                     Dst                     Packets Bytes
-    tcp     TIME_WAIT       10.1.1.13:38040         203.0.113.2:80          203.0.113.2  192.168.188.71
-    udp                     10.1.1.13:41891         198.51.100.3:53         198.51.100.3 192.168.188.71
-    udp                     10.1.1.13:55437         198.51.100.3:53         198.51.100.3 192.168.188.71
-
-Restart
-*******
+##############
+Load-balancing
+##############
 
-.. code-block:: none
+.. toctree::
+   :maxdepth: 1
+   :includehidden:
 
-    restart wan-load-balance
+   wan
+   reverse-proxy