Introduce port range feature
This is usefull in listen blocks for definition of multiple servers
that differs only by port number in port range block. This situation
can be result of multiple single-thread servers deployed in multi-core
environment to better utilize the available cores.
For example five contrail-api workers occupy ports 9100-9104.
This can be achieved by using port_range_length in the pillar,
port_range_length: 5 in this case.
For skipping first worker (worker_id 0), because it has other
responsibilities and to avoid overloading it by http requests
use the port_range_start_offset in the pillar,
port_range_start_offset: 1 in this case, it will only use ports
9101-9104 (skipping 9100).
PROD-18175
Change-Id: Ia1ac04660e0876f58c48a287c2d0c2adf9231a1c
diff --git a/README.rst b/README.rst
index 09bcdd7..1be4d81 100644
--- a/README.rst
+++ b/README.rst
@@ -209,6 +209,83 @@
port: 5000
params: check
+Sample pillar with port range and port offset
+
+This is usefull in listen blocks for definition of multiple servers
+that differs only by port number in port range block. This situation
+can be result of multiple single-thread servers deployed in multi-core
+environment to better utilize the available cores.
+
+For example five contrail-api workers occupy ports ``9100-9104``.
+This can be achieved by using ``port_range_length`` in the pillar,
+``port_range_length: 5`` in this case.
+For skipping first worker (``worker_id 0``), because it has other
+responsibilities and to avoid overloading it by http requests
+use the ``port_range_start_offset`` in the pillar,
+``port_range_start_offset: 1`` in this case, it will only use ports
+9101-9104 (skipping 9100).
+
+- ``port_range_length`` parameter is used to calculate port range end
+- ``port_range_start_offset`` will skip first n ports in port range
+
+For backward compatibility, the name of the first server in port range
+has no ``pN`` suffix.
+
+The following sample will result in
+
+.. code-block:: text
+
+ listen contrail_api
+ bind 172.16.10.252:8082
+ option nolinger
+ balance leastconn
+ server ntw01p1 172.16.10.95:9101 check inter 2000 rise 2 fall 3
+ server ntw01p2 172.16.10.95:9102 check inter 2000 rise 2 fall 3
+ server ntw01p3 172.16.10.95:9103 check inter 2000 rise 2 fall 3
+ server ntw01p4 172.16.10.95:9104 check inter 2000 rise 2 fall 3
+ server ntw02 172.16.10.96:9100 check inter 2000 rise 2 fall 3
+ server ntw02p1 172.16.10.96:9101 check inter 2000 rise 2 fall 3
+ server ntw02p2 172.16.10.96:9102 check inter 2000 rise 2 fall 3
+ server ntw02p3 172.16.10.96:9103 check inter 2000 rise 2 fall 3
+ server ntw02p4 172.16.10.96:9104 check inter 2000 rise 2 fall 3
+ server ntw03 172.16.10.94:9100 check inter 2000 rise 2 fall 3
+ server ntw03p1 172.16.10.94:9101 check inter 2000 rise 2 fall 3
+ server ntw03p2 172.16.10.94:9102 check inter 2000 rise 2 fall 3
+ server ntw03p3 172.16.10.94:9103 check inter 2000 rise 2 fall 3
+ server ntw03p4 172.16.10.94:9104 check inter 2000 rise 2 fall 3
+
+.. code-block:: yaml
+
+ haproxy:
+ proxy:
+ listen:
+ contrail_api:
+ type: contrail-api
+ service_name: contrail
+ balance: leastconn
+ binds:
+ - address: 10.10.10.10
+ port: 8082
+ servers:
+ - name: ntw01
+ host: 10.10.10.11
+ port: 9100
+ port_range_length: 5
+ port_range_start_offset: 1
+ params: check inter 2000 rise 2 fall 3
+ - name: ntw02
+ host: 10.10.10.12
+ port: 9100
+ port_range_length: 5
+ port_range_start_offset: 0
+ params: check inter 2000 rise 2 fall 3
+ - name: ntw03
+ host: 10.10.10.13
+ port: 9100
+ port_range_length: 5
+ params: check inter 2000 rise 2 fall 3
+
+
Custom more complex listener (for Artifactory and subdomains for docker
registries)