[topo] Add t1-isolated-d32u1s2 topology (#24521)

### Description of PR

Summary:
Add a new topology `t1-isolated-d32u1s2`, a reduced version of
`t1-isolated-d508u1s2` with 32 T0 downlinks (instead of 508) plus the
same 1 T2 uplink and 2 PT1 peers. Useful for scaled-down testbeds that
still exercise the d508u1s2 layout shape without requiring 508 downlink
VMs.

Reduction rule applied to the 508 downlink panel ports (0..507): keep
only the 1st and 25th port of every 32-port block (panel ports where `p
% 32 in {0, 24}`). Uplink (508) and peer ports (509, 510) are unchanged.

---------

Signed-off-by: r12f <r12f.code@gmail.com>
Co-authored-by: r12f <r12f.code@gmail.com>
Signed-off-by: mssonicbld <sonicbld@microsoft.com>

Author: 2 people

ansible/generate_topo.py

@@ -193,6 +193,13 @@ def __contains__(self, key):
                          "peer_ports": [509, 510],
                          "skip_ports": [],
                          "panel_port_step": 1},
+    'd32u1s2':          {"ds_breakout": 1, "us_breakout": 1, "ds_link_step": 1, "us_link_step": 1,
+                         "uplink_ports": [508],
+                         "peer_ports": [509, 510],
+                         # Reduced from d508u1s2: keep only the 1st and 25th downlink port of every
+                         # 32-port block (i.e. p % 32 in {0, 24}), giving 32 T0 downlinks total.
+                         "skip_ports": [p for p in range(508) if p % 32 not in (0, 24)],
+                         "panel_port_step": 1},
 }
 
 overwrite_file_name = {
@@ -722,6 +729,7 @@ def main(role: str, keyword: str, template: str, port_count: int, uplinks: str,
     - ./generate_topo.py -r t1 -k isolated-v6 -t t1-isolated-v6 -c 64 -l 'c448o16-lag'
     - ./generate_topo.py -r t1 -k isolated-v6 -t t1-isolated-v6 -c 64 -l 'c448o16-lag-sparse'
     - ./generate_topo.py -r t1 -k isolated -t t1-isolated -c 509 -l 'd508u1s2'
+    - ./generate_topo.py -r t1 -k isolated -t t1-isolated -c 509 -l 'd32u1s2'  # 509 matches d508u1s2 IPs
     - ./generate_topo.py -r lt2 -k o128 -t lt2_128 -c 64 -l 'o128lt2'
     - ./generate_topo.py -r lt2 -k p32o64 -t lt2_p32o64 -c 64 -l 'p32o64lt2'
     - ./generate_topo.py -r t0 -k f2 -t t0 -c 64 -l 'p32v128f2'

ansible/roles/eos/templates/t1-isolated-d32u1s2-pleaf.j2

@@ -0,0 +1 @@
+t0-leaf.j2

ansible/roles/eos/templates/t1-isolated-d32u1s2-spine.j2

@@ -0,0 +1 @@
+t1-spine.j2

ansible/roles/eos/templates/t1-isolated-d32u1s2-tor.j2

@@ -0,0 +1 @@
+t1-tor.j2

ansible/roles/eos/templates/t1-isolated-d508u1s2-pleaf.j2

@@ -0,0 +1 @@
+t0-leaf.j2

ansible/templates/topo_t1-isolated.j2

@@ -24,6 +24,8 @@ configuration_properties:
     swrole: spine
   tor:
     swrole: tor
+  pleaf:
+    swrole: pleaf
 
 configuration:
 {%- for vm in vm_list %}
@@ -35,6 +37,8 @@ configuration:
     tornum: {{vm.tornum}}
     {%- elif vm.role == 't2' %}
     - spine
+    {%- elif vm.role == 'pt1' %}
+    - pleaf
     {%- endif %}
     bgp:
       asn: {{vm.asn}}