Do some explaining

Author: crosmuller

roles/haproxy_mgnt/README.md

@@ -0,0 +1,31 @@
+usage for rood/blauw deployment:
+
+an example playbook:
+
+---
+- name: Change loadbalancer state
+  hosts: loadbalancer_ha
+  become: false
+  gather_facts: false
+  roles:
+    - { role: haproxy_mgnt, tags: ['haproxy_mgnt'] }
+
+in group_vars set haproxy_applications:
+
+haproxy_applications:
+
+  - name: <APP>
+    vhost_name: <APP>.{{ base_domain }}
+    ha_method: "GET"
+    ha_url: "/health"
+    port: "{{ loadbalancing.engine.port }}"
+    servers: "{{ docker_servers }}"
+
+and set servers, add a color label:
+
+docker_servers:
+   - { ip: "<IPROOD>", label: "docker", color: "rood" }
+   - { ip: "<IPBLAUW>", label: "docker", color: "blauw" }
+
+ansible-playbook -i <INVENTORY> --tags haproxy_mgnt <PLAYBOOKNAME> -e "weight=<WEIGHT>" -e "app_name=<APP>" -e app_filter=color
+ -e "app_filtervalue=<COLOR>"

roles/haproxy_mgnt/tasks/main.yml

@@ -16,6 +16,7 @@
   ansible.builtin.set_fact:
     weight_complementing: "{{ 100 - weight | int }}"
 
+# get a list of servers from haproxy_applications, we filter on app_name
 - name: Get the server list from the servers configured in haproxy_applications
   ansible.builtin.set_fact:
     selected_servers: "{{ (haproxy_applications | selectattr('name', 'equalto', app_name) | map(attribute='servers') | first) }}"
@@ -36,6 +37,9 @@
   ansible.builtin.set_fact:
     server_labels_with_weights: []
 
+# Here we set weight for app_filter = app_filtervalue (for example color=blauw) to weight
+# weight_complementing (100 - weight) on other servers (for example color=rood)
+# we get the corresponding label (for example DOCKER2ROOD ) and add this to the list of dictionaries
 - name: Create list with labels and weights as dictionaries
   ansible.builtin.set_fact:
     server_labels_with_weights: "{{ server_labels_with_weights + [{ 'label': item.label, 'weight': (weight if  item[app_filter]  ==  app_filtervalue  else weight_complementing) }] }}"
@@ -45,6 +49,8 @@
   ansible.builtin.debug:
     msg: "{{ server_labels_with_weights }}"
 
+# Now we have a label and the weight we want to set
+# lets write it to the socket
 - name: Set weights for haproxy hosts
   community.general.haproxy:
     state: enabled