add deprecation warnings (#120)

[patch] release

tasks/preflight.yml

@@ -48,31 +48,6 @@
     - "('linux-' + go_arch + '.tar.gz') in item"
     - alertmanager_binary_local_dir | length == 0
 
-- name: Backward compatibility of variable [part 1]
-  set_fact:
-    alertmanager_config_flags_extra: "{{ alertmanager_cli_flags }}"
-  when: alertmanager_cli_flags is defined
-
-- name: Backward compatibility of variable [part 2]
-  set_fact:
-    alertmanager_web_listen_address: "{{ alertmanager_listen_address }}"
-  when: alertmanager_listen_address is defined
-
-- name: Backward compatibility of variable [part 3]
-  set_fact:
-    alertmanager_web_external_url: "{{ alertmanager_external_url }}"
-  when: alertmanager_external_url is defined
-
-- name: Backward compatibility of variable [part 4]
-  set_fact:
-    alertmanager_route: "{{ alertmanager_route | combine({'routes': alertmanager_child_routes}) }}"
-  when: alertmanager_child_routes is defined
-
-- name: HA config compatibility with alertmanager<0.15.0
-  set_fact:
-    alertmanager_cluster: "{{ alertmanager_mesh }}"
-  when: alertmanager_mesh is defined
-
 - name: Fail when extra config flags are duplicating ansible variables
   fail:
     msg: "Detected duplicate configuration entry. Please check your ansible variables and role README.md."
@@ -96,7 +71,58 @@
     - alertmanager_config_file == 'alertmanager.yml.j2'
     - alertmanager_route == {}
 
-- name: "DEPRECATION WARNING: `alertmanager_child_routes` is no longer supported"
-  debug:
+- name: "DEPRECATION WARNING: alertmanager version 0.15 and earlier are no longer supported and will be dropped from future releases"
+  ignore_errors: true
+  fail:
+    msg: "Please use `alertmanager_version >= v0.16.0`"
+  when: alertmanager_version is version_compare('0.16.0', '<')
+
+- block:
+    - name: Backward compatibility of variable [part 1]
+      set_fact:
+        alertmanager_config_flags_extra: "{{ alertmanager_cli_flags }}"
+
+    - name: "DEPRECATION WARNING: `alertmanager_cli_flags` is no longer supported and will be dropped from future releases"
+      ignore_errors: true
+      fail:
+        msg: "Please use `alertmanager_config_flags_extra` instead of `alertmanager_cli_flags`"
+  when: alertmanager_cli_flags is defined
+
+- block:
+    - name: Backward compatibility of variable [part 2]
+      set_fact:
+        alertmanager_web_listen_address: "{{ alertmanager_listen_address }}"
+
+    - name: "DEPRECATION WARNING: `alertmanager_listen_address` is no longer supported and will be dropped from future releases"
+      ignore_errors: true
+      fail:
+        msg: "Please use `alertmanager_web_listen_address` instead of `alertmanager_listen_address`"
+  when: alertmanager_listen_address is defined
+
+- block:
+    - name: Backward compatibility of variable [part 3]
+      set_fact:
+        alertmanager_web_external_url: "{{ alertmanager_external_url }}"
+
+    - name: "DEPRECATION WARNING: `alertmanager_external_url` is no longer supported and will be dropped from future releases"
+      ignore_errors: true
+      fail:
+        msg: "Please use `alertmanager_web_external_url` instead of `alertmanager_external_url`"
+  when: alertmanager_external_url is defined
+
+- block:
+    - name: HA config compatibility with alertmanager<0.15.0
+      set_fact:
+        alertmanager_cluster: "{{ alertmanager_mesh }}"
+
+    - name: "DEPRECATION WARNING: `alertmanager_mesh` is no longer supported and will be dropped from future releases"
+      ignore_errors: true
+      fail:
+        msg: "Please use `alertmanager_cluster` instead of `alertmanager_cluster`"
+  when: alertmanager_mesh is defined
+
+- name: "DEPRECATION WARNING: `alertmanager_child_routes` is no longer supported and will be dropped from future releases"
+  ignore_errors: true
+  fail:
     msg: "Please move content of `alertmanager_child_routes` to `alertmanager_route.routes` as the former variable is deprecated and will be removed in future versions."
   when: alertmanager_child_routes is defined