enhancement(alertmanager): add skip_install variable

This is similar to prometheus_skip_install variable and does what the
name says: when set, it won't try to re-download alertmanager binaries

Signed-off-by: Christian Brabandt <cb@256bit.org>

roles/alertmanager/README.md

@@ -19,6 +19,7 @@ All variables which can be overridden are stored in [defaults/main.yml](defaults
 | Name           | Default Value | Description                        |
 | -------------- | ------------- | -----------------------------------|
 | `alertmanager_version` | 0.21.0 | Alertmanager package version. Also accepts `latest` as parameter. |
+| `alertmanager_skip_install` | false | Alertmanager installation tasks gets skipped when set to true. |
 | `alertmanager_binary_local_dir` | "" | Allows to use local packages instead of ones distributed on github. As parameter it takes a directory where `alertmanager` AND `amtool` binaries are stored on host on which ansible is ran. This overrides `alertmanager_version` parameter |
 | `alertmanager_binary_url` | `https://github.com/prometheus/alertmanager/releases/download/v{{ alertmanager_version }}/alertmanager-{{ alertmanager_version }}.linux-{{ go_arch }}.tar.gz` | URL of the alertmanager binaries .tar.gz file |
 | `alertmanager_checksums_url` | `https://github.com/prometheus/alertmanager/releases/download/v{{ alertmanager_version }}/sha256sums.txt` | URL of the alertmanager checksums file |

roles/alertmanager/defaults/main.yml

@@ -4,6 +4,7 @@ alertmanager_binary_local_dir: ''
 alertmanager_binary_url: "https://github.com/{{ _alertmanager_repo }}/releases/download/v{{ alertmanager_version }}/\
                           alertmanager-{{ alertmanager_version }}.linux-{{ go_arch }}.tar.gz"
 alertmanager_checksums_url: "https://github.com/{{ _alertmanager_repo }}/releases/download/v{{ alertmanager_version }}/sha256sums.txt"
+alertmanager_skip_install: false
 
 alertmanager_config_dir: /etc/alertmanager
 alertmanager_db_dir: /var/lib/alertmanager

roles/alertmanager/meta/argument_specs.yml

@@ -11,6 +11,10 @@ argument_specs:
       alertmanager_version:
         description: "Alertmanager package version. Also accepts `latest` as parameter."
         default: 0.21.0
+      alertmanager_skip_install:
+        description: "Alertmanager installation tasks gets skipped when set to true."
+        type: bool
+        default: false
       alertmanager_binary_local_dir:
         description:
           - "Allows to use local packages instead of ones distributed on github."

roles/alertmanager/tasks/install.yml

@@ -27,7 +27,9 @@
     - "{{ _alertmanager_amtool_config_dir }}"
 
 - name: Get alertmanager binary
-  when: alertmanager_binary_local_dir | length == 0
+  when:
+    - alertmanager_binary_local_dir | length == 0
+    - not alertmanager_skip_install
   block:
 
     - name: Download alertmanager binary to local folder
@@ -78,6 +80,8 @@
   with_items:
     - alertmanager
     - amtool
-  when: alertmanager_binary_local_dir | length > 0
+  when:
+    - alertmanager_binary_local_dir | length > 0
+    - not alertmanager_skip_install
   notify:
     - restart alertmanager

roles/alertmanager/tasks/preflight.yml

@@ -29,10 +29,12 @@
   when:
     - alertmanager_version == "latest"
     - alertmanager_binary_local_dir | length == 0
+    - not alertmanager_skip_install
 
 - name: Get alertmanager binary checksum
   when:
     - alertmanager_binary_local_dir | length == 0
+    - not alertmanager_skip_install
   block:
     - name: "Get checksum list"
       ansible.builtin.set_fact: