enhancement(node_exporter): 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 the node exporter
binary

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

roles/node_exporter/README.md

@@ -19,6 +19,7 @@ All variables which can be overridden are stored in [defaults/main.yml](defaults
 | Name           | Default Value | Description                        |
 | -------------- | ------------- | -----------------------------------|
 | `node_exporter_version` | 1.1.2 | Node exporter package version. Also accepts `latest` as parameter. |
+| `node_exporter_skip_install` | false | Node exporter installation tasks gets skipped when set to true. |
 | `node_exporter_binary_local_dir` | "" | Enables the use of local packages instead of those distributed on github. The parameter may be set to a directory where the `node_exporter` binary is stored on the host where ansible is run. This overrides the `node_exporter_version` parameter |
 | `node_exporter_binary_url` | `https://github.com/prometheus/node_exporter/releases/download/v{{ node_exporter_version }}/node_exporter-{{ node_exporter_version }}.linux-{{ go_arch }}.tar.gz` | URL of the node exporter binaries .tar.gz file |
 | `node_exporter_checksums_url` | `https://github.com/prometheus/node_exporter/releases/download/v{{ node_exporter_version }}/sha256sums.txt` | URL of the node exporter checksums file |

roles/node_exporter/defaults/main.yml

@@ -4,6 +4,7 @@ node_exporter_binary_local_dir: ""
 node_exporter_binary_url: "https://github.com/{{ _node_exporter_repo }}/releases/download/v{{ node_exporter_version }}/\
                            node_exporter-{{ node_exporter_version }}.linux-{{ go_arch }}.tar.gz"
 node_exporter_checksums_url: "https://github.com/{{ _node_exporter_repo }}/releases/download/v{{ node_exporter_version }}/sha256sums.txt"
+node_exporter_skip_install: false
 
 node_exporter_web_listen_address: "0.0.0.0:9100"
 node_exporter_web_telemetry_path: "/metrics"

roles/node_exporter/meta/argument_specs.yml

@@ -11,6 +11,10 @@ argument_specs:
       node_exporter_version:
         description: "Node exporter package version. Also accepts latest as parameter."
         default: "1.1.2"
+      node_exporter_skip_install:
+        description: "Node exporter installation tasks gets skipped when set to true."
+        type: bool
+        default: false
       node_exporter_binary_local_dir:
         description:
           - "Enables the use of local packages instead of those distributed on github."

roles/node_exporter/tasks/install.yml

@@ -18,7 +18,9 @@
   when: node_exporter_system_user != "root"
 
 - name: Discover latest version
-  when: node_exporter_binary_local_dir | length == 0
+  when:
+    - node_exporter_binary_local_dir | length == 0
+    - not node_exporter_skip_install
   block:
 
     - name: Download node_exporter binary to local folder
@@ -61,5 +63,7 @@
     mode: 0755
     owner: root
     group: root
-  when: node_exporter_binary_local_dir | length > 0
+  when:
+    - node_exporter_binary_local_dir | length > 0
+    - not node_exporter_skip_install
   notify: restart node_exporter

roles/node_exporter/tasks/preflight.yml

@@ -82,9 +82,12 @@
   when:
     - node_exporter_version == "latest"
     - node_exporter_binary_local_dir | length == 0
+    - not node_exporter_skip_install
 
 - name: Get node_exporter binary checksum
-  when: node_exporter_binary_local_dir | length == 0
+  when:
+    - node_exporter_binary_local_dir | length == 0
+    - not node_exporter_skip_install
   block:
     - name: Get checksum list from github
       ansible.builtin.set_fact: