parse scw-cli config file for oauth_token (#3250) (#3276)

If `api_token` is not set and config file exists, it will try to fetch
the value from the activated profile and fallback on default.

This should not break existing workflows.

(cherry picked from commit cc458f7c37)

Co-authored-by: Nicolas Karolak <nikaro@users.noreply.github.com>

changelogs/fragments/3250-parse-scw-config.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - scaleway plugin inventory - parse scw-cli config file for ``oauth_token`` (https://github.com/ansible-collections/community.general/pull/3250).

plugins/inventory/scaleway.py

@@ -13,6 +13,8 @@ DOCUMENTATION = r'''
     short_description: Scaleway inventory source
     description:
         - Get inventory hosts from Scaleway.
+    requirements:
+        - PyYAML
     options:
         plugin:
             description: Token that ensures this is a source file for the 'scaleway' plugin.
@@ -30,9 +32,10 @@ DOCUMENTATION = r'''
             description: Filter results on a specific tag.
             type: list
         oauth_token:
-            required: True
             description:
             - Scaleway OAuth token.
+            - If not explicitly defined or in environment variables, it will try to lookup in the scaleway-cli configuration file
+              (C($SCW_CONFIG_PATH), C($XDG_CONFIG_HOME/scw/config.yaml), or C(~/.config/scw/config.yaml)).
             - More details on L(how to generate token, https://www.scaleway.com/en/docs/generate-api-keys/).
             env:
                 # in order of precedence
@@ -95,13 +98,22 @@ variables:
   ansible_user: "'admin'"
 '''
 
+import os
 import json
 
+try:
+    import yaml
+except ImportError as exc:
+    YAML_IMPORT_ERROR = exc
+else:
+    YAML_IMPORT_ERROR = None
+
 from ansible.errors import AnsibleError
 from ansible.plugins.inventory import BaseInventoryPlugin, Constructable
 from ansible_collections.community.general.plugins.module_utils.scaleway import SCALEWAY_LOCATION, parse_pagination_link
 from ansible.module_utils.urls import open_url
 from ansible.module_utils.common.text.converters import to_native, to_text
+from ansible.module_utils.six import raise_from
 
 import ansible.module_utils.six.moves.urllib.parse as urllib_parse
 
@@ -278,13 +290,38 @@ class InventoryModule(BaseInventoryPlugin, Constructable):
                 # Composed variables
                 self._set_composite_vars(self.get_option('variables'), host_infos, hostname, strict=False)
 
+    def get_oauth_token(self):
+        oauth_token = self.get_option('oauth_token')
+
+        if 'SCW_CONFIG_PATH' in os.environ:
+            scw_config_path = os.getenv('SCW_CONFIG_PATH')
+        elif 'XDG_CONFIG_HOME' in os.environ:
+            scw_config_path = os.path.join(os.getenv('XDG_CONFIG_HOME'), 'scw', 'config.yaml')
+        else:
+            scw_config_path = os.path.join(os.path.expanduser('~'), '.config', 'scw', 'config.yaml')
+
+        if not oauth_token and os.path.exists(scw_config_path):
+            with open(scw_config_path) as fh:
+                scw_config = yaml.safe_load(fh)
+                active_profile = scw_config.get('active_profile', 'default')
+                if active_profile == 'default':
+                    oauth_token = scw_config.get('secret_key')
+                else:
+                    oauth_token = scw_config['profiles'][active_profile].get('secret_key')
+
+        return oauth_token
+
     def parse(self, inventory, loader, path, cache=True):
+        if YAML_IMPORT_ERROR:
+            raise_from(AnsibleError('PyYAML is probably missing'), YAML_IMPORT_ERROR)
         super(InventoryModule, self).parse(inventory, loader, path)
         self._read_config_data(path=path)
 
         config_zones = self.get_option("regions")
         tags = self.get_option("tags")
-        token = self.get_option("oauth_token")
+        token = self.get_oauth_token()
+        if not token:
+            raise AnsibleError("'oauth_token' value is null, you must configure it either in inventory, envvars or scaleway-cli config.")
         hostname_preference = self.get_option("hostnames")
 
         for zone in self._get_zones(config_zones):