Add binary_file lookup (#10616)

* Add binary_file lookup.

* Remove sentence on deprecation.

plugins/lookup/binary_file.py

@@ -0,0 +1,114 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2025, Felix Fontein <felix@fontein.de>
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+DOCUMENTATION = r"""
+name: binary_file
+author: Felix Fontein (@felixfontein)
+short_description: Read binary file and return it Base64 encoded
+version_added: 11.2.0
+description:
+  - This lookup returns the contents from a file on the Ansible controller's file system.
+  - The file is read as a binary file and its contents are returned Base64 encoded.
+    This is similar to using P(ansible.builtin.file#lookup) combined with P(ansible.builtin.b64encode#filter),
+    except that P(ansible.builtin.file#lookup) does not support binary files as it interprets the contents as UTF-8,
+    which can cause the wrong content being Base64 encoded.
+options:
+  _terms:
+    description:
+      - Paths of the files to read.
+      - Relative paths will be searched for in different places. See R(Ansible task paths, playbook_task_paths) for more details.
+    required: true
+    type: list
+    elements: str
+  not_exist:
+    description:
+      - Determine how to react if the specified file cannot be found.
+    type: str
+    choices:
+      error: Raise an error.
+      empty: Return an empty string for the file.
+      empty_str:
+        - Return the string C(empty) for the file.
+        - This cannot be confused with Base64 encoding due to the missing padding.
+    default: error
+notes:
+  - This lookup does not understand 'globbing' - use the P(ansible.builtin.fileglob#lookup) lookup instead.
+seealso:
+  - plugin: ansible.builtin.b64decode
+    plugin_type: filter
+    description: >-
+      The b64decode filter can be used to decode Base64 encoded data.
+      Note that Ansible cannot handle binary data, the data will be interpreted as UTF-8 text!
+  - plugin: ansible.builtin.file
+    plugin_type: lookup
+    description: You can use this lookup plugin to read text files from the Ansible controller.
+  - module: ansible.builtin.slurp
+    description: >-
+      Also allows to read binary files Base64 encoded, but from remote targets.
+      With C(delegate_to: localhost) can be redirected to run on the controller, but you have to know the path to the file to read.
+      Both this plugin and P(ansible.builtin.file#lookup) use some search path logic to for example also find files in the C(files)
+      directory of a role.
+  - ref: playbook_task_paths
+    description: Search paths used for relative files.
+"""
+
+EXAMPLES = r"""
+---
+- name: Output Base64 contents of binary files on screen
+  ansible.builtin.debug:
+    msg: "Content: {{ lookup('community.general.binary_file', item) }}"
+  loop:
+    - some-binary-file.bin
+"""
+
+RETURN = r"""
+_raw:
+  description:
+    - Base64 encoded content of requested files, or an empty string resp. the string C(empty), depending on the O(not_exist) option.
+    - This list contains one string per element of O(_terms) in the same order as O(_terms).
+  type: list
+  elements: str
+  returned: success
+"""
+
+import base64
+
+from ansible.errors import AnsibleLookupError
+from ansible.plugins.lookup import LookupBase
+
+from ansible.utils.display import Display
+
+display = Display()
+
+
+class LookupModule(LookupBase):
+
+    def run(self, terms, variables=None, **kwargs):
+        self.set_options(var_options=variables, direct=kwargs)
+        not_exist = self.get_option("not_exist")
+
+        result = []
+        for term in terms:
+            display.debug(f"Searching for binary file: {term!r}")
+            path = self.find_file_in_search_path(variables, "files", term, ignore_missing=(not_exist != "error"))
+            display.vvvv(f"community.general.binary_file lookup using {path} as file")
+
+            if not path:
+                if not_exist == "empty":
+                    result.append("")
+                    continue
+                if not_exist == "empty_str":
+                    result.append("empty")
+                    continue
+                raise AnsibleLookupError(f"Could not locate file in community.general.binary_file lookup: {term}")
+
+            try:
+                with open(path, "rb") as f:
+                    result.append(base64.b64encode(f.read()).decode("utf-8"))
+            except Exception as exc:
+                raise AnsibleLookupError(f"Error while reading {path}: {exc}")
+
+        return result