Allow pip like version syntax for installing collections (#79405)

changelogs/fragments/galaxy-install-no-colon.yml

@@ -0,0 +1,3 @@
+minor_changes:
+- ansible-galaxy - Add ability to specify collection versions on the CLI without the need for a colon.
+  Such as ``namespace.name==1.2.3`` vs ``namespace.name:1.2.3``.

lib/ansible/galaxy/dependency_resolution/dataclasses.py

@@ -29,6 +29,7 @@ if t.TYPE_CHECKING:
 
 from ansible.errors import AnsibleError
 from ansible.galaxy.api import GalaxyAPI
+from ansible.galaxy.collection import HAS_PACKAGING, PkgReq
 from ansible.module_utils._text import to_bytes, to_native, to_text
 from ansible.module_utils.common.arg_spec import ArgumentSpecValidator
 from ansible.utils.collection_loader import AnsibleCollectionRef
@@ -268,13 +269,25 @@ class _ComputedReqKindsMixin:
     @classmethod
     def from_string(cls, collection_input, artifacts_manager, supplemental_signatures):
         req = {}
-        if _is_concrete_artifact_pointer(collection_input):
+        if _is_concrete_artifact_pointer(collection_input) or AnsibleCollectionRef.is_valid_collection_name(collection_input):
-            # Arg is a file path or URL to a collection
+            # Arg is a file path or URL to a collection, or just a collection
             req['name'] = collection_input
-        else:
+        elif ':' in collection_input:
             req['name'], _sep, req['version'] = collection_input.partition(':')
             if not req['version']:
                 del req['version']
+        else:
+            if not HAS_PACKAGING:
+                raise AnsibleError("Failed to import packaging, check that a supported version is installed")
+            try:
+                pkg_req = PkgReq(collection_input)
+            except Exception as e:
+                # packaging doesn't know what this is, let it fly, better errors happen in from_requirement_dict
+                req['name'] = collection_input
+            else:
+                req['name'] = pkg_req.name
+                if pkg_req.specifier:
+                    req['version'] = to_text(pkg_req.specifier)
         req['signatures'] = supplemental_signatures
 
         return cls.from_requirement_dict(req, artifacts_manager)

test/integration/targets/ansible-galaxy-collection/tasks/upgrade.yml

@@ -142,7 +142,7 @@
     - directory
 
 - name: install a collection
-  command: ansible-galaxy collection install namespace1.name1:0.0.1 {{ galaxy_verbosity }}
+  command: ansible-galaxy collection install namespace1.name1==0.0.1 {{ galaxy_verbosity }}
   register: result
   failed_when:
     - '"namespace1.name1:0.0.1 was installed successfully" not in result.stdout_lines'