fix(rcm): check if the product callback exists [backport to 1.9] (#5259)

Backport to 1.9 of: #5249

## Checklist

- [X] Change(s) are motivated and described in the PR description.
- [X] Testing strategy is described if automated tests are not included
in the PR.
- [X] Risk is outlined (performance impact, potential for breakage,
maintainability, etc).
- [X] Change is maintainable (easy to change, telemetry, documentation).
- [X] [Library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/contributing.html#Release-Note-Guidelines)
are followed.
- [X] Documentation is included (in-code, generated user docs, [public
corp docs](https://github.com/DataDog/documentation/)).
- [X] Author is aware of the performance implications of this PR as
reported in the benchmarks PR comment.

## Reviewer Checklist

- [x] Title is accurate.
- [x] No unnecessary changes are introduced.
- [x] Description motivates each change.
- [x] Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes unless absolutely necessary.
- [x] Testing strategy adequately addresses listed risk(s).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] Release note makes sense to a user of the library.
- [x] Reviewer is aware of, and discussed the performance implications
of this PR as reported in the benchmarks PR comment.

---------

Signed-off-by: Juanjo Alvarez <[email protected]>

Author: avara1986

ddtrace/appsec/_remoteconfiguration.py

@@ -35,10 +35,14 @@
 log = get_logger(__name__)
 
 
-def enable_appsec_rc():
-    # type: () -> None
+def enable_appsec_rc(test_tracer=None):
+    # type: (Optional[Tracer]) -> None
+    # Tracer is a parameter for testing propose
     # Import tracer here to avoid a circular import
-    from ddtrace import tracer
+    if test_tracer is None:
+        from ddtrace import tracer
+    else:
+        tracer = test_tracer
 
     if _appsec_rc_features_is_enabled():
         from ddtrace.internal.remoteconfig import RemoteConfig

ddtrace/internal/remoteconfig/client.py

@@ -239,7 +239,7 @@ def base64_to_struct(val, cls):
         self.converter.register_structure_hook(SignedRoot, base64_to_struct)
         self.converter.register_structure_hook(SignedTargets, base64_to_struct)
 
-        self._products = dict()  # type: MutableMapping[str, ProductCallback]
+        self._products = dict()  # type: MutableMapping[str, Optional[ProductCallback]]
         self._applied_configs = dict()  # type: Mapping[str, ConfigMetadata]
         self._last_targets_version = 0
         self._last_error = None  # type: Optional[str]
@@ -348,7 +348,8 @@ def _process_response(self, data):
         if last_targets_version is None or targets is None:
             log.debug("No targets in configuration payload")
             for callback in self._products.values():
-                callback(None, None)
+                if callback:
+                    callback(None, None)
             return
 
         client_configs = {k: v for k, v in targets.items() if k in payload.client_configs}
@@ -374,34 +375,35 @@ def _process_response(self, data):
                 log.debug("Disable configuration: %s", target)
                 callback_action = False
 
-            callback = self._products[config.product_name]
-
-            try:
-                callback(config, callback_action)
-            except Exception:
-                log.debug("error while removing product %s config %r", config.product_name, config)
-                continue
+            callback = self._products.get(config.product_name)
+            if callback:
+                try:
+                    callback(config, callback_action)
+                except Exception:
+                    log.debug("error while removing product %s config %r", config.product_name, config)
+                    continue
 
         # 3. Load new configurations
         for target, config in client_configs.items():
-            callback = self._products[config.product_name]
-
-            applied_config = self._applied_configs.get(target)
-            if applied_config == config:
-                continue
-
-            config_content = _extract_target_file(payload, target, config)
-            if config_content is None:
-                continue
-
-            try:
-                log.debug("Load new configuration: %s. content %s", target, config_content)
-                callback(config, config_content)
-            except Exception:
-                log.debug("error while loading product %s config %r", config.product_name, config)
-                continue
-            else:
-                applied_configs[target] = config
+            callback = self._products.get(config.product_name)
+
+            if callback:
+                applied_config = self._applied_configs.get(target)
+                if applied_config == config:
+                    continue
+
+                config_content = _extract_target_file(payload, target, config)
+                if config_content is None:
+                    continue
+
+                try:
+                    log.debug("Load new configuration: %s. content %s", target, config_content)
+                    callback(config, config_content)
+                except Exception:
+                    log.debug("error while loading product %s config %r", config.product_name, config)
+                    continue
+                else:
+                    applied_configs[target] = config
 
         self._last_targets_version = last_targets_version
         self._applied_configs = applied_configs

releasenotes/notes/rcm-fix-product-callback-d4d33b56ed8e17b4.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fix for KeyError exceptions when when `ASM_FEATURES` (1-click activation) disabled all ASM products. This could
+    cause 1-click activation to work incorrectly in some cases.