From b4fb4b3b5d10cd13b1162324353f6d5efc5e2bb0 Mon Sep 17 00:00:00 2001
From: William Richard <wrichard@indigoag.com>
Date: Mon, 4 Nov 2019 12:43:37 -0500
Subject: [PATCH] Store all parameter versions, not just the latest version

---
 moto/ssm/models.py | 39 +++++++++++++++++++++++----------------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/moto/ssm/models.py b/moto/ssm/models.py
index 0e0f8d353..0f58a5ad5 100644
--- a/moto/ssm/models.py
+++ b/moto/ssm/models.py
@@ -259,7 +259,10 @@ class Command(BaseModel):
 
 class SimpleSystemManagerBackend(BaseBackend):
     def __init__(self):
-        self._parameters = {}
+        # each value is a list of all of the versions for a parameter
+        # to get the current value, grab the last item of the list
+        self._parameters = defaultdict(list)
+
         self._resource_tags = defaultdict(lambda: defaultdict(dict))
         self._commands = []
         self._errors = []
@@ -294,8 +297,8 @@ class SimpleSystemManagerBackend(BaseBackend):
         self._validate_parameter_filters(parameter_filters, by_path=False)
 
         result = []
-        for param in self._parameters:
-            ssm_parameter = self._parameters[param]
+        for param_name in self._parameters:
+            ssm_parameter = self.get_parameter(param_name, False)
             if not self._match_filters(ssm_parameter, parameter_filters):
                 continue
 
@@ -504,7 +507,7 @@ class SimpleSystemManagerBackend(BaseBackend):
         result = []
         for name in names:
             if name in self._parameters:
-                result.append(self._parameters[name])
+                result.append(self.get_parameter(name, with_decryption))
         return result
 
     def get_parameters_by_path(self, path, with_decryption, recursive, filters=None):
@@ -513,14 +516,16 @@ class SimpleSystemManagerBackend(BaseBackend):
         # path could be with or without a trailing /. we handle this
         # difference here.
         path = path.rstrip("/") + "/"
-        for param in self._parameters:
-            if path != "/" and not param.startswith(path):
+        for param_name in self._parameters:
+            if path != "/" and not param_name.startswith(path):
                 continue
-            if "/" in param[len(path) + 1 :] and not recursive:
+            if "/" in param_name[len(path) + 1 :] and not recursive:
                 continue
-            if not self._match_filters(self._parameters[param], filters):
+            if not self._match_filters(self.get_parameter(param_name, with_decryption), filters):
                 continue
-            result.append(self._parameters[param])
+            result.append(self.get_parameter(param_name, with_decryption))
+
+        return result
 
         return result
 
@@ -579,23 +584,25 @@ class SimpleSystemManagerBackend(BaseBackend):
 
     def get_parameter(self, name, with_decryption):
         if name in self._parameters:
-            return self._parameters[name]
+            return self._parameters[name][-1]
         return None
 
     def put_parameter(
         self, name, description, value, type, allowed_pattern, keyid, overwrite
     ):
-        previous_parameter = self._parameters.get(name)
-        version = 1
-
-        if previous_parameter:
+        previous_parameter_versions = self._parameters[name]
+        if len(previous_parameter_versions) == 0:
+            previous_parameter = None
+            version = 1
+        else:
+            previous_parameter = previous_parameter_versions[-1]
             version = previous_parameter.version + 1
 
             if not overwrite:
                 return
 
         last_modified_date = time.time()
-        self._parameters[name] = Parameter(
+        self._parameters[name].append(Parameter(
             name,
             value,
             type,
@@ -604,7 +611,7 @@ class SimpleSystemManagerBackend(BaseBackend):
             keyid,
             last_modified_date,
             version,
-        )
+        ))
         return version
 
     def add_tags_to_resource(self, resource_type, resource_id, tags):