SSM Parameter Store

Overview

CloudMock emulates AWS Systems Manager Parameter Store, providing hierarchical configuration storage with support for String, StringList, and SecureString parameter types.

Supported Operations

Operation	Status	Notes
PutParameter	Supported	Creates or updates a parameter (String, StringList, SecureString)
GetParameter	Supported	Returns a single parameter by name
GetParameters	Supported	Returns multiple parameters by name list
GetParametersByPath	Supported	Returns all parameters under a path prefix
DeleteParameter	Supported	Deletes a single parameter
DeleteParameters	Supported	Deletes multiple parameters
DescribeParameters	Supported	Returns parameter metadata (no values)

Quick Start

curl

# Put a parameter
curl -X POST http://localhost:4566 \
  -H "X-Amz-Target: AmazonSSM.PutParameter" \
  -H "Content-Type: application/x-amz-json-1.1" \
  -d '{"Name": "/app/env", "Value": "production", "Type": "String"}'

# Get a parameter
curl -X POST http://localhost:4566 \
  -H "X-Amz-Target: AmazonSSM.GetParameter" \
  -H "Content-Type: application/x-amz-json-1.1" \
  -d '{"Name": "/app/env"}'

Node.js

import { SSMClient, PutParameterCommand, GetParametersByPathCommand } from '@aws-sdk/client-ssm';

const ssm = new SSMClient({
  endpoint: 'http://localhost:4566',
  region: 'us-east-1',
  credentials: { accessKeyId: 'test', secretAccessKey: 'test' },
});

await ssm.send(new PutParameterCommand({
  Name: '/service/db-host', Value: 'localhost', Type: 'String',
}));
await ssm.send(new PutParameterCommand({
  Name: '/service/db-pass', Value: 'secret', Type: 'SecureString',
}));

const { Parameters } = await ssm.send(new GetParametersByPathCommand({
  Path: '/service', WithDecryption: true,
}));
Parameters?.forEach(p => console.log(p.Name, '=', p.Value));

Python

import boto3

ssm = boto3.client('ssm', endpoint_url='http://localhost:4566',
                   aws_access_key_id='test', aws_secret_access_key='test',
                   region_name='us-east-1')

ssm.put_parameter(Name='/service/db-host', Value='localhost', Type='String')
ssm.put_parameter(Name='/service/db-pass', Value='secret', Type='SecureString')

response = ssm.get_parameters_by_path(Path='/service', WithDecryption=True)
for param in response['Parameters']:
    print(param['Name'], '=', param['Value'])

Configuration

cloudmock.yml

services:
  ssm:
    enabled: true

No additional service-specific configuration is required.

Known Differences from AWS

• SecureString type is accepted and stored; encryption is simulated (not cryptographically secure).
• GetParametersByPath supports recursive path lookups.
• Parameter versioning stores each PutParameter call as a new version; the latest version is returned by default.
• GetParameterHistory is not implemented.
• Advanced parameters (larger size, policies) are not distinguished from standard parameters.

Error Codes

Code	HTTP Status	Description
ParameterNotFound	400	The specified parameter does not exist
ParameterAlreadyExists	400	The parameter already exists (when Overwrite is false)
InvalidKeyId	400	The KMS key ID is not valid
TooManyUpdates	429	Too many updates for this parameter