feat: Add python example for appsync-graphql-dynamodb (aws-samples#121)

* add appsync-graphql-dynamodb

* add appsync-graphql-dynamodb

* Delete README.md

* feat: add appsync-graphql-dynamodb python example

* pep8 lint

* rm setup.py

python/appsync-graphql-dynamodb/app.py

@@ -0,0 +1,11 @@
+#!/usr/bin/env python3
+
+from aws_cdk import core
+
+from app_sync_cdk.app_sync_cdk_stack import AppSyncCdkStack
+
+
+app = core.App()
+AppSyncCdkStack(app, "AppSyncGraphQLDynamoDBExample")
+
+app.synth()

python/appsync-graphql-dynamodb/app_sync_cdk/app_sync_cdk_stack.py

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+from aws_cdk import core
+from aws_cdk.aws_appsync import (
+    CfnGraphQLSchema,
+    CfnGraphQLApi,
+    CfnApiKey,
+    CfnDataSource,
+    CfnResolver
+)
+from aws_cdk.aws_dynamodb import (
+    Table,
+    Attribute,
+    AttributeType,
+    StreamViewType,
+    BillingMode
+)
+from aws_cdk.aws_iam import (
+    Role,
+    ServicePrincipal,
+    ManagedPolicy
+)
+
+
+class AppSyncCdkStack(core.Stack):
+
+    def __init__(self, scope: core.Construct, id: str, **kwargs) -> None:
+        super().__init__(scope, id, **kwargs)
+
+        table_name = 'items'
+
+        items_graphql_api = CfnGraphQLApi(
+            self, 'ItemsApi',
+            name='items-api',
+            authentication_type='API_KEY'
+        )
+
+        CfnApiKey(
+            self, 'ItemsApiKey',
+            api_id=items_graphql_api.attr_api_id
+        )
+
+        api_schema = CfnGraphQLSchema(
+            self, 'ItemsSchema',
+            api_id=items_graphql_api.attr_api_id,
+            definition=f"""\
+                type {table_name} {{
+                    {table_name}Id: ID!
+                    name: String
+                }}
+                type Paginated{table_name} {{
+                    items: [{table_name}!]!
+                    nextToken: String
+                }}
+                type Query {{
+                    all(limit: Int, nextToken: String): Paginated{table_name}!
+                    getOne({table_name}Id: ID!): {table_name}
+                }}
+                type Mutation {{
+                    save(name: String!): {table_name}
+                    delete({table_name}Id: ID!): {table_name}
+                }}
+                type Schema {{
+                    query: Query
+                    mutation: Mutation
+                }}"""
+        )
+
+        items_table = Table(
+            self, 'ItemsTable',
+            table_name=table_name,
+            partition_key=Attribute(
+                name=f'{table_name}Id',
+                type=AttributeType.STRING
+            ),
+            billing_mode=BillingMode.PAY_PER_REQUEST,
+            stream=StreamViewType.NEW_IMAGE,
+
+            # The default removal policy is RETAIN, which means that cdk
+            # destroy will not attempt to delete the new table, and it will
+            # remain in your account until manually deleted. By setting the
+            # policy to DESTROY, cdk destroy will delete the table (even if it
+            # has data in it)
+            removal_policy=core.RemovalPolicy.DESTROY # NOT recommended for production code
+        )
+
+        items_table_role = Role(
+            self, 'ItemsDynamoDBRole',
+            assumed_by=ServicePrincipal('appsync.amazonaws.com')
+        )
+
+        items_table_role.add_managed_policy(
+            ManagedPolicy.from_aws_managed_policy_name(
+                'arn:aws:iam::aws:policy/AmazonDynamoDBFullAccess'
+            )
+        )
+
+        data_source = CfnDataSource(
+            self, 'ItemsDataSource',
+            api_id=items_graphql_api.attr_api_id,
+            name='ItemsDynamoDataSource',
+            type='AMAZON_DYNAMODB',
+            dynamo_db_config=CfnDataSource.DynamoDBConfigProperty(
+                table_name=items_table.table_name,
+                aws_region=self.region
+            ),
+            service_role_arn=items_table_role.role_arn
+        )
+
+        get_one_resolver = CfnResolver(
+            self, 'GetOneQueryResolver',
+            api_id=items_graphql_api.attr_api_id,
+            type_name='Query',
+            field_name='getOne',
+            data_source_name=data_source.name,
+            request_mapping_template=f"""\
+            {{
+                "version": "2017-02-28",
+                "operation": "GetItem",
+                "key": {{
+                "{table_name}Id": $util.dynamodb.toDynamoDBJson($ctx.args.{table_name}Id)
+                }}
+            }}""",
+            response_mapping_template="$util.toJson($ctx.result)"
+        )
+
+        get_one_resolver.add_depends_on(api_schema)
+
+        get_all_resolver = CfnResolver(
+            self, 'GetAllQueryResolver',
+            api_id=items_graphql_api.attr_api_id,
+            type_name='Query',
+            field_name='all',
+            data_source_name=data_source.name,
+            request_mapping_template=f"""\
+            {{
+                "version": "2017-02-28",
+                "operation": "Scan",
+                "limit": $util.defaultIfNull($ctx.args.limit, 20),
+                "nextToken": $util.toJson($util.defaultIfNullOrEmpty($ctx.args.nextToken, null))
+            }}""",
+            response_mapping_template="$util.toJson($ctx.result)"
+        )
+
+        get_all_resolver.add_depends_on(api_schema)
+
+        save_resolver = CfnResolver(
+            self, 'SaveMutationResolver',
+            api_id=items_graphql_api.attr_api_id,
+            type_name='Mutation',
+            field_name='save',
+            data_source_name=data_source.name,
+            request_mapping_template=f"""\
+            {{
+                "version": "2017-02-28",
+                "operation": "PutItem",
+                "key": {{
+                    "{table_name}Id": {{ "S": "$util.autoId()" }}
+                }},
+                "attributeValues": {{
+                    "name": $util.dynamodb.toDynamoDBJson($ctx.args.name)
+                }}
+            }}""",
+            response_mapping_template="$util.toJson($ctx.result)"
+        )
+
+        save_resolver.add_depends_on(api_schema)
+
+        delete_resolver = CfnResolver(
+            self, 'DeleteMutationResolver',
+            api_id=items_graphql_api.attr_api_id,
+            type_name='Mutation',
+            field_name='delete',
+            data_source_name=data_source.name,
+            request_mapping_template=f"""\
+            {{
+                "version": "2017-02-28",
+                "operation": "DeleteItem",
+                "key": {{
+                "{table_name}Id": $util.dynamodb.toDynamoDBJson($ctx.args.{table_name}Id)
+                }}
+            }}""",
+            response_mapping_template="$util.toJson($ctx.result)"
+        )
+
+        delete_resolver.add_depends_on(api_schema)

python/appsync-graphql-dynamodb/cdk.json

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+{
+    "app": "python3 app.py"
+}

python/appsync-graphql-dynamodb/requirements.txt

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+aws_cdk.core
+aws_cdk.aws_appsync
+aws_cdk.aws_dynamodb
+aws_cdk.aws_iam