How to use modify_context_region method in localstack

Best Python code snippet using localstack_python

provider.py

Source:provider.py

...262        return None263    original_region = list(replicas.keys())[0]264    return original_region if target_region in replicas[original_region] else None265@contextmanager266def modify_context_region(context: RequestContext, region: str):267    """268    Context manager that modifies the region of a `RequestContext`. At the exit, the context is restored to its269    original state.270    :param context: the context to modify271    :param region: the modified region272    :return: a modified `RequestContext`273    """274    original_region = context.region275    original_authorization = context.request.headers.get("Authorization")276    context.region = region277    context.request.headers["Authorization"] = re.sub(278        r"Credential=([^/]+/[^/]+)/(.*?)/",279        rf"Credential=\1/{region}/",280        original_authorization or "",281        flags=re.IGNORECASE,282    )283    yield context284    # revert the original context285    context.region = original_region286    context.request.headers["Authorization"] = original_authorization287class DynamoDBProvider(DynamodbApi, ServiceLifecycleHook):288    def __init__(self):289        self.request_forwarder = get_request_forwarder_http(self.get_forward_url)290    def on_after_init(self):291        # add response processor specific to ddblocal292        handlers.modify_service_response.append(self.service, self._modify_ddblocal_arns)293        # routes for the shell ui294        ROUTER.add(295            path="/shell",296            endpoint=self.handle_shell_ui_redirect,297            methods=["GET"],298        )299        ROUTER.add(300            path="/shell/<regex('.*'):req_path>",301            endpoint=self.handle_shell_ui_request,302        )303    def _modify_ddblocal_arns(self, chain, context: RequestContext, response: Response):304        """A service response handler that modifies the dynamodb backend response."""305        if response_content := response.get_data(as_text=True):306            # fix the table and latest stream ARNs (DynamoDBLocal hardcodes "ddblocal" as the region)307            content_replaced = re.sub(308                r'("TableArn"|"LatestStreamArn"|"StreamArn")\s*:\s*"arn:([a-z-]+):dynamodb:ddblocal:([^"]+)"',309                rf'\1: "arn:\2:dynamodb:{aws_stack.get_region()}:\3"',310                response_content,311            )312            if content_replaced != response_content:313                response.data = content_replaced314                context.service_response = (315                    None  # make sure the service response is parsed again later316                )317        # update x-amz-crc32 header required by some clients318        response.headers["x-amz-crc32"] = crc32(response.data) & 0xFFFFFFFF319    def forward_request(320        self, context: RequestContext, service_request: ServiceRequest = None321    ) -> ServiceResponse:322        # check rate limiting for this request and raise an error, if provisioned throughput is exceeded323        self.check_provisioned_throughput(context.operation.name)324        # note: modifying headers in-place here before forwarding the request325        self.prepare_request_headers(context.request.headers)326        return self.request_forwarder(context, service_request)327    def get_forward_url(self) -> str:328        """Return the URL of the backend DynamoDBLocal server to forward requests to"""329        return f"http://{LOCALHOST}:{server.get_server().port}"330    def on_before_start(self):331        start_dynamodb()332        wait_for_dynamodb()333    def handle_shell_ui_redirect(self, request: werkzeug.Request) -> Response:334        headers = {"Refresh": f"0; url={config.service_url('dynamodb')}/shell/index.html"}335        return Response("", headers=headers)336    def handle_shell_ui_request(self, request: werkzeug.Request, req_path: str) -> Response:337        # TODO: "DynamoDB Local Web Shell was deprecated with version 1.16.X and is not available any338        #  longer from 1.17.X to latest. There are no immediate plans for a new Web Shell to be introduced."339        #  -> keeping this for now, to allow configuring custom installs; should consider removing it in the future340        # https://repost.aws/questions/QUHyIzoEDqQ3iOKlUEp1LPWQ#ANdBm9Nz9TRf6VqR3jZtcA1g341        req_path = f"/{req_path}" if not req_path.startswith("/") else req_path342        url = f"{self.get_forward_url()}/shell{req_path}"343        result = requests.request(344            method=request.method, url=url, headers=request.headers, data=request.data345        )346        return Response(result.content, headers=dict(result.headers), status=result.status_code)347    @handler("CreateTable", expand=False)348    def create_table(349        self,350        context: RequestContext,351        create_table_input: CreateTableInput,352    ) -> CreateTableOutput:353        # Check if table exists, to avoid error log output from DynamoDBLocal354        table_name = create_table_input["TableName"]355        if self.table_exists(table_name):356            raise ResourceInUseException("Cannot create preexisting table")357        billing_mode = create_table_input.get("BillingMode")358        provisioned_throughput = create_table_input.get("ProvisionedThroughput")359        if billing_mode == BillingMode.PAY_PER_REQUEST and provisioned_throughput is not None:360            raise ValidationException(361                "One or more parameter values were invalid: Neither ReadCapacityUnits nor WriteCapacityUnits can be "362                "specified when BillingMode is PAY_PER_REQUEST"363            )364        # forward request to backend365        result = self.forward_request(context)366        table_description = result["TableDescription"]367        backend = get_store(context)368        backend.table_definitions[table_name] = table_definitions = dict(create_table_input)369        if "TableId" not in table_definitions:370            table_definitions["TableId"] = long_uid()371        if "SSESpecification" in table_definitions:372            sse_specification = table_definitions.pop("SSESpecification")373            table_definitions["SSEDescription"] = SSEUtils.get_sse_description(sse_specification)374        if table_definitions:375            table_content = result.get("Table", {})376            table_content.update(table_definitions)377            table_description.update(table_content)378        if "StreamSpecification" in table_definitions:379            create_dynamodb_stream(table_definitions, table_description.get("LatestStreamLabel"))380        if "TableClass" in table_definitions:381            table_class = table_description.pop("TableClass", None) or table_definitions.pop(382                "TableClass"383            )384            table_description["TableClassSummary"] = {"TableClass": table_class}385        tags = table_definitions.pop("Tags", [])386        if tags:387            table_arn = table_description["TableArn"]388            table_arn = self.fix_table_arn(table_arn)389            get_store(context).TABLE_TAGS[table_arn] = {tag["Key"]: tag["Value"] for tag in tags}390        # remove invalid attributes from result391        table_description.pop("Tags", None)392        table_description.pop("BillingMode", None)393        return result394    def delete_table(self, context: RequestContext, table_name: TableName) -> DeleteTableOutput:395        # Check if table exists, to avoid error log output from DynamoDBLocal396        if not self.table_exists(table_name):397            raise ResourceNotFoundException("Cannot do operations on a non-existent table")398        # forward request to backend399        result = self.forward_request(context)400        table_arn = result.get("TableDescription", {}).get("TableArn")401        table_arn = self.fix_table_arn(table_arn)402        self.delete_all_event_source_mappings(table_arn)403        dynamodbstreams_api.delete_streams(table_arn)404        get_store(context).TABLE_TAGS.pop(table_arn, None)405        return result406    def _forward_request(self, context: RequestContext, region: str | None) -> ServiceResponse:407        if region:408            with modify_context_region(context, region):409                return self.forward_request(context)410        return self.forward_request(context)411    def describe_table(self, context: RequestContext, table_name: TableName) -> DescribeTableOutput:412        global_table_region: str | None = find_global_table_region(413            table_name=table_name, target_region=context.region414        )415        # Check if table exists, to avoid error log output from DynamoDBLocal416        if not self.table_exists(table_name) and not global_table_region:417            raise ResourceNotFoundException("Cannot do operations on a non-existent table")418        result = self._forward_request(context=context, region=global_table_region)419        # update response with additional props420        table_props = get_store(context).table_properties.get(table_name)421        if table_props:422            result.get("Table", {}).update(table_props)...

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