lambda_rest_api#

Stack defining an API Gateway mapping to a Lambda function with the FastAPI app.




Classes#

RootskiLambdaRestApiStack

An API Gateway mapping to a Lambda function with the backend code inside.

StackOutputs

Stack output keys for the RootskiLambdaRestApiStack.

class RootskiLambdaRestApiStack#

class rootski_backend_cdk.lambda_rest_api.stacks.lambda_rest_api.RootskiLambdaRestApiStack(*args: Any, **kwargs)[source]#

Bases: aws_cdk.Stack

An API Gateway mapping to a Lambda function with the backend code inside.

property account: str#

The AWS account into which this stack will be deployed.

This value is resolved according to the following rules:

  1. The value provided to env.account when the stack is defined. This can either be a concerete account (e.g. 585695031111) or the Aws.accountId token.

  2. Aws.accountId, which represents the CloudFormation intrinsic reference { "Ref": "AWS::AccountId" } encoded as a string token.

Preferably, you should use the return value as an opaque string and not attempt to parse it to implement your logic. If you do, you must first check that it is a concerete value an not an unresolved token. If this value is an unresolved token (Token.isUnresolved(stack.account) returns true), this implies that the user wishes that this stack will synthesize into a account-agnostic template. In this case, your code should either fail (throw an error, emit a synth error using Annotations.of(construct).addError()) or implement some other region-agnostic behavior.

add_dependency(target: aws_cdk.Stack, reason: Optional[str] = None) → None#

Add a dependency between this stack and another stack.

This can be used to define dependencies between any two stacks within an app, and also supports nested stacks.

Parameters

  • target –

  • reason –

add_transform(transform: str) → None#

Add a Transform to this stack. A Transform is a macro that AWS CloudFormation uses to process your template.

Duplicate values are removed when stack is synthesized.

Parameters

transform – The transform to add.

See

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/transform-section-structure.html

Example:

# Example automatically generated from non-compiling source. May contain errors.
# stack: Stack


stack.add_transform("AWS::Serverless-2016-10-31")
property artifact_id: str#

The ID of the cloud assembly artifact for this stack.

property availability_zones: List[str]#

Returns the list of AZs that are available in the AWS environment (account/region) associated with this stack.

If the stack is environment-agnostic (either account and/or region are tokens), this property will return an array with 2 tokens that will resolve at deploy-time to the first two availability zones returned from CloudFormation’s Fn::GetAZs intrinsic function.

If they are not available in the context, returns a set of dummy values and reports them as missing, and let the CLI resolve them by calling EC2 DescribeAvailabilityZones on the target environment.

To specify a different strategy for selecting availability zones override this method.

property bundling_required: bool#

Indicates whether the stack requires bundling or not.

property dependencies: List[aws_cdk.Stack]#

Return the stacks this stack depends on.

property environment: str#

The environment coordinates in which this stack is deployed.

In the form aws://account/region. Use stack.account and stack.region to obtain the specific values, no need to parse.

You can use this value to determine if two stacks are targeting the same environment.

If either stack.account or stack.region are not concrete values (e.g. Aws.account or Aws.region) the special strings unknown-account and/or unknown-region will be used respectively to indicate this stack is region/account-agnostic.

export_value(exported_value: Any, *, name: Optional[str] = None) → str#

Create a CloudFormation Export for a value.

Returns a string representing the corresponding Fn.importValue() expression for this Export. You can control the name for the export by passing the name option.

If you don’t supply a value for name, the value you’re exporting must be a Resource attribute (for example: bucket.bucketName) and it will be given the same name as the automatic cross-stack reference that would be created if you used the attribute in another Stack.

One of the uses for this method is to remove the relationship between two Stacks established by automatic cross-stack references. It will temporarily ensure that the CloudFormation Export still exists while you remove the reference from the consuming stack. After that, you can remove the resource and the manual export.

Example

Here is how the process works. Let’s say there are two stacks, producerStack and consumerStack, and producerStack has a bucket called bucket, which is referenced by consumerStack (perhaps because an AWS Lambda Function writes into it, or something like that).

It is not safe to remove producerStack.bucket because as the bucket is being deleted, consumerStack might still be using it.

Instead, the process takes two deployments:

Deployment 1: break the relationship

  • Make sure consumerStack no longer references bucket.bucketName (maybe the consumer stack now uses its own bucket, or it writes to an AWS DynamoDB table, or maybe you just remove the Lambda Function altogether).

  • In the ProducerStack class, call this.exportValue(this.bucket.bucketName). This will make sure the CloudFormation Export continues to exist while the relationship between the two stacks is being broken.

  • Deploy (this will effectively only change the consumerStack, but it’s safe to deploy both).

Deployment 2: remove the bucket resource

  • You are now free to remove the bucket resource from producerStack.

  • Don’t forget to remove the exportValue() call as well.

  • Deploy again (this time only the producerStack will be changed – the bucket will be deleted).

Parameters

  • exported_value –

  • name – The name of the export to create. Default: - A name is automatically chosen

fast_api_function: aws_cdk.aws_lambda.Function#

lambda function containing the rootski FastAPI application code

format_arn(*, resource: str, service: str, account: Optional[str] = None, arn_format: Optional[aws_cdk.ArnFormat] = None, partition: Optional[str] = None, region: Optional[str] = None, resource_name: Optional[str] = None) → str#

Creates an ARN from components.

If partition, region or account are not specified, the stack’s partition, region and account will be used.

If any component is the empty string, an empty string will be inserted into the generated ARN at the location that component corresponds to.

The ARN will be formatted as follows:

arn:{partition}:{service}:{region}:{account}:{resource}{sep}}{resource-name}

The required ARN pieces that are omitted will be taken from the stack that the ‘scope’ is attached to. If all ARN pieces are supplied, the supplied scope can be ‘undefined’.

Parameters

  • resource – Resource type (e.g. “table”, “autoScalingGroup”, “certificate”). For some resource types, e.g. S3 buckets, this field defines the bucket name.

  • service – The service namespace that identifies the AWS product (for example, ‘s3’, ‘iam’, ‘codepipline’).

  • account – The ID of the AWS account that owns the resource, without the hyphens. For example, 123456789012. Note that the ARNs for some resources don’t require an account number, so this component might be omitted. Default: The account the stack is deployed to.

  • arn_format – The specific ARN format to use for this ARN value. Default: - uses value of sep as the separator for formatting, ArnFormat.SLASH_RESOURCE_NAME if that property was also not provided

  • partition – The partition that the resource is in. For standard AWS regions, the partition is aws. If you have resources in other partitions, the partition is aws-partitionname. For example, the partition for resources in the China (Beijing) region is aws-cn. Default: The AWS partition the stack is deployed to.

  • region – The region the resource resides in. Note that the ARNs for some resources do not require a region, so this component might be omitted. Default: The region the stack is deployed to.

  • resource_name – Resource name or path within the resource (i.e. S3 bucket object key) or a wildcard such as "*". This is service-dependent.

get_logical_id(element: aws_cdk.CfnElement) → str#

Allocates a stack-unique CloudFormation-compatible logical identity for a specific resource.

This method is called when a CfnElement is created and used to render the initial logical identity of resources. Logical ID renames are applied at this stage.

This method uses the protected method allocateLogicalId to render the logical ID for an element. To modify the naming scheme, extend the Stack class and override this method.

Parameters

element – The CloudFormation element for which a logical identity is needed.

classmethod is_construct(x: Any) → bool#

Checks if x is a construct.

Use this method instead of instanceof to properly detect Construct instances, even when the construct library is symlinked.

Explanation: in JavaScript, multiple copies of the constructs library on disk are seen as independent, completely different libraries. As a consequence, the class Construct in each copy of the constructs library is seen as a different class, and an instance of one class will not test as instanceof the other class. npm install will not create installations like this, but users may manually symlink construct libraries together or use a monorepo tool: in those cases, multiple copies of the constructs library can be accidentally installed, and instanceof will behave unpredictably. It is safest to avoid using instanceof, and using this type-testing method instead.

Parameters

x – Any object.

Returns

true if x is an object created from a class which extends Construct.

classmethod is_stack(x: Any) → bool#

Return whether the given object is a Stack.

We do attribute detection since we can’t reliably use ‘instanceof’.

Parameters

x –

lambda_rest_api#

API Gateway that proxies all incoming requests to the fast_api_function

make_fast_api_function() → aws_cdk.aws_lambda.Function[source]#

Create a lambda function with the FastAPI app.

To prepare the python depencies for the lambda function, this stack will essentially run the following command:

docker run                 --rm                 -v "path/to/rootski_api:/assets_input"                 -v "path/to/cdk.out/asset.<some hash>:/assets_output"                 lambci/lambda:build-python3.8                 /bin/bash -c "... several commands to install the requirements to /assets_output ..."

The reason for using docker to install the requirements is because the “lambci/lambda:build-pythonX.X” image uses the same underlying operating system as is used in the real AWS Lambda runtime. This means that python packages that rely on compiled C/C++ binaries will be compiled correctly for the AWS Lambda runtime. If we did not do it this way, packages such as pandas, numpy, psycopg2-binary, asyncpg, sqlalchemy, and others relying on C/C++ bindings would not work when uploaded to lambda.

We use the lambci/* images instead of the images maintained by AWS CDK because the AWS CDK images were failing to correctly install C/C++ based python packages. An extra benefit of using lambci/* over the AWS CDK images is that the lambci/* images are in docker hub so they can be pulled without doing any sort of docker login command before executing this script. The AWS CDK images are stored in public.ecr.aws which requires a docker login command to be run first.

property nested: bool#

Indicates if this is a nested stack, in which case parentStack will include a reference to it’s parent.

property nested_stack_parent: Optional[aws_cdk.Stack]#

If this is a nested stack, returns it’s parent stack.

property nested_stack_resource: Optional[aws_cdk.CfnResource]#

If this is a nested stack, this represents its AWS::CloudFormation::Stack resource.

undefined for top-level (non-nested) stacks.

property node: constructs.Node#

The tree node.

property notification_arns: List[str]#

Returns the list of notification Amazon Resource Names (ARNs) for the current stack.

classmethod of(construct: constructs.IConstruct) → aws_cdk.Stack#

Looks up the first stack scope in which construct is defined.

Fails if there is no stack up the tree.

Parameters

construct – The construct to start the search from.

property partition: str#

The partition in which this stack is defined.

property region: str#

The AWS region into which this stack will be deployed (e.g. us-west-2).

This value is resolved according to the following rules:

  1. The value provided to env.region when the stack is defined. This can either be a concerete region (e.g. us-west-2) or the Aws.region token.

  2. Aws.region, which is represents the CloudFormation intrinsic reference { "Ref": "AWS::Region" } encoded as a string token.

Preferably, you should use the return value as an opaque string and not attempt to parse it to implement your logic. If you do, you must first check that it is a concerete value an not an unresolved token. If this value is an unresolved token (Token.isUnresolved(stack.region) returns true), this implies that the user wishes that this stack will synthesize into a region-agnostic template. In this case, your code should either fail (throw an error, emit a synth error using Annotations.of(construct).addError()) or implement some other region-agnostic behavior.

regional_fact(fact_name: str, default_value: Optional[str] = None) → str#

Look up a fact value for the given fact for the region of this stack.

Will return a definite value only if the region of the current stack is resolved. If not, a lookup map will be added to the stack and the lookup will be done at CDK deployment time.

What regions will be included in the lookup map is controlled by the @aws-cdk/core:target-partitions context value: it must be set to a list of partitions, and only regions from the given partitions will be included. If no such context key is set, all regions will be included.

This function is intended to be used by construct library authors. Application builders can rely on the abstractions offered by construct libraries and do not have to worry about regional facts.

If defaultValue is not given, it is an error if the fact is unknown for the given region.

Parameters

  • fact_name –

  • default_value –

rename_logical_id(old_id: str, new_id: str) → None#

Rename a generated logical identities.

To modify the naming scheme strategy, extend the Stack class and override the allocateLogicalId method.

Parameters

  • old_id –

  • new_id –

report_missing_context_key(*, key: str, props: Union[aws_cdk.cloud_assembly_schema.AmiContextQuery, aws_cdk.cloud_assembly_schema.AvailabilityZonesContextQuery, aws_cdk.cloud_assembly_schema.HostedZoneContextQuery, aws_cdk.cloud_assembly_schema.SSMParameterContextQuery, aws_cdk.cloud_assembly_schema.VpcContextQuery, aws_cdk.cloud_assembly_schema.EndpointServiceAvailabilityZonesContextQuery, aws_cdk.cloud_assembly_schema.LoadBalancerContextQuery, aws_cdk.cloud_assembly_schema.LoadBalancerListenerContextQuery, aws_cdk.cloud_assembly_schema.SecurityGroupContextQuery, aws_cdk.cloud_assembly_schema.KeyContextQuery, aws_cdk.cloud_assembly_schema.PluginContextQuery], provider: aws_cdk.cloud_assembly_schema.ContextProvider) → None#

Indicate that a context key was expected.

Contains instructions which will be emitted into the cloud assembly on how the key should be supplied.

Parameters

  • key – The missing context key.

  • props – A set of provider-specific options.

  • provider – The provider from which we expect this context key to be obtained.

resolve(obj: Any) → Any#

Resolve a tokenized value in the context of the current stack.

Parameters

obj –

rootski_api_subdomain#

DNS rule routing the API_SUBDOMAIN to the rootski API Gateway

split_arn(arn: str, arn_format: aws_cdk.ArnFormat) → aws_cdk.ArnComponents#

Splits the provided ARN into its components.

Works both if ‘arn’ is a string like ‘arn:aws:s3:::bucket’, and a Token representing a dynamic CloudFormation expression (in which case the returned components will also be dynamic CloudFormation expressions, encoded as Tokens).

Parameters

  • arn – the ARN to split into its components.

  • arn_format – the expected format of ‘arn’ - depends on what format the service ‘arn’ represents uses.

property stack_id: str#

The ID of the stack.

Example:

# Example automatically generated from non-compiling source. May contain errors.
# After resolving, looks like
"arn:aws:cloudformation:us-west-2:123456789012:stack/teststack/51af3dc0-da77-11e4-872e-1234567db123"
property stack_name: str#

The concrete CloudFormation physical stack name.

This is either the name defined explicitly in the stackName prop or allocated based on the stack’s location in the construct tree. Stacks that are directly defined under the app use their construct id as their stack name. Stacks that are defined deeper within the tree will use a hashed naming scheme based on the construct path to ensure uniqueness.

If you wish to obtain the deploy-time AWS::StackName intrinsic, you can use Aws.stackName directly.

property synthesizer: aws_cdk.IStackSynthesizer#

Synthesis method for this stack.

property tags: aws_cdk.TagManager#

Tags to be applied to the stack.

property template_file: str#

The name of the CloudFormation template file emitted to the output directory during synthesis.

Example value: MyStack.template.json

property template_options: aws_cdk.ITemplateOptions#

Options for CloudFormation template (like version, transform, description).

property termination_protection: Optional[bool]#

Whether termination protection is enabled for this stack.

to_json_string(obj: Any, space: Optional[Union[int, float]] = None) → str#

Convert an object, potentially containing tokens, to a JSON string.

Parameters

  • obj –

  • space –

to_string() → str#

Returns a string representation of this construct.

property url_suffix: str#

The Amazon domain suffix for the region in which this stack is defined.

class StackOutputs#

class rootski_backend_cdk.lambda_rest_api.stacks.lambda_rest_api.StackOutputs(value)[source]#

Bases: str, enum.Enum

Stack output keys for the RootskiLambdaRestApiStack.