foundation

Path and S3 layout managers for Lambda source deployment artifacts.

Defines two pure-convention layout classes that encode the directory structure used by the Lambda source build workflow:

• SourcePathLayout — local filesystem paths under {dir_project_root}/build/lambda/source/

• SourceS3Layout — S3 paths whose root is the source/-scoped S3 directory, e.g. s3://bucket/path/to/lambda/source/

Neither class performs I/O; they only compute paths so callers can stay decoupled from the hard-coded directory names.

Relationship to the higher-level s3dir_lambda prefix

s3dir_lambda is a shared parent used by multiple artifact types (source, layer, …). Each type owns a scoped sub-prefix so that “delete everything under this layout’s root” is safe and never touches sibling artifacts. SourceS3Layout is constructed directly with the already-scoped source/ directory as dir_root. Use the convenience factory SourceS3Layout.from_s3dir_lambda() to derive that scoped root automatically from the shared s3dir_lambda parent.

class aws_lbd_art_builder_core.source.foundation.SourcePathLayout(dir_root: Path = REQ)

Local filesystem path layout for Lambda source build artifacts.

Parameters:

dir_root – Root directory for source artifacts, e.g. /path/to/git-repo/build/lambda/source

Layout:

{dir_root}/build/        ← pip install target (temporary files)
{dir_root}/source.zip    ← final deployment package

property dir_build: Path

Directory where pip installs the package (temporary files).

property path_source_zip: Path

Final deployment zip archive.

class aws_lbd_art_builder_core.source.foundation.SourceS3Layout(dir_root: S3Path = REQ)

S3 path layout manager for Lambda source artifacts.

The root is scoped to the source-specific S3 directory so that operations such as “delete everything under root” only affect source artifacts and never accidentally touch sibling prefixes (e.g. layer/).

Parameters:

dir_root – Source-specific S3 root directory, e.g. s3://bucket/path/to/lambda/source/

Layout, see get_s3path_source_zip():

{dir_root}/0.1.1/{source_sha256}/source.zip
{dir_root}/0.1.2/{source_sha256}/source.zip
{dir_root}/0.1.3/{source_sha256}/source.zip
...

classmethod from_s3dir_lambda(s3dir_lambda: S3Path) → SourceS3Layout

Derive a SourceS3Layout from the shared Lambda S3 base directory.

s3dir_lambda is the higher-level anchor shared by all Lambda artifact types (source, layer, …). This factory pins the root to the source/ sub-prefix, giving the source layout an isolated namespace.

Parameters:

s3dir_lambda – Base S3 directory for Lambda artifacts, e.g. s3://bucket/path/to/lambda/

Returns:

SourceS3Layout rooted at {s3dir_lambda}/source/

get_s3path_source_zip(source_version: str, source_sha256: str) → S3Path

Generate S3 path for a specific version of the Lambda source zip.

Parameters:

• source_version – Semantic version string, e.g., "0.1.1"

• source_sha256 – SHA256 hash of the source build directory

Returns:

S3Path pointing to the versioned source.zip file, e.g. {dir_root}/{source_version}/{source_sha256}/source.zip

Note

Including the SHA256 hash in the path ensures that any code change produces a new S3 key, which forces CDK / CloudFormation / AWS APIs to recognise and deploy the updated Lambda function code.