S3 and Plant Tracer

Plant Tracer uses three distinct S3 locations:

Location

Configuration

Purpose and lifetime

Runtime movie archive

PLANTTRACER_S3_BUCKET / SAM ImageBucketName

Upload staging, original movies, and derived movie artifacts. The bucket is pre-existing, shared, and outlives every application stack.

Operational artifacts

s3://planttracer-artifacts/artifacts/

Temporary diagnostics such as CloudWatch Synthetics output. These are not movie data and expire according to bucket lifecycle rules.

SAM deployment artifacts

SAM CLI managed bucket selected by resolve_s3=true

Packaged Lambda deployment files consumed by CloudFormation.

Runtime Movie Archive

The runtime bucket is supplied to the stack; template.yaml does not create or delete it. DynamoDB stores complete S3 URNs so existing rows remain readable when they refer to an older bucket or object layout.

Creating a Runtime Movie Bucket

The following procedure creates a new runtime movie archive for stacks in the same AWS account and region. Bucket names are globally unique. Use a project-specific bucket name and the region in which the Plant Tracer stacks run; an S3 bucket sends its events to EventBridge in that same region.

  1. Load the AWS environment, choose the bucket name and region, verify the active AWS identity, and create the bucket:

    source .envrc
export PT_BUCKET=planttracer-example
export PT_BUCKET_REGION=us-east-1
aws sts get-caller-identity --no-cli-pager
aws s3 mb "s3://${PT_BUCKET}" --region "${PT_BUCKET_REGION}"

  2. Keep the archive private and make the bucket owner the owner of every object. Plant Tracer uses presigned requests; it does not require public bucket or object access:

    aws s3api put-public-access-block \
  --bucket "${PT_BUCKET}" \
  --public-access-block-configuration \
  'BlockPublicAcls=true,IgnorePublicAcls=true,BlockPublicPolicy=true,RestrictPublicBuckets=true'
aws s3api put-bucket-ownership-controls \
  --bucket "${PT_BUCKET}" \
  --ownership-controls 'Rules=[{ObjectOwnership=BucketOwnerEnforced}]'

  3. Explicitly enable server-side encryption with Amazon S3 managed keys:

    aws s3api put-bucket-encryption \
  --bucket "${PT_BUCKET}" \
  --server-side-encryption-configuration \
  '{"Rules":[{"ApplyServerSideEncryptionByDefault":{"SSEAlgorithm":"AES256"}}]}'

  4. Configure CORS for browser presigned uploads and downloads. CORS permission does not make objects public; S3 still requires a valid presigned request. The configuration matches CORS_CONFIGURATION in src/app/s3_presigned.py:

    aws s3api put-bucket-cors \
  --bucket "${PT_BUCKET}" \
  --cors-configuration \
  '{"CORSRules":[{"AllowedHeaders":["*"],"AllowedMethods":["GET","POST","PUT","DELETE"],"AllowedOrigins":["*"],"MaxAgeSeconds":3600}]}'

  5. Enable S3 delivery to EventBridge. This is a one-time operation for each bucket, regardless of how many Plant Tracer stacks share it. The Makefile helper preserves any existing S3 topic, queue, and Lambda notification configuration:

    PLANTTRACER_S3_BUCKET="${PT_BUCKET}" \
  CONFIRM_BUCKET="${PT_BUCKET}" \
  make s3-eventbridge-enable

  6. Verify the bucket configuration:

    aws s3api head-bucket --bucket "${PT_BUCKET}"
aws s3api get-public-access-block --bucket "${PT_BUCKET}"
aws s3api get-bucket-ownership-controls --bucket "${PT_BUCKET}"
aws s3api get-bucket-encryption --bucket "${PT_BUCKET}"
aws s3api get-bucket-cors --bucket "${PT_BUCKET}"
PLANTTRACER_S3_BUCKET="${PT_BUCKET}" make s3-eventbridge-status

  7. Supply the bucket name, without an s3:// prefix, as ImageBucketName when running STACK=<name> make sam-deploy-guided (or using the equivalent STACK_NAME=<name> alias). The SAM template then grants that stack’s Lambda execution roles access to the named bucket and creates an EventBridge rule restricted to uploads/<stack-name>/. No bucket policy is required for this same-account setup.

Do not add a bucket-wide expiration rule: objects under movies/ are the durable archive and must outlive application stacks. S3 Versioning is not required and is disabled by default. If it is enabled as an operational choice, remember that application deletes create delete markers and do not immediately reclaim storage. Cross-account buckets require additional bucket and EventBridge policies and are outside this procedure.

Current Object Layout

PLANTTRACER_STACK_NAME is the deployment identifier used in current object keys. Application code must use the templates in src/app/constants.py and the formatting helpers in src/app/s3_presigned.py rather than reconstruct paths from this page.

Current keys are namespaced by deployment. Legacy un-namespaced keys remain readable through the complete S3 URNs stored in DynamoDB.

The resulting objects are:

Artifact

Current key

DynamoDB field

Lifetime

Upload staging

uploads/{deployment_id}/{course_id}/{movie_id}.mov

upload_staging_urn

Temporary; removed after a verified server-side copy

Original movie

movies/{deployment_id}/{course_id}/{movie_id}.mov

movie_data_urn

Durable archive

Traced movie

movies/{deployment_id}/{course_id}/{movie_id}_traced.mov

movie_traced_urn

Derived and regenerable

Analysis-frame ZIP

movies/{deployment_id}/{course_id}/{movie_id}_zipfile.mov

movie_zipfile_urn

Derived and regenerable

Persisted JPEG frame

movies/{deployment_id}/{course_id}/{movie_id}/{frame_number:06d}.jpg

frame_urn on a movie_frames row

Optional and regenerable

The ZIP key retains the original movie extension for compatibility even though the object contains ZIP bytes. Derived-artifact helpers preserve the original bucket, path, and extension, so legacy un-namespaced URNs remain readable and retraceable. Course migration supports both legacy and deployment-scoped keys.

Upload Processing

POST /api/new-movie creates a movie row with status="uploading", created_at, and upload_bytes_expected. It records both the temporary upload_staging_urn and durable movie_data_urn and returns a presigned POST for the staging object. The signed policy requires the exact declared byte count.

For deployed stacks:

  1. The browser uploads to uploads/{deployment_id}/....

  2. S3 sends an Object Created event to EventBridge.

  3. Each stack’s EventBridge rule matches the shared bucket and its exact uploads/{deployment_id}/ prefix. Other stacks do not match the key.

  4. lambda-resize validates the Pydantic event envelope, bucket, deployment, key identifiers, DynamoDB row, and expected byte count.

  5. lambda-resize copies the staging object to its durable movies/ key while preserving metadata, verifies the copy, conditionally records uploaded_at and total_bytes, and deletes the staging object.

  6. The post-upload job records width, height, encoded fps, frame count, and resize lifecycle timestamps. The browser polls movie metadata before requesting the first frame.

EventBridge and SQS delivery are at least once. Conditional movie updates and verified durable-object checks make duplicate upload events safe. EventBridge retries failed invocations and sends exhausted events to the stack’s upload dead-letter queue.

POST /resize-api/v1/process-upload remains an authenticated local- development adapter for MinIO, which does not supply the deployed AWS EventBridge path. It invokes the same completion service; production browsers do not use it.

Shared Bucket EventBridge Configuration

S3 EventBridge delivery is enabled once on the shared bucket. This is bucket configuration, not stack-owned infrastructure, so deleting a stack does not disable it. Each stack owns only its prefix-filtered EventBridge rule.

Inspect the current notification configuration:

PLANTTRACER_S3_BUCKET=planttracer-movies make s3-eventbridge-status

Enable EventBridge after verifying the exact bucket:

PLANTTRACER_S3_BUCKET=planttracer-movies \
  CONFIRM_BUCKET=planttracer-movies \
  make s3-eventbridge-enable

Updating an S3 notification configuration replaces the complete configuration. etc/s3_upload_trigger.py therefore reads and preserves existing topic, queue, and Lambda destinations, adds EventBridgeConfiguration, then reads the bucket again to verify the change.

Metadata Stored with Original Movies

The presigned POST fixes Content-Type to video/mp4 and signs these S3 object metadata fields:

  • sha256

  • research-use

  • credit-by-name

  • attribution-name

  • fpm

The server-side staging-to-durable copy preserves this metadata. Research-use, attribution, and capture-interval metadata are also stored in DynamoDB and, where supported, in MP4 metadata. See Movie attribution and research metadata.

Access, CORS, and Local Development

Browser uploads and downloads use time-limited presigned S3 requests. Bucket CORS must allow the application origin to issue the required methods and headers. lambda-web and lambda-resize receive the bucket name through PLANTTRACER_S3_BUCKET and have the read/write permissions required for their operations.

Local development and integration tests use MinIO and DynamoDB Local, not mocked clients. AWS_ENDPOINT_URL_S3 selects MinIO and the default local deployment identifier is local. Use Makefile targets to start services, create the bucket, and run tests.

Operational and Deployment Artifacts

s3://planttracer-artifacts is manually managed project infrastructure for temporary operational output. Objects under artifacts/ expire; do not put movie data, .ptb backups, or releases there.

SAM uses its own managed deployment bucket for packaged Lambda artifacts. The application never addresses those keys at runtime.

Implementation Sources

  • src/app/constants.py – canonical templates and deployment identifier

  • src/app/s3_presigned.py – key helpers, URNs, presigning, and CORS

  • src/app/flask_api.py – staging and durable upload allocation

  • lambda-resize/src/resize_app/upload_event.py – EventBridge validation

  • lambda-resize/src/resize_app/movie_glue.py – upload completion and post-upload processing

  • src/app/odb_movie_data.py – object and persisted-frame operations

  • src/dbbackup.py – backup/restore and course migration

  • etc/s3_upload_trigger.py – shared-bucket EventBridge enablement

  • template.yaml – per-stack EventBridge rule, retry, and dead-letter queue