ex_aws_s3_direct_upload v1.0.4 ExAws.S3.DirectUpload View Source

Pre-signed S3 upload helper for client-side multipart POSTs, with support for using AWS Instance Roles, which produce temporary credentials. This approach reduces the number of ENV variables to pass, among other benefits.

See:

Browser-Based Upload using HTTP POST (Using AWS Signature Version 4)

Task 3: Calculate the Signature for AWS Signature Version 4

This module does not require any further configuration other than the default already in place, when using ex_aws or ex_aws_s3. The default configuration is as follows:

  config :ex_aws,
  access_key_id: [{:system, "AWS_ACCESS_KEY_ID"}, :instance_role],
  secret_access_key: [{:system, "AWS_SECRET_ACCESS_KEY"}, :instance_role]

The Authentication Resolver will look for credentials in ENV variables, and fall back to Instance Role.

Link to this section Summary

Functions

%ExAws.S3.DirectUpload{}

The S3DirectUpload struct represents the data necessary to generate an S3 pre-signed upload object

presigned(upload)

Returns a map with url and credentials keys

presigned_json(upload)

Returns a json object with url and credentials properties

Link to this section Functions

%ExAws.S3.DirectUpload{} (struct)

The S3DirectUpload struct represents the data necessary to generate an S3 pre-signed upload object.

The required fields are:

file_name the name of the file being uploaded
mimetype the mimetype of the file being uploaded
path the path where the file will be uploaded in the bucket
bucket the name of the bucket to which to upload the file

Fields that can be over-ridden are:

acl defaults to public-read

presigned(upload)

Returns a map with url and credentials keys.

url - the form action URL
credentials - name/value pairs for hidden input fields

Examples

iex> %ExAws.S3.DirectUpload{file_name: "image.jpg", mimetype: "image/jpeg", path: "path/to/file", bucket: "s3-bucket"}
...> |> ExAws.S3.DirectUpload.presigned
...> |> Map.get(:url)
"https://s3-bucket.s3.us-east-1.amazonaws.com"

iex> %ExAws.S3.DirectUpload{file_name: "image.jpg", mimetype: "image/jpeg", path: "path/to/file", bucket: "s3-bucket"}
...> |> ExAws.S3.DirectUpload.presigned
...> |> Map.get(:credentials) |> Map.get(:"x-amz-credential")
"123abc/20170101/us-east-1/s3/aws4_request"

iex> %ExAws.S3.DirectUpload{file_name: "image.jpg", mimetype: "image/jpeg", path: "path/to/file", bucket: "s3-bucket"}
...> |> ExAws.S3.DirectUpload.presigned
...> |> Map.get(:credentials) |> Map.get(:key)
"path/to/file/image.jpg"

presigned_json(upload)

Returns a json object with url and credentials properties.

url - the form action URL
credentials - name/value pairs for hidden input fields