The object service provides storage for large blobs of data.
This service supports pluggable backends, as defined in the service configuration.
Each backend has its own configuration and specifies a backend type, which corresponds to an implementation in src/backends
.
Each object is assigned a backend when it is created.
The base class for backends, in src/backends/base.js
, is authoritative for the methods and behaviors that a backend must display.
Within this service, "middleware" modules can inspect and modify requests and responses for calls to the download API. The most common use of this support is to redirect simple downloads of public objects to a CDN.
Middleware is defined in src/middleware
and middleware implementations inherit from src/backends/base.js
.
The capabilities of middleware are fairly limited, but can easily be expanded as necessary.
Upload API methods should be idempotent, in case some transient error causes an issue.
That is, automatic client retries of an upload call should not fail if the first call partially completed.
To achieve this, callers pass an uploadId
known only to that caller.
If that ID matches a previously-recorded call to the method, then the call silently succeeds.
Once an object is completely uploaded, its uploadId
is cleared, signalling that the object can be downloaded.
Until this time, download requests for the object are rejected.
No special configuration is required for development.
Run yarn workspace taskcluster-object test
to run the tests.
Some of the tests will be skipped without additional credentials, but it is fine to make a pull request as long as no tests fail.