3.1 Object storage
You can store and serve files at any scale, publicly or privately, on purpose.
Before:02. ComputeUnlocks:04. Networking in the Cloud08. Observability & Reliability
The same thing, three names
One idea, sold under a different brand by each provider. Learn it once and you can read any job advertisement.
- On AWS
- S3
- On Azure
- Blob Storage
- On Google Cloud
- Cloud Storage
Object storage is the cloud's warehouse: buckets of objects addressed by key, effectively unlimited, with storage classes and lifecycle rules deciding what data costs as it ages. This topic opens the storage module because more cloud data lives here than anywhere else. It gives the leak its own item on purpose: a bucket made public by accident is the single most common cloud data exposure, and presigned URLs exist precisely so files can be served without opening the bucket. The common confusion is folders — there are none, only keys with slashes in them.
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Buckets, objects, keys and why there are no real folders
Object storage holds files by name in a flat container, and the folder structure you see is a convention in the naming rather than a real hierarchy. Understanding that explains several otherwise puzzling behaviours.
Storage classes and lifecycle rules
Storage classes trade retrieval speed and cost against each other, and lifecycle rules move objects between them automatically as they age. Setting this up early is one of the largest savings available.
Public access: the single most common cloud data leak
A container accidentally left readable by everyone is the most common way cloud data becomes public. This item is worth reading slowly, because the mistake takes one click and announces itself to nobody afterwards.
Presigned URLs and serving files without exposing the bucket
A time-limited signed link lets one person fetch one file without the container being open to anyone else. It is the standard answer to sharing a file safely.
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