Blob containers and access levels in Azure - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Blob Container Public Access Levels

Which of the following describes the Private access level for an Azure Blob container?

A Only the container owner can read blobs and container metadata; no anonymous access is allowed.

B Anyone can read blobs within the container, but container metadata is private.

C Anyone can read both blobs and container metadata without authentication.

D Anyone can write blobs to the container without authentication.

💡 Hint

Think about who can access the blobs when the container is set to private.

Private access means only authenticated users with proper permissions can read blobs and metadata. No anonymous access is allowed.

❓ service_behavior

intermediate

Effect of Blob Container Access Level on Anonymous Read

You set an Azure Blob container's access level to Blob. What is the expected behavior for anonymous users?

A Anonymous users can write blobs but cannot read any blobs or metadata.

B Anonymous users can list blobs and read container metadata but cannot read blob content.

C Anonymous users can read blobs but cannot list blobs or read container metadata.

D Anonymous users cannot access blobs or container metadata at all.

💡 Hint

Consider what 'Blob' access level allows compared to 'Container' and 'Private'.

The 'Blob' access level allows anonymous read access to blobs only, but not to container metadata or blob listings.

❓ Configuration

advanced

Configuring a Blob Container for Public Read Access

You want to configure an Azure Blob container so that anyone can list blobs and read blob content without authentication. Which access level should you set?

A Private

B Container

C Blob

D Off

💡 Hint

Think about which access level allows listing blobs publicly.

The 'Container' access level allows anonymous users to list blobs and read blob content and container metadata.

❓ security

advanced

Security Risks of Setting Blob Container Access Level to Container

What is a potential security risk when setting an Azure Blob container's access level to Container?

A Anyone can list and read all blobs and container metadata without authentication.

B Anyone can delete blobs without authentication.

C Only authenticated users can read blobs, but metadata is public.

D Anyone can upload malicious blobs without authentication.

💡 Hint

Consider what public access means for data visibility.

Setting access to 'Container' exposes all blobs and metadata to anyone, which can lead to data leakage.

❓ Architecture

expert

Designing Blob Storage Access for a Public Website with Private Data

You are designing Azure Blob storage for a website that serves public images but also stores private user documents. How should you configure the containers?

A Set both containers to 'Private' and use anonymous access for images.

B Set one container to 'Blob' access level for images and another to 'Blob' for user documents.

C Set both containers to 'Container' access level and rely on SAS tokens for private documents.

D Set one container to 'Container' access level for images and another container to 'Private' for user documents.

💡 Hint

Think about separating public and private data with different access levels.

Using separate containers with appropriate access levels ensures public images are accessible while private documents remain secure.

Practice

1. What does setting a blob container's access level to private mean?

easy

A. Anyone can read blobs but cannot list them.

B. Anyone can read and list blobs in the container.

C. Only the owner can read or list blobs in the container.

D. The container is deleted automatically after 24 hours.

Solution

1. Step 1: Understand the meaning of private access level

   Private means no public access; only authorized users can access blobs.

2. Step 2: Compare with other access levels

   Unlike blob or container levels, private restricts all public read or list operations.

3. Final Answer:

   Only the owner can read or list blobs in the container. -> Option C

4. Quick Check:

   Private access = owner-only access [OK]

Hint: Private means no public read or list access [OK]

Common Mistakes:

• Confusing private with blob-level public read
• Thinking private allows public listing
• Assuming private deletes container automatically

2. Which of the following is the correct way to set a blob container's access level to allow public read of blobs but not listing containers using Azure CLI?

easy

A. az storage container set-permission --name mycontainer --public-access container

B. az storage container set-permission --name mycontainer --public-access blob

C. az storage container set-permission --name mycontainer --public-access private

D. az storage container set-permission --name mycontainer --public-access none

Solution

1. Step 1: Identify the access level for public read of blobs only

   The blob access level allows public read of blobs but not container listing.

2. Step 2: Match the Azure CLI command syntax

   The command uses --public-access blob to set this level correctly.

3. Final Answer:

   az storage container set-permission --name mycontainer --public-access blob -> Option B

4. Quick Check:

   Blob access = public read blobs only [OK]

Hint: Use '--public-access blob' for public blob read only [OK]

Common Mistakes:

• Using 'container' instead of 'blob' for public read
• Using 'private' which disables public access
• Using 'none' which is invalid in Azure CLI

3. Given a container with access level set to container, what will happen if an anonymous user tries to list blobs in the container?

medium

A. The user can list blobs and read blob content anonymously.

B. The container will block all anonymous requests.

C. The user can read blobs but cannot list them.

D. The user will receive an error because listing is not allowed.

Solution

1. Step 1: Understand the container access level

   This level allows anonymous users to list blobs and read blob content.

2. Step 2: Analyze anonymous user permissions

   Anonymous users can list blobs and read blobs but cannot modify or delete.

3. Final Answer:

   The user can list blobs and read blob content anonymously. -> Option A

4. Quick Check:

   Container access = public list and read [OK]

Hint: Container access allows public list and read [OK]

Common Mistakes:

• Confusing container with blob access level
• Assuming anonymous users cannot list blobs
• Thinking container blocks anonymous requests

4. You set a blob container's access level to blob but anonymous users report they cannot list blobs. What is the most likely cause?

medium

A. The storage account is disabled.

B. The container name is incorrect in the URL.

C. The blobs are encrypted and cannot be read.

D. Blob access level does not allow listing blobs publicly.

Solution

1. Step 1: Recall what blob access level permits

   Blob access allows anonymous read of blobs but not listing blobs in the container.

2. Step 2: Evaluate other options for likelihood

   Incorrect container name or disabled account would cause different errors; encryption does not block listing.

3. Final Answer:

   Blob access level does not allow listing blobs publicly. -> Option D

4. Quick Check:

   Blob access = no public listing [OK]

Hint: Blob access disables public listing, only allows read [OK]

Common Mistakes:

• Expecting blob access to allow listing
• Blaming encryption for listing issues
• Ignoring container name correctness

5. You want to share some files publicly but prevent users from listing all files in your Azure blob container. Which access level should you choose and why?

hard

A. Set access level to blob to allow public read of blobs but block listing.

B. Set access level to private to block all public access.

C. Set access level to container to allow public read and listing.

D. Set access level to public to allow full access.

Solution

1. Step 1: Identify the requirement for public read without listing

   You want users to read files but not see all file names.

2. Step 2: Match access level to requirement

   blob access allows public read of blobs but prevents listing container contents.

3. Step 3: Exclude other options

   private blocks public read; container allows listing; public is not a valid access level.

4. Final Answer:

   Set access level to blob to allow public read of blobs but block listing. -> Option A

5. Quick Check:

   Blob access = public read, no listing [OK]

Hint: Use blob access to share files without listing [OK]

Common Mistakes:

• Choosing container access which allows listing
• Using private which blocks public read
• Thinking 'public' is a valid access level