Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
You are deploying a batch processing application to Azure Container Instances (ACI). The application processes multiple files from an Azure Blob Storage container and writes results to another container. Each container instance processes a single file and then exits. The processing logic is written in a Docker image that reads input and output connection strings from environment variables. You need to configure the container group so that it writes the results to the output container durably and efficiently. The environment variables must be provided at runtime but must not be exposed in the ACI configuration. Which approach should you use?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
Mount an Azure File Share volume for the output container and configure the application to write output files to a directory on that share. Store the connection string for the file share in a secure fashion using Key Vault and pass it as an environment variable.
While using Azure File Share is durable, the requirement is to write results back to Blob Storage (output container), not a file share. Also, the application is designed to use Blob Storage SDK, not file system I/O.
B
Best answer
Use a managed identity for the container group, grant the identity access to an Azure Key Vault secret that contains the storage account connection string. The application retrieves the secret at startup using the managed identity and then writes directly to Azure Blob Storage.
This approach uses managed identity to securely access Key Vault, avoiding any credentials in the container configuration. The application then uses the connection string to write to Blob Storage via the SDK, which is efficient and durable.
C
Distractor review
Embed the storage account connection string directly into the Docker image during build time and rely on the container's environment to provide the output blob container name.
Embedding secrets in a Docker image is insecure and makes rotation difficult. It also violates the principle of least privilege.
D
Distractor review
Set the storage account connection string as an environment variable in the ACI container group definition (YAML or ARM template) and have the application use it at runtime.
Setting secrets as environment variables in the ACI configuration exposes them in the deployment artifacts and logs. This is not secure; secrets should be retrieved from a secure store like Key Vault.
Common exam trap
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Technical deep dive
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
Related practice questions
Related AZ-204 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
An application stores customer invoices in Azure Blob Storage. Deleted blobs must be recoverable for 14 days. What should be enabled?
Question 2
You are deploying a containerized application to Azure Container Instances. The application requires a custom domain name and SSL/TLS termination. You need to configure these features. Which resource should you create alongside the container group?
Question 3
A developer needs to run a Kusto query against application request data to identify 95th percentile latency by operation. Where should the query be run? The architecture review board prefers a managed AWS-native control.
Question 4
You are developing a web app that authenticates users via Microsoft Entra ID. The app needs to read the user's profile and send emails on their behalf. You want to minimize user consent prompts. Which OAuth 2.0 grant type should you use?
Question 5
You are developing an Azure Function that processes messages from an Azure Service Bus queue. The function uses a Service Bus queue trigger and runs on a Consumption Plan. The queue receives a high volume of messages in bursts. You need to ensure that the function scales out to handle the load but does not exceed 10 concurrent instances. Which configuration should you apply?
Question 6
You are monitoring an Azure App Service using Application Insights. You notice that the server response time is high for certain requests. You need to drill down to see which external dependencies (like databases or APIs) are causing the delay. Which Application Insights feature should you use?
FAQ
Questions learners often ask
What does this AZ-204 question test?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: Use a managed identity for the container group, grant the identity access to an Azure Key Vault secret that contains the storage account connection string. The application retrieves the secret at startup using the managed identity and then writes directly to Azure Blob Storage. — To provide environment variables securely, use Azure Key Vault with managed identity. ACI supports mounting secrets from Key Vault as environment variables using managed identity. For output storage, the container can use the connection string from environment variable to write directly to Blob Storage. Alternatively, using Azure File Share mount is for persistent file system storage, but the output is already being written to Blob Storage via the SDK. The best approach is to use managed identity and Key Vault for secrets, and then the application writes directly to Azure Storage using those credentials. Option B correctly describes using managed identity to access Key Vault to get the storage connection string, and then writing to Blob Storage via the SDK. Option A suggests mounting a volume which is unnecessary. Option C suggests using a custom container image with hardcoded secrets, insecure. Option D suggests using environment variables directly in the ACI YAML, which exposes them in the configuration. So correct is B.
What should I do if I get this AZ-204 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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