Issue Description

The Azure Blob Storage configuration correctly injects the connection string, but fails to resolve the container name. Instead of retrieving the expected value from the environment variable (e.g., mdfinfra-ms-container), it prints the literal string $(AZURE_STORAGE_TIME_REGISTRATION_CONTAINER_NAME).

Observed Logs

2025-03-11 19:41:16 [main] INFO  c.s.m.c.c.AzureBlobStorageConfig - SUCCESS: Azure Storage container name loaded: $(AZURE_STORAGE_TIME_REGISTRATION_CONTAINER_NAME)

This indicates that the placeholder $(AZURE_STORAGE_TIME_REGISTRATION_CONTAINER_NAME) is not being replaced with its actual value.

Root Cause Analysis

1. Spring Boot Property Resolution Issue
   • The placeholder ${AZURE_STORAGE_TIME_REGISTRATION_CONTAINER_NAME} is not being resolved correctly.
   • This could be due to the environment variable not being available at runtime or Spring not expanding the variable.
2. Use of Shell-style Variable Notation ($()) Instead of Spring Property Syntax (${})

   • The application configuration (application-dev.properties) uses:

     
     azure.storage.container-name=$(AZURE_STORAGE_TIME_REGISTRATION_CONTAINER_NAME)
     

   • However, in Spring Boot properties files, the correct syntax should be:

     azure.storage.container-name=${AZURE_STORAGE_TIME_REGISTRATION_CONTAINER_NAME}
     
     

   • The $(...) syntax is used in shell scripts, not in property files.

3. Missing Environment Variable in Spring Context

   • If the environment variable is not set at runtime, Spring will not replace the placeholder and will keep it as a raw string.

   • You can check whether the environment variable is set properly by running:

     echo $AZURE_STORAGE_TIME_REGISTRATION_CONTAINER_NAME
     

   • If this command does not output mdfinfra-ms-container, then the environment variable is not correctly set.

**Solution:

As can be seen, this was really the solution:**

• The ${} syntax tells Spring to resolve the value from environment variables or system properties.
• The $(...) syntax is incorrect for Spring and is used for shell variable expansion.

So, was this a troubleshoot case worthy?

Not really, but always good to also document human errors that can occur 😎