Distributed Transactions in Microservices with Spring Boot

When I’m talking about microservices with other people they are often asking me about approach to distributed transactions. My advice is always the same – try to completely avoid distributed transactions in your microservices architecture. It is a very complex process with a lot of moving parts that can fail. That’s why it does not fit to the nature of microservices-based systems.

Testing Spring Boot Integration with Vault and Postgres using Testcontainers Framework

I have already written many articles, where I was using Docker containers for running some third-party solutions integrated with my sample applications. Building integration tests for such applications may not be an easy task without Docker containers. Especially, if our application integrates with databases, message brokers or some other popular tools. If you are planning to build such integration tests you should definitely take a look on Testcontainers (https://www.testcontainers.org/). Testcontainers is a Java library that supports JUnit tests, providing fast and lightweight way for running instances of common databases, Selenium web browsers, or anything else that can run in a Docker container. It provides modules for the most popular relational and NoSQL databases like Postgres, MySQL, Cassandra or Neo4j. It also allows to run popular products like Elasticsearch, Kafka, Nginx or HashiCorp’s Vault. Today I’m going to show you more advanced sample of JUnit tests that use Testcontainers to check out an integration between Spring Boot/Spring Cloud application, Postgres database and Vault. For the purposes of that example we will use the case described in one of my previous articles Secure Spring Cloud Microservices with Vault and Nomad. Let us recall that use case.

Secure Spring Cloud Microservices with Vault and Nomad

One of the significant topics related to microservices security is managing and protecting sensitive data like tokens, passwords or certificates used by your application. As a developer you probably often implement a software that connects with external databases, message brokers or just the other applications. How do you store the credentials used by your application? To be honest, most of the software code I have seen in my life just stored a sensitive data as a plain text in the configuration files. Thanks to that, I could always be able to retrieve the credentials to every database I needed at a given time just by looking at the application source code. Of course, we can always encrypt sensitive data, but if we working with many microservices having separated databases I may not be very comfortable solution.