Daily Resource For Devs

Introduction In order to be able to search our logs based on a key/value pattern, we need to prepare our application to log and send information in a structured way to our log aggregation tool. In this article I am going to show you how to send structured log to ElasticSearch using Logstash as a data pipeline tool and how to visualize and filter log information using Kibana. According to a definition from the Wikipedia website: Elasticsearch is a search engine based on the Lucene library. It provides a distributed, multitenant-capable full-text search engine with an HTTP web interface and schema-free JSON documents. According to Elasticsearch platform website , Elasticsearch is the heart of the Elastic stack, which centrally stores your data for lightning fast search. The use of Elasticsearch, Kibana, Beats and Logstash as a search platform is commonly known as the ELK stack. Next we are going to start up Elasticsearch, Kibana and Logstash using docker so we can better underst...

Introduction RabbitMQ is a centralized message broker based on the AMQP (Advanced Message Queuing Protocol) protocol, acting as a Middleware between Producers and Consumers of different systems. In a message system, Publishers sends a message to a message broker where messages are consumed some time later by one or more Subscribers. By introducing a message brokeer between systems we are decoupling the sender application from the receiver. In this case the service that is responsible for sending or publishing the message does not need to know about any other service. All it needs to care about is the message and its format. With a message system you send a message to a message broker first and when the consumers or listeners of it become online they can start consuming from the message queue. This means you can keep sending messages without even care if the other application is online or if they had any failures. RabbitMQ Architecture Exchange, queue and bindings are the ...

Introduction In this post we are going to see how we can create a Spring Configuration Server to externalize our Spring Boot application configuration files. In order to do that we need one Spring Boot application running as a configuration server, one Spring Boot application running as a configuration client and one external repo like GitHub to keep our configuration yml files. Config Server Let´s start by going to the Spring Initializr web site to create a Spring Boot project. For this project we just need one dependency, the Config Server from Spring Cloud Config as shown in the image below: This is all you need. You can go ahead and click in generate to download your Spring Boot project. Next, open your application.yml file and add the code below. We just need to add this configuration to let Spring know where to get our yml configuration files. Under repos we can add configurations for all the environments we need. I am just adding a section for my developme...

Introduction In this post we are going to see how we can create a REST API pagination in Spring Boot with Spring HATEOAS and Spring Data MongoDB . For basic queries, we can interact with MongoDB using the MongoRepository interface which is what we are going to use in this tutorial. For more advanced operations like update and aggregations we can use the MongoTemplate class. With Spring applications we start adding the needed dependencies to our pom file if using Maven as our build tool. For this project we are going to use the following dependencies: Spring Web , Spring Data MongoDB and Spring HATEOAS . To quickly create your Spring Boot project with all your dependencies you can go to the Spring Initializr web page. This is how your project should look like: As with any MVC application like Spring there are some minimal layers that we need to create in our application in order to make it accessible like the Controller , Service , Model and Repository layers . For this...

An http interceptor can become handy if you need to log all your requests or add a bearer token to every request when calling a protected resource with an access token in OAuth 2.0 . To create an interceptor you basically need to create an OkHttpClient by calling the OkHttpClient Builder and add an interceptor to it. OkHttpClient okHttpClient = new OkHttpClient.Builder() You can have access to the current request by calling chain.request(). Once you get the request you can then add or build on top of it by adding an additional header to send your Bearer Token. Request auth_request = chain.request() The last step is to return a Response object by calling chain.proceed, passing the new request. return chain.proceed(auth_request); And the final code: OkHttpClient okHttpClient = new OkHttpClient.Builder() .addInterceptor(new Interceptor() { @Override public Response intercept(Chain chain) throws IOException { Request auth_request = cha...