Introduction To Devops

What is DevOps?

DevOps is a set of practices that combines software development (Dev) and IT operations (Ops). It aims to shorten the systems development life cycle and provide continuous delivery with high software quality. DevOps is complementary to Agile software development; several DevOps aspects came from Agile methodology.

Key Principles of DevOps

DevOps relies on the following principles:

Continuous Integration
Continuous Delivery
Microservices
Infrastructure as Code
Monitoring and Logging
Communication and Collaboration

Tools and Technologies in DevOps

Various tools are used in DevOps to facilitate integration, delivery, and monitoring:

Examples of DevOps tools:

Git for version control
Jenkins for continuous integration
Docker for containerization
Kubernetes for container orchestration
Prometheus for monitoring
Elasticsearch for logging and searching

Elasticsearch in DevOps

Elasticsearch is a search engine based on the Lucene library. It provides a distributed, multi-tenant capable full-text search engine with an HTTP web interface and schema-free JSON documents. In the context of DevOps, Elasticsearch is commonly used for log and event data analysis.

Setting Up Elasticsearch

To get started with Elasticsearch, follow these steps:

Download and install Elasticsearch:

wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.10.1-linux-x86_64.tar.gz

tar -xvf elasticsearch-7.10.1-linux-x86_64.tar.gz

cd elasticsearch-7.10.1

./bin/elasticsearch

Once Elasticsearch is running, you can interact with it using HTTP requests. For example, to check the cluster health:

curl -X GET "localhost:9200/_cluster/health?pretty"

{ "cluster_name" : "elasticsearch", "status" : "yellow", "timed_out" : false, "number_of_nodes" : 1, "number_of_data_nodes" : 1, "active_primary_shards" : 1, "active_shards" : 1, "relocating_shards" : 0, "initializing_shards" : 0, "unassigned_shards" : 1, "delayed_unassigned_shards" : 0, "number_of_pending_tasks" : 0, "number_of_in_flight_fetch" : 0, "task_max_waiting_in_queue_millis" : 0, "active_shards_percent_as_number" : 50.0 }

Continuous Integration and Continuous Delivery (CI/CD)

CI/CD is a method to frequently deliver apps to customers by introducing automation into the stages of app development. The main concepts attributed to CI/CD are continuous integration, continuous delivery, and continuous deployment.

Continuous Integration

Continuous Integration is a development practice where developers integrate code into a shared repository frequently, preferably several times a day. Each integration can then be verified by an automated build and automated tests.

Continuous Delivery

Continuous Delivery is a software development practice where code changes are automatically prepared for a release to production. It expands upon continuous integration by deploying all code changes to a testing environment and/or a production environment after the build stage.

Infrastructure as Code (IaC)

Infrastructure as Code (IaC) is the process of managing and provisioning computing infrastructure through machine-readable definition files, rather than physical hardware configuration or interactive configuration tools.

Benefits of IaC

Speed and Efficiency
Consistency
Reduced Costs

Monitoring and Logging

Monitoring and logging are crucial components in the DevOps lifecycle. They ensure that the applications and infrastructure are running smoothly and help in identifying issues before they affect the end users.

Monitoring

Monitoring involves observing the performance of the applications and infrastructure. Tools like Prometheus and Grafana are commonly used for this purpose.

Logging

Logging involves recording the application and infrastructure events. Elasticsearch, Logstash, and Kibana (the ELK stack) are popular tools used for logging in the DevOps ecosystem.

Communication and Collaboration

Effective communication and collaboration are essential for the success of DevOps practices. Teams need to work together closely, share knowledge, and automate as many processes as possible to achieve continuous delivery and integration.