Mastering the Installation: A Comprehensive Guide to Setting Up Docker, Kubernetes, Jenkins, Prometheus, Helm, MongoDB, Kong, and HAproxy

Introduction

In the ever-evolving landscape of software development, the ability to effectively deploy, manage, and scale applications has become paramount. To achieve this, numerous tools have been developed, each catering to a different aspect of the software lifecycle. This guide aims to provide a step-by-step approach to installing Docker, Kubernetes, Jenkins, Prometheus, Helm, MongoDB, Kong, and HAproxy, forming a robust environment for deploying and managing your applications.

Docker: The Cornerstone of Containerization

Docker is an open-source platform that automates the deployment, scaling, and management of applications using containerization. It wraps software in a complete filesystem that contains everything the software needs to run, ensuring that it will always execute the same, regardless of the environment.

Installing Docker on CentOS

1. Update the yum package database with the command sudo yum check-update.
2. Install the necessary packages for Docker's installation with sudo yum install -y yum-utils device-mapper-persistent-data lvm2.
3. Add Docker's stable repository to yum using sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo.
4. Install Docker with sudo yum install docker-ce.
5. Start Docker using sudo systemctl start docker.
6. To ensure Docker starts at boot, use sudo systemctl enable docker.

You can verify Docker's installation by running docker --version. You should see the Docker version in the output.

Kubernetes: Orchestrating Your Containers

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It groups containers into "Pods" for easy management and discovery.

Installing Kubernetes on CentOS

1. First, you'll need to disable SELinux by using sudo setenforce 0 and sudo sed -i --follow-symlinks 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/sysconfig/selinux.
2. Enable the br_netfilter module for network traffic routing sudo modprobe br_netfilter.
3. Enable IP forwarding with these commands sudo echo '1' > /proc/sys/net/bridge/bridge-nf-call-iptables and sudo echo '1' > /proc/sys/net/ipv4/ip_forward.
4. Add Kubernetes' repository to yum by creating the file /etc/yum.repos.d/kubernetes.repo and adding the following:

[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg

5. Install Kubernetes using sudo yum install kubeadm kubelet kubectl.
6. Enable Kubernetes to start at boot with sudo systemctl enable kubelet.

To verify the installation, you can use the command kubectl version.

Jenkins: Automating Your Builds and Deployments

Jenkins is an open-source automation server that enables developers to build, test, and deploy their software. It integrates with a large number of testing and deployment technologies.

Installing Jenkins on CentOS

1. To start, add the Jenkins repository to your system with sudo wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo.
2. Import a key file from Jenkins-CI to enable installation from the package with sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key.
3. Install Jenkins with sudo yum install jenkins.
4. Start the Jenkins server with sudo systemctl start jenkins.
5. To ensure Jenkins starts at boot, use sudo systemctl enable jenkins.

You can verify Jenkins' installation by accessing the Jenkins UI on your browser at http://your_server_ip:8080.

Prometheus: Your Eyes on the System

Prometheus is an open-source systems monitoring and alerting toolkit. It provides powerful data querying capabilities which are key to monitoring the health of your applications.

Installing Prometheus on CentOS

1. First, create a new directory for Prometheus' configuration files with sudo mkdir /etc/prometheus.
2. Create a new Prometheus user with sudo useradd --no-create-home --shell /bin/false prometheus.
3. Give ownership of the new directory to the Prometheus user with sudo chown prometheus:prometheus /etc/prometheus.
4. Download and extract the latest Prometheus release from their GitHub using wget and tar.
5. Move the Prometheus and promtool binaries to the /usr/local/bin directory.
6. Start the Prometheus service using sudo systemctl start prometheus.

You can verify Prometheus' installation by accessing the Prometheus UI on your browser at http://your_server_ip:9090.

Helm: Kubernetes Package Manager

Helm is the package manager for Kubernetes. It simplifies deployment of applications on Kubernetes through the use of Helm charts.

Installing Helm on CentOS

1. Download the latest Helm binary from GitHub with wget https://get.helm.sh/helm-v3.0.0-linux-amd64.tar.gz.
2. Extract the downloaded tar file with tar -zxvf helm-v3.0.0-linux-amd64.tar.gz.
3. Move the helm binary to /usr/local/bin with mv linux-amd64/helm /usr/local/bin/helm.

You can verify the Helm installation by running helm version.

MongoDB: Storing Your Data

MongoDB is a popular NoSQL database that provides high performance, high availability, and easy scalability. It works on the concept of collections and documents.

Installing MongoDB on CentOS

1. Create a /etc/yum.repos.d/mongodb-org.repo file and add the following:

[mongodb-org-4.2]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/4.2/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-4.2.asc

2. Install MongoDB with sudo yum install -y mongodb-org.
3. Start MongoDB with sudo systemctl start mongod.
4. To ensure MongoDB starts at boot, use sudo systemctl enable mongod.

You can verify MongoDB's installation by running mongo --eval 'db.runCommand({ connectionStatus: 1 })'.

Kong: Managing Your APIs

Installing Kong on CentOS

1. First, you need to create a Kong repository configuration file with sudo touch /etc/yum.repos.d/kong.repo and add the following:

2. Install Kong with sudo yum install -y kong.
3. You'll need to configure Kong to use your MongoDB instance. You can do this by editing the kong.conf file and setting the database and pg_host values.
4. Initialize Kong's database with kong migrations bootstrap.
5. Start Kong with kong start.

You can verify Kong's installation by sending a request to http://localhost:8001 and expecting a JSON response.

HAproxy: Load Balancing Your Services

HAproxy is a free, very fast, and reliable solution offering high availability, load balancing, and proxying for TCP and HTTP-based applications.

Installing HAproxy on CentOS

1. Install HAproxy with sudo yum install -y haproxy.
2. To configure HAproxy, you'll need to edit the /etc/haproxy/haproxy.cfg file to match your environment.
3. Start HAproxy with sudo systemctl start haproxy.
4. To ensure HAproxy starts at boot, use sudo systemctl enable haproxy.

You can verify HAproxy's installation by running haproxy -v.

Conclusion

By following the above steps, you should have successfully set up a robust environment for deploying and managing your applications. Each of these tools plays a vital role in different aspects of the software lifecycle, from development and deployment to scaling and monitoring. It's important to understand the functionality of each tool and how they interconnect, as this will allow you to take full advantage of their capabilities and ensure the smooth operation of your applications. Remember, every setup is unique, so feel free to adjust these steps according to the needs of your own environment. Happy deploying!