What’s the story of Docker Compose under Docker 1.12.1 “Swarm Mode”?

What’s the story of Docker compose in 1.12.1 Swarm Mode? How does it integrates with the new APIs – service, node and swarm? How compose will handle containers or services in swarm mode?Is the newer docker compose still limited to spawning individual containers and Docker engine takes care of just scheduling all the jobs/tasks in a single host? What is all about Docker Stack & Distributed Application Bundle? – Let us spend some time in understanding what is the state of Docker compose in terms of newer Docker 1.12.1 Swarm Mode. Docker Compose is a “tool for defining and running...

Running Prometheus Docker container for monitoring Microservices on Raspberry Pi

In the previous post, we talked about running Nagios container on Raspberry Pi for the first time.Nagios is a free and open source monitoring and alerting service which basically collects the statistics of your server using agents like nrpe, check_mk or using SNMP and sends the alert if the metric value is above the predefined threshold. It is a great tool for monitoring the nodes or monolithic application but with the advent of the ‘microservices’ architecture and Docker, monitoring the small piece of services running across the cluster becomes very important.With that also grows the need to monitor these services...

Turn Your Raspberry Pi into Out-of-band Monitoring Device using Docker

Why should I deploy Docker to IoT devices? What are the use cases of running containers inside the IoT device like Raspberry Pi? Is Docker on IoT devices just for hobbyists? – To answer all these burning queries, I just thought of sharing one of the most interesting use case inside the datacentre lab which will surely attract infinite number of possibilities and implementation with Docker containers. Imagine a small credit card size server sitting just below your ToR (Top of the Rack) switch, consuming very low power ( similar to your mobile device), not bound by wired Ethernet( Wi-Fi...

Docker 1.12.1 Swarm Mode & Persistent Storage with DellEMC RexRay

“Does Docker Engine 1.12 has storage discovery similar to Service Discovery and Orchestration Feature? What is the Volume/Persistent Storage story in 1.12 Swarm Mode? Which will be the best solution for my DB persistence? ” – are few common questions which I faced in almost every online meetup, blogs and Docker webinar. Docker 1.12 release was totally focused on Orchestration feature but there has been subtle changes in regards to volumes, volume drivers and storage. Under this blog post, I will be answering the following queries: What’s new in Docker 1.12 Persistent Storage? How does Persistent storage work in case...

Building the first CentOS 7.2 ARM docker image on Raspberry Pi 3

In the previous post, I showed how to get Docker 1.12.1 up and running on Raspberry Pi3 in just 5 minutes. Under 1.12.1 release, Docker Inc. provided a FIRST ARM debian package which can be installed using a single curl command. It works great and there has been numerous Ubuntu, Alpine and Debian based ARM Docker images been built and pushed out to Dockerhub. If you are CentOS/Red Hat user, you might be interested in building CentOS based ARM images on top of Raspberry Pi. As of today, there is NO CentOS based Docker image available for ARM architecture under...

What’s new in Docker 1.12 Scheduling? – Part-I

In our previous posts, we spent considerable amount of time deep-diving into Swarm Mode which is in-built orchestration engine in Docker 1.12 release. The Swarm Mode orchestration engine comprises of desired state reconciliation, replicated and global services, configuration updates in the form of parallelism/delay and restart policies to name a few. Docker Engine 1.12 is not just about the multi-host and multi-container orchestration but there are numerous improvements in terms of Scheduling, Cluster management and Security. Under this post, I am going to talk about scheduling(primarily Engine & Swarm Labels) aspect in terms of new service API introduced under 1.12...

Docker 1.12.1 on Raspberry Pi 3 in 5 minutes

Docker 1.12.1 Final Release got announced last Friday. This update release holds solid number of bug fixes and feature improvements targeted to make Swarm Mode orchestration more stable and consistent. There has been critical bug fixes around node management, service discovery,  ingress load-balancing and much more. But the BIG news comes for “Raspberry Pi” enthusiasts. With 1.12.1, a FIRST ARM debian package has been officially made available.In case you are wondering what it actually means? – If you have Raspberry Pi box and microSD card loaded with Raspbian OS inserted into Pi box, all you need is to power-on your...

What’s new in Docker 1.12.0 Load-Balancing feature?

In the previous blog post, we deep-dived into Service Discovery aspects of Docker. A service is now a first class citizen in Docker 1.12.0 which allows replication, update of images and dynamic load-balancing. With Docker 1.12, services can be exposed on ports on all Swarm nodes and load balanced internally by Docker using either a virtual IP(VIP) based or DNS round robin(RR) based Load-Balancing method or both. In case you are very new to Load-balancing concept, the load balancer assigns workload to a set of networked computer servers or components in such a manner that the computing resources are used in...

Demonstrating Docker 1.12 Service Discovery with Docker Compose

Docker 1.12 is GA now. Thanks to Docker Inc. core Team and community support for releasing it on time as promised during DockerCon 2016.In my earlier post, I briefed around Service Discovery concept and how does it work in terms of  Swarm Mode. As we are well aware, Swarm Mode is an optional mode which can be ON and OFF based on your choice and requirement. Under this blog post, I am going to demonstrate service discovery while playing around with docker-compose. I have a Ubuntu 16.04 machine upgraded with Docker 1.12 GA version. I have docker-compose 1.8.0 running on the...

Demystifying Service Discovery under Docker Engine 1.12.0

Prior to Docker 1.12 release, setting up Swarm cluster needed some sort of service discovery backend. There are multiple discovery backends available like hosted discovery service, using a static file describing the cluster, etcd, consul, zookeeper or using static list of IP address. Thanks to Docker 1.12 Swarm Mode, we don’t have to depend upon these external tools and complex configurations. Docker Engine 1.12 runs it’s own internal DNS service to route services by name.Swarm manager nodes assign each service in the swarm a unique DNS name and load balances running containers. You can query every container running in the swarm through...