Better application deployment. Monitoring your application with Graphite/Grafana

Intro In the previous part I explained how to use Terraform, Ansible, Docker and Spring Boot to deploy applications in the cloud. Today I’d like to introduce something, which will work as a monitoring tool, inside our infrastructure. If you follow my blog posts, you should remember a post about Spring and Dropwizard Module - there I explained how you could get a meaningful metrics from your app. But wait, why you should even do monitoring and can you skip this part? Well, when I first came to the project, when a wide variety of metrics was present in each of the microservices in the ecosystem, I had a feeling that this is something which I won’t use in the future. I was right, and I didn’t use them…until my first incident, on which I had to understand what’s going on. I start looking for some explanations, and found that our service is sending many 500 statuses. Then I found out, that one dependant service, which we use to get some part of response, is broken, and problem is not on our side. From that period I introduced a couple of custom dashboards, and during incidents/crashes, I can answer most...

watch - useful unix command I've never heard of

I use ImageMagick for resizing images in one of the projects, and I needed a command to monitor folder changes in a temporary folder. So I found watch: watch -d -n 0.3 'ls -l | grep ivanursul' This command check every 0.3 seconds for current folder, and find all files, created by user ivanursul Links Linux Watch

Better application deployment with DigitalOcean, Terraform, Ansible and Docker. Connecting Terraform with Ansible.

Just creating instances in the cloud is an intermediate result. Yes, you know don’t need to create them manually, but it’s not a target. We need to configure them somehow, deploy logic, restart, etc. That’s why this article is about describing how to work with Terraform instances - using Ansible tool. What do you need to do before starting Create terraform instance - here’s how Install ansible: brew install ansible How Ansible knows about Terraform Let’s take a close look how Ansible will recognize terraform instances. Normally, this is being done by specifying instances in inventory file - the idea is to have a file, which contains all the IP addresses, organized by the group. Let’s say, you have one load balancer and three instances of an application, then you need to have following inventory file: [lb] [app] Because we are creating instances on the fly, we don’t have a predefined set of IP addresses, which we’re going to use. That’s why we should use dynamic inventory. As we’re using Terraform, we need some tool, which knows how to read instances from terraform.tfstate file and represent them to ansible. Personally, I found it useful to use...

Better application deployment with DigitalOcean, Terraform, Ansible and Docker. DNS Records

As we are creating our instances on the fly, using Terraform declarative scripts, we can also need to create dns domains and records. Let’s say, you have two environments: dev and prod, and you you want to have your backend application stored under and Luckily, terraform allows to do such things Required steps Digitalocean account Ready and bought domain somewhere Already defined terraform instances. See article from previous part. Digital Ocean Domain Add additional declaration to your terraform file: resource "digitalocean_domain" "default" { name = "" ip_address = "${}" } DigitalOcean Record If you want your app to be accessible through, without wwwm you should add this lines: resource "digitalocean_record" "CNAME-www" { domain = "${}" type = "CNAME" name = "www" value = "@" } Final Check You should see your domain name in the list of networking domains here - On the next part we will see how to start working with cloud instances using ansible, and how to connect ansible with terraform.

Better application deployment with DigitalOcean, Terraform, Ansible and Docker. Creating basic terraform instances

Argumentation It’s not a rare examples, when people need to deploy their applications somewhere in the cloud, without having mature infrastructure, and just for testing purpose. Let’s say, you’re writing a backend part for mobile application, and your android developer needs to have backend right and now. Your actions ? Of course, create EC2/Droplet instance, scp all binaries, connect via ssh, run them. You can even write some bash script, which will do all the work. And what should you do, if some day you will decide to go live ? The same thing, you will order some instances in your favorite cloud, configure load balancer, add 1-5 instances and start running your application. But how to scale ? What, if you will decide to add couple servers, and balance them ? By the time you will need to do that, you will be the author of many scripts, which potentially have bugs. You should have something better in your arsenal. I spend couple of weeks to find an instrument, which will fit my needs, and want to share it here, in my blog. It’s not claims to be the best solution, I’m sure, there’s plenty of them, but by...