Tag Archives: Docker

Monitor Docker resource metrics with Grafana, InfluxDB, and Telegraf

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I needed a way to monitor Docker resource usage and metrics (CPU, Memory, Network, Disk). I also wanted historical data, and ideally, pretty graphs that I could navigate and drill into.

Whatever the solution was going to be, it had to be very open and customizable, easy to setup and scale for a production-like environment (stability, size), and ideally cheap/free. But most of all — it had to make sense and really be straight forward.

3 Containers and 10 minutes is all you need

To get this:
docker_metrics01

docker_metrics02
There are 3 components that are started via containers:

Grafana (dashboard/visual metrics and analytics)
InfluxDB (time-series DB)
Telegraf (time-series collector) – 1 per Docker host

The idea is that you first launch Grafana, and then launch InfluxDB. You configure Grafana (via the web) to point to InfluxDB’s IP, and then you setup a Telegraf container on each Docker host that you want to monitor. Telegraf collects all the metrics and feeds them into a central InfluxDB, and Grafana displays them.

Setup Tutorial/Examples

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Docker Swarm Tutorial with Consul (Service Discovery) and Examples

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If you have not used Swarm, skim the non-service-discovery tutorial to get a feel for how it works:
https://blog.vpetkov.net/2015/12/07/docker-swarm-tutorial-and-examples. It’s very easy, and it should give you an idea of how it works within a couple of minutes.

Using Swarm with pre-generated static tokens is useful, but there are many benefits to using a service discovery backend. For example, you can utilize network overlays and have common “bridges” that span multiple hosts (https://docs.docker.com/engine/userguide/networking/get-started-overlay/). It also provides service registration and discovery for the Docker containers launched into the Swarm. Now lets get into how to use it with service discovery – which is what you would use in a scaled out environment/production.

Again, assuming you have a bunch of servers running docker:
vm01 (10.0.0.101), vm02 (10.0.0.102), vm03 (10.0.0.103), vm04 (10.0.0.104)

Normally, you can do “docker ps” on each host for example:
ssh vm01 ‘docker ps’
ssh vm04 ‘docker ps’

If you enable the API for remote bind on each host you can manage them from a central place:
docker -H tcp://vm01:2375 ps
docker -H tcp://vm04:2375 ps
(note: port is optional for default)

But if you want to use all of these docker engines as a cluster, you need Swarm.
Here we will go one step further and use a common service discovery backend (Consul).

Docker Swarm Tutorial with Consul and How-To/Examples

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Plex server on a VPS Docker setup without port forwarding

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[ updated 10-30-2016 | Upgraded Plex to plexmediaserver-1.1.4.2757-24ffd60.x86_64.rpm and CentOS ]

Recently I tried setting up a Plex server in a docker container. The first problem was the 127.0.0.1:32400 bind which required logging in locally or port forwarding. After doing this once, I realized that you could use the Preferences.xml file, but that meant that you couldn’t truly automate this/deploy it elegantly in a docker container. And what if you wanted to run other servers — for friends? I finally figured out how to do this in the most elegant way possible.

First – Grab your Unique Plex Access Token

Login at https://app.plex.tv/web/app with your username and password
Open your javascript console (in Chrome: View -> Developer -> JavaScript Console)
and type:
console.log(window.PLEXWEB.myPlexAccessToken);

Note the token, which will look like this: “PZwoXix8vxhQJyrdqAbY”

At this stage DO NOT click log out of your account until you register the new server. Otherwise your token will regenerate.
Once you register the server, it won’t matter after that if the token changes.

Grab my Docker Image

Check out: https://hub.docker.com/r/ventz/plex/
You can pull it down by doing:

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Docker Swarm Tutorial and Examples

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A bit of background and the “old/normal way”

If you use Docker, you very quickly run into a common question: how do you make Docker work across multiple hosts, datacenters, and different clouds. One of the simplest solutions is Docker Swarm. Docker summarizes it best as “a native clustering for Docker…[which] allows you create and access to a pool of Docker hosts using the full suite of Docker tools.”

One of the biggest benefits to using Docker Swarm is that it provides the standard Docker API, which means that all of the existing Docker management tools (and 3rd party products) just work out of the box as they do with a single host. The only difference is that they now scale transparently over multiple hosts.

After reading up on it HERE and HERE, it was evident that this is a pretty simple service, but it wasn’t 100% clear what went where. After searching around the web, I realized that almost all of the tutorials and examples on Docker Swarm involved either docker-machine or very convoluted examples which did not explain what was happening on which component. With that said, here is a very simple Docker Swarm Tutorial with some practical examples.

Assuming you have a bunch of servers running docker:
vm01 (10.0.0.101), vm02 (10.0.0.102), vm03 (10.0.0.103), vm04 (10.0.0.104)

Continue Reading →Docker Swarm Tutorial and Examples