IT Cloud. Eugeny Shtoltc

will only respond to metrics on the same server from different sources. In order for us to collect metrics from different nodes and see the aggregated result, we need to put an agent collecting metrics on each node:

      essh @ kubernetes-master: ~ $ docker run -d \

      –v "/ proc: / host / proc" \

      –v "/ sys: / host / sys" \

      –v "/: / rootfs" \

      –-net = "host" \

      –-name = explorer \

      quay.io/prometheus/node-exporter:v0.13.0 \

      –collector.procfs / host / proc \

      –collector.sysfs / host / sys \

      –collector.filesystem.ignored-mount-points "^ / (sys | proc | dev | host | etc) ($ | /)"

      1faf800c878447e6110f26aa3c61718f5e7276f93023ab4ed5bc1e782bf39d56

      and register to listen to the address of the node, but for now everything is local, localhost: 9100. Now let's tell Prometheus to listen to agent and docker:

      essh @ kubernetes-master: ~ $ mkdir prometheus && cd $ _

      essh @ kubernetes-master: ~ / prometheus $ cat << EOF> ./prometheus.yml

      global:

      scrape_interval: 1s

      evaluation_interval: 1s

      scrape_configs:

      – job_name: 'prometheus'

      static_configs:

      – targets: ['127.0.0.1:9090', '127.0.0.1:9100', '127.0.0.1:9323']

      labels:

      group: 'prometheus'

      EOF

      essh @ kubernetes-master: ~ / prometheus $ docker rm -f prometheus

      prometheus

      essh @ kubernetes-master: ~ / prometheus $ docker run \

      –d \

      –-net = host \

      –-restart always \

      –-name prometheus \

      –v $ (pwd) /prometheus.yml:/etc/prometheus/prometheus.yml

      prom / prometheus

      7dd991397d43597ded6be388f73583386dab3d527f5278b7e16403e7ea633eef

      essh @ kubernetes-master: ~ / prometheus $ docker ps \

      –f name = prometheus

      CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

      7dd991397d43 prom / prometheus "/ bin / prometheus –c…" 53 seconds ago Up 53 seconds prometheus

      1702 host metrics are now available:

      essh @ kubernetes-master: ~ / prometheus $ curl http: // localhost: 9100 / metrics | grep -v '#' | wc -l

      1702

      out of all the variety, it is difficult to find the ones you need for everyday tasks, for example, the amount of memory used by node_memory_Active. There are metrics aggregators for this:

      http: // localhost: 9090 / consoles / node.html

      http: // localhost: 9090 / consoles / node-cpu.html

      But it's better to use Grafana. Let's install it too, you can see an example:

      essh @ kubernetes-master: ~ / prometheus $ docker run \

      –d \

      –-name = grafana \

      –-net = host

      grafana / grafana

      Unable to find image 'grafana / grafana: latest' locally

      latest: Pulling from grafana / grafana

      9d48c3bd43c5: Already exists

      df58635243b1: Pull complete

      09b2e1de003c: Pull complete

      f21b6d64aaf0: Pull complete

      719d3f6b4656: Pull complete

      d18fca935678: Pull complete

      7c7f1ccbce63: Pull complete

      Digest: sha256: a10521576058f40427306fcb5be48138c77ea7c55ede24327381211e653f478a

      Status: Downloaded newer image for grafana / grafana: latest

      6f9ca05c7efb2f5cd8437ddcb4c708515707dbed12eaa417c2dca111d7cb17dc

      essh @ kubernetes-master: ~ / prometheus $ firefox localhost: 3000

      We will enter the login admin and the password admin, after which we will be prompted to change the password. Next, you need to perform the subsequent configuration.

      In Grafana, the initial login is admin and this password. First, we are prompted to select a source – select Prometheus, enter localhost: 9090, select the connection not as to the server, but as to the browser (that is, over the network) and select that we have basic authentication – that's all – click Save and Test and Prometheus is connected.

      It is clear that it is not worth giving out a password and login from admin rights to everyone. To do this, you will need to create users or integrate them with an external user database such as Microsoft Active Directory.

      I will select in the Dashboard tab and activate all three reconfigured dashboards. From the New Dashboard list in the top menu, select the Prometheus 2.0 Stats dashboard. But, there is no data:

      I click on the "+" menu item and select "Dashboard", it is proposed to create a dashboard. A dashboard can contain several widgets, for example, charts that can be positioned and customized, so click on the add chart button and select its type. On the graph itself, we select edit by choosing a size, click edit, and the most important thing here is the choice of the displayed metric. Choosing Prometheus

      Complete assembly available:

      essh @ kubernetes-master: ~ / prometheus $ wget \

      https://raw.githubusercontent.com/grafana/grafana/master/devenv/docker/ha_test/docker-compose.yaml

      –-2019-10-30 07: 29: 52– https://raw.githubusercontent.com/grafana/grafana/master/devenv/docker/ha_test/docker-compose.yaml

      Resolving raw.githubusercontent.com (raw.githubusercontent.com) … 151.101.112.133

      Connecting to raw.githubusercontent.com (raw.githubusercontent.com) | 151.101.112.133 |: 443 … connected.

      HTTP request sent, awaiting response … 200 OK

      Length: 2996 (2.9K) [text / plain]

      Saving to: 'docker-compose.yaml'

      docker-compose.yaml 100% [=========>] 2.93K –.– KB / s in 0s

      2019-10-30 07:29:52 (23.4 MB / s) – 'docker-compose.yaml' saved [2996/2996]

      Obtaining application metrics

      Up to this point, we have looked at the case where Prometheus polled the standard metric accumulator, getting the standard metrics. Now let's try to create an application and submit our metrics. First, let's take a NodeJS server and write an application for it. To do this, let's create a NodeJS project:

      vagrant @ ubuntu: ~ $ mkdir nodejs && cd $ _

      vagrant @ ubuntu: ~ / nodejs $ npm init

      This utility will walk you through creating a package.json file.

      It only covers the most common items, and tries to guess sensible defaults.

      See `npm help json` for definitive documentation on these fields

      and exactly what they do.

      Use `npm install <pkg> –save` afterwards to install a package and

      save it as a dependency in the package.json file.

      name: (nodejs)

      version: (1.0.0)

      description:

      entry point: (index.js)

      test