vpa-exporter

Vertical pod autoscaler (VPA) frees up users from having to update the resource requests for containers in the pods. It sets the requests based on usage. This enables proper scheduling by ensuring that appropriate resource amount is available for each pod.

A VerticalPodAutoscaler resource allows to specify which pods should be vertically autoscaled as well as if/how the resource recommendations are applied. The resource requests that are updated in the containers of the pod are computed by the VPA based on historical resource usage. The resource suggestions are available in the status of the VerticalPodAutoscaler resource.

vpa-exporter exposes the /metrics endpoint which can be used by Prometheus to scrape VPA metadata information and suggestions.

Table of Contents

• Prerequisites
• Build
• Dependency management
  • Updating dependencies
• Usage

Prerequisites

Although the following installation instructions are for Mac OS X, similar alternate commands could be found for any Linux distribution

Installing Golang environment

Install the latest version of Golang (at least v1.9.4 is required). For Mac OS, you could use Homebrew:

brew install golang

For other OS, please check Go installation documentation.

Make sure to set your $GOPATH environment variable properly (conventionally, it points to $HOME/go).

For your convenience, you can add the bin directory of the $GOPATH to your $PATH: PATH=$PATH:$GOPATH/bin, but it is not necessarily required.

We use Dep for managing golang package dependencies. Please install it on Mac OS via

brew install dep

On other operating systems, please check the Dep installation documentation and the Dep releases page. After downloading the appropriate release in your $GOPATH/bin folder, you need to make it executable via chmod +x <dep-release> and rename it to dep via mv dep-<release> dep.

Golint

In order to perform linting on the Go source code, please install Golint:

go get -u github.com/golang/lint/golint

Installing git

We use git as VCS which you would need to install.

On Mac OS run

brew install git

Installing Docker (Optional)

In case you want to build Docker images, you have to install Docker itself. We recommend using Docker for Mac OS X which can be downloaded from here.

Build

First, you need to create a target folder structure before cloning and building vpa-exporter.

mkdir -p ~/go/src/github.com/gardener
cd ~/go/src/github.com/gardener
git clone https://github.com/gardener/vpa-exporter.git
cd vpa-exporter

To build the binary in your local machine environment, use make target build-local.

make build-local

This will build the binary vpa-exporter under the bin directory.

Next you can make it available to use as shell command by moving the executable to /usr/local/bin.

Dependency management

We use Dep to manage golang dependencies.. In order to add a new package dependency to the project, you can perform dep ensure -add <PACKAGE> or edit the Gopkg.toml file and append the package along with the version you want to use as a new [[constraint]].

Updating dependencies

The Makefile contains a rule called revendor which performs a dep ensure -update and a dep prune command. This updates all the dependencies to its latest versions (respecting the constraints specified in the Gopkg.toml file). The command also installs the packages which do not already exist in the vendor folder but are specified in the Gopkg.toml (in case you have added new ones).

make revendor

The dependencies are installed into the vendor folder which should be added to the VCS.

⚠️ Make sure you test the code after you have updated the dependencies!

Usage

Use the help option of the vpa-exporter command to show usage details.

vpa-exporter --help
Usage of vpa-exporter:
  -kubeconfig string
    	Path to a kubeconfig. Only required if out-of-cluster.
  -master string
    	The address of the Kubernetes API server. Overrides any value in kubeconfig. Only required if out-of-cluster.