Do-Agent

General

The do-agent extracts system metrics from DigitalOcean Droplets and transmits them to the DigitalOcean monitoring service. When the agent is initiated on a Droplet it will automatically configure itself with the appropriate settings.

Flags

Flag	Option	Description
-log_syslog	bool	Log to syslog.
-log_level	string	Sets the log level. [ INFO, ERROR, DEBUG ] Default=INFO
-force_update	bool	force an agent update.
-v	bool	Prints DigitalOcean Agent version.
-h	bool	Prints do-agent usage information.

Env Flags

Generally used during development and debugging.

Flag	Option	Description
DO_AGENT_AUTHENTICATION_URL	string	Override the authentication URL
DO_AGENT_APPKEY	string	Override AppKey
DO_AGENT_METRICS_URL	string	Override metrics URL
DO_AGENT_DROPLET_ID	int64	Override Droplet ID
DO_AGENT_AUTHTOKEN	string	Override AuthToken
DO_AGENT_UPDATE_URL	string	Override Update URL
DO_AGENT_REPO_PATH	string	Override Local repository path
DO_AGENT_PLUGIN_PATH	string	Override plugin directory path
DO_AGENT_PROCFS_ROOT	string	Override location of /proc

Building and running

make build
sudo -u nobody ./do-agent <flags>

Running Tests

make test

Installing via package managers

Deb Repository

echo "deb https://repos.sonar.digitalocean.com/apt main main" > /etc/apt/sources.list.d/sonar.list
curl https://repos.sonar.digitalocean.com/sonar-agent.asc | sudo apt-key add -
sudo apt-get update
sudo apt-get install do-agent

Yum Repository

cat <'EOF' > /etc/yum.repos.d/DigitalOcean-Sonar.repo
[sonar]
name=do agent
baseurl=https://repos.sonar.digitalocean.com/yum/$basearch
failovermethod=priority
enabled=1
gpgcheck=1
gpgkey=https://repos.sonar.digitalocean.com/sonar-agent.asc
EOF

rpm --import https://repos.sonar.digitalocean.com/sonar-agent.asc
yum install do-agent

Update via package managers

Yum

yum update do-agent

Apt

apt-get update && apt-get install --only-upgrade do-agent

Removal via package managers

Yum

sudo yum remove do-agent

Apt

sudo apt-get purge do-agent

Package installation

Deb

dpkg -i do-agent_<version>_<build>.deb

Rpm

rpm -Uvh do-agent-<version>_<build>.rpm

Package removal

Deb

dpkg --remove do-agent

Rpm

rpm -e do-agent

Docker

You can optionally run the Agent in Docker. To do so: make docker

In order for the agent to report accurate metrics, you need to bind mount in /proc inside the container: docker run --rm \ -v /proc:/agent/proc:ro \ do-agent

Plugins

do-agent builds in a common set of metrics, and provides a plugin mechanism to add additional metric collectors. Plugins are executable files that are placed in the agent's plugin directory (see DO_AGENT_PLUGIN_PATH). When do-agent starts, it will find all executables in the plugin path and call them during metric collection.

A collection agent must do two things:

1. report metric configuration to stdout when a "config" argument is passed.
2. report metric values to stdout when no argument is passed.

See plugins/test.sh for a simple static plugin, in the form of a shell script. Plugins may be written in any language, and must only know how to produce serialized results in json format.

Definitions

When test.sh is run with "config" as the argument, it produces the following:

{
  "definitions": {
    "test": {
      "type": 1,
      "labels": {
        "user": "foo"
      },
      "label_keys": ["timezone", "country"]
    }
  }
}

Definitions is a mapping of metric name to configuration. type is an integer type, compatible with the Prometheus client definition. The following types are supported:

Type Value	Description
0	Counter
1	Gauge

Two types of labels are supported: fixed and dynamic. Fixed labels are specified once in the metric definition and never specified in the metric value. In the example above, there is a fixed label user:foo. This label will be set on all values of the metric.

The second type of label is a dynamic label. Dynamic labels have a fixed key but the value is specified with every update of the metric. The example above has two dynamic labels, with the keys timezone and country. The values for these labels will be provided on each metric update.

Values

When test.sh is run without any arguments, it produces the current value of the collected metrics. For example:

{
  "metrics": {
    "test": {
      "value": 42.0,
      "label_values": ["est", "usa"]
    }
  }
}

The (optional) label_values must correspond to the label_keys in the definition. If there were two label keys in the definition, then there must be exactly two label values in each metric update.

Contributing

The do-agent project makes use of the GitHub Flow for contributions.

If you'd like to contribute to the project, please open an issue or find an existing issue that you'd like to take on. This ensures that efforts are not duplicated, and that a new feature aligns with the focus of the rest of the repository.

Once your suggestion has been submitted and discussed, please be sure that your code meets the following criteria:

• code is completely gofmt'd
• new features or codepaths have appropriate test coverage
• go test ./... passes
• go vet ./... passes
• golint ./... returns no warnings, including documentation comment warnings

In addition, if this is your first time contributing to the do-agent project, add your name and email address to the AUTHORS file under the "Contributors" section using the format: First Last <email@example.com>.

First, to setup the project, ensure that $GOPATH variable is pointing to an existing directory, where all your Go code will be available.

After forking the repo on Github, run:

go get github.com/digitalocean/do-agent
cd $GOPATH/src/github.com/digitalocean/do-agent

git remote add my-fork <the url for your fork>
make test # ensure tests are passing

Push your changes to your fork:

git push -u master my-fork

Finally, submit a pull request for review!

Report a bug

If you discover a software bug, please feel free to report it by:

1. Search through the existing issues to ensure that the bug hasn't already been filed.
2. Open an issue for a new bug.