nextcloud-exporter

A prometheus exporter for getting some metrics of a Nextcloud server instance.

Installation

Docker Image

The preferred way to use nextcloud-exporter is by running the provided Docker image. It is currently provided on Docker Hub and GitHub Container Registry:

• ghcr.io/xperimental/nextcloud-exporter
• xperimental/nextcloud-exporter

The following tags are available:

• x.y.z pointing to the release with that version
• latest pointing to the most recent released version
• master pointing to the latest build from the default branch

Pre-built binaries

The releases page contains pre-built binaries for AMD64 and ARM64 linux.

Build from Source

If you have a recent Go installation (see go.mod for the minimum version), Git and GNU Make, the following commands will check out the repository and compile the binary from source:

git clone https://github.com/xperimental/nextcloud-exporter.git
cd nextcloud-exporter
make

After this there should be a nextcloud-exporter binary in your current directory.

Client credentials

The exporter supports two different approaches for authenticating with the Nextcloud server:

• Token authentication (needs Nextcloud 22 or newer)
• Username and password

If you have Nextcloud 22 then using the token authentication is recommended, because it does not need a normal user account with admin privileges.

If both a token and username/password are specified in the configuration, the token will take precedence.

Token authentication

Nextcloud 22 and newer versions support "token authentication" for the serverinfo. That way, accessing this information does not need a normal user account with admin privileges. You can set the token to anything you like, but the recommendation is to set it to a long random number:

# Generate random value (for example using openssl)
TOKEN=$(openssl rand -hex 32)
# Set token (using the occ console application)
occ config:app:set serverinfo token --value "$TOKEN"

You can then use this generated token in the exported configuration instead of username and password.

Username and password authentication

To access the serverinfo API you will need the credentials of an admin user. It is recommended to create a separate user for that purpose. It's also possible for the exporter to generate an "app password", so that the real user password is never saved to the configuration. This also makes the exporter show up in the security panel of the user as a connected application.

To let the nextcloud-exporter create an app password, start it with the --login parameter:

nextcloud-exporter --login --server https://nextcloud.example.com

The exporter will generate a login URL that you need to open in your browser. Be sure to login with the correct user if you created a special user for the exporter as the app password will be bound to the logged-in user. Once the access has been granted using the browser the exporter will output the username and password that need to be entered into the configuration.

When the login process is done, it is possible to disable filesystem access for the generated token in the user's settings:

---

The interactive login can also be done using a Docker container:

docker run --rm -it ghcr.io/xperimental/nextcloud-exporter --login --server https://nextcloud.example.com

The login flow needs at least Nextcloud 16 to work.

Usage

$ nextcloud-exporter --help
Usage of nextcloud-exporter:
  -a, --addr string          Address to listen on for connections. (default ":9205")
      --auth-token string    Authentication token. Can replace username and password when using Nextcloud 22 or newer.
  -c, --config-file string   Path to YAML configuration file.
      --enable-info-apps     Enable gathering of apps-related metrics.
      --enable-info-update   Enable gathering of system update-related metrics.
      --login                Use interactive login to create app password.
  -p, --password string      Password for connecting to Nextcloud.
  -s, --server string        URL to Nextcloud server.
  -t, --timeout duration     Timeout for getting server info document. (default 5s)
      --tls-skip-verify      Skip certificate verification of Nextcloud server.
  -u, --username string      Username for connecting to Nextcloud.
  -V, --version              Show version information and exit.

After starting the server will offer the metrics on the /metrics endpoint, which can be used as a target for prometheus.

Example Dashboard

The repository contains an example Grafana dashboard that can be imported into Grafana. The dashboard is also available as ID 20716 from the Grafana Dashboard Exchange.

Configuration methods

There are three methods of configuring the nextcloud-exporter (higher methods take precedence over lower ones):

• Environment variables
• Configuration file
• Command-line parameters

Environment variables

All settings can also be specified through environment variables:

Configuration file

The --config-file option can be used to read the configuration options from a YAML file:

# required
server: "https://example.com"
# required for token authentication
authToken: "example-token"
# required for username/password authentication
username: "example"
password: "example"
# optional
listenAddress: ":9205"
timeout: "5s"
tlsSkipVerify: false
info:
  apps: false
  update: false

Loading Credentials from Files

Both the authentication token and the password can optionally be read from a separate file instead of directly from the input methods above.

This can be achieved by setting the value to the path of the file prefixed with an "@", for example:

# Authentication token
nextcloud-exporter -c config-without-token.yml --auth-token @/path/to/tokenfile
# Password
nextcloud-exporter -c config-without-password.yml -p @/path/to/passwordfile

This also works when the password or token is set using one of the other configuration modes (configuration file or environment variables).

Other information

Info URL

The exporter reads the metrics from the Nextcloud server using its "serverinfo" API. You can find the URL of this API in the administrator settings in the "Monitoring" section. It should look something like this:

https://example.com/ocs/v2.php/apps/serverinfo/api/v1/info

The path will be automatically added to the server URL you provide, so in the above example setting --server https://example.com would be sufficient.

If you open this URL in a browser you should see an XML structure with the information that will be used by the exporter.

Scrape configuration

The exporter will query the nextcloud server every time it is scraped by prometheus. If you want to reduce load on the nextcloud server you need to change the scrape interval accordingly:

scrape_configs:
  - job_name: 'nextcloud'
    scrape_interval: 90s
    static_configs:
      - targets: ['localhost:9205']

Exported metrics

These metrics are exported by nextcloud-exporter: