Monitoring the registry¶

zot supports a range of monitoring tools including logging, metrics, and benchmarking.

The following sections describe how to configure logging and monitoring with zot. You can use zot's benchmarking tool to test your configuration and deployment, as described in Benchmarking zot with zb.

Logging¶

Logging for zot operations is configured with the log attribute in the configuration file, as shown in the following example.

"log":{
  "level":"debug",
  "output":"/tmp/zot.log",
  "audit": "/tmp/zot-audit.log"
}

The following table lists the configurable attributes.

Attribute	Description
`level`	The minimum level for logged events. The levels are: `panic,` `fatal,` `error,` `warn,` `info,` `debug,` and `trace.`
`output`	The filesystem path for the log output file. The default is `stdout`.
`audit`	(Optional) If a filesystem path is specified for audit logging, an audit log is enabled and will be stored at the specified path.

Metrics¶

The available methods for collecting metrics varies depending on whether your zot installation is a minimal (distribution-spec-only) image or a full image including extensions.

Enabling metrics for a full zot image with extensions¶

Add the metrics attribute under extensions in the configuration file to enable and configure metrics, as shown in the following example.

"extensions": {
    "metrics": {
        "enable": true,
        "prometheus": {
            "path": "/metrics"
        }
    }
}

The following table lists the configurable attributes for metrics collection.

Attribute	Description
`enable`	If this attribute is missing, metrics collection is enabled by default. Metrics collection can be disabled by setting this attribute to `false`.
`prometheus`	Attributes under `prometheus` contain configuration settings for the Prometheus node exporter.
`path`	The server path on which metrics will be exposed.

Collecting metrics from a minimal zot image using a node exporter¶

Although a minimal zot image does not contain a node exporter, it exposes internal metrics in a Prometheus format for collection by a separate node exporter tool such as zxp. The zot companion binary zxp is a node exporter that can be deployed with a minimal zot image in order to scrape metrics from the zot server.

Metrics are automatically enabled in the zot server upon first scrape from the node exporter and the metrics are automatically disabled when the node exporter has not performed any scraping for some period. No extra zot configuration is needed for this behavior.

You can download the zxp executable binary for your server platform and architecture under "Assets" on the GitHub zot releases page.

The binary image is named using the target platform and architecture. For example, the binary for an Intel-based MacOS server is zxp-darwin-amd64. To configure the zxp example image, run this command:

zxp-darwin-amd64 config zxp-config-file

For convenience, you can rename the binary image file to simply zxp.

A sample Dockerfile for zxp is available at Dockerfile-zxp.

The configuration file of zxp contains connection details for the zot server from which it will scrape metrics. The following JSON structure is an example of the zxp-config-file contents:

{
    "Server": {
        "protocol": "http",
        "host": "127.0.0.1",
        "port": "8080"
    },
    "Exporter": {
        "port": "8081",
        "log": {
            "level": "debug"
        }
    }
}

The zxp module does not have Prometheus integration.

The zxp module is not needed with a full zot image.

Last update: September 1, 2023