io.prometheus.metrics.config.PrometheusPropertiesLoader Maven / Gradle / Ivy
package io.prometheus.metrics.config;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* The Properties Loader is early stages.
*
* It would be great to implement a subset of
* Spring Boot's Externalized Configuration,
* like support for YAML, Properties, and env vars, or support for Spring's naming conventions for properties.
*/
public class PrometheusPropertiesLoader {
/**
* See {@link PrometheusProperties#get()}.
*/
public static PrometheusProperties load() throws PrometheusPropertiesException {
return load(new Properties());
}
public static PrometheusProperties load(Map externalProperties) throws PrometheusPropertiesException {
Map properties = loadProperties(externalProperties);
Map metricsConfigs = loadMetricsConfigs(properties);
MetricsProperties defaultMetricsProperties = MetricsProperties.load("io.prometheus.metrics", properties);
ExemplarsProperties exemplarConfig = ExemplarsProperties.load("io.prometheus.exemplars", properties);
ExporterProperties exporterProperties = ExporterProperties.load("io.prometheus.exporter", properties);
ExporterFilterProperties exporterFilterProperties = ExporterFilterProperties.load("io.prometheus.exporter.filter", properties);
ExporterHttpServerProperties exporterHttpServerProperties = ExporterHttpServerProperties.load("io.prometheus.exporter.httpServer", properties);
ExporterPushgatewayProperties exporterPushgatewayProperties = ExporterPushgatewayProperties.load("io.prometheus.exporter.pushgateway", properties);
ExporterOpenTelemetryProperties exporterOpenTelemetryProperties = ExporterOpenTelemetryProperties.load("io.prometheus.exporter.opentelemetry", properties);
validateAllPropertiesProcessed(properties);
return new PrometheusProperties(defaultMetricsProperties, metricsConfigs, exemplarConfig, exporterProperties, exporterFilterProperties, exporterHttpServerProperties, exporterPushgatewayProperties, exporterOpenTelemetryProperties);
}
// This will remove entries from properties when they are processed.
private static Map loadMetricsConfigs(Map properties) {
Map result = new HashMap<>();
// Note that the metric name in the properties file must be as exposed in the Prometheus exposition formats,
// i.e. all dots replaced with underscores.
Pattern pattern = Pattern.compile("io\\.prometheus\\.metrics\\.([^.]+)\\.");
// Create a copy of the keySet() for iterating. We cannot iterate directly over keySet()
// because entries are removed when MetricsConfig.load(...) is called.
Set propertyNames = new HashSet<>();
for (Object key : properties.keySet()) {
propertyNames.add(key.toString());
}
for (String propertyName : propertyNames) {
Matcher matcher = pattern.matcher(propertyName);
if (matcher.find()) {
String metricName = matcher.group(1).replace(".", "_");
if (!result.containsKey(metricName)) {
result.put(metricName, MetricsProperties.load("io.prometheus.metrics." + metricName, properties));
}
}
}
return result;
}
// If there are properties left starting with io.prometheus it's likely a typo,
// because we didn't use that property.
// Throw a config error to let the user know that this property doesn't exist.
private static void validateAllPropertiesProcessed(Map properties) {
for (Object key : properties.keySet()) {
if (key.toString().startsWith("io.prometheus")) {
throw new PrometheusPropertiesException(key + ": Unknown property");
}
}
}
private static Map loadProperties(Map externalProperties) {
Map properties = new HashMap<>();
properties.putAll(loadPropertiesFromClasspath());
properties.putAll(loadPropertiesFromFile()); // overriding the entries from the classpath file
properties.putAll(System.getProperties()); // overriding the entries from the properties file
properties.putAll(externalProperties); // overriding all the entries above
// TODO: Add environment variables like EXEMPLARS_ENABLED.
return properties;
}
private static Properties loadPropertiesFromClasspath() {
Properties properties = new Properties();
try (InputStream stream = Thread.currentThread().getContextClassLoader().getResourceAsStream("prometheus.properties")) {
properties.load(stream);
} catch (Exception ignored) {
}
return properties;
}
private static Properties loadPropertiesFromFile() throws PrometheusPropertiesException {
Properties properties = new Properties();
String path = System.getProperty("prometheus.config");
if (System.getenv("PROMETHEUS_CONFIG") != null) {
path = System.getenv("PROMETHEUS_CONFIG");
}
if (path != null) {
try (InputStream stream = Files.newInputStream(Paths.get(path))) {
properties.load(stream);
} catch (IOException e) {
throw new PrometheusPropertiesException("Failed to read Prometheus properties from " + path + ": " + e.getMessage(), e);
}
}
return properties;
}
}