/**
* Prometheus HTTP API Client
*
* Wraps the Prometheus HTTP API for querying metrics and alerts.
* Used by the observability_gateway tool.
*/
export interface PrometheusConfig {
url: string;
timeout?: number;
}
export interface PrometheusQueryResult {
status: 'success' | 'error';
data?: {
resultType: 'vector' | 'matrix' | 'scalar' | 'string';
result: PrometheusMetric[];
};
errorType?: string;
error?: string;
}
export interface PrometheusMetric {
metric: Record<string, string>;
value?: [number, string]; // [timestamp, value] for instant queries
values?: [number, string][]; // [[timestamp, value], ...] for range queries
}
export interface PrometheusAlert {
labels: Record<string, string>;
annotations: Record<string, string>;
state: 'firing' | 'pending' | 'inactive';
activeAt?: string;
value?: string;
}
export interface PrometheusAlertsResult {
status: 'success' | 'error';
data?: {
alerts: PrometheusAlert[];
};
errorType?: string;
error?: string;
}
export interface PrometheusTargetsResult {
status: 'success' | 'error';
data?: {
activeTargets: Array<{
health: 'up' | 'down' | 'unknown';
labels: Record<string, string>;
lastScrape: string;
scrapeUrl: string;
}>;
};
}
export class PrometheusClient {
private readonly baseUrl: string;
private readonly timeout: number;
constructor(config: PrometheusConfig) {
this.baseUrl = config.url.replace(/\/$/, '');
this.timeout = config.timeout ?? 10000;
}
/**
* Execute an instant query (single point in time)
*/
async query(promql: string, time?: string): Promise<PrometheusQueryResult> {
const params = new URLSearchParams({ query: promql });
if (time) {
params.set('time', time);
}
return this.fetch<PrometheusQueryResult>(`/api/v1/query?${params}`);
}
/**
* Execute a range query (time series)
*/
async queryRange(
promql: string,
start: string,
end: string,
step?: string
): Promise<PrometheusQueryResult> {
const params = new URLSearchParams({
query: promql,
start,
end,
step: step ?? '15s',
});
return this.fetch<PrometheusQueryResult>(`/api/v1/query_range?${params}`);
}
/**
* Get active alerts from Prometheus alertmanager integration
*/
async alerts(): Promise<PrometheusAlertsResult> {
return this.fetch<PrometheusAlertsResult>('/api/v1/alerts');
}
/**
* Get scrape targets and their health
*/
async targets(): Promise<PrometheusTargetsResult> {
return this.fetch<PrometheusTargetsResult>('/api/v1/targets');
}
/**
* Check if Prometheus is reachable
*/
async isHealthy(): Promise<boolean> {
try {
const response = await fetch(`${this.baseUrl}/-/healthy`, {
signal: AbortSignal.timeout(this.timeout),
});
return response.ok;
} catch {
return false;
}
}
private async fetch<T>(path: string): Promise<T> {
const response = await fetch(`${this.baseUrl}${path}`, {
headers: {
Accept: 'application/json',
},
signal: AbortSignal.timeout(this.timeout),
});
if (!response.ok) {
throw new Error(`Prometheus API error: ${response.status} ${response.statusText}`);
}
return response.json() as Promise<T>;
}
}
