CloudWatch 使用适用于 JavaScript (v3) 的 SDK 记录示例 - Amazon SDK for JavaScript
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Amazon SDK for JavaScript V3 API 参考指南详细描述了 Amazon SDK for JavaScript 版本 3 (V3) 的所有 API 操作。

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CloudWatch 使用适用于 JavaScript (v3) 的 SDK 记录示例

以下代码示例向您展示了如何使用带 CloudWatch 日志的 Amazon SDK for JavaScript (v3) 来执行操作和实现常见场景。

操作是大型程序的代码摘录,必须在上下文中运行。您可以通过操作了解如何调用单个服务函数,还可以通过函数相关场景和跨服务示例的上下文查看操作。

场景 是展示如何通过在同一服务中调用多个函数来完成特定任务的代码示例。

每个示例都包含一个指向的链接 GitHub,您可以在其中找到有关如何在上下文中设置和运行代码的说明。

操作

以下代码示例演示了如何使用 CreateLogGroup

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

import { CreateLogGroupCommand } from "@aws-sdk/client-cloudwatch-logs"; import { client } from "../libs/client.js"; const run = async () => { const command = new CreateLogGroupCommand({ // The name of the log group. logGroupName: process.env.CLOUDWATCH_LOGS_LOG_GROUP, }); try { return await client.send(command); } catch (err) { console.error(err); } }; export default run();
  • 有关 API 的详细信息,请参阅 Amazon SDK for JavaScript API 参考中的CreateLog群组

以下代码示例演示了如何使用 DeleteLogGroup

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

import { DeleteLogGroupCommand } from "@aws-sdk/client-cloudwatch-logs"; import { client } from "../libs/client.js"; const run = async () => { const command = new DeleteLogGroupCommand({ // The name of the log group. logGroupName: process.env.CLOUDWATCH_LOGS_LOG_GROUP, }); try { return await client.send(command); } catch (err) { console.error(err); } }; export default run();
  • 有关 API 的详细信息,请参阅 Amazon SDK for JavaScript API 参考中的DeleteLog群组

以下代码示例演示了如何使用 DeleteSubscriptionFilter

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

import { DeleteSubscriptionFilterCommand } from "@aws-sdk/client-cloudwatch-logs"; import { client } from "../libs/client.js"; const run = async () => { const command = new DeleteSubscriptionFilterCommand({ // The name of the filter. filterName: process.env.CLOUDWATCH_LOGS_FILTER_NAME, // The name of the log group. logGroupName: process.env.CLOUDWATCH_LOGS_LOG_GROUP, }); try { return await client.send(command); } catch (err) { console.error(err); } }; export default run();
  • 有关 API 的详细信息,请参阅《Amazon SDK for JavaScript API 参考》中的 “DeleteSubscription筛选”。

适用于 JavaScript (v2) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

// Load the AWS SDK for Node.js var AWS = require("aws-sdk"); // Set the region AWS.config.update({ region: "REGION" }); // Create the CloudWatchLogs service object var cwl = new AWS.CloudWatchLogs({ apiVersion: "2014-03-28" }); var params = { filterName: "FILTER", logGroupName: "LOG_GROUP", }; cwl.deleteSubscriptionFilter(params, function (err, data) { if (err) { console.log("Error", err); } else { console.log("Success", data); } });

以下代码示例演示了如何使用 DescribeLogGroups

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

import { paginateDescribeLogGroups, CloudWatchLogsClient, } from "@aws-sdk/client-cloudwatch-logs"; const client = new CloudWatchLogsClient({}); export const main = async () => { const paginatedLogGroups = paginateDescribeLogGroups({ client }, {}); const logGroups = []; for await (const page of paginatedLogGroups) { if (page.logGroups && page.logGroups.every((lg) => !!lg)) { logGroups.push(...page.logGroups); } } console.log(logGroups); return logGroups; };
  • 有关 API 的详细信息,请参阅 Amazon SDK for JavaScript API 参考中的DescribeLog群组

以下代码示例演示了如何使用 DescribeSubscriptionFilters

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

import { DescribeSubscriptionFiltersCommand } from "@aws-sdk/client-cloudwatch-logs"; import { client } from "../libs/client.js"; const run = async () => { // This will return a list of all subscription filters in your account // matching the log group name. const command = new DescribeSubscriptionFiltersCommand({ logGroupName: process.env.CLOUDWATCH_LOGS_LOG_GROUP, limit: 1, }); try { return await client.send(command); } catch (err) { console.error(err); } }; export default run();
适用于 JavaScript (v2) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

// Load the AWS SDK for Node.js var AWS = require("aws-sdk"); // Set the region AWS.config.update({ region: "REGION" }); // Create the CloudWatchLogs service object var cwl = new AWS.CloudWatchLogs({ apiVersion: "2014-03-28" }); var params = { logGroupName: "GROUP_NAME", limit: 5, }; cwl.describeSubscriptionFilters(params, function (err, data) { if (err) { console.log("Error", err); } else { console.log("Success", data.subscriptionFilters); } });

以下代码示例演示了如何使用 GetQueryResults

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

/** * Simple wrapper for the GetQueryResultsCommand. * @param {string} queryId */ _getQueryResults(queryId) { return this.client.send(new GetQueryResultsCommand({ queryId })); }
  • 有关 API 的详细信息,请参阅 Amazon SDK for JavaScript API 参考中的GetQuery结果

以下代码示例演示了如何使用 PutSubscriptionFilter

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

import { PutSubscriptionFilterCommand } from "@aws-sdk/client-cloudwatch-logs"; import { client } from "../libs/client.js"; const run = async () => { const command = new PutSubscriptionFilterCommand({ // An ARN of a same-account Kinesis stream, Kinesis Firehose // delivery stream, or Lambda function. // https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/SubscriptionFilters.html destinationArn: process.env.CLOUDWATCH_LOGS_DESTINATION_ARN, // A name for the filter. filterName: process.env.CLOUDWATCH_LOGS_FILTER_NAME, // A filter pattern for subscribing to a filtered stream of log events. // https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/FilterAndPatternSyntax.html filterPattern: process.env.CLOUDWATCH_LOGS_FILTER_PATTERN, // The name of the log group. Messages in this group matching the filter pattern // will be sent to the destination ARN. logGroupName: process.env.CLOUDWATCH_LOGS_LOG_GROUP, }); try { return await client.send(command); } catch (err) { console.error(err); } }; export default run();
  • 有关 API 的详细信息,请参阅《Amazon SDK for JavaScript API 参考》中的 “PutSubscription筛选”。

适用于 JavaScript (v2) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

// Load the AWS SDK for Node.js var AWS = require("aws-sdk"); // Set the region AWS.config.update({ region: "REGION" }); // Create the CloudWatchLogs service object var cwl = new AWS.CloudWatchLogs({ apiVersion: "2014-03-28" }); var params = { destinationArn: "LAMBDA_FUNCTION_ARN", filterName: "FILTER_NAME", filterPattern: "ERROR", logGroupName: "LOG_GROUP", }; cwl.putSubscriptionFilter(params, function (err, data) { if (err) { console.log("Error", err); } else { console.log("Success", data); } });

以下代码示例演示了如何使用 StartLiveTail

适用于 JavaScript (v3) 的软件开发工具包

包含所需的文件。

import { CloudWatchLogsClient, StartLiveTailCommand } from "@aws-sdk/client-cloudwatch-logs";

处理 Live Tail 会话中的事件。

async function handleResponseAsync(response) { try { for await (const event of response.responseStream) { if (event.sessionStart !== undefined) { console.log(event.sessionStart); } else if (event.sessionUpdate !== undefined) { for (const logEvent of event.sessionUpdate.sessionResults) { const timestamp = logEvent.timestamp; const date = new Date(timestamp); console.log("[" + date + "] " + logEvent.message); } } else { console.error("Unknown event type"); } } } catch (err) { // On-stream exceptions are captured here console.error(err) } }

启动 Live Tail 会话。

const client = new CloudWatchLogsClient(); const command = new StartLiveTailCommand({ logGroupIdentifiers: logGroupIdentifiers, logStreamNames: logStreamNames, logEventFilterPattern: filterPattern }); try{ const response = await client.send(command); handleResponseAsync(response); } catch (err){ // Pre-stream exceptions are captured here console.log(err); }

经过一段时间后停止 Live Tail 会话。

/* Set a timeout to close the client. This will stop the Live Tail session. */ setTimeout(function() { console.log("Client timeout"); client.destroy(); }, 10000);
  • 有关 API 的详细信息,请参阅《Amazon SDK for JavaScript API 参考》中的 Tai StartLivel

以下代码示例演示了如何使用 StartQuery

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

/** * Wrapper for the StartQueryCommand. Uses a static query string * for consistency. * @param {[Date, Date]} dateRange * @param {number} maxLogs * @returns {Promise<{ queryId: string }>} */ async _startQuery([startDate, endDate], maxLogs = 10000) { try { return await this.client.send( new StartQueryCommand({ logGroupNames: this.logGroupNames, queryString: "fields @timestamp, @message | sort @timestamp asc", startTime: startDate.valueOf(), endTime: endDate.valueOf(), limit: maxLogs, }), ); } catch (err) { /** @type {string} */ const message = err.message; if (message.startsWith("Query's end date and time")) { // This error indicates that the query's start or end date occur // before the log group was created. throw new DateOutOfBoundsError(message); } throw err; } }
  • 有关 API 的详细信息,请参阅 Amazon SDK for JavaScript API 参考StartQuery中的。

场景

以下代码示例展示了如何使用 CloudWatch 日志查询超过 10,000 条记录。

适用于 JavaScript (v3) 的软件开发工具包
注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例,了解如何进行设置和运行。

这是入口点。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 import { CloudWatchLogsClient } from "@aws-sdk/client-cloudwatch-logs"; import { CloudWatchQuery } from "./cloud-watch-query.js"; console.log("Starting a recursive query..."); if (!process.env.QUERY_START_DATE || !process.env.QUERY_END_DATE) { throw new Error( "QUERY_START_DATE and QUERY_END_DATE environment variables are required.", ); } const cloudWatchQuery = new CloudWatchQuery(new CloudWatchLogsClient({}), { logGroupNames: ["/workflows/cloudwatch-logs/large-query"], dateRange: [ new Date(parseInt(process.env.QUERY_START_DATE)), new Date(parseInt(process.env.QUERY_END_DATE)), ], }); await cloudWatchQuery.run(); console.log( `Queries finished in ${cloudWatchQuery.secondsElapsed} seconds.\nTotal logs found: ${cloudWatchQuery.results.length}`, );

该类可在必要时将查询拆分为多个步骤。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 import { StartQueryCommand, GetQueryResultsCommand, } from "@aws-sdk/client-cloudwatch-logs"; import { splitDateRange } from "@aws-doc-sdk-examples/lib/utils/util-date.js"; import { retry } from "@aws-doc-sdk-examples/lib/utils/util-timers.js"; class DateOutOfBoundsError extends Error {} export class CloudWatchQuery { /** * Run a query for all CloudWatch Logs within a certain date range. * CloudWatch logs return a max of 10,000 results. This class * performs a binary search across all of the logs in the provided * date range if a query returns the maximum number of results. * * @param {import('@aws-sdk/client-cloudwatch-logs').CloudWatchLogsClient} client * @param {{ logGroupNames: string[], dateRange: [Date, Date], queryConfig: { limit: number } }} config */ constructor(client, { logGroupNames, dateRange, queryConfig }) { this.client = client; /** * All log groups are queried. */ this.logGroupNames = logGroupNames; /** * The inclusive date range that is queried. */ this.dateRange = dateRange; /** * CloudWatch Logs never returns more than 10,000 logs. */ this.limit = queryConfig?.limit ?? 10000; /** * @type {import("@aws-sdk/client-cloudwatch-logs").ResultField[][]} */ this.results = []; } /** * Run the query. */ async run() { this.secondsElapsed = 0; const start = new Date(); this.results = await this._largeQuery(this.dateRange); const end = new Date(); this.secondsElapsed = (end - start) / 1000; return this.results; } /** * Recursively query for logs. * @param {[Date, Date]} dateRange * @returns {Promise<import("@aws-sdk/client-cloudwatch-logs").ResultField[][]>} */ async _largeQuery(dateRange) { const logs = await this._query(dateRange, this.limit); console.log( `Query date range: ${dateRange .map((d) => d.toISOString()) .join(" to ")}. Found ${logs.length} logs.`, ); if (logs.length < this.limit) { return logs; } const lastLogDate = this._getLastLogDate(logs); const offsetLastLogDate = new Date(lastLogDate); offsetLastLogDate.setMilliseconds(lastLogDate.getMilliseconds() + 1); const subDateRange = [offsetLastLogDate, dateRange[1]]; const [r1, r2] = splitDateRange(subDateRange); const results = await Promise.all([ this._largeQuery(r1), this._largeQuery(r2), ]); return [logs, ...results].flat(); } /** * Find the most recent log in a list of logs. * @param {import("@aws-sdk/client-cloudwatch-logs").ResultField[][]} logs */ _getLastLogDate(logs) { const timestamps = logs .map( (log) => log.find((fieldMeta) => fieldMeta.field === "@timestamp")?.value, ) .filter((t) => !!t) .map((t) => `${t}Z`) .sort(); if (!timestamps.length) { throw new Error("No timestamp found in logs."); } return new Date(timestamps[timestamps.length - 1]); } // snippet-start:[javascript.v3.cloudwatch-logs.actions.GetQueryResults] /** * Simple wrapper for the GetQueryResultsCommand. * @param {string} queryId */ _getQueryResults(queryId) { return this.client.send(new GetQueryResultsCommand({ queryId })); } // snippet-end:[javascript.v3.cloudwatch-logs.actions.GetQueryResults] /** * Starts a query and waits for it to complete. * @param {[Date, Date]} dateRange * @param {number} maxLogs */ async _query(dateRange, maxLogs) { try { const { queryId } = await this._startQuery(dateRange, maxLogs); const { results } = await this._waitUntilQueryDone(queryId); return results ?? []; } catch (err) { /** * This error is thrown when StartQuery returns an error indicating * that the query's start or end date occur before the log group was * created. */ if (err instanceof DateOutOfBoundsError) { return []; } else { throw err; } } } // snippet-start:[javascript.v3.cloudwatch-logs.actions.StartQuery] /** * Wrapper for the StartQueryCommand. Uses a static query string * for consistency. * @param {[Date, Date]} dateRange * @param {number} maxLogs * @returns {Promise<{ queryId: string }>} */ async _startQuery([startDate, endDate], maxLogs = 10000) { try { return await this.client.send( new StartQueryCommand({ logGroupNames: this.logGroupNames, queryString: "fields @timestamp, @message | sort @timestamp asc", startTime: startDate.valueOf(), endTime: endDate.valueOf(), limit: maxLogs, }), ); } catch (err) { /** @type {string} */ const message = err.message; if (message.startsWith("Query's end date and time")) { // This error indicates that the query's start or end date occur // before the log group was created. throw new DateOutOfBoundsError(message); } throw err; } } // snippet-end:[javascript.v3.cloudwatch-logs.actions.StartQuery] /** * Call GetQueryResultsCommand until the query is done. * @param {string} queryId */ _waitUntilQueryDone(queryId) { const getResults = async () => { const results = await this._getQueryResults(queryId); const queryDone = [ "Complete", "Failed", "Cancelled", "Timeout", "Unknown", ].includes(results.status); return { queryDone, results }; }; return retry( { intervalInMs: 1000, maxRetries: 60, quiet: true }, async () => { const { queryDone, results } = await getResults(); if (!queryDone) { throw new Error("Query not done."); } return results; }, ); } }
  • 有关 API 详细信息,请参阅《Amazon SDK for JavaScript API 参考》中的以下主题。