Tail log entries
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Demonstrates how to tail live log entries.
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For detailed documentation that includes this code sample, see the following:
Code sample
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[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],[],[],[],null,["# Tail log entries\n\nDemonstrates how to tail live log entries.\n\nExplore further\n---------------\n\n\nFor detailed documentation that includes this code sample, see the following:\n\n- [Streaming and live tailing log entries](/logging/docs/view/streaming-live-tailing)\n\nCode sample\n-----------\n\n### Go\n\n\nTo learn how to install and use the client library for Logging, see\n[Logging client libraries](/logging/docs/reference/libraries).\n\n\nTo authenticate to Logging, set up Application Default Credentials.\nFor more information, see\n\n[Set up authentication for a local development environment](/docs/authentication/set-up-adc-local-dev-environment).\n\n import (\n \t\"context\"\n \t\"fmt\"\n \t\"io\"\n\n \tlogging \"cloud.google.com/go/logging/apiv2\"\n \t\"cloud.google.com/go/logging/apiv2/loggingpb\"\n )\n\n // tailLogs creates a channel to stream log entries that were recently ingested for a project\n func tailLogs(projectID string) error {\n \t// projectID := \"your_project_id\"\n\n \tctx := context.Background()\n \tclient, err := logging.https://cloud.google.com/go/docs/reference/cloud.google.com/go/logging/latest/apiv2.html#cloud_google_com_go_logging_apiv2_Client_NewClient(ctx)\n \tif err != nil {\n \t\treturn fmt.Errorf(\"NewClient error: %w\", err)\n \t}\n \tdefer client.Close()\n\n \tstream, err := client.TailLogEntries(ctx)\n \tif err != nil {\n \t\treturn fmt.Errorf(\"TailLogEntries error: %w\", err)\n \t}\n \tdefer stream.CloseSend()\n\n \treq := &loggingpb.TailLogEntriesRequest{\n \t\tResourceNames: []string{\n \t\t\t\"projects/\" + projectID,\n \t\t},\n \t}\n \tif err := stream.Send(req); err != nil {\n \t\treturn fmt.Errorf(\"stream.Send error: %w\", err)\n \t}\n\n \t// read and print two or more streamed log entries\n \tfor counter := 0; counter \u003c 2; {\n \t\tresp, err := stream.Recv()\n \t\tif err == io.EOF {\n \t\t\tbreak\n \t\t}\n \t\tif err != nil {\n \t\t\treturn fmt.Errorf(\"stream.Recv error: %w\", err)\n \t\t}\n \t\tfmt.Printf(\"received:\\n%v\\n\", resp)\n \t\tif resp.Entries != nil {\n \t\t\tcounter += len(resp.Entries)\n \t\t}\n \t}\n \treturn nil\n }\n\n### Java\n\n\nTo learn how to install and use the client library for Logging, see\n[Logging client libraries](/logging/docs/reference/libraries).\n\n\nTo authenticate to Logging, set up Application Default Credentials.\nFor more information, see\n\n[Set up authentication for a local development environment](/docs/authentication/set-up-adc-local-dev-environment).\n\n import com.google.cloud.logging.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LogEntry.html;\n import com.google.cloud.logging.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LogEntryServerStream.html;\n import com.google.cloud.logging.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.Logging.html;\n import com.google.cloud.logging.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.Logging.html.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.Logging.TailOption.html;\n import com.google.cloud.logging.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LoggingOptions.html;\n\n public class TailLogEntries {\n\n public static void main(String[] args) throws Exception {\n // TODO(developer): Optionally provide the logname as an argument.\n String logName = args.length \u003e 0 ? args[0] : \"\";\n\n https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LoggingOptions.html options = https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LoggingOptions.html.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LoggingOptions.html#com_google_cloud_logging_LoggingOptions_getDefaultInstance__();\n try (https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.Logging.html logging = options.getService()) {\n\n // Optionally compose a filter to tail log entries only from specific log\n https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LogEntryServerStream.html stream;\n\n if (logName != \"\") {\n stream =\n logging.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.Logging.html#com_google_cloud_logging_Logging_tailLogEntries_com_google_cloud_logging_Logging_TailOption____(\n https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.Logging.TailOption.html.filter(\n \"logName=projects/\" + options.getProjectId() + \"/logs/\" + logName));\n } else {\n stream = logging.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.Logging.html#com_google_cloud_logging_Logging_tailLogEntries_com_google_cloud_logging_Logging_TailOption____();\n }\n System.out.println(\"start streaming..\");\n for (https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LogEntry.html log : stream) {\n System.out.println(log);\n // cancel infinite streaming after receiving first entry\n stream.https://cloud.google.com/java/docs/reference/google-cloud-logging/latest/com.google.cloud.logging.LogEntryServerStream.html#com_google_cloud_logging_LogEntryServerStream_cancel__();\n }\n }\n }\n }\n\n### Node.js\n\n\nTo learn how to install and use the client library for Logging, see\n[Logging client libraries](/logging/docs/reference/libraries).\n\n\nTo authenticate to Logging, set up Application Default Credentials.\nFor more information, see\n\n[Set up authentication for a local development environment](/docs/authentication/set-up-adc-local-dev-environment).\n\n const {Logging} = require('https://cloud.google.com/nodejs/docs/reference/logging/latest/overview.html');\n const logging = new https://cloud.google.com/nodejs/docs/reference/logging/latest/logging/logging.html();\n\n /**\n * TODO(developer): Replace logName with the name of your log.\n */\n const log = logging.log(logName);\n console.log('running tail log entries test');\n\n const stream = log\n .tailEntries({\n filter: 'timestamp \u003e \"2021-01-01T23:00:00Z\"',\n })\n .on('error', console.error)\n .on('https://cloud.google.com/nodejs/docs/reference/logging/latest/logging/entry.html', resp =\u003e {\n console.log(resp.entries);\n console.log(resp.suppressionInfo);\n // If you anticipate many results, you can end a stream early to prevent\n // unnecessary processing and API requests.\n https://cloud.google.com/nodejs/docs/reference/logging-bunyan/latest/logging-bunyan/loggingbunyan.html.end();\n })\n .on('end', () =\u003e {\n console.log('log entry stream has ended');\n });\n\n // Note: to get all project logs, invoke logging.tailEntries\n\nWhat's next\n-----------\n\n\nTo search and filter code samples for other Google Cloud products, see the\n[Google Cloud sample browser](/docs/samples?product=logging)."]]
