Enable secure logs¶

This guide will show you how to enable shipping of secure logs for your application

Some applications have logs with information that should not be stored with the normal application logs. To support this a directory for these logs can be mounted in the application, and the content of logs written here will be transferred to separate indices in Elasticsearch.

Deprecated syntax

This is guide contains a deprecated syntax for enabling secure logs. With the new syntax all logs will be sent to secure logs when enabled and will not require any special log configuration.

1. Prerequisites¶

If your NAIS team has already at any point produced secure logs, you can skip this step.

If your team has never before produced secure logs, before enabling them for the first time, give a warning in #kibana Slack channel. There are some things that need to be adjusted before a new team can start sending. Remember to include the name of your NAIS team in the message.

2. Enabling secure logs manifest ¶

.nais/app.yaml

spec:
    secureLogs:
        enabled: true

3. Set log rotation¶

With secure logs enabled a directory /secure-logs/ will be mounted in the application container. Every *.log file in this directory will be monitored and the content transferred to Elasticsearch. Make sure that these files are readable for the log shipper (the process runs as uid/gid 1065).

directory size limit

The /secure-logs/ directory has a size limit of 128Mb, and it's the application's responsibility to ensure that this limit is not exceeded.

If the limit is exceeded the application pod will be evicted and restarted.

Example log configuration¶

Log files should be in JSON format as the normal application logs. Here is an example configuration of JSON logging with a size based rolling file appender in Logback:

  <appender name="secureLog" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>/secure-logs/secure.log</file>
    <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
      <fileNamePattern>/secure-logs/secure.log.%i</fileNamePattern>
      <minIndex>1</minIndex>
      <maxIndex>1</maxIndex>
    </rollingPolicy>
    <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
      <maxFileSize>50MB</maxFileSize>
    </triggeringPolicy>
    <encoder class="net.logstash.logback.encoder.LogstashEncoder" />
  </appender>

4. Configure log shipping¶

Example configuration selecting which logs go to secure logs

logback.xml

<configuration>
    <appender name="appLog" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="net.logstash.logback.encoder.LogstashEncoder"/>
        <filter class="ch.qos.logback.core.filter.EvaluatorFilter">
            <evaluator class="ch.qos.logback.classic.boolex.OnMarkerEvaluator">
                <marker>SECURE_LOG</marker>
            </evaluator>
            <OnMismatch>NEUTRAL</OnMismatch>
            <OnMatch>DENY</OnMatch>
        </filter>
    </appender>

    <appender name="secureLog" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>/secure-logs/secure.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
            <fileNamePattern>/secure-logs/secure.log.%i</fileNamePattern>
            <minIndex>1</minIndex>
            <maxIndex>1</maxIndex>
        </rollingPolicy>
        <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
            <maxFileSize>128MB</maxFileSize>
        </triggeringPolicy>
        <encoder class="net.logstash.logback.encoder.LogstashEncoder"/>
        <filter class="ch.qos.logback.core.filter.EvaluatorFilter">
            <evaluator class="ch.qos.logback.classic.boolex.OnMarkerEvaluator">
                <marker>SECURE_LOG</marker>
            </evaluator>
            <OnMismatch>DENY</OnMismatch>
            <OnMatch>NEUTRAL</OnMatch>
        </filter>
    </appender>

    <root level="INFO">
        <appender-ref ref="appLog"/>
        <appender-ref ref="secureLog"/>
    </root>
</configuration>

5. Use secure logs in application¶

Using the Logback config below you can log to secure logs by writing Kotlin-code like this:

import org.slf4j.Logger
import org.slf4j.Marker
import org.slf4j.MarkerFactory
...
val log: Logger = ...
val SECURE: Marker= MarkerFactory.getMarker("SECURE_LOG")
...
log.info(SECURE, "Sensitive data here") // Logging to secure logs
log.info("Non-sensitive data here") // Logging to non-secure app logs

See doc on Logback filters and markers See Example log configuration for further configuration examples.

Non-JSON logs¶

If the logging framework used doesn't support JSON logging, it is also possible to use multiline logs in this format:

<iso8601 timestamp> <log level> <message>
<message cont.>
<message cont.>

Files on this format must be named *.mlog.

Sending logs with HTTP¶

If you do not want to have these logs as files in the pod, it is also possible to use HTTP to write logs. POST your log entry as JSON to http://localhost:19880

curl -X POST -d '{"log":"hello world","field1":"value1"}' -H 'Content-Type: application/json' http://localhost:19880/