Utility for request tracing, log enrichment and auditing.

Maven Dependency to use this project

<dependency>
    <groupId>com.ge.predix</groupId>
    <artifactId>spring-log-filter</artifactId>
    <version>${spring-log-filter.version}</version>
    <exclusions>
        <exclusion>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
        </exclusion>
    </exclusions>
</dependency>

HTTP Request tracing

• You will need to configure the following bean to specify how the filter determines tenant in a request

  <bean id="logFilter" class="com.ge.predix.log.filter.LogFilter">
      <constructor-arg>
          <set value-type="java.lang.String">
              <value>${BASE_DOMAIN:localhost}</value>
          </set>
      </constructor-arg>
      <constructor-arg>
          <set value-type="java.lang.String">
              <value>Predix-Zone-Id</value>
          </set>
      </constructor-arg>
      <constructor-arg value="DEFAULT_ZONE_NAME" />
  </bean>

Enable logging in Predix common format

Sample log message:

{
    "time": "2017-07-10T20:59:48.923+0000",
    "tnt": "uaa",
    "corr": "02b47904ae01e8ec",
    "appn": "uaa-local",
    "dpmt": "b408c0ad-854f-44c4-8166-820259f6b4c0",
    "inst": "c089b940-0626-4d0b-5817-3f2d1229d7d2",
    "tid": "http-nio-8080-exec-3",
    "mod": "ClientController.java",
    "lvl": "ERROR",
    // either:
    "msg": "Failure during:\nPOST /v1/client",
    // or:
    "msg": [
        "Failure during:",
        "POST /v1/client"
    ],
    "stck": [
        "error=\"access_denied\", error_description=\"Error requesting access token.\"",
        "at org.springframework.security.oauth2.client.token.OAuth2AccessTokenSupport.retrieveToken(OAuth2AccessTokenSupport.java:145)",
        "at org.springframework.security.oauth2.client.token.grant.client.ClientCredentialsAccessTokenProvider.obtainAccessToken(ClientCredentialsAccessTokenProvider.java:44)",
        "at org.springframework.security.oauth2.client.token.AccessTokenProviderChain.obtainNewAccessTokenInternal(AccessTokenProviderChain.java:148)",
        "at org.springframework.security.oauth2.client.token.AccessTokenProviderChain.obtainAccessToken(AccessTokenProviderChain.java:121)",
        "... 150 more"
    ]
}

MDC enrichment

• LogFilter enriches SLF4J MDC with Cloud Foundry VCAP information.
  • The log filter adds the following VCAP information to the MDC:

    APP_ID
    APP_NAME
    INSTANCE_ID
    

    • APP_NAME value can be customized using LogFilter.setCustomAppName
  • It also adds the following from HTTP headers:

    Zone-Id
    

This information can be used by logging formatters to include in log messages. (see below)

Logback configuration

The PredixEncoder formats the log in JSON and includes the cloudfoundry VCAP info listed in the section above.

• Configure logback.xml to use PredixEncoder:

  <appender name="myAppender" class="ch.qos.logback.core.ConsoleAppender">
      <encoder class="com.ge.predix.logback.PredixEncoder">
          <tenantKey>tenant</tenantKey>
          <correlationKey>traceId</correlationKey>
          <messageLineSeparatorRegex>\n</messageLineSeparatorRegex>
      </encoder>
  </appender>

All properties are optional. See the following sections for more details.

Log4J 2 configuration

The PredixLayout formats the log in JSON and includes the cloudfoundry VCAP info listed in the section above.

• Configure log4j2.xml to use PredixLayout:

  <Console name="CONSOLE" target="SYSTEM_OUT">
      <PredixLayout tenantKey="tenant" correlationKey="traceId" messageLineSeparatorRegex="\n" />
  </Console>

All properties are optional. See the following sections for more details.

Tenant field customization

In the default mode, the logger populates the tnt field of the log using the "Zone-Id" attribute of the SLF4J MDC. This provides out-of-the-box integration with the LogFilter. See the section on MDC enrichment for more details.

If tenant information is published to a different MDC field, the optional tenantKey property can be used to configure the alternate field. If this property is set, the tnt field of the log is populated with the value of that MDC field.

Correlation field customization

In the default mode, the logger populates the corr field of the log using the "traceId" attribute of the SLF4J MDC. This provides out-of-the-box integration with OpenTelemetry and Spring Cloud Sleuth.

If correlation information is published to a different MDC field, the optional correlationKey property can be used to configure the alternate field. If this property is set, the corr field of the log is populated with the value of that MDC field.

Multi-line message support

In the default mode, the encoder outputs the log message using the msg field.

If the optional messageLineSeparatorRegex property is explicitly set, it activates line detection on the encoder. In this mode, the message is pre-processed to split it into multiple lines using the provided regex.

Integration with Predix Audit

Optionally, this filter can also be used to generate audit events which includes the request and response payload.

• Wire an AuditEventProcessor bean to LogFilter, to receive AuditEvent for each request.

Build

mvn clean package

Run Integration Tests

mvn clean verify

LICENSE

This project is licensed under Apache v2.