Remote log tailing

[pun-ky]

Imagine

sh gradlew aemTail -Paem.instance.name=int-publish -Paem.tail.name=logs/error.log

or using shorthand syntax:

sh gradlew aemTail -Paem.tail=int-publish:logs/error.log

or even if default specified as:

aem {
    config {
        tail = propParser.string("aem.tail", "int-author:logs/error.log")
        tailMaxErrors = 20
        tailMaxWarnings = 30
        /*
        tailStatus = { status-> 
            if (status.logs.filter { it.contains("error") }.isNotEmpty()  {
                status.text = "UNSTABLE"
            } else 
                status.text = "STABLE" {
            }
           def grep = propParser.string("aem.tail.grep")
           if (grep != null) {
                status.grep(grep)
           }
         }
    }
}

then just

sh gradlew aemTail

will grab logs using url http://x.x.x.x:4503/system/console/slinglog/tailer.txt?_dc=1520834477194&tail=400&name=%2Flogs%2Ferror.log

and output it interactively as aemAwait does.

it would be nice that status bar will compute some summary like below:

<-------------> 0% EXECUTING [9m 33s]
> :aem:aemTail > local-author [errors: 40, warnings: 120] - UNSTABLE
12.03.2018 06:57:02.117 *INFO* [qtp687303746-206125] org.apache.sling.auth.core.impl.SlingAuthenticator getAnonymousResolver: Anonymous access not allowed by configuration - requesting credentials
12.03.2018 06:57:04.119 *INFO* [qtp687303746-206125] org.apache.sling.auth.core.impl.SlingAuthenticator getAnonymousResolver: Anonymous access not allowed by configuration - requesting credentials

UNSTABLE/STABLE displayed will depend on configured maximum error/warnings per minute rate.

[pun-ky]

I can consider implementing it if there will be some positive votes on comment above

[piotr-wilczynski]

Could be useful with filtering capability

[pun-ky]

yep, in callback, I've just updated comment for DSL proposal

[pun-ky]

This feature will have another form as illustrated because multi-line logging in progress logger is not possible directly. Instead aemTail will continously grab and append log lines from all instances into local files e. G build/aem/aemTail/local- author/logs/error.log. User will be able to view that file in any tool that he like e.g Unix tail program or even some advanced tool like intellij grep console plugin or other tool which could highlight log lines or parse it. In progress logger there will be printed summary similar to which aemAwait is showing but it will count errors and warnings per instance / that will be configurable / what will be displayed there

[pun-ky]

final design / default behavior:

sh gradlew aemTail -Paem.tail=[int-author:logs/error.log,int-publish:logs/error.log]

• interactively grab all logs from all instances and write them to files aemTail/[instance.name]/[error.log]
• append only new ones basing on timestamp in log entries gathered using /system/console/slinglog/tailer.txt?_dc=1520834477194&tail=400&name=%2Flogs%2Ferror.log
• display combined lines from all instances that are matching filter lambda or one of predefined filters like for displaying only errors and warn, optionally infos etc
• display summary on progress logger (error rate per minute etc)

[mierzwid]

Additional comments:

• this task will be added in the tooling plugin

Next steps:

• some exceptions can be blacklisted - if they are known not harmful that are frequent in logs the plugin will ignore them
• developer would get notified about problematic log entries from all environments after deployment, or even when clicking through one instance
  • notification in a popup, so there is no need to tail all log files from all instances

[pun-ky]

released as 6.1.0-beta :)