Hi Florian, I don’t know the answer to your specific question, but I would like to suggest a different approach. Excuse me in advance, I usually hate suggesting different approaches.
The reason why I suggest a different approach is because logging via HTTP can be blocking a thread e.g. until a timeout. I wrote a bit more here: https://sematext.com/blog/logging-libraries-vs-log-shippers/ In your particular case, I would let Solr log normally (to stdout) and have something pick the logs up from the Docker socket. I’m used to Logagent (see https://sematext.com/docs/logagent/installation-docker/) which can parse Solr logs out of the box (see https://github.com/sematext/logagent-js/blob/master/patterns.yml#L140). But there are other options, like Fluentd or Logstash. Best regards, Radu > On 17 Jun 2020, at 10:33, Krönert Florian <florian.kroen...@orbis.de> wrote: > > Hello everyone, > > We want to log our queries to a HTTP endpoint and tried configuring our log4j > settings accordingly. > We are using Solr inside Docker with the official Solr image (version > solr:8.3.1). > > As soon as we add a http appender, we receive errors on startup and solr > fails to start completely: > > 2020-06-17T07:06:54.976390509Z DEBUG StatusLogger > JsonLayout$Builder(propertiesAsList="null", objectMessageAsJsonObject="null", > ={}, eventEol="null", compact="null", complete="null", locationInfo="null", > properties="true", includeStacktrace="null", stacktraceAsString="null", > includeNullDelimiter="null", ={}, charset="null", footerSerializer=null, > headerSerializer=null, Configuration(/var/solr/log4j2.xml), footer="null", > header="null") > 2020-06-17T07:06:55.121825039Z 2020-06-17 > 07:06:55.104:WARN:oejw.WebAppContext:main: Failed startup of context > o.e.j.w.WebAppContext@611df6e3{/solr,file:///opt/solr-8.3.1/server/solr-webapp/webapp/,UNAVAILABLE}{/opt/solr-8.3.1/server/solr-webapp/webapp} > 2020-06-17T07:06:55.121856339Z java.lang.NoClassDefFoundError: Failed to > initialize Apache Solr: Could not find necessary SLF4j logging jars. If using > Jetty, the SLF4j logging jars need to go in the jetty lib/ext directory. For > other containers, the corresponding directory should be used. For more > information, see: http://wiki.apache.org/solr/SolrLogging > > It seems that only when using the http appender these jars are needed, > without this appender everything works. > Can you point me in the right direction, where I need to place the needed > jars? Seems to be a little special since I only access the /var/solr mount > directly, the rest is running in docker. > > Kind Regards, > > Florian Krönert > Senior Software Developer > > > > ORBIS AG | Planckstraße 10 | D-88677 Markdorf > Phone: +49 7544 50398 21 | Mobile: +49 162 3065972 | E-Mail: > florian.kroen...@orbis.de > www.orbis.de > > > > > Registered Seat: Saarbrücken > Commercial Register Court: Amtsgericht Saarbrücken, HRB 12022 > Board of Management: Thomas Gard (Chairman), Michael Jung, Stefan Mailänder, > Frank Schmelzer > Chairman of the Supervisory Board: Ulrich Holzer > > > > > >