Come impostare ulimits in servizio con systemd?

Come impostare un ulimit su un'unità di servizio systemd?

Questa domanda di StackOver spiega che systemd ignora gli ulimits di sistema

Come sarebbe la sintassi per impostare le seguenti ulimits?

ulimit -c
ulimit -v
ulimit -m

[Unit]
Description=Apache Solr
After=syslog.target network.target remote-fs.target nss-lookup.target

[Service]
Type=forking
SOLR_INSTALL_DIR=/opt/solr
SOLR_ENV=/etc/default/solr.in.sh
RUNAS=solr

SOLR_PID_DIR="/var/solr"
SOLR_HOME="/opt/solr/server/solr"
LOG4J_PROPS="/var/solr/log4j.properties"
SOLR_LOGS_DIR="/opt/solr/server/logs"
SOLR_PORT="8389"

PIDFile=/var/solr/solr-8389.pid
ExecStart=/opt/solr/bin/solr start
ExecStatus=/opt/solr/bin/solr status
ExecStop=/opt/solr/bin/solr stop
Restart=on-failure
User=solr

SuccessExitStatus=143 0

[Install]
WantedBy=multi-user.target

La mappatura di systemd limita a ulimit

Directive        ulimit equivalent     Unit
LimitCPU=        ulimit -t             Seconds      
LimitFSIZE=      ulimit -f             Bytes
LimitDATA=       ulimit -d             Bytes
LimitSTACK=      ulimit -s             Bytes
LimitCORE=       ulimit -c             Bytes
LimitRSS=        ulimit -m             Bytes
LimitNOFILE=     ulimit -n             Number of File Descriptors 
LimitAS=         ulimit -v             Bytes
LimitNPROC=      ulimit -u             Number of Processes 
LimitMEMLOCK=    ulimit -l             Bytes
LimitLOCKS=      ulimit -x             Number of Locks 
LimitSIGPENDING= ulimit -i             Number of Queued Signals 
LimitMSGQUEUE=   ulimit -q             Bytes
LimitNICE=       ulimit -e             Nice Level 
LimitRTPRIO=     ulimit -r             Realtime Priority  
LimitRTTIME=     No equivalent

Se un ulimit è impostato su "illimitato", impostarlo su "infinito" nella configurazione di systemd

ulimit -c unlimitedè uguale LimitCORE=infinity
ulimit -v unlimitedè uguale LimitAS=infinity
ulimit -m unlimitedè la stessaLimitRSS=infinity

Quindi sarebbe una configurazione finale

[Unit]
Description=Apache Solr
After=syslog.target network.target remote-fs.target nss-lookup.target

[Service]
WorkingDirectory=/opt/solr/server
User=solr
Group=solr
LimitAS=infinity
LimitRSS=infinity
LimitCORE=infinity
LimitNOFILE=65536
ExecStart=/opt/solr/bin/solr-foo
Restart=on-failure
SuccessExitStatus=143 0
SyslogIdentifier=solr


[Install]
WantedBy=multi-user.target

In questo caso particolare, non conosco il percorso java completo (poiché cambia in base al tipo di server) e systemd non è contento dei percorsi relativi, avvolgo il comando java in un semplice script bash situato in /opt/solr/bin/solr-foo

#!/bin/bash

. /opt/solr/bin/solr.in.sh

# Load $JAVA_HOME from 1 of 2 places where it could be defined
# Last one wins
if [[ -f "/etc/profile.d/jdk.sh" ]]; then
  . /etc/profile.d/jdk.sh
fi

if [[ -f "/etc/profile.d/zing.sh" ]]; then
  . /etc/profile.d/zing.sh
fi

exec ${JAVA_HOME}/bin/java -server \
  -Djetty.port=${SOLR_PORT} \
  ${SOLR_JAVA_MEM} \
  ${GC_TUNE} \
  ${GC_LOG_OPTS} \
  -DzkClientTimeout=${ZK_CLIENT_TIMEOUT} \
  -DzkHost=${ZK_HOST} \
  -DSTOP.PORT=7900 \
  -DSTOP.KEY=foobar \
  -Dhost=${SOLR_HOST} \
  -Duser.timezone=${SOLR_TIMEZONE} \
  -Djetty.home=/opt/solr/server \
  -Dsolr.solr.home=${SOLR_HOME} \
  -Dsolr.install.dir=/opt/solr \
  -Dlog4j.configuration=file:/var/solr/log4j.properties \
  -Xss256k \
  -Dbootstrap_conf=true \
  -Dbootstrap_confdir=/opt/solr/server/solr/configsets/foobar/conf \
  -Dcollection.configName=foobar \
  -jar start.jar --module=http