# problem with postfix

1) doesnt populate the mail relay correctly - this needs to do a group check on item[0] or something so we can get mail01 as the actual relay for clients
2) sudo nano -cw /etc/postfix/header_check does an outbound replace - we dont want that for alertmanager as we may want to send out different classes of email 

# node exporter stats collection

systemctl service file /usr/lib/systemd/system/node_exporter.service loads $OPTIONS
/etc/sysconfig/node_exporter contains $OPTIONS

OPTIONS="--collector.textfile.directory /var/lib/node_exporter/textfile_collector"

Chris used the following switches, and a custom/cut-down dashboard:

    --collector.cpu \
    --collector.diskstats \
    --collector.filesystem \
    --collector.loadavg \
    --collector.meminfo \
    --collector.filefd \
    --collector.netdev \
    --collector.stat \
    --collector.netstat \
    --collector.systemd \
    --collector.uname \
    --collector.vmstat \
    --collector.time \
    --collector.mdadm \
    --collector.tcpstat \
    --collector.hwmon \
    --collector.arp \
    --web.max-requests=40 \
    --web.listen-address=0.0.0.0:{{ node_exporter_port }} \
    --web.telemetry-path=/metrics

    The full list of node exporter collections is @ https://github.com/prometheus/node_exporter
    we can disable all collectors and then enable only the once we want

    --web.disable-exporter-metrics
    arp WANT
    bonding WANT
    # boottime - provided in stat
    cpu WANT
    diskstats WANT
    filesystem WANT
    hardwaremon
    infiniband WANT
    loadavgs WANT
    meminfo WANT
    # netclass - lots of useful stuff but remains static really
    netdev WANT
    nfs WANT
    nfsd WANT
    nvme WANT
    # os - fairly static do we need a million entries of rhel8
    powersupplyclass
    sockstat
    stat WANT
    thermal_zone
    time
    vmstat WANT
    xfs WANT - we assume nearly everything will run xfs now
    
    15/~80 collectors should chop out a lot of data 
    we dont know how to marry metric names to fields though? - this guy has a methodology - its nice too https://mac-blog.org.ua/node-exporter-metrics