Red Branch | For Future Reference …
Courtesy of Pete in work. To enable hostname auto completion in Bash, do the following: dig pop @dns.server.tld axfr | awk ‘$4 ~ /\yA\y/ && gsub(/.$/,””,$1) {print $1}’ > ~/.hosts If you would prefer to filter out hosts e.g. dev and swi, change awk to: awk ‘$4 ~ /\yA\y/ && ! /dev/ && ! /swi/… Read more »
The default user and password combination for a Dell iDRAC interface is root / calvin It can be manually reset when logging in to the web interface but when doing many machines at once and many actions at the same time the racadm tool is handy. To change the password use: racadm -r 192.168.1.23 -u… Read more »
Install the prerequisites. Below works for Debian-based distros such as Ubuntu/Mint:
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apt-get install libzookeeper-mt-dev |
Install python libraries:
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pip install zkpython pykeeper |
Example code below shows making a connection, getting the names of some child nodes and pulling info from each of those child nodes:
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import pykeeper import json client = pykeeper.ZooKeeper('192.168.1.2:2181') client.connect() coords = client.get_children('/druid/coordinator/_COORDINATOR') list_of_coord_addresses = [] for coord in coords: zk_coord = client.get('/druid/coordinator/_COORDINATOR/%s' % coord ) list_of_coord_addresses.append(zk_coord[0]) print(list_of_coord_addresses) |
Unfortunately I can’t get this installed on CentOS.
Ubuntu 18.04 includes check-mk in the repository version but it is an older version 1.2.8 (at the time of writing). Download check mk raw (get the latest stable URL from the website) :
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wget https://mathias-kettner.de/support/1.5.0p7/check-mk-raw-1.5.0p7_0.bionic_amd64.deb |
Try installing it:
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dpkg -i dpkg -i check-mk-raw-*.deb |
You may get dependency issues which can be resolved with:
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apt-get install -f |
Then try the install again:
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dpkg -i check-mk-raw-*.deb |
In the update from iDRAC 8 to iDRAC 9 it has been infuriating searching the ‘Storage’ menu only to discover that the storage is managed under ‘Configuration > Storage Configuration’ I’m convinced the user experience could be better! At the very least a link through for configuration.
Journald logs can be cleared by timescale or size as follows. Keep only 5 days worth of logs journalctl –vacuum-time=5d Retain only the past 500 MB: journalctl –vacuum-size=500M
The puppet agent can be disabled from running with:
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puppet disable "Some message here" |
And it can be re-enabled with:
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puppet enable |
But to check if puppet is currently disabled there is no check command. Instead look for the existence of the agent_disabled.lock file under:
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$vardir/state/agent_disabled.lock |
For the systems I was checking this was at:
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/opt/puppetlabs/puppet/cache/state/agent_disabled.lock |
I sometimes want to omit directories from my disk usage (du -sh *) checks. This includes virtual files systems such as proc / dev and also mounts to other filesystems (data in the example below). This is what works for me:
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du --exclude={proc,sys,dev,data} -sh * |
The equals sign appears to be optional and worked both ways for me…. Read more »
I was checking the memory on approximately 140 servers using ansible:
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ansible --user root -k -i servers.list -m shell -a "free -h; mysql" test |
but the output appears over several lines e.g.
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server103.domain.dev | SUCCESS | rc=0 >> total used free shared buffers cached Mem: 94G 44G 49G 59M 203M 4.6G -/+ buffers/cache: 39G 54G Swap: 0B 0B 0B |
but what I wanted was the server name and the total memory available. So I first grepped the output to remove the lines I didn’t want e.g.
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grep -A3 "domain.dev" | egrep -v "^--|Swap|total|buffer" |
leaving me with two lines of… Read more »
In a Cloudera cluster we had a few nodes reporting the following error message in the logs under hadoop-cmf-hdfs-DATANODE-whatever.com.log.out The error included: Datanode denied communication with namenode because the host is not in the include-list: : DatanodeRegistration One solution could be to ‘Refresh Node List’ as shown in the screenshot below. Find it by clicking… Read more »
