SRE – Systems and Network
Tips and tricks
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Requirements This tutorial has been written for this specific following configuration. It might work if you have something similar, but you might have to tweak some parameters. Here are the components that have been used: Initial setup As a start,…
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Get timing details with curl command
It is sometimes useful to get the timing details of a curl request, for analysis, investigation or just monitoring. Thanks to curl implementation, there’s an easy way to get timing details. This can be done with two ways: a formatting…
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Equivalent of tail -f for Windows – monitor log file
It’s easy on a linux system to monitor in real time the content of a log file by using If you want to do the same thing with windows, you can easily do that by using
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Display log file with timestamp in human-readable format
By default, some logs (like squid logs) will be recorded with unix timestamp, stored as <unixtimestamp>.<centisecond> which are hard to read for analysis. You would have for example this kind of logs: In order to display them in human readable…
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Check expiration dates for local certificates
This script does allow a quick check of the local certificates, in order to make sure none of them is expired: The output will look like:
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Find parent PID of a running process in Linux
When a process is starting sub-processes on a linux system, you would have to stop every single child processes in order to stop them all. Instead of that, you can easily kill the parent process so it can stop spawning…
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Kill all sub-processes of a bash script with SIGINT (CTRL-C)
If you have a bash script running with a very long loop (or infinite one) and starting multiple background processes, you will notice that when you stop the main process, all the child processes will continue to live until you…
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Install pip packages offline
Sometimes you might need to download some pip packages offline on a device with no Internet access. This is entirely feasible through multiple ways. Install a single package: You first need to download that package on a device with Internet…
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Issue with sudo – sudo:auth could not identify password for [user]
If you get the following error when trying to execute a sudo command, despite the fact that you configured your sudoers or sudoers.d config file properly: Then, you might need to have a look at the PAM configuration on your…
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Use rsyslog omprog with a Python script
If you want to filter some specific logs and redirect them to another server or to another file, you can use the module provided with rsyslog called “omprog”. Thanks to that module, you can just ask rsyslog to execute a…