I've been using rundeck (an automation platform) to manage Linux servers for quite a while. Recently I've expanded the practice to Windows servers and have had some difficulties with authentication because either OS packages or Python modules were missing. Rundeck supports 4 types of authentication -- basic, credssp, ntlm, kerberos for the Windows system. It … Continue reading Managing Windows servers with Rundeck?
Category: Linux
sudo not working with wildcard matching?
When working with sudo, one subtle thing is about shell wildcard matching. I didn't notice this until recently I needed to use a script to copy files from a remote server with one user A, but eventually put the files under another user B with changing owernship and permissions. My steps were scp, mv, chown, … Continue reading sudo not working with wildcard matching?
Troubleshooting SSH slow login
In another post I wrote before, slow SSH login issue -- after you enter the username, it takes some time (a minute or a few) to show the password prompt, could be due to the wrong DNS configuration. And there is a configuration option UseDNS for sshd and by default it's enabled (value yes) which … Continue reading Troubleshooting SSH slow login
reboot, shutdown, halt & systemctl
If you have been working on Linux for some time -- longer than a few years, you probably has come from runlevel days which the services are managed by SysV init scripts. So you are familiar with the commands like shutdown, init, halt, reboot etc. which are used to start, stop or bring the system … Continue reading reboot, shutdown, halt & systemctl
BASH auto complete doesn’t work? Watch out the mount option “noexec”
BASH is one of popular shell environment on Linux OS. And when using it, everyone loves the auto complete feature, you just tab after you enter first few letters and BASH will match commands/files for you. However, a few weeks ago when I went into a newly staged Oracle Linux 8 system with some kind … Continue reading BASH auto complete doesn’t work? Watch out the mount option “noexec”
Could not open file /var/log/sssd/sssd.log –Permission denied
This was the exactly the same problem I ran into before on auditd. The log directory for sssd was recreated somehow but the context of SELinux was not restored. That caused even root could not create the sssd logs under the directory and the service could not start. sssd[sssd][17594]: Could not open file [/var/log/sssd/sssd.log]. Error: … Continue reading Could not open file /var/log/sssd/sssd.log –Permission denied
Ubuntu — Stop constantly blinking WiFi LED
After installing Ubuntu on an old Dell laptop to replace Windows 7, I've noticed the WiFi LED indicator kept blinking all the time which is quite annoying. That reminded me a couple year ago when I switched on winter tires for the first time on my car, the tire pressure warning light turned on because … Continue reading Ubuntu — Stop constantly blinking WiFi LED
PowerShell on Linux
When working in a heterogeneous envrionment with different types of OS (Windows, Linux etc.), you probably want to manage systems from a central place. People usually have a RDP session of Windows, then using a multi connection manager like mRemoteNG to connect those systems. To automate your tasks with scripts, you want them fired from … Continue reading PowerShell on Linux
bash (sh): Operation not permitted
Ran into an issue on another day when login as a normal user on an Oralce Linux 8 system. Once login, there were messages on the screen like /bin/sh: /usr/libexec/grepconf.sh: Operation not permitted It looks like loading the user's shell profile which failed to exeute this script. It didn't really affect what I was doing, … Continue reading bash (sh): Operation not permitted
Can’t login to Ubuntu GUI with correct password
I barely use any Debian linux distribution although it's quite popular such as Ubuntu desktop is widely used on personal computer. A few weeks ago a friend asked me what to do with his old laptop with Windows 7 which is end of life, he would like to give it to his young kid to … Continue reading Can’t login to Ubuntu GUI with correct password
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