I recently installed an Ubuntu 21.04 and when I wanted to install Atom editor, I was given the following warning about apt-key being deprecated: Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)). After a bit of Googling around, I stumbled on this post on askubuntu.com explaining why apt-key was being deprecated. Then the folks at docker.com give a nice easy command to convert an old PGP key in base64 to a keyring. ...

After reading many articles and trying many things, this is how I solved it. For docker daemon itself to use a proxy, configure environment variables using systemd file /etc/systemd/system/docker.service.d/http-proxy.conf : [Service] Environment="HTTP_PROXY=http://user:pass@proxy.domain.com:3128/" Environment="HTTPS_PROXY=http://user:pass@proxy.domain.com:3128/" Environment="NO_PROXY=localhost,docker,*.domain.com" For gitlab-runner daemon itself to use a proxy, configure environment variables using systemd file /etc/systemd/system/gitlab-runner.service.d/http-proxy.conf : [Service] Environment="HTTP_PROXY=http://user:pass@proxy.domain.com:3128/" Environment="HTTPS_PROXY=http://user:pass@proxy.domain.com:3128/" Environment="NO_PROXY=localhost,docker,*.domain.com" Reload systemd and restart docker daemon: systemctl daemon-reload systemctl restart docker For git commands run by gitlab-runner to use a proxy, use gitlab-runner config file. In /etc/gitlab-runner/config.toml , under [[runners]] , add the following line: ...

It happens I recently had to install Gitlab and was a bit lost about what to do right after the setup finished, perhaps this will help. By default, Gitlab stores its data files in /var/opt/gitlab and its backups in /var/opt/gitlab/backups. It would be a good idea to use dedicated partitions for each of those directories. Let’s say you use /dev/sdb1 for Gitlab data and /dev/sdc1 for the backups. gitlab-ctl stop mkdir /mnt/gitlab mount /dev/sdb1 /mnt/gitlab mkdir /mnt/gitlab/backups mount /dev/sdc1 /mnt/gitlab/backups tar -C /var/opt -cf - gitlab | tar -C /mnt -xpsf - umount /mnt/gitlab/backups umount /mnt/gitlab mv /var/opt/gitlab /var/opt/gitlab.old mkdir /var/opt/gitlab mount /dev/sdb1 /var/opt/gitlab mount /dev/sdc1 /var/opt/gitlab/backups gitlab-ctl start Do not forget to edit /etc/fstab. Configure your timezone: https://docs.gitlab.com/ee/administration/timezone.html Note: all usual timezones are not available. ...

Here is how to establish an IPsec tunnel between an Ubuntu 20.04 host and a Mikrotik router using IKEv2. The 2 endpoints of the tunnel are: ubuntu.xentoo.info : the Ubuntu server. This server has a local private subnet 10.0.0.0/24 and a fixed public IPv4 address 1.2.3.4 . The hostname ubuntu.xentoo.info resolves to the public IP address. mikrotik.xentoo.info : the Mikrotik router. This router has a local private subnet 192.168.0.0/24 and a dynamic public IPv4 address. I will use fqdn identifiers, pre-shared-key and both IKE and ESP will have the same parameters: ...

“Firefly III” is a (self-hosted) manager for your personal finances. You can find more about it on the following sites: https://github.com/firefly-iii/firefly-iii https://docs.firefly-iii.org/ Install prerequisites Let’s first install the requirements to run Firefly. Firefly documentation says it runs on PHP 7.2 but that’s wrong, it needs >=7.3 . Unfortunately, Ubuntu 19.04 comes with PHP 7.2 by default, so we need to use a PPA to have a more recent version. ondrej/php PPA has version 7.4 at this time, that will be perfect. ...

Hi guys, I moved to Luxembourg and I have opted for Tango Fiber. Their router is a Fritz!box which I do not like at all. I have a spare Mikrotik router, so here is how to configure. Tango Fiber uses PPPoE over VLAN 35, MTU is 1480. You need to ask the PPP credentials via a contact form on the website, they will answer within a few days. I have decided to use ether1 to connect the Fiber and create a VLAN interface named ether1.35 on it. ...

As a personal note to myself :-) apt-get install make gcc pkg-config libasound2-dev wget http://www.pjsip.org/release/2.6/pjproject-2.6.tar.bz2 tar -xjf pjproject-2.6.tar.bz2 cd pjproject ./configure && make dep && make sudo make install sudo cp pjsip-apps/bin/pjsua-x86_64-unknown-linux-gnu /usr/local/bin/pjsua That’s it!

For easier use with Cacti, it is easier to group statistics per type instead of per CPU. So you would have a parent OID for CPU time spent by user with many values (one per CPU). Put the following in /etc/snmp/percpudetail: #!/bin/bash case "$1" in "user") grep ^cpu /proc/stat | awk '{print 2}' ;; "nice") grep ^cpu /proc/stat | awk '{print 3}' ;; "system") grep ^cpu /proc/stat | awk '{print 4}' ;; "idle") grep ^cpu /proc/stat | awk '{print 5}' ;; "iowait") grep ^cpu /proc/stat | awk '{print 6}' ;; "irq") grep ^cpu /proc/stat | awk '{print 7}' ;; "softirq") grep ^cpu /proc/stat | awk '{print 8}' ;; esac Make it executable: ...

I needed to export detailed CPU statistics from Linux servers using SNMP. While UCD-SNMP-MIB export some detailed stats, it only does it for the whole system. I may have missed something easier though :-) So here is a BASH script, put it in /etc/snmp/percpustats: #!/bin/bash /bin/grep "^$1 " /proc/stat | sed -e 's/^cpu[0-9]* *//' | tr ' ' '\n' Make it executable: chmod +x /etc/snmp/percpustats This simple script takes a single argument, which is the cpu id you want to look at. By “cpu id”, I mean the first word of cpu* lines in /proc/stat . So cpu, cpu0, cpu1, etc. Here is a sample content of my /proc/stat file: ...

So you have your Unified Networking Lab (UNL) server running and you want to use arbitrary QEMU images with it. Here is how to create one. All UNL data is stored under /opt/unetlab , images are stored under /opt/unetlab/addons and QEMU images are a folder deeper under /opt/unetlab/addons/qemu . UNL expects to find images within directories named according to some scheme. The directory names must start with some keywords followed by anything you want. For Linux images, you need to name the directory linux-something, e.g. linux-ubuntu-14.04.5-amd64. You can find the list of supported image “types” in /opt/unetlab/html/templates. The names of the files are the prefixes needed for directory names. If you want to, you can edit those files to change the default parameters of the images (make a backup before you change anything). ...