Docker 20.10 fails to start on CentOS 8 and Fedora 33

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After upgrading Docker to version 20.10 on CentOS 8 and Fedora 33 we can see that it fails to start docker.service. In docker.service logs and firewalld.service logs we can see following message: ERROR: ZONE_CONFLICT: 'docker0' already bound to a zone Solution for this issue: sudo firewall-cmd --zone=trusted --remove-interface=docker0 sudo firewall-cmd --zone=trusted --remove-interface=docker0 --permanent

Deploy Nextcloud containerized service using Docker and docker-compose

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Template for deploying Nextcloud containerized service using Docker and docker-compose, you can use in on both x86_64 and ARM (32/64bit) architecture: https://github.com/openterprise/docker/blob/master/docker-compose-nextcloud.yml This template deploys Nextcloud with following setup: • application: Nextcloud • application server: Apache + PHP • database: MariaDB / PostgreSQL • cache: Redis • scheduler: crontab Requirements: • Docker • docker-compose

Fedora 33 - make DNS (systemd-resolved) working with NetworkManager's ForitSSL VPN connections

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In Fedora 33 there is a systemd-resolved service enabled by default. Use following steps to make DSN working after establishing FortiSSL VPN connection using Network Manager (using NetworkManager-fortisslvpn-gnome plugin). Assuming that "ppp0" is you virtual network interface for VPN connection, you can set X.X.X.X and Y.Y.Y.Y as DNS servers: resolvectl dns ppp0 X.X.X.X Y.Y.Y.Y Add… Continue reading Fedora 33 - make DNS (systemd-resolved) working with NetworkManager's ForitSSL VPN connections

Working with kernel network namespaces created by Docker

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To work with kernel network namespaces created by Docker create necessary symbolic link: ln -s /var/run/docker/netns  /var/run/netns List network namespaces: ip netns list Result will be similar to: # ip netns list 644c14147ad2 (id: 2) bb230cf5f65f (id: 1) e2772d19bfd0 (id: 0) Execute command inside network namespace: ip netns exec <namespace> <command> Example - listing network… Continue reading Working with kernel network namespaces created by Docker

Prevent battery drain during suspend mode on Linux

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cat /sys/power/mem_sleep will return "s2idle" and "deep" values, value surrounded by square brackets will show which mode is currently activated. Probably when you observer battery drain during suspend, you will see "s2idle" highlighted. To change it do deep sleep mode use command: echo deep > /sys/power/mem_sleep To make change permanent add the following to your… Continue reading Prevent battery drain during suspend mode on Linux