Install Docker in Fedora 31

#  sudo dnf install docker

- Installs containerd and moby-engine

# sudo systemctl enable docker

- Enable docker at startup

# sudo systemctl start docker 

- fails because of cgroup

# sudo vi /etc/defaults/grub

- append systemd.unified_cgroup_hierarchy=0 to the end of GRUB_CMDLINE_LINUX line

# sudo  grub2-mkconfig  -o /boot/grub2/grub.cfg

- Recreate grub.cfg.  Note:  The grub.cfg might be in a different place like /boot/efi/EFI/fedora

# sudo shutdown now -r

- reboot for grub changes to take effect

# sudo systemctl status docker

● docker.service - Docker Application Container Engine

   Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)

   Active: active (running) since Sat 2020-03-21 11:39:20 EDT; 8min ago

     Docs: https://docs.docker.com

 Main PID: 3976 (dockerd)

    Tasks: 37 (limit: 19071)

   Memory: 174.1M

   CGroup: /system.slice/docker.service

           ├─3976 /usr/bin/dockerd --host=fd:// --exec-opt native.cgroupdriver=systemd --selinux-enabled --log-driver=journald --li>

           └─3988 containerd --config /var/run/docker/containerd/containerd.toml --log-level info

#  sudo usermod -aG docker $(whoami)

- Add user account to docker group


# sudo docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
1b930d010525: Pull complete 
Digest: sha256:f9dfddf63636d84ef479d645ab5885156ae030f611a56f3a7ac7f2fdd86d7e4e
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

Find and delete files 1 week old (or older)

find /data/files -type f -name "*.txt" -mtime +7 -exec rm {} \;

/data/files - directory
-type f  - find files, not directories, etc
-name "*.txt" - specify file type if necessary
-mtime +7 - modified 7 days or more.  Last accessed time is -atime
-exec rm {}\; - execute rm with the results returned from 'find'

OR

find /data/files -type f -name "*.txt" -mtime +7 | xargs rm

Linux rename file to all lower case

Basic for a directory that only contains files

for file in $(ls); do mv -i ${file} ${file,,}; done

Ignoring directories that contain directories

for file in $(ls -F |grep -v /); do mv -i ${file} ${file,,}; done

Visual Studio Code on Fedora

Import gpg key

sudo rpm --import https://packages.microsoft.com/keys/microsoft.asc


Create the Repository

sudo sh -c 'echo -e "[code]\nname=Visual Studio Code\nbaseurl=https://packages.microsoft.com/yumrepos/vscode\nenabled=1\ngpgcheck=1\ngpgkey=https://packages.microsoft.com/keys/microsoft.asc" > /etc/yum.repos.d/vscode.repo'

Install the software

sudo dnf install code