Add article alpine-installation

1 files changed, 191 insertions, 0 deletions

diff --git a/content/articles/alpine-installation.md b/content/articles/alpine-installation.md
new file mode 100644
index 0000000..f3144fa
--- /dev/null
+++ b/content/articles/alpine-installation.md
@@ -0,0 +1,191 @@
+{
+	"title": "Alpine Linux installation",
+	"subtitle": "Installation guide for the Alpine Linux operating system"
+}
+
+#### Introduction
+
+[Alpine Linux](https://alpinelinux.org/) is a very lightweight and simple Linux
+distribution. It is especially well suited to run servers. This article should
+provide a reference how to install it inside a
+[QEMU](https://www.qemu.org/)-based virtual machine.
+
+It has to be noted that the installation mode will be the [diskless
+mode](https://wiki.alpinelinux.org/wiki/Installation#Diskless_Mode) which
+erases all changes on a reboot if they were not saved by the
+[lbu](https://wiki.alpinelinux.org/wiki/Alpine_local_backup) utility.
+
+#### Create virtual machine image file
+
+The first step to setup the virtual Alpine machine is to create a `vm.qcow2`
+file which will be used as the disk for the final virtual machine:
+
+```
+qemu-img create -f qcow2 vm.qcow2 30G
+```
+
+It has to be noted that the size is set to 30 gigabytes which is what the VM
+will see. Independent of that virtual size the `vm.qcow2` file will use only as
+much disk space as required on the host system so that the file is actually way
+smaller than 30 GB.
+
+#### Start and setup temporary Alpine system
+
+An Alpine Linux image file is required for the first run of the virtual
+machine. They can be obtained on the [Alpine Linux download
+page](https://alpinelinux.org/downloads/).
+
+For this article the image `alpine-standard-3.18.4-x86_64.iso` was selected. To
+start QEMU with the created `vm.qcow2` disk connected and the Alpine image file
+inserted the following command is used:
+
+```
+qemu-system-x86_64 \
+    -enable-kvm \
+    -m 4G \
+    -nic user,model=virtio \
+    -drive file=vm.qcow2,media=disk,if=virtio \
+    -smp cpus=4 \
+    -display sdl \
+    -cdrom alpine-standard-3.18.4-x86_64.iso
+```
+
+After booting this the live system has to be prepared. For this purpose one can
+log in with the username `root` and use the following setup script:
+
+```
+setup-alpine
+```
+
+This interactive program will configure the system. A quite minimal
+configuration should be preferred. The defaults are usually sufficient. Disks
+and SSH servers should not be configured.
+
+Future versions of this article should provide a so called "answers file" for
+`setup-alpine` so that the script can run without user interaction.
+
+#### Make disk bootable
+
+Since the created virtual disk `vm.qcow2` is empty and thus cannot be used
+without the Alpine image file the next step is to make it independently
+bootable.
+
+Since `lsblk` is not included in the default Alpine image file the command `ls
+-l /dev/block` has to be used to list all block devices which include the
+created virtual disk.
+
+```
+ls -l /dev/block
+```
+
+The output should contain a symbolic link to a file like `/dev/vda` which
+corresponds to the created `vm.qcow2` file on the host system.
+
+The next step is to create a partition table and one partition on that disk to
+store the operating system. The interactive program `fdisk` is used for that
+purpose. The exact inputs are noted down below. An empty line requires to
+accept the default by hitting only 'Enter':
+
+```
+fdisk /dev/vda
+o
+n
+p
+1
+2048
+
+t
+0c
+a
+1
+p
+w
+```
+
+This will create a new DOS partition table, create one primary partition which
+takes the whole size of the disk, set the type of this partition and make it
+bootable. Finally the result is printed with `p` and the changes are written to
+disk with `w`. The process can be aborted by hitting `q` before `w` is used.
+`m` will print details about all available options.
+
+After partitioning the only created primary partition has to be formatted. This
+can be done with the following command:
+
+```
+mkdosfs /dev/vda1
+```
+
+To allow mounting DOS filesystems and prevent errors on the next command the
+`vfat` kernel module has to be loaded with `modprobe`:
+
+```
+modprobe vfat
+```
+
+The final command to make `vm.qcow2` bootable is
+
+```
+setup-bootable /media/cdrom /dev/vda1
+```
+
+It will copy the contents of the Alpine live image mounted at
+`/media/cdrom` to the just formatted DOS partition `/dev/vda1` and installs the
+syslinux bootloader to the disk `/dev/vda`.
+
+The temporary Alpine system can be powered off with `poweroff`.
+
+#### Configure final system
+
+Booting the final system the first time works like with the
+`qemu-system-x86_64` command for the temporary system except that the `-cdrom`
+option has to be ommitted. This is possible since `vm.qcow2` is now
+independently bootable.
+
+The final system can be configured like the temporary one:
+
+```
+setup-alpine
+```
+
+By default only the `main` package repository is enabled. If it is required to
+also install packages from the `community` repository it has to be enabled in
+the related configuration file:
+
+```
+vi /etc/apk/repositories
+```
+
+An upgrade to the latest package revisions on the Alpine Linux package servers
+is a good idea at that point:
+
+```
+apk upgrade -a
+```
+
+Finally the changes have to be changed with the `lbu` tool to make it
+persistent after reboots:
+
+```
+lbu commit -d
+```
+
+#### Install a desktop system
+
+The optional installation of a graphical desktop is also well supported by a
+setup script:
+
+```
+setup-desktop
+```
+
+Currently the GNOME desktop, KDE Plasma and Xfce are supported. Xfce worked
+best so far.
+
+Finally the installation of the desktop environment has to be committed too:
+
+```
+lbu commit -d
+```
+
+The last step can be ommitted to remove the desktop environment cleanly after a
+reboot.