debootstrap-ubuntu-qemu.sh

Author: cirosantilli

.gitignore

@@ -1,7 +1,8 @@
 # Output and temporary files.
+*.tmp
 _out/
 _tmp/
-*.tmp
+tmp
 
 # Compiled stuff.
 *.slo
@@ -14,4 +15,3 @@ _tmp/
 *.la
 *.a
 *.s
-

README.md

@@ -287,12 +287,14 @@ Includes Linux concepts and utilities that work on Linux, not necessarily in the
     1. [Pandoc](pandoc/)
     1. [RST](rst/)
 1.  [Virtualization](virtualization.md)
-    1. [Docker](docker/)
-    1. [QEMU](qemu.md)
-    1. [Xen](xen.md)
-    1. [Vagrant](vagrang/)
-    1. [Intel SDE](intel-sde.md)
-    1. [gem5](gem5.md)
+    1.  [Docker](docker/)
+    1.  [QEMU](qemu.md)
+        1. [debootstrap-ubuntu-qemu.sh](debootstrap-ubuntu-qemu.sh)
+        1. [debootstrap-debian-qemu.sh](debootstrap-debian-qemu.sh)
+    1.  [Xen](xen.md)
+    1.  [Vagrant](vagrang/)
+    1.  [Intel SDE](intel-sde.md)
+    1.  [gem5](gem5.md)
 1.  [Configuration automation](config-automation.md)
     1. [chef](chef/)
     1. [puppet](puppet.md)

debootstrap-debian-qemu.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+
+# https://unix.stackexchange.com/questions/275429/creating-bootable-debian-image-with-debootstrap/473256#473256
+
+set -eux
+
+debootstrap_dir=debootstrap
+root_filesystem=img.ext2.qcow2
+
+sudo apt-get install \
+  debootstrap \
+  libguestfs-tools \
+  qemu-system-x86 \
+;
+
+if [ ! -d "$debootstrap_dir" ]; then
+  # Create debootstrap directory.
+  # - linux-image-amd64: downloads the kernel image
+  sudo debootstrap \
+    --include linux-image-amd64 \
+    stretch \
+    "$debootstrap_dir" \
+    http://deb.debian.org/debian/ \
+  ;
+fi
+
+linux_image="$(printf "${debootstrap_dir}/boot/vmlinuz-"*)"
+
+if [ ! -f "$root_filesystem" ]; then
+
+  # Set root password.
+  echo 'root:root' | sudo chroot "$debootstrap_dir" chpasswd
+
+  # Remount root filesystem as rw.
+  # Otherwise, systemd shows:
+  #     [FAILED] Failed to start Create Volatile Files and Directories.
+  # and then this leads to further failures in the network setup.
+  cat << EOF | sudo tee "${debootstrap_dir}/etc/fstab"
+/dev/sda / ext4 errors=remount-ro,acl 0 1
+EOF
+
+  # Network.
+  # We use enp0s3 because the kernel boot prints:
+  #     8139cp 0000:00:03.0 enp0s3: renamed from eth0
+  # This can also be observed with:
+  #     ip link show
+  # Without this, systemd shows many network errors, the first of which is:
+  #     [FAILED] Failed to start Network Time Synchronization.
+  cat << EOF | sudo tee "${debootstrap_dir}/etc/network/interfaces.d/00mytest"
+auto lo
+iface lo inet loopback
+auto enp0s3
+iface enp0s3 inet dhcp
+EOF
+
+  # Generate image file from debootstrap directory.
+  # Leave 1Gb extra empty space in the image.
+  sudo virt-make-fs \
+    --format qcow2 \
+    --size +1G \
+    --type ext2 \
+    "$debootstrap_dir" \
+    "$root_filesystem" \
+  ;
+  sudo chmod 666 "$root_filesystem"
+fi
+
+linux_img="${debootstrap_dir}/boot/vmlinuz-"*
+
+# Build the Linux kernel.
+git clone --depth 1 --branch v4.18 git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
+cd linux
+wget https://gist.githubusercontent.com/cirosantilli/6e2f4975c1929162a86be09f839874ca/raw/6d151d231a233408a6e1b541bf4a92fd55bf5338/.config
+make olddefconfig
+make -j`nproc`
+cd -
+linux_img="linux/arch/x86_64/boot/bzImage"
+
+qemu-system-x86_64 \
+  -append 'console=ttyS0 root=/dev/sda' \
+  -drive "file=img.ext2.qcow2,format=qcow2" \
+  -enable-kvm \
+  -serial mon:stdio \
+  -m 2G \
+  -kernel="$linux_img"
+  -device rtl8139,netdev=net0 \
+  -netdev user,id=net0 \
+;

debootstrap-ubuntu-qemu.sh

@@ -0,0 +1,85 @@
+#!/usr/bin/env bash
+
+# https://askubuntu.com/questions/281763/is-there-any-prebuilt-qemu-ubuntu-image32bit-online/1081171#1081171
+
+set -eux
+
+debootstrap_dir=debootstrap
+root_filesystem=debootstrap.ext2.qcow2
+
+sudo apt-get install \
+  debootstrap \
+  libguestfs-tools \
+  qemu-system-x86 \
+;
+
+if [ ! -d "$debootstrap_dir" ]; then
+  # Create debootstrap directory.
+  # - linux-image-generic: downloads the kernel image we will use under /boot
+  # - network-manager: automatically starts the network at boot for us
+  sudo debootstrap \
+    --include linux-image-generic \
+    bionic \
+    "$debootstrap_dir" \
+    http://archive.ubuntu.com/ubuntu \
+  ;
+  sudo rm -f "$root_filesystem"
+fi
+
+linux_image="$(printf "${debootstrap_dir}/boot/vmlinuz-"*)"
+
+if [ ! -f "$root_filesystem" ]; then
+  # Set root password.
+  echo 'root:root' | sudo chroot "$debootstrap_dir" chpasswd
+
+  # Remount root filesystem as rw.
+  cat << EOF | sudo tee "${debootstrap_dir}/etc/fstab"
+/dev/sda / ext4 errors=remount-ro,acl 0 1
+EOF
+
+  # Automaticaly start networking.
+  # Otherwise network commands fail with:
+  #     Temporary failure in name resolution
+  # https://askubuntu.com/questions/1045278/ubuntu-server-18-04-temporary-failure-in-name-resolution/1080902#1080902
+  cat << EOF | sudo tee "$debootstrap_dir/etc/systemd/system/dhclient.service"
+[Unit]
+Description=DHCP Client
+Documentation=man:dhclient(8)
+Wants=network.target
+Before=network.target
+[Service]
+Type=forking
+PIDFile=/var/run/dhclient.pid
+ExecStart=/sbin/dhclient -4 -q
+[Install]
+WantedBy=multi-user.target
+EOF
+  sudo ln -sf "$debootstrap_dir/etc/systemd/system/dhclient.service" \
+    "${debootstrap_dir}/etc/systemd/system/multi-user.target.wants/dhclient.service"
+
+  # Why Ubuntu, why.
+  # https://bugs.launchpad.net/ubuntu/+source/linux/+bug/759725
+  sudo chmod +r "${linux_image}"
+
+  # Generate image file from debootstrap directory.
+  # Leave 1Gb extra empty space in the image.
+  sudo virt-make-fs \
+    --format qcow2 \
+    --size +1G \
+    --type ext2 \
+    "$debootstrap_dir" \
+    "$root_filesystem" \
+  ;
+  sudo chmod 666 "$root_filesystem"
+fi
+
+qemu-system-x86_64 \
+  -append 'console=ttyS0 root=/dev/sda' \
+  -drive "file=${root_filesystem},format=qcow2" \
+  -enable-kvm \
+  -serial mon:stdio \
+  -m 2G \
+  -kernel "${linux_image}" \
+  -device rtl8139,netdev=net0 \
+  -netdev user,id=net0 \
+;