Add helpers for creating VMs

README.md

@@ -7,9 +7,9 @@ A few *little* scripts for things I do often so that I can type less
 or make fewer clicks.\
 I'm just a bit lazy...
 
-Only tested on Windows.\
-`git-` scripts are Bash scripts so they should work on Unix systems as well,
-but the AutoHotkey and Batch scripts will obviously only work on Windows.
+Scripts that aren't OS-specific (`bin/virt-*`, `bin/*.cmd`, `ahk_scripts/*`) have been tested on Linux and Windows.\
+`bin/virt-*` scripts are Linux-specific and require `libvirt` and `virtinst` packages.\
+`bin/*.cmd` and `ahk_scripts/*` scripts are Windows-specific.
 
 ## Usage/Installation
 
@@ -111,6 +111,57 @@ before all other branches. This is meant to make it easier to find *your* recent
 Each entry on the branch list takes two lines which, while making it less concise,
 allows it to show more of the commit message and is, arguably, more readable.
 
+### vm-run
+
+This scripts run a temporary VM with the given Linux image.
+
+Image's default user is set up with the `~/.ssh/id_rsa` key and additionally,
+`vm` user with `vm` password and the aforementioned key is also created.
+
+See documentation of `vm-image-add` for details about image management.
+
+Usage: `vm-run <image_name>`
+
+The domain (VM) name will be set to `tmp-<image_name>`, optionally suffixed with
+a number (`tmp-<image_name>-2`) when a machine with same name exists.
+
+### vm-connect
+
+Connect to a VM created by `vm-run` or `libvirt`.
+
+In case of VMs created by `vm-run`, `<vm_name>` is equivalent to image name
+with a `tmp-` prefix and an optional `-N` suffix when multiple VMs with same name
+are running at the same time, e.g. `tmp-ubuntu2204` or `tmp-ubuntu2204-2`.
+
+Usage: `vm-connect <vm_name>`
+
+### vm-image-add
+
+Add a Linux VM image for use by `vm-run`.
+
+Usage: `vm-image-add <image_name> <sums_url> <sum_type> <filename_pattern>`
+
+The script expects to be able to download a Linux image based on
+a provided `CHECKSUMS` file in a format returned by `sha256sum`/`sha512sum` program
+ran with or without `--tag` option. `<filename_pattern>` is used to extract
+the relevant checksum. This setup is generally supported by the data that is provided
+by the distro maintainers though there are 2 notable outliers:
+- Red Hat Enterprise Linux - requires subscription
+- Oracle Linux - does not provide checksum file in a parsable format
+
+You can find examples for different distros at:
+https://github.com/Jackenmen/dotfiles/tree/main/private_dot_config/little-helpers-vm-images
+
+### vm-image-fetch
+
+Fetch latest Linux VM image (added through `vm-image-add`) with the given name.
+
+This tool is typically invoked automatically.
+
+Usage: `vm-image-fetch [-f] <image_name>`
+
+Without the `-f` flag, the image only gets fetched when it isn't already in cache.
+
 ## Available AHK scripts (`ahk_scripts/` directory)
 
 ### win_terminal_hotkeys

bin/vm-connect

@@ -0,0 +1,40 @@
+#!/usr/bin/bash
+#
+# Connect to a VM created by `vm-run` or `libvirt`.
+#
+# In case of VMs created by `vm-run`, `<vm_name>` is equivalent to image name
+# with a `tmp-` prefix and an optional `-N` suffix when multiple VMs with same name
+# are running at the same time, e.g. `tmp-ubuntu2204` or `tmp-ubuntu2204-2`.
+#
+# Usage: `vm-connect <vm_name>`
+#
+#
+# Copyright 2024 Jakub Kuczys (https://github.com/Jackenmen)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -eo pipefail
+
+help() {
+    echo 'Usage: vm-connect <vm_name>'
+}
+
+vm_name=$1
+if [[ -z "$vm_name" ]]; then
+    help
+    exit 2
+fi
+
+vm_ip=$(virsh domifaddr "$vm_name" | awk -F'[ /]+' '/^[[:blank:]]vnet/ {print $5}' | head -1)
+
+ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no "vm@$vm_ip"

bin/vm-image-add

@@ -0,0 +1,81 @@
+#!/bin/bash
+#
+# Add a Linux VM image for use by `vm-run`.
+#
+# Usage: `vm-image-add <image_name> <sums_url> <sum_type> <filename_pattern>`
+#
+# The script expects to be able to download a Linux image based on
+# a provided `CHECKSUMS` file in a format returned by `sha256sum`/`sha512sum` program
+# ran with or without `--tag` option. `<filename_pattern>` is used to extract
+# the relevant checksum. This setup is generally supported by the data that is provided
+# by the distro maintainers though there are 2 notable outliers:
+# - Red Hat Enterprise Linux - requires subscription
+# - Oracle Linux - does not provide checksum file in a parsable format
+#
+# You can find examples for different distros at:
+# https://github.com/Jackenmen/dotfiles/tree/main/private_dot_config/little-helpers-vm-images
+#
+#
+# Copyright 2024 Jakub Kuczys (https://github.com/Jackenmen)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -eo pipefail
+
+help() {
+    echo 'Usage: vm-image-add <image_name> <sums_url> <sum_type> <filename_pattern>'
+}
+
+image_name=$1
+if [[ -z "$image_name" ]]; then
+    help
+    exit 2
+fi
+sums_url=$2
+if [[ -z "$sums_url" ]]; then
+    help
+    exit 2
+fi
+sum_type=$3
+if [[ -z "$sum_type" ]]; then
+    help
+    exit 2
+fi
+filename_pattern=$4
+if [[ -z "$filename_pattern" ]]; then
+    help
+    exit 2
+fi
+
+image_cfg_dir="${XDG_CONFIG_HOME:-$HOME/.config}/little-helpers-vm-images"
+mkdir -p "$image_cfg_dir"
+image_file="$image_cfg_dir/$image_name"
+if [[ -e "$image_file" ]]; then
+    echo 'Image with this name already exists:'
+    echo "- Image name: $(sed '1q;d' "$image_file")"
+    echo "- Checksums file URL: $(sed '2q;d' "$image_file")"
+    echo "- Checksum type: $(sed '3q;d' "$image_file")"
+    echo "- Filename pattern: $(sed '4q;d' "$image_file")"
+    exit 1
+fi
+
+echo "$image_name" > "$image_file"
+echo "$sums_url" >> "$image_file"
+echo "$sum_type" >> "$image_file"
+echo "$filename_pattern" >> "$image_file"
+
+if ! vm-image-fetch "$image_name"; then
+    exit_code=$?
+    rm "$image_file"
+    exit "$exit_code"
+fi

bin/vm-image-fetch

@@ -0,0 +1,99 @@
+#!/bin/bash
+#
+# Fetch latest Linux VM image (added through `vm-image-add`) with the given name.
+#
+# This tool is typically invoked automatically.
+#
+# Usage: `vm-image-fetch [-f] <image_name>`
+#
+# Without the `-f` flag, the image only gets fetched when it isn't already in cache.
+#
+#
+# Copyright 2024 Jakub Kuczys (https://github.com/Jackenmen)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -eo pipefail
+
+help() {
+    echo 'Usage: vm-image-fetch [-f] <image_name>'
+}
+
+force_download=0
+OPTIND=1
+while getopts 'f' flag; do
+    case "$flag" in
+        f)
+            force_download=1
+            ;;
+        *)
+            help
+            exit 2
+            ;;
+    esac
+done
+shift "$((OPTIND-1))"
+
+image_name=$1
+if [[ -z "$image_name" ]]; then
+    help
+    exit 2
+fi
+
+image_cfg_dir="${XDG_CONFIG_HOME:-$HOME/.config}/little-helpers-vm-images"
+image_file="$image_cfg_dir/$image_name"
+if [[ ! -f "$image_file" ]]; then
+    echo 'ERROR: Image with this name does not exist!'
+    exit 2
+fi
+
+sums_url=$(sed '2q;d' "$image_file")
+if [[ -z "$sums_url" ]]; then
+    if [[ ! -f "$image_file" ]]; then
+        echo 'ERROR: No sum URL set but the image does not already exist.'
+        exit 1
+    fi
+    echo 'Using cached image as no sums URL is defined.'
+    exit 0
+fi
+
+sum_type=$(sed '3q;d' "$image_file")
+filename_pattern=$(sed '4q;d' "$image_file")
+
+checksums=$(curl -L "$sums_url")
+checksums+=$(echo '' && echo "$checksums" | sed -nE "s/^${sum_type^^} \(($filename_pattern)\) = ([^ \t]+)\$/\2 \1/p")
+matching_files=$(echo "$checksums" | grep -P "^[^ \t]+[ \t]+\*?$filename_pattern\$")
+if [[ "$(echo "$matching_files" | wc -l)" -ne 1 ]]; then
+    echo 'ERROR: Expected only one filename to match but got these matches instead:'
+    echo "$matching_files"
+    exit 1
+fi
+
+base_url="${sums_url%/*}"
+new_checksum=$(echo "$matching_files" | awk '{print $1}')
+filename=$(echo "$matching_files" | awk '{print $2}')
+filename="${filename#\*}"
+image_url="$base_url/$filename"
+
+cache_dir="${XDG_CACHE_HOME:-$HOME/.cache}/little-helpers-vm-images"
+mkdir -p "$cache_dir"
+old_checksum=$( (cat "$cache_dir/$image_name.${sum_type}sum" 2>/dev/null || echo '') | awk '{print $1}' )
+
+if [[ "$force_download" -eq 1 || "$old_checksum" != "$new_checksum" ]]; then
+    echo 'Downloading new version of the image...'
+    wget -O "$cache_dir/$image_name.img" "$image_url"
+    echo "$new_checksum  $image_name.img" > "$cache_dir/$image_name.${sum_type}sum"
+    echo 'Image downloaded and cached.'
+else
+    echo 'Cached image already up-to-date.'
+fi

bin/vm-run

@@ -0,0 +1,103 @@
+#!/usr/bin/bash
+#
+# This scripts run a temporary VM with the given Linux image.
+#
+# Image's default user is set up with the `~/.ssh/id_rsa` key and additionally,
+# `vm` user with `vm` password and the aforementioned key is also created.
+#
+# See documentation of `vm-image-add` for details about image management.
+#
+# Usage: `vm-run <image_name>`
+#
+# The domain (VM) name will be set to `tmp-<image_name>`, optionally suffixed with
+# a number (`tmp-<image_name>-2`) when a machine with same name exists.
+#
+#
+# Copyright 2024 Jakub Kuczys (https://github.com/Jackenmen)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -eo pipefail
+
+DELETE_DOMAIN=0
+
+help() {
+    echo 'Usage: vm-run <image_name>'
+}
+
+cleanup() {
+    if [[ "$DELETE_DOMAIN" -eq 1 ]]; then
+        echo "Undefining VM's domain..."
+        virsh undefine "$domain_name"
+        echo 'Shutting down VM...'
+        if ! virsh shutdown "$domain_name" 2>/dev/null; then
+            echo 'VM was already powered off.'
+        fi
+    fi
+    echo "Removing VM's temporary directory..."
+    rm -rf "$vm_dir"
+    echo 'Removed.'
+}
+
+image_name=$1
+if [[ -z "$image_name" ]]; then
+    help
+    exit 2
+fi
+
+vm-image-fetch "$image_name"
+
+vm_dir=$(mktemp -d)
+trap cleanup EXIT
+chgrp libvirt-qemu "$vm_dir"
+chmod 0770 "$vm_dir"
+base_image_file="${XDG_CACHE_HOME:-$HOME/.cache}/little-helpers-vm-images/$image_name.img"
+
+image_file="$vm_dir/disk.img"
+qemu-img convert -O qcow2 "$base_image_file" "$image_file"
+qemu-img resize "$image_file" 50G
+chgrp libvirt-qemu "$image_file"
+chmod 0660 "$image_file"
+
+user_data_file="$vm_dir/user-data"
+echo '#cloud-config' > "$user_data_file"
+echo 'power_state:' >> "$user_data_file"
+echo '  mode: poweroff' >> "$user_data_file"
+echo '  condition: true' >> "$user_data_file"
+echo 'ssh_authorized_keys:' >> "$user_data_file"
+echo "  - $(<"$HOME/.ssh/id_rsa.pub")" >> "$user_data_file"
+echo 'users:' >> "$user_data_file"
+echo '  - default' >> "$user_data_file"
+echo '  - name: vm' >> "$user_data_file"
+echo '    plain_text_passwd: vm' >> "$user_data_file"
+echo '    lock_passwd: false' >> "$user_data_file"
+echo '    sudo: ALL=(ALL) NOPASSWD:ALL' >> "$user_data_file"
+echo '    shell: /bin/bash' >> "$user_data_file"
+echo '    ssh_authorized_keys:' >> "$user_data_file"
+echo "      - $(<"$HOME/.ssh/id_rsa.pub")" >> "$user_data_file"
+
+domain_name="tmp-$image_name"
+i=1
+while virsh dominfo "$domain_name" 2>/dev/null; do
+    domain_name="tmp-$image_name-$i"
+done
+
+DELETE_DOMAIN=1
+virt-install \
+    --memory 2048 --osinfo linux2016 \
+    --name "$domain_name" \
+    --events on_reboot=restart \
+    --cloud-init "user-data=$user_data_file" \
+    --disk "$image_file"
+
+virsh start --console "$domain_name"