From aad39c5ffc9ed879c3327224e1bf79d121615290 Mon Sep 17 00:00:00 2001 From: Jacob Salmela Date: Thu, 6 Jul 2017 19:25:56 -0500 Subject: [PATCH] add comments for nearly every line of code. --- automated install/basic-install.sh | 690 +++++++++++++++++++++++++---- 1 file changed, 597 insertions(+), 93 deletions(-) diff --git a/automated install/basic-install.sh b/automated install/basic-install.sh index 3c6b77af..4a30461b 100755 --- a/automated install/basic-install.sh +++ b/automated install/basic-install.sh @@ -12,28 +12,49 @@ # pi-hole.net/donate # -# Install with this command (from your Pi): +# Install with this command (from your Linux machine): # # curl -L install.pi-hole.net | bash + +# -e option instructs bash to immediately exit if any command [1] has a non-zero exit status +# We do not want users to end up with a partially working install, so we exit the script +# instead of continuing the installation with something broken set -e + ######## VARIABLES ######### +# For better maintainability, we store as much information that can change in variables +# This allows us to make a change in one place that can propogate to all instances of the variable +# These variables should all be GLOBAL variables, written in CAPS +# Local variables will be in lowercase and will exist only within functions +# It's still a work in progress, so you may see some variance in this guideline until it is complete + +# We write to a temporary file before moving the log to the pihole folder tmpLog=/tmp/pihole-install.log instalLogLoc=/etc/pihole/install.log +# This is an important file as it contains information specific to the machine it's being installed on setupVars=/etc/pihole/setupVars.conf +# Pi-hole uses lighttpd as a Web server, and this is the config file for it lighttpdConfig=/etc/lighttpd/lighttpd.conf +# This is a file used for the colorized output coltable=/opt/pihole/COL_TABLE +# We store several other folders and webInterfaceGitUrl="https://github.com/pi-hole/AdminLTE.git" webInterfaceDir="/var/www/html/admin" piholeGitUrl="https://github.com/pi-hole/pi-hole.git" PI_HOLE_LOCAL_REPO="/etc/.pihole" +# These are the names of piholes files, stored in an array PI_HOLE_FILES=(chronometer list piholeDebug piholeLogFlush setupLCD update version gravity uninstall webpage) +# This folder is where the Pi-hole scripts will be installed PI_HOLE_INSTALL_DIR="/opt/pihole" useUpdateVars=false +# Pi-hole needs an IP address; to begin, these variables are empty since we don't know what the IP is until +# this script can run IPV4_ADDRESS="" IPV6_ADDRESS="" +# By default, query logging is enabled and the dashboard is set to be installed QUERY_LOGGING=true INSTALL_WEB=true @@ -51,13 +72,19 @@ r=$(( r < 20 ? 20 : r )) c=$(( c < 70 ? 70 : c )) ######## Undocumented Flags. Shhh ######## +# These are undocumented flags; some of which we can use when repairing an installation +# The runUnattended flag is one example of this skipSpaceCheck=false reconfigure=false runUnattended=false +# If the color table file exists, if [[ -f ${coltable} ]]; then + # source it source ${coltable} +# Othwerise, else + # Set these values so the installer can still run in color COL_NC='\e[0m' # No Color COL_LIGHT_GREEN='\e[1;32m' COL_LIGHT_RED='\e[1;31m' @@ -68,7 +95,8 @@ else OVER="\r\033[K" fi - +# A simple function that just echoes out our logo in ASCII format +# This lets users know that it is a Pi-hole, LLC product show_ascii_berry() { echo -e " ${COL_LIGHT_GREEN}.;;,. @@ -97,41 +125,63 @@ show_ascii_berry() { # Compatibility distro_check() { +# If apt-get is isntalled, then we know it's part of the Debian family if command -v apt-get &> /dev/null; then - #Debian Family - ############################################# + # Set some global variables here + # We don't set them earlier since the family might be Red Hat, so these values would be different PKG_MANAGER="apt-get" + # A variable to store the command used to update the package cache UPDATE_PKG_CACHE="${PKG_MANAGER} update" + # An array for something... PKG_INSTALL=(${PKG_MANAGER} --yes --no-install-recommends install) # grep -c will return 1 retVal on 0 matches, block this throwing the set -e with an OR TRUE PKG_COUNT="${PKG_MANAGER} -s -o Debug::NoLocking=true upgrade | grep -c ^Inst || true" - # ######################################### - # fixes for dependency differences - # Debian 7 doesn't have iproute2 use iproute + # Some distros vary slightly so these fixes for dependencies may apply + # Debian 7 doesn't have iproute2 so if the dry run install is successful, if ${PKG_MANAGER} install --dry-run iproute2 > /dev/null 2>&1; then + # we can install it iproute_pkg="iproute2" + # Otherwise, else + # use iproute iproute_pkg="iproute" fi - # Prefer the php metapackage if it's there, fall back on the php5 packages + # We prefer the php metapackage if it's there if ${PKG_MANAGER} install --dry-run php > /dev/null 2>&1; then phpVer="php" + # If not, else + # fall back on the php5 packages phpVer="php5" fi - # ######################################### + + # Since our instal script is so large, we need several other programs to successfuly get a machine provisioned + # These programs are stored in an array so they can be looped through later INSTALLER_DEPS=(apt-utils dialog debconf dhcpcd5 git ${iproute_pkg} whiptail) + # Pi-hole itself has several dependencies that also need to be installed PIHOLE_DEPS=(bc cron curl dnsmasq dnsutils iputils-ping lsof netcat sudo unzip wget) + # The Web dashboard has some that also need to be installed + # It's useful to separate the two since our repos are also setup as "Core" code and "Web" code PIHOLE_WEB_DEPS=(lighttpd ${phpVer}-common ${phpVer}-cgi) + # The Web server user, LIGHTTPD_USER="www-data" + # group, LIGHTTPD_GROUP="www-data" + # and config file LIGHTTPD_CFG="lighttpd.conf.debian" + # The DNS server user DNSMASQ_USER="dnsmasq" - test_dpkg_lock() { +# A function to check... +test_dpkg_lock() { + # An iterator used for counting loop iterations i=0 + # fuser is a program to show which processes use the named files, sockets, or filesystems + # So while the command is true while fuser /var/lib/dpkg/lock >/dev/null 2>&1 ; do + # Wait half a second sleep 0.5 + # and increase the iterator ((i=i+1)) done # Always return success, since we only return if there is no @@ -139,15 +189,16 @@ if command -v apt-get &> /dev/null; then return 0 } +# If apt-get is not found, check for rpm to see if it's a Red Hat family OS elif command -v rpm &> /dev/null; then - # Fedora Family + # Then check if dnf or yum is the package manager if command -v dnf &> /dev/null; then PKG_MANAGER="dnf" else PKG_MANAGER="yum" fi -# Fedora and family update cache on every PKG_INSTALL call, no need for a separate update. + # Fedora and family update cache on every PKG_INSTALL call, no need for a separate update. UPDATE_PKG_CACHE=":" PKG_INSTALL=(${PKG_MANAGER} install -y) PKG_COUNT="${PKG_MANAGER} check-update | egrep '(.i686|.x86|.noarch|.arm|.src)' | wc -l" @@ -162,113 +213,176 @@ elif command -v rpm &> /dev/null; then LIGHTTPD_CFG="lighttpd.conf.fedora" DNSMASQ_USER="nobody" +# If neither apt-get or rmp/dnf are not found else + # it's not an OS we can support, echo -e " ${CROSS} OS distribution not supported" + # so exit the installer exit fi } +# A function for checking if a folder is a git repository is_repo() { - # Use git to check if directory is currently under VCS, return the value 128 - # if directory is not a repo. Return 1 if directory does not exist. + # Use a named, local variable instead of the vague $1, which is the first arguement passed to this function + # These local variables should always be lowercase local directory="${1}" + # A local variabled for the current directory local curdir + # A variable to store the return code local rc - + # Assign the current directory variable by using pwd curdir="${PWD}" + # If the first argument passed to this function is a directory, if [[ -d "${directory}" ]]; then - # git -C is not used here to support git versions older than 1.8.4 + # move into the directory cd "${directory}" + # Use git to check if the folder is a repo + # git -C is not used here to support git versions older than 1.8.4 git status --short &> /dev/null || rc=$? + # If the command was not successful, else - # non-zero return code if directory does not exist + # Set a non-zero return code if directory does not exist rc=1 fi + # Move back into the directory the user started in cd "${curdir}" + # Return the code; if one is not set, return 0 return "${rc:-0}" } +# A function to clone a repo make_repo() { + # Set named variables for better readability local directory="${1}" local remoteRepo="${2}" + # The message to display when this function is running str="Clone ${remoteRepo} into ${directory}" + # Display the message and use the color table to preface the message with an "info" indicator echo -ne " ${INFO} ${str}..." - # Clean out the directory if it exists for git to clone into + # If the directory exists, if [[ -d "${directory}" ]]; then + # delete everything in it so git can clone into it rm -rf "${directory}" fi + # Clone the repo and return the return code from this command git clone -q --depth 1 "${remoteRepo}" "${directory}" &> /dev/null || return $? + # Show a colored message showing it's status echo -e "${OVER} ${TICK} ${str}" + # Always return 0? Not sure this is correct return 0 } +# We need to make sure the repos are up-to-date so we can effectively install Clean out the directory if it exists for git to clone into update_repo() { + # Use named, local variables + # As you can see, these are the same variable names used in the last function, + # but since they are local, their scope does not go beyond this function + # This helps prevent the wrong value from being assigned if you were to set the variable as a GLOBAL one local directory="${1}" local curdir + # A variable to store the message we want to display; + # Again, it's useful to store these in variables in case we need to reuse or change the message; + # we only need to make one change here local str="Update repo in ${1}" + + # Make sure we know what directory we are in so we can move back into it curdir="${PWD}" + # Move into the directory that was passed as an argument cd "${directory}" &> /dev/null || return 1 - # Pull the latest commits + # Let the user know what's happening echo -ne " ${INFO} ${str}..." + # Stash any local commits as they conflict with our working code git stash --all --quiet &> /dev/null || true # Okay for stash failure git clean --quiet --force -d || true # Okay for already clean directory + # Pull the latest commits git pull --quiet &> /dev/null || return $? + # Show a completion message echo -e "${OVER} ${TICK} ${str}" + # Move back into the oiginal directory cd "${curdir}" &> /dev/null || return 1 return 0 } +# A function that combines the functions previously made getGitFiles() { - # Setup git repos for directory and repository passed - # as arguments 1 and 2 + # Setup named variables for the git repos + # We need the directory local directory="${1}" + # as well as the repo URL local remoteRepo="${2}" + # A local varible containing the message to be displayed local str="Check for existing repository in ${1}" + # Show the message echo -ne " ${INFO} ${str}..." + # Check if the directory is a repository if is_repo "${directory}"; then + # Show that we're checking it echo -e "${OVER} ${TICK} ${str}" + # Update the repo, returning an error message on failure update_repo "${directory}" || { echo -e "\n ${COL_LIGHT_RED}Error: Could not update local repository. Contact support.${COL_NC}"; exit 1; } + # If it's not a .git repo, else + # Show an error echo -e "${OVER} ${CROSS} ${str}" + # Attempt to make the repository, showing an error on falure make_repo "${directory}" "${remoteRepo}" || { echo -e "\n ${COL_LIGHT_RED}Error: Could not update local repository. Contact support.${COL_NC}"; exit 1; } fi + # echo a blank line echo "" + # and return success? return 0 } +# Reset a repo to get rid of any local changed resetRepo() { + # Use named varibles for arguments local directory="${1}" - + # Move into the directory cd "${directory}" &> /dev/null || return 1 + # Store the message in a varible str="Resetting repository within ${1}..." + # Show the message echo -ne " ${INFO} ${str}" + # Use git to remove the local changes git reset --hard &> /dev/null || return $? + # And show the status echo -e "${OVER} ${TICK} ${str}" + # Returning success anyway? return 0 } +# We need to know the IPv4 information so we can effectively setup the DNS server +# Without this information, we won't know where to Pi-hole will be found find_IPv4_information() { + # Named, local variables local route - # Find IP used to route to outside world + # Find IP used to route to outside world by checking the the route to Google's public DNS server route=$(ip route get 8.8.8.8) + # Use awk to strip out just the interface device as it is used in future commands IPv4dev=$(awk '{for (i=1; i<=NF; i++) if ($i~/dev/) print $(i+1)}' <<< "${route}") + # Get just the IP address IPv4bare=$(awk '{print $7}' <<< "${route}") + # Append the CIDR notation to the IP address IPV4_ADDRESS=$(ip -o -f inet addr show | grep "${IPv4bare}" | awk '{print $4}' | awk 'END {print}') + # Get the default gateway (the way to reach the Internet) IPv4gw=$(awk '{print $3}' <<< "${route}") } +# Get available interfaces that are UP get_available_interfaces() { - # Get available UP interfaces. + # There may be more than one so it's all stored in a variable availableInterfaces=$(ip --oneline link show up | grep -v "lo" | awk '{print $2}' | cut -d':' -f1 | cut -d'@' -f1) } +# A function for displaying the dialogs the user sees when first running the installer welcomeDialogs() { - # Display the welcome dialog + # Display the welcome dialog using an approriately sized window via the calculation conducted earlier in the script whiptail --msgbox --backtitle "Welcome" --title "Pi-hole automated installer" "\n\nThis installer will transform your device into a network-wide ad blocker!" ${r} ${c} - # Support for a part-time dev + # Request that users donate if they enjoy the software since we all work on it in our free time whiptail --msgbox --backtitle "Plea" --title "Free and open source" "\n\nThe Pi-hole is free, but powered by your donations: http://pi-hole.net/donate" ${r} ${c} # Explain the need for a static address @@ -277,43 +391,54 @@ welcomeDialogs() { In the next section, you can choose to use your current network settings (DHCP) or to manually edit them." ${r} ${c} } +# We need to make sure there is enough space before installing, so there is a function to check this verifyFreeDiskSpace() { # 50MB is the minimum space needed (45MB install (includes web admin bootstrap/jquery libraries etc) + 5MB one day of logs.) # - Fourdee: Local ensures the variable is only created, and accessible within this function/void. Generally considered a "good" coding practice for non-global variables. local str="Disk space check" + # Reqired space in KB local required_free_kilobytes=51200 + # Calculate existing free space on this machine local existing_free_kilobytes=$(df -Pk | grep -m1 '\/$' | awk '{print $4}') - # - Unknown free disk space , not a integer + # If the existing space is not an integer, if ! [[ "${existing_free_kilobytes}" =~ ^([0-9])+$ ]]; then + # show an error that we can't determine the free space echo -e " ${CROSS} ${str} Unknown free disk space! We were unable to determine available free disk space on this system. You may override this check, however, it is not recommended The option '${COL_LIGHT_RED}--i_do_not_follow_recommendations${COL_NC}' can override this e.g: curl -L https://install.pi-hole.net | bash /dev/stdin ${COL_LIGHT_RED}