mailinabox/setup/system.sh

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source /etc/mailinabox.conf
2014-06-03 11:12:38 +00:00
source setup/functions.sh # load our functions
# Basic System Configuration
# -------------------------
# ### Set hostname of the box
# If the hostname is not correctly resolvable sudo can't be used. This will result in
# errors during the install
#
# First set the hostname in the configuration file, then activate the setting
echo $PRIMARY_HOSTNAME > /etc/hostname
hostname $PRIMARY_HOSTNAME
# ### Add swap space to the system
# If the physical memory of the system is below 2GB it is wise to create a
# swap file. This will make the system more resiliant to memory spikes and
# prevent for instance spam filtering from crashing
# We will create a 1G file, this should be a good balance between disk usage
# and buffers for the system. We will only allocate this file if there is more
# than 5GB of disk space available
# The following checks are performed:
# - Check if swap is currently mountend by looking at /proc/swaps
# - Check if the user intents to activate swap on next boot by checking fstab entries.
# - Check if a swapfile already exists
# - Check if the root file system is not btrfs, might be an incompatible version with
# swapfiles. User should hanle it them selves.
# - Check the memory requirements
# - Check available diskspace
# See https://www.digitalocean.com/community/tutorials/how-to-add-swap-on-ubuntu-14-04
# for reference
SWAP_MOUNTED=$(cat /proc/swaps | tail -n+2)
SWAP_IN_FSTAB=$(grep "swap" /etc/fstab)
ROOT_IS_BTRFS=$(grep "\/ .*btrfs" /proc/mounts)
TOTAL_PHYSICAL_MEM=$(head -n 1 /proc/meminfo | awk '{print $2}')
AVAILABLE_DISK_SPACE=$(df / --output=avail | tail -n 1)
if
[ -z "$SWAP_MOUNTED" ] &&
[ -z "$SWAP_IN_FSTAB" ] &&
[ ! -e /swapfile ] &&
[ -z "$ROOT_IS_BTRFS" ] &&
[ $TOTAL_PHYSICAL_MEM -lt 1900000 ] &&
[ $AVAILABLE_DISK_SPACE -gt 5242880 ]
then
echo "Adding a swap file to the system..."
# Allocate and activate the swap file. Allocate in 1KB chuncks
# doing it in one go, could fail on low memory systems
dd if=/dev/zero of=/swapfile bs=1024 count=$[1024*1024] status=none
if [ -e /swapfile ]; then
chmod 600 /swapfile
hide_output mkswap /swapfile
swapon /swapfile
fi
# Check if swap is mounted then activate on boot
if swapon -s | grep -q "\/swapfile"; then
echo "/swapfile none swap sw 0 0" >> /etc/fstab
else
echo "ERROR: Swap allocation failed"
fi
fi
# ### Add Mail-in-a-Box's PPA.
# We've built several .deb packages on our own that we want to include.
# One is a replacement for Ubuntu's stock postgrey package that makes
# some enhancements. The other is dovecot-lucene, a Lucene-based full
# text search plugin for (and by) dovecot, which is not available in
# Ubuntu currently.
#
# So, first ensure add-apt-repository is installed, then use it to install
# the [mail-in-a-box ppa](https://launchpad.net/~mail-in-a-box/+archive/ubuntu/ppa).
if [ ! -f /usr/bin/add-apt-repository ]; then
echo "Installing add-apt-repository..."
hide_output apt-get update
apt_install software-properties-common
fi
hide_output add-apt-repository -y ppa:mail-in-a-box/ppa
# ### Update Packages
# Update system packages to make sure we have the latest upstream versions of things from Ubuntu.
echo Updating system packages...
hide_output apt-get update
apt_get_quiet upgrade
# ### Install System Packages
# Install basic utilities.
#
# * haveged: Provides extra entropy to /dev/random so it doesn't stall
# when generating random numbers for private keys (e.g. during
# ldns-keygen).
# * unattended-upgrades: Apt tool to install security updates automatically.
# * cron: Runs background processes periodically.
# * ntp: keeps the system time correct
# * fail2ban: scans log files for repeated failed login attempts and blocks the remote IP at the firewall
# * netcat-openbsd: `nc` command line networking tool
# * git: we install some things directly from github
# * sudo: allows privileged users to execute commands as root without being root
2015-08-16 23:46:23 +00:00
# * coreutils: includes `nproc` tool to report number of processors, mktemp
# * bc: allows us to do math to compute sane defaults
echo Installing system packages...
apt_install python3 python3-dev python3-pip \
netcat-openbsd wget curl git sudo coreutils bc \
haveged pollinate unzip \
unattended-upgrades cron ntp fail2ban gist
2014-03-16 20:50:24 +00:00
# ### Suppress Upgrade Prompts
# Since Mail-in-a-Box might jump straight to 18.04 LTS, there's no need
# to be reminded about 16.04 on every login.
if [ -f /etc/update-manager/release-upgrades ]; then
tools/editconf.py /etc/update-manager/release-upgrades Prompt=never
rm -f /var/lib/ubuntu-release-upgrader/release-upgrade-available
fi
# ### Set the system timezone
#
# Some systems are missing /etc/timezone, which we cat into the configs for
# Z-Push and ownCloud, so we need to set it to something. Daily cron tasks
# like the system backup are run at a time tied to the system timezone, so
# letting the user choose will help us identify the right time to do those
# things (i.e. late at night in whatever timezone the user actually lives
# in).
#
# However, changing the timezone once it is set seems to confuse fail2ban
# and requires restarting fail2ban (done below in the fail2ban
# section) and syslog (see #328). There might be other issues, and it's
# not likely the user will want to change this, so we only ask on first
# setup.
if [ -z "$NONINTERACTIVE" ]; then
if [ ! -f /etc/timezone ] || [ ! -z $FIRST_TIME_SETUP ]; then
# If the file is missing or this is the user's first time running
# Mail-in-a-Box setup, run the interactive timezone configuration
# tool.
dpkg-reconfigure tzdata
restart_service rsyslog
fi
else
# This is a non-interactive setup so we can't ask the user.
# If /etc/timezone is missing, set it to UTC.
if [ ! -f /etc/timezone ]; then
echo "Setting timezone to UTC."
echo "Etc/UTC" > /etc/timezone
restart_service rsyslog
fi
fi
# ### Seed /dev/urandom
#
# /dev/urandom is used by various components for generating random bytes for
# encryption keys and passwords:
#
# * TLS private key (see `ssl.sh`, which calls `openssl genrsa`)
# * DNSSEC signing keys (see `dns.sh`)
# * our management server's API key (via Python's os.urandom method)
# * Roundcube's SECRET_KEY (`webmail.sh`)
# * ownCloud's administrator account password (`owncloud.sh`)
#
# Why /dev/urandom? It's the same as /dev/random, except that it doesn't wait
# for a constant new stream of entropy. In practice, we only need a little
# entropy at the start to get going. After that, we can safely pull a random
# stream from /dev/urandom and not worry about how much entropy has been
# added to the stream. (http://www.2uo.de/myths-about-urandom/) So we need
# to worry about /dev/urandom being seeded properly (which is also an issue
# for /dev/random), but after that /dev/urandom is superior to /dev/random
# because it's faster and doesn't block indefinitely to wait for hardware
# entropy. Note that `openssl genrsa` even uses `/dev/urandom`, and if it's
# good enough for generating an RSA private key, it's good enough for anything
# else we may need.
#
# Now about that seeding issue....
#
# /dev/urandom is seeded from "the uninitialized contents of the pool buffers when
# the kernel starts, the startup clock time in nanosecond resolution,...and
# entropy saved across boots to a local file" as well as the order of
# execution of concurrent accesses to /dev/urandom. (Heninger et al 2012,
# https://factorable.net/weakkeys12.conference.pdf) But when memory is zeroed,
# the system clock is reset on boot, /etc/init.d/urandom has not yet run, or
# the machine is single CPU or has no concurrent accesses to /dev/urandom prior
# to this point, /dev/urandom may not be seeded well. After this, /dev/urandom
# draws from the same entropy sources as /dev/random, but it doesn't block or
# issue any warnings if no entropy is actually available. (http://www.2uo.de/myths-about-urandom/)
# Entropy might not be readily available because this machine has no user input
# devices (common on servers!) and either no hard disk or not enough IO has
# ocurred yet --- although haveged tries to mitigate this. So there's a good chance
# that accessing /dev/urandom will not be drawing from any hardware entropy and under
# a perfect-storm circumstance where the other seeds are meaningless, /dev/urandom
# may not be seeded at all.
#
# The first thing we'll do is block until we can seed /dev/urandom with enough
# hardware entropy to get going, by drawing from /dev/random. haveged makes this
# less likely to stall for very long.
echo Initializing system random number generator...
dd if=/dev/random of=/dev/urandom bs=1 count=32 2> /dev/null
# This is supposedly sufficient. But because we're not sure if hardware entropy
# is really any good on virtualized systems, we'll also seed from Ubuntu's
# pollinate servers:
pollinate -q -r
# Between these two, we really ought to be all set.
Support for rsync+ssh backup target (#678) * Added support for backup to a remote server using rsync * updated web interface to get data from user * added way to list files from server It’s not using the “username” field of the yaml configuration file to minimise the amount of patches needed. So the username is actually sorted within the rsync URL. Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * Added ssh key generation upon installation for root user. Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * Removed stale blank lines, and fixed typo Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * fix backup-location lines, by switching it from id to class * Various web UI fixes - fixed user field being shadowed ; - fixed settings reading comparaison ; - fixed forgotten min-age field. Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * Added SSH Public Key shown on the web interface UI Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * trailing spaces. Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * fixed the extraneous environment Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * Updated key setup - made key lower in bits, but stronger (using -a option), - made ssh-keygen run in background using nohup, - added independent key file, as id_rsa_miab, - added ssh-options to all duplicity calls to use the id_rsa_miab keyfile, - changed path to the public key display Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * added rsync options for ssh identity support Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * removed strict host checking for all backup operations Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net> * Remove nohup from ssh-keygen so errors aren't hidden. Also only generate a key if none exists yet * Add trailing slash when checking a remote backup. Also check if we actually can read the remote size * Factorisation of the repeated rsync/ssh options cf https://github.com/mail-in-a-box/mailinabox/pull/678#discussion_r81478919 * Updated message SSH key creation https://github.com/mail-in-a-box/mailinabox/pull/678#discussion_r81478886
2016-11-12 14:28:55 +00:00
# We need an ssh key to store backups via rsync, if it doesn't exist create one
if [ ! -f /root/.ssh/id_rsa_miab ]; then
echo 'Creating SSH key for backup…'
ssh-keygen -t rsa -b 2048 -a 100 -f /root/.ssh/id_rsa_miab -N '' -q
fi
# ### Package maintenance
#
# Allow apt to install system updates automatically every day.
cat > /etc/apt/apt.conf.d/02periodic <<EOF;
APT::Periodic::MaxAge "7";
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";
APT::Periodic::Verbose "1";
EOF
# ### Firewall
# Various virtualized environments like Docker and some VPSs don't provide #NODOC
# a kernel that supports iptables. To avoid error-like output in these cases, #NODOC
# we skip this if the user sets DISABLE_FIREWALL=1. #NODOC
if [ -z "$DISABLE_FIREWALL" ]; then
# Install `ufw` which provides a simple firewall configuration.
apt_install ufw
# Allow incoming connections to SSH.
ufw_allow ssh;
# ssh might be running on an alternate port. Use sshd -T to dump sshd's #NODOC
# settings, find the port it is supposedly running on, and open that port #NODOC
# too. #NODOC
SSH_PORT=$(sshd -T 2>/dev/null | grep "^port " | sed "s/port //") #NODOC
if [ ! -z "$SSH_PORT" ]; then
if [ "$SSH_PORT" != "22" ]; then
echo Opening alternate SSH port $SSH_PORT. #NODOC
ufw_allow $SSH_PORT #NODOC
fi
fi
ufw --force enable;
fi #NODOC
# ### Local DNS Service
# Install a local DNS server, rather than using the DNS server provided by the
# ISP's network configuration.
#
# We do this to ensure that DNS queries
# that *we* make (i.e. looking up other external domains) perform DNSSEC checks.
# We could use Google's Public DNS, but we don't want to create a dependency on
# Google per our goals of decentralization. `bind9`, as packaged for Ubuntu, has
# DNSSEC enabled by default via "dnssec-validation auto".
#
# So we'll be running `bind9` bound to 127.0.0.1 for locally-issued DNS queries
# and `nsd` bound to the public ethernet interface for remote DNS queries asking
# about our domain names. `nsd` is configured later.
#
# About the settings:
#
# * RESOLVCONF=yes will have `bind9` take over /etc/resolv.conf to tell
# local services that DNS queries are handled on localhost.
# * Adding -4 to OPTIONS will have `bind9` not listen on IPv6 addresses
# so that we're sure there's no conflict with nsd, our public domain
# name server, on IPV6.
# * The listen-on directive in named.conf.options restricts `bind9` to
# binding to the loopback interface instead of all interfaces.
apt_install bind9 resolvconf
tools/editconf.py /etc/default/bind9 \
RESOLVCONF=yes \
"OPTIONS=\"-u bind -4\""
if ! grep -q "listen-on " /etc/bind/named.conf.options; then
# Add a listen-on directive if it doesn't exist inside the options block.
sed -i "s/^}/\n\tlisten-on { 127.0.0.1; };\n}/" /etc/bind/named.conf.options
fi
if [ -f /etc/resolvconf/resolv.conf.d/original ]; then
echo "Archiving old resolv.conf (was /etc/resolvconf/resolv.conf.d/original, now /etc/resolvconf/resolv.conf.original)." #NODOC
mv /etc/resolvconf/resolv.conf.d/original /etc/resolvconf/resolv.conf.original #NODOC
fi
# Restart the DNS services.
restart_service bind9
restart_service resolvconf
# ### Fail2Ban Service
# Configure the Fail2Ban installation to prevent dumb bruce-force attacks against dovecot, postfix, ssh, etc.
rm -f /etc/fail2ban/jail.local # we used to use this file but don't anymore
cat conf/fail2ban/jails.conf \
| sed "s/PUBLIC_IP/$PUBLIC_IP/g" \
| sed "s#STORAGE_ROOT#$STORAGE_ROOT#" \
> /etc/fail2ban/jail.d/mailinabox.conf
cp -f conf/fail2ban/filter.d/* /etc/fail2ban/filter.d/
# On first installation, the log files that the jails look at don't all exist.
# e.g., The roundcube error log isn't normally created until someone logs into
# Roundcube for the first time. This causes fail2ban to fail to start. Later
# scripts will ensure the files exist and then fail2ban is given another
# restart at the very end of setup.
restart_service fail2ban