feature: adding getmail as an alternative to fetchmail (#2803)

Co-authored-by: Brennan Kinney <5098581+polarathene@users.noreply.github.com>
Co-authored-by: Georg Lauterbach <44545919+georglauterbach@users.noreply.github.com>
Co-authored-by: Casper <casperklein@users.noreply.github.com>

target/scripts/build/packages.sh

@@ -201,6 +201,21 @@ function _install_fail2ban
   sedfile -i -r 's/^_nft_add_set = .+/_nft_add_set = <nftables> add set <table_family> <table> <addr_set> \\{ type <addr_type>\\; flags interval\\; \\}/' /etc/fail2ban/action.d/nftables.conf
 }
 
+# Presently the getmail6 package is v6.14, which is too old.
+# v6.18 contains fixes for Google and Microsoft OAuth support.
+# using pip to install getmail.
+# TODO This can be removed when the base image is updated to Debian 12 (Bookworm)
+function _install_getmail
+{
+  _log 'debug' 'Installing getmail6'
+  apt-get "${QUIET}" --no-install-recommends install python3-pip
+  pip3 install --no-cache-dir 'getmail6~=6.18.12'
+  ln -s /usr/local/bin/getmail /usr/bin/getmail
+  ln -s /usr/local/bin/getmail-gmail-xoauth-tokens /usr/bin/getmail-gmail-xoauth-tokens
+  apt-get "${QUIET}" purge python3-pip
+  apt-get "${QUIET}" autoremove
+}
+
 function _remove_data_after_package_installations
 {
   _log 'debug' 'Deleting sensitive files (secrets)'
@@ -225,5 +240,6 @@ _install_packages
 _install_dovecot
 _install_rspamd
 _install_fail2ban
+_install_getmail
 _remove_data_after_package_installations
 _post_installation_steps

target/scripts/start-mailserver.sh

@@ -97,6 +97,8 @@ function _register_functions
   # needs to come after _setup_postfix_early
   _register_setup_function '_setup_spoof_protection'
 
+_register_setup_function '_setup_getmail'
+
   if [[ ${ENABLE_SRS} -eq 1  ]]
   then
     _register_setup_function '_setup_SRS'

target/scripts/startup/setup.d/getmail.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+function _setup_getmail
+{
+  if [[ ${ENABLE_GETMAIL} -eq 1 ]]
+  then
+    _log 'trace' 'Preparing Getmail configuration'
+
+    local GETMAILRC ID CONFIGS
+
+    GETMAILRC='/etc/getmailrc.d'
+    CONFIGS=0
+
+    mkdir -p "${GETMAILRC}"
+
+    # Generate getmailrc configs, starting with the `/etc/getmailrc_general` base config,
+    # Add a unique `message_log` config, then append users own config to the end.
+    for FILE in /tmp/docker-mailserver/getmail-*.cf
+    do
+      if [[ -f ${FILE} ]]
+      then
+        CONFIGS=1
+        ID=$(cut -d '-' -f 3 <<< "${FILE}" | cut -d '.' -f 1)
+        local GETMAIL_CONFIG="${GETMAILRC}/getmailrc-${ID}"
+        cat /etc/getmailrc_general >"${GETMAIL_CONFIG}.tmp"
+        echo -e "message_log = /var/log/mail/getmail-${ID}.log\n" >>"${GETMAIL_CONFIG}.tmp"
+        cat "${GETMAIL_CONFIG}.tmp" "${FILE}" >"${GETMAIL_CONFIG}"
+        rm "${GETMAIL_CONFIG}.tmp"
+      fi
+    done
+
+    if [[ ${CONFIGS} -eq 1 ]]
+    then
+      cat >/etc/cron.d/getmail << EOF
+*/${GETMAIL_POLL} * * * * root /usr/local/bin/getmail-cron
+EOF
+      chmod -R 600 "${GETMAILRC}"
+    fi
+  else
+    _log 'debug' 'Getmail is disabled'
+  fi
+}

target/scripts/startup/setup.d/mail_state.sh

@@ -25,6 +25,7 @@ function _setup_save_states
     [[ ${ENABLE_CLAMAV}       -eq 1 ]] && SERVICEDIRS+=('lib/clamav')
     [[ ${ENABLE_FAIL2BAN}     -eq 1 ]] && SERVICEDIRS+=('lib/fail2ban')
     [[ ${ENABLE_FETCHMAIL}    -eq 1 ]] && SERVICEDIRS+=('lib/fetchmail')
+    [[ ${ENABLE_GETMAIL}      -eq 1 ]] && SERVICEDIRS+=('lib/getmail')
     [[ ${ENABLE_POSTGREY}     -eq 1 ]] && SERVICEDIRS+=('lib/postgrey')
     [[ ${ENABLE_RSPAMD}       -eq 1 ]] && SERVICEDIRS+=('lib/rspamd')
     [[ ${ENABLE_RSPAMD_REDIS} -eq 1 ]] && SERVICEDIRS+=('lib/redis')

target/scripts/startup/variables-stack.sh

@@ -74,6 +74,7 @@ function __environment_variables_general_setup
   VARS[ENABLE_DNSBL]="${ENABLE_DNSBL:=0}"
   VARS[ENABLE_FAIL2BAN]="${ENABLE_FAIL2BAN:=0}"
   VARS[ENABLE_FETCHMAIL]="${ENABLE_FETCHMAIL:=0}"
+  VARS[ENABLE_GETMAIL]="${ENABLE_GETMAIL:=0}"
   VARS[ENABLE_MANAGESIEVE]="${ENABLE_MANAGESIEVE:=0}"
   VARS[ENABLE_OPENDKIM]="${ENABLE_OPENDKIM:=1}"
   VARS[ENABLE_OPENDMARC]="${ENABLE_OPENDMARC:=1}"
@@ -125,6 +126,7 @@ function __environment_variables_general_setup
   VARS[ACCOUNT_PROVISIONER]="${ACCOUNT_PROVISIONER:=FILE}"
   VARS[FETCHMAIL_PARALLEL]="${FETCHMAIL_PARALLEL:=0}"
   VARS[FETCHMAIL_POLL]="${FETCHMAIL_POLL:=300}"
+  VARS[GETMAIL_POLL]="${GETMAIL_POLL:=5}"
   VARS[LOG_LEVEL]="${LOG_LEVEL:=info}"
   VARS[LOGROTATE_INTERVAL]="${LOGROTATE_INTERVAL:=weekly}"
   VARS[LOGWATCH_INTERVAL]="${LOGWATCH_INTERVAL:=none}"