Lint alarm notify (#5164)

* manually lint alarm-notify.sh code

* run automatic bash formatter (shfmt)

* bring back unused variable

1 files changed, 1134 insertions, 1222 deletions

diff --git a/health/notifications/alarm-notify.sh.in b/health/notifications/alarm-notify.sh.in
index dd3cda9178..04c0d2e06e 100755
--- a/health/notifications/alarm-notify.sh.in
+++ b/health/notifications/alarm-notify.sh.in
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+#shellcheck source=/dev/null disable=SC2086,SC2154
 
 # netdata
 # real-time performance and health monitoring, done right!
@@ -35,40 +36,36 @@
 # -----------------------------------------------------------------------------
 # testing notifications
 
-
-if [ \( "${1}" = "test" -o "${2}" = "test" \) -a "${#}" -le 2 ]
-then
-    if [ "${2}" = "test" ]
-    then
-        recipient="${1}"
-    else
-        recipient="${2}"
-    fi
-
-    [ -z "${recipient}" ] && recipient="sysadmin"
-
-    id=1
-    last="CLEAR"
-    test_res=0
-    for x in "WARNING" "CRITICAL"  "CLEAR"
-    do
-        echo >&2
-        echo >&2 "# SENDING TEST ${x} ALARM TO ROLE: ${recipient}"
-
-        "${0}" "${recipient}" "$(hostname)" 1 1 "${id}" "$(date +%s)" "test_alarm" "test.chart" "test.family" "${x}" "${last}" 100 90 "${0}" 1 $((0 + id)) "units" "this is a test alarm to verify notifications work" "new value" "old value" "evaluated expression" "expression variable values" 0 0
-        if [ $? -ne 0 ]
-        then
-            echo >&2 "# FAILED"
-            test_res=1
-        else
-            echo >&2 "# OK"
-        fi
-
-        last="${x}"
-        id=$((id + 1))
-    done
-
-    exit $test_res
+if { [ "${1}" = "test" ] || [ "${2}" = "test" ]; } && [ "${#}" -le 2 ]; then
+	if [ "${2}" = "test" ]; then
+		recipient="${1}"
+	else
+		recipient="${2}"
+	fi
+
+	[ -z "${recipient}" ] && recipient="sysadmin"
+
+	id=1
+	last="CLEAR"
+	test_res=0
+	for x in "WARNING" "CRITICAL" "CLEAR"; do
+		echo >&2
+		echo >&2 "# SENDING TEST ${x} ALARM TO ROLE: ${recipient}"
+
+		"${0}" "${recipient}" "$(hostname)" 1 1 "${id}" "$(date +%s)" "test_alarm" "test.chart" "test.family" "${x}" "${last}" 100 90 "${0}" 1 $((0 + id)) "units" "this is a test alarm to verify notifications work" "new value" "old value" "evaluated expression" "expression variable values" 0 0
+		#shellcheck disable=SC2181
+		if [ $? -ne 0 ]; then
+			echo >&2 "# FAILED"
+			test_res=1
+		else
+			echo >&2 "# OK"
+		fi
+
+		last="${x}"
+		id=$((id + 1))
+	done
+
+	exit $test_res
 fi
 
 export PATH="${PATH}:/sbin:/usr/sbin:/usr/local/sbin"
@@ -79,68 +76,67 @@ export LC_ALL=C
 PROGRAM_NAME="$(basename "${0}")"
 
 logdate() {
-    date "+%Y-%m-%d %H:%M:%S"
+	date "+%Y-%m-%d %H:%M:%S"
 }
 
 log() {
-    local status="${1}"
-    shift
+	local status="${1}"
+	shift
 
-    echo >&2 "$(logdate): ${PROGRAM_NAME}: ${status}: ${*}"
+	echo >&2 "$(logdate): ${PROGRAM_NAME}: ${status}: ${*}"
 
 }
 
 warning() {
-    log WARNING "${@}"
+	log WARNING "${@}"
 }
 
 error() {
-    log ERROR "${@}"
+	log ERROR "${@}"
 }
 
 info() {
-    log INFO "${@}"
+	log INFO "${@}"
 }
 
 fatal() {
-    log FATAL "${@}"
-    exit 1
+	log FATAL "${@}"
+	exit 1
 }
 
 debug=${NETDATA_ALARM_NOTIFY_DEBUG-0}
 debug() {
-    [ "${debug}" = "1" ] && log DEBUG "${@}"
+	[ "${debug}" = "1" ] && log DEBUG "${@}"
 }
 
 docurl() {
-    if [ -z "${curl}" ]
-        then
-        error "\${curl} is unset."
-        return 1
-    fi
-
-    if [ "${debug}" = "1" ]
-        then
-        echo >&2 "--- BEGIN curl command ---"
-        printf >&2 "%q " ${curl} "${@}"
-        echo >&2
-        echo >&2 "--- END curl command ---"
-
-        local out=$(mktemp /tmp/netdata-health-alarm-notify-XXXXXXXX)
-        local code=$(${curl} ${curl_options} --write-out %{http_code} --output "${out}" --silent --show-error "${@}")
-        local ret=$?
-        echo >&2 "--- BEGIN received response ---"
-        cat >&2 "${out}"
-        echo >&2
-        echo >&2 "--- END received response ---"
-        echo >&2 "RECEIVED HTTP RESPONSE CODE: ${code}"
-        rm "${out}"
-        echo "${code}"
-        return ${ret}
-    fi
-
-    ${curl} ${curl_options} --write-out %{http_code} --output /dev/null --silent --show-error "${@}"
-    return $?
+	if [ -z "${curl}" ]; then
+		error '${curl} is unset.'
+		return 1
+	fi
+
+	if [ "${debug}" = "1" ]; then
+		echo >&2 "--- BEGIN curl command ---"
+		printf >&2 "%q " ${curl} "${@}"
+		echo >&2
+		echo >&2 "--- END curl command ---"
+
+		local out code ret
+		out=$(mktemp /tmp/netdata-health-alarm-notify-XXXXXXXX)
+		code=$(${curl} ${curl_options} --write-out "%{http_code}" --output "${out}" --silent --show-error "${@}")
+		ret=$?
+		echo >&2 "--- BEGIN received response ---"
+		cat >&2 "${out}"
+		echo >&2
+		echo >&2 "--- END received response ---"
+		echo >&2 "RECEIVED HTTP RESPONSE CODE: ${code}"
+		rm "${out}"
+		echo "${code}"
+		return ${ret}
+	fi
+
+	${curl} ${curl_options} --write-out "%{http_code}" --output /dev/null --silent --show-error "${@}"
+	return $?
 }
 
 # -----------------------------------------------------------------------------
@@ -166,94 +162,92 @@ custom
 msteam
 kavenegar
 prowl
+awssns
 "
 
 # -----------------------------------------------------------------------------
 # this is to be overwritten by the config file
 
 custom_sender() {
-    info "not sending custom notification for ${status} of '${host}.${chart}.${name}'"
+	info "not sending custom notification for ${status} of '${host}.${chart}.${name}'"
 }
 
-
 # -----------------------------------------------------------------------------
 
 # check for BASH v4+ (required for associative arrays)
-[ $(( ${BASH_VERSINFO[0]} )) -lt 4 ] && \
-    fatal "BASH version 4 or later is required (this is ${BASH_VERSION})."
+if [ ${BASH_VERSINFO[0]} -lt 4 ]; then
+	fatal "BASH version 4 or later is required (this is ${BASH_VERSION})."
+fi
 
 # -----------------------------------------------------------------------------
 # defaults to allow running this script by hand
 
-[ -z "${NETDATA_USER_CONFIG_DIR}"  ] && NETDATA_USER_CONFIG_DIR="@configdir_POST@"
+[ -z "${NETDATA_USER_CONFIG_DIR}" ] && NETDATA_USER_CONFIG_DIR="@configdir_POST@"
 [ -z "${NETDATA_STOCK_CONFIG_DIR}" ] && NETDATA_STOCK_CONFIG_DIR="@libconfigdir_POST@"
-[ -z "${NETDATA_CACHE_DIR}"        ] && NETDATA_CACHE_DIR="@cachedir_POST@"
-[ -z "${NETDATA_REGISTRY_URL}"     ] && NETDATA_REGISTRY_URL="https://registry.my-netdata.io"
+[ -z "${NETDATA_CACHE_DIR}" ] && NETDATA_CACHE_DIR="@cachedir_POST@"
+[ -z "${NETDATA_REGISTRY_URL}" ] && NETDATA_REGISTRY_URL="https://registry.my-netdata.io"
 
 # -----------------------------------------------------------------------------
 # parse command line parameters
 
-if [ ${1} = "unittest" ] ; then
-    unittest=1                 # enable unit testing mode
-    roles="${2}"               # the role that should be used for unit testing
-    cfgfile="${3}"             # the location of the config file to use for unit testing
-    status="${4}"              # the current status : REMOVED, UNINITIALIZED, UNDEFINED, CLEAR, WARNING, CRITICAL
-    old_status="${5}"          # the previous status: REMOVED, UNINITIALIZED, UNDEFINED, CLEAR, WARNING, CRITICAL
+if [ ${1} = "unittest" ]; then
+	unittest=1        # enable unit testing mode
+	roles="${2}"      # the role that should be used for unit testing
+	cfgfile="${3}"    # the location of the config file to use for unit testing
+	status="${4}"     # the current status : REMOVED, UNINITIALIZED, UNDEFINED, CLEAR, WARNING, CRITICAL
+	old_status="${5}" # the previous status: REMOVED, UNINITIALIZED, UNDEFINED, CLEAR, WARNING, CRITICAL
 else
-    roles="${1}"               # the roles that should be notified for this event
-    args_host="${2}"                # the host generated this event
-    unique_id="${3}"           # the unique id of this event
-    alarm_id="${4}"            # the unique id of the alarm that generated this event
-    event_id="${5}"            # the incremental id of the event, for this alarm id
-    when="${6}"                # the timestamp this event occurred
-    name="${7}"                # the name of the alarm, as given in netdata health.d entries
-    chart="${8}"               # the name of the chart (type.id)
-    family="${9}"              # the family of the chart
-    status="${10}"             # the current status : REMOVED, UNINITIALIZED, UNDEFINED, CLEAR, WARNING, CRITICAL
-    old_status="${11}"         # the previous status: REMOVED, UNINITIALIZED, UNDEFINED, CLEAR, WARNING, CRITICAL
-    value="${12}"              # the current value of the alarm
-    old_value="${13}"          # the previous value of the alarm
-    src="${14}"                # the line number and file the alarm has been configured
-    duration="${15}"           # the duration in seconds of the previous alarm state
-    non_clear_duration="${16}" # the total duration in seconds this is/was non-clear
-    units="${17}"              # the units of the value
-    info="${18}"               # a short description of the alarm
-    value_string="${19}"       # friendly value (with units)
-    old_value_string="${20}"   # friendly old value (with units)
-    calc_expression="${21}"	   # contains the expression that was evaluated to trigger the alarm
-    calc_param_values="${22}"  # the values of the parameters in the expression, at the time of the evaluation
-    total_warnings="${23}"     # Total number of alarms in WARNING state
-    total_critical="${24}"     # Total number of alarms in CRITICAL state
+	roles="${1}"               # the roles that should be notified for this event
+	args_host="${2}"           # the host generated this event
+	unique_id="${3}"           # the unique id of this event
+	alarm_id="${4}"            # the unique id of the alarm that generated this event
+	event_id="${5}"            # the incremental id of the event, for this alarm id
+	when="${6}"                # the timestamp this event occurred
+	name="${7}"                # the name of the alarm, as given in netdata health.d entries
+	chart="${8}"               # the name of the chart (type.id)
+	family="${9}"              # the family of the chart
+	status="${10}"             # the current status : REMOVED, UNINITIALIZED, UNDEFINED, CLEAR, WARNING, CRITICAL
+	old_status="${11}"         # the previous status: REMOVED, UNINITIALIZED, UNDEFINED, CLEAR, WARNING, CRITICAL
+	value="${12}"              # the current value of the alarm
+	old_value="${13}"          # the previous value of the alarm
+	src="${14}"                # the line number and file the alarm has been configured
+	duration="${15}"           # the duration in seconds of the previous alarm state
+	non_clear_duration="${16}" # the total duration in seconds this is/was non-clear
+	units="${17}"              # the units of the value
+	info="${18}"               # a short description of the alarm
+	value_string="${19}"       # friendly value (with units)
+	# shellcheck disable=SC2034 variable is unused, but https://github.com/netdata/netdata/pull/5164#discussion_r255572947
+	old_value_string="${20}"   # friendly old value (with units), previously named "old_value_string"
+	calc_expression="${21}"    # contains the expression that was evaluated to trigger the alarm
+	calc_param_values="${22}"  # the values of the parameters in the expression, at the time of the evaluation
+	total_warnings="${23}"     # Total number of alarms in WARNING state
+	total_critical="${24}"     # Total number of alarms in CRITICAL state
 fi
 
-
 # -----------------------------------------------------------------------------
 # find a suitable hostname to use, if netdata did not supply a hostname
 
-if [ -z ${args_host} ]
-    then
-    this_host=$(hostname -s 2>/dev/null)
-    host="${this_host}"
-    args_host="${this_host}"
+if [ -z ${args_host} ]; then
+	this_host=$(hostname -s 2>/dev/null)
+	host="${this_host}"
+	args_host="${this_host}"
 else
-    host="${args_host}"
+	host="${args_host}"
 fi
 
 # -----------------------------------------------------------------------------
 # screen statuses we don't need to send a notification
 
 # don't do anything if this is not WARNING, CRITICAL or CLEAR
-if [ "${status}" != "WARNING" -a "${status}" != "CRITICAL" -a "${status}" != "CLEAR" ]
-then
-    info "not sending notification for ${status} of '${host}.${chart}.${name}'"
-    exit 1
+if [ "${status}" != "WARNING" ] && [ "${status}" != "CRITICAL" ] && [ "${status}" != "CLEAR" ]; then
+	info "not sending notification for ${status} of '${host}.${chart}.${name}'"
+	exit 1
 fi
 
 # don't do anything if this is CLEAR, but it was not WARNING or CRITICAL
-if [ "${clear_alarm_always}" != "YES" -a "${old_status}" != "WARNING" -a "${old_status}" != "CRITICAL" -a "${status}" = "CLEAR" ]
-then
-    info "not sending notification for ${status} of '${host}.${chart}.${name}' (last status was ${old_status})"
-    exit 1
+if [ "${clear_alarm_always}" != "YES" ] && [ "${old_status}" != "WARNING" ] && [ "${old_status}" != "CRITICAL" ] && [ "${status}" = "CLEAR" ]; then
+	info "not sending notification for ${status} of '${host}.${chart}.${name}' (last status was ${old_status})"
+	exit 1
 fi
 
 # -----------------------------------------------------------------------------
@@ -277,13 +271,13 @@ curl=
 sendmail=
 
 # enable / disable features
-for method_name in ${method_names^^} ; do
-    declare SEND_${method_name}="YES"
-    declare DEFAULT_RECIPIENT_${method_name}
+for method_name in ${method_names^^}; do
+	declare SEND_${method_name}="YES"
+	declare DEFAULT_RECIPIENT_${method_name}
 done
 
-for method_name in ${method_names} ; do
-    declare -A role_recipients_${method_name}
+for method_name in ${method_names}; do
+	declare -A role_recipients_${method_name}
 done
 
 # slack configs
@@ -344,9 +338,7 @@ PD_SERVICE_KEY=
 FLEEP_SENDER="${host}"
 
 # Amazon SNS configs
-DEFAULT_RECIPIENT_AWSSNS=
 AWSSNS_MESSAGE_FORMAT=
-declare -A role_recipients_awssns=()
 
 # syslog configs
 SYSLOG_FACILITY=
@@ -355,7 +347,6 @@ SYSLOG_FACILITY=
 EMAIL_SENDER=
 EMAIL_CHARSET=$(locale charmap 2>/dev/null)
 EMAIL_THREADING=
-DEFAULT_RECIPIENT_EMAIL="root"
 
 # irc configs
 IRC_NICKNAME=
@@ -365,95 +356,88 @@ IRC_NETWORK=
 # load the stock and user configuration files
 # these will overwrite the variables above
 
-if [ ${unittest} ] ;
-    then
-    source "${cfgfile}"
-    [ $? -ne 0 ] && error "Failed to load requested config file." && exit 1
+if [ ${unittest} ]; then
+	if source "${cfgfile}"; then
+		error "Failed to load requested config file."
+		exit 1
+	fi
 else
-    for CONFIG in "${NETDATA_STOCK_CONFIG_DIR}/health_alarm_notify.conf" "${NETDATA_USER_CONFIG_DIR}/health_alarm_notify.conf"
-    do
-        if [ -f "${CONFIG}" ]
-            then
-            debug "Loading config file '${CONFIG}'..."
-            source "${CONFIG}"
-            [ $? -ne 0 ] && error "Failed to load config file '${CONFIG}'."
-        else
-            warning "Cannot find file '${CONFIG}'."
-        fi
-    done
+	for CONFIG in "${NETDATA_STOCK_CONFIG_DIR}/health_alarm_notify.conf" "${NETDATA_USER_CONFIG_DIR}/health_alarm_notify.conf"; do
+		if [ -f "${CONFIG}" ]; then
+			debug "Loading config file '${CONFIG}'..."
+			source "${CONFIG}" || error "Failed to load config file '${CONFIG}'."
+		else
+			warning "Cannot find file '${CONFIG}'."
+		fi
+	done
 fi
 
 # If we didn't autodetect the character set for e-mail and it wasn't
 # set by the user, we need to set it to a reasonable default.  UTF-8
 # should be correct for almost all modern UNIX systems.
-if [ -z ${EMAIL_CHARSET} ]
-    then
-    EMAIL_CHARSET="UTF-8"
+if [ -z ${EMAIL_CHARSET} ]; then
+	EMAIL_CHARSET="UTF-8"
 fi
 
 # If we've been asked to use FQDN's for the URL's in the alarm, do so,
 # unless we're sending an alarm for a slave system which we can't get the
 # FQDN of easily.
-if [ "${use_fqdn}" = "YES" -a "${host}" = "$(hostname -s 2>/dev/null)" ]
-    then
-    host="$(hostname -f 2>/dev/null)"
+if [ "${use_fqdn}" = "YES" ] && [ "${host}" = "$(hostname -s 2>/dev/null)" ]; then
+	host="$(hostname -f 2>/dev/null)"
 fi
 
 # -----------------------------------------------------------------------------
 # filter a recipient based on alarm event severity
 
 filter_recipient_by_criticality() {
-    local method="${1}" x="${2}" r s
-    shift
-
-    r="${x/|*/}" # the recipient
-    s="${x/*|/}" # the severity required for notifying this recipient
-
-    # no severity filtering for this person
-    [ "${r}" = "${s}" ] && return 0
-
-    # the severity is invalid
-    s="${s^^}"
-    if [ "${s}" != "CRITICAL" ]
-    then
-        error "SEVERITY FILTERING for ${x} VIA ${method}: invalid severity '${s,,}', only 'critical' is supported."
-        return 0
-    fi
-
-    # create the status tracking directory for this user
-    [ ! -d "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}" ] && \
-        mkdir -p "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}"
-
-    case "${status}" in
-        CRITICAL)
-            # make sure he will get future notifications for this alarm too
-            touch "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}/${alarm_id}"
-            debug "SEVERITY FILTERING for ${x} VIA ${method}: ALLOW: the alarm is CRITICAL (will now receive next status change)"
-            return 0
-            ;;
-
-        WARNING)
-            if [ -f "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}/${alarm_id}" ]
-            then
-                # we do not remove the file, so that he will get future notifications of this alarm
-                debug "SEVERITY FILTERING for ${x} VIA ${method}: ALLOW: recipient has been notified for this alarm in the past (will still receive next status change)"
-                return 0
-            fi
-            ;;
-
-        *)
-            if [ -f "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}/${alarm_id}" ]
-            then
-                # remove the file, so that he will only receive notifications for CRITICAL states for this alarm
-                rm "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}/${alarm_id}"
-                debug "SEVERITY FILTERING for ${x} VIA ${method}: ALLOW: recipient has been notified for this alarm (will only receive CRITICAL notifications from now on)"
-                return 0
-            fi
-            ;;
-    esac
-
-    debug "SEVERITY FILTERING for ${x} VIA ${method}: BLOCK: recipient should not receive this notification"
-    return 1
+	local method="${1}" x="${2}" r s
+	shift
+
+	r="${x/|*/}" # the recipient
+	s="${x/*|/}" # the severity required for notifying this recipient
+
+	# no severity filtering for this person
+	[ "${r}" = "${s}" ] && return 0
+
+	# the severity is invalid
+	s="${s^^}"
+	if [ "${s}" != "CRITICAL" ]; then
+		error "SEVERITY FILTERING for ${x} VIA ${method}: invalid severity '${s,,}', only 'critical' is supported."
+		return 0
+	fi
+
+	# create the status tracking directory for this user
+	[ ! -d "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}" ] &&
+		mkdir -p "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}"
+
+	case "${status}" in
+	CRITICAL)
+		# make sure he will get future notifications for this alarm too
+		touch "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}/${alarm_id}"
+		debug "SEVERITY FILTERING for ${x} VIA ${method}: ALLOW: the alarm is CRITICAL (will now receive next status change)"
+		return 0
+		;;
+
+	WARNING)
+		if [ -f "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}/${alarm_id}" ]; then
+			# we do not remove the file, so that he will get future notifications of this alarm
+			debug "SEVERITY FILTERING for ${x} VIA ${method}: ALLOW: recipient has been notified for this alarm in the past (will still receive next status change)"
+			return 0
+		fi
+		;;
+
+	*)
+		if [ -f "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}/${alarm_id}" ]; then
+			# remove the file, so that he will only receive notifications for CRITICAL states for this alarm
+			rm "${NETDATA_CACHE_DIR}/alarm-notify/${method}/${r}/${alarm_id}"
+			debug "SEVERITY FILTERING for ${x} VIA ${method}: ALLOW: recipient has been notified for this alarm (will only receive CRITICAL notifications from now on)"
+			return 0
+		fi
+		;;
+	esac
+
+	debug "SEVERITY FILTERING for ${x} VIA ${method}: BLOCK: recipient should not receive this notification"
+	return 1
 }
 
 # -----------------------------------------------------------------------------
@@ -481,107 +465,100 @@ filter_recipient_by_criticality() {
 [ -z "${PUSHBULLET_ACCESS_TOKEN}" ] && SEND_PUSHBULLET="NO"
 
 # check twilio
-[ -z "${TWILIO_ACCOUNT_TOKEN}" -o -z "${TWILIO_ACCOUNT_SID}" -o -z "${TWILIO_NUMBER}" ] && SEND_TWILIO="NO"
+{ [ -z "${TWILIO_ACCOUNT_TOKEN}" ] || [ -z "${TWILIO_ACCOUNT_SID}" ] || [ -z "${TWILIO_NUMBER}" ]; } && SEND_TWILIO="NO"
 
 # check hipchat
 [ -z "${HIPCHAT_AUTH_TOKEN}" ] && SEND_HIPCHAT="NO"
 
 # check messagebird
-[ -z "${MESSAGEBIRD_ACCESS_KEY}" -o -z "${MESSAGEBIRD_NUMBER}" ] && SEND_MESSAGEBIRD="NO"
+{ [ -z "${MESSAGEBIRD_ACCESS_KEY}" ] || [ -z "${MESSAGEBIRD_NUMBER}" ]; } && SEND_MESSAGEBIRD="NO"
 
 # check kavenegar
-[ -z "${KAVENEGAR_API_KEY}" -o -z "${KAVENEGAR_SENDER}" ] && SEND_KAVENEGAR="NO"
+{ [ -z "${KAVENEGAR_API_KEY}" ] || [ -z "${KAVENEGAR_SENDER}" ]; } && SEND_KAVENEGAR="NO"
 
 # check telegram
 [ -z "${TELEGRAM_BOT_TOKEN}" ] && SEND_TELEGRAM="NO"
 
 # check kafka
-[ -z "${KAFKA_URL}" -o -z "${KAFKA_SENDER_IP}" ] && SEND_KAFKA="NO"
+{ [ -z "${KAFKA_URL}" ] || [ -z "${KAFKA_SENDER_IP}" ]; } && SEND_KAFKA="NO"
 
 # check irc
 [ -z "${IRC_NETWORK}" ] && SEND_IRC="NO"
 
 # check fleep
-[ -z "${FLEEP_SERVER}" -o -z "${FLEEP_SENDER}" ] && SEND_FLEEP="NO"
-
-# if we need curl, check for the curl command
-if [ \( \
-           "${SEND_PUSHOVER}"    = "YES" \
-        -o "${SEND_SLACK}"       = "YES" \
-        -o "${SEND_ROCKETCHAT}"  = "YES" \
-        -o "${SEND_ALERTA}"      = "YES" \
-        -o "${SEND_PD}"          = "YES" \
-        -o "${SEND_FLOCK}"       = "YES" \
-        -o "${SEND_DISCORD}"     = "YES" \
-        -o "${SEND_HIPCHAT}"     = "YES" \
-        -o "${SEND_TWILIO}"      = "YES" \
-        -o "${SEND_MESSAGEBIRD}" = "YES" \
-        -o "${SEND_KAVENEGAR}"   = "YES" \
-        -o "${SEND_TELEGRAM}"    = "YES" \
-        -o "${SEND_PUSHBULLET}"  = "YES" \
-        -o "${SEND_KAFKA}"       = "YES" \
-        -o "${SEND_FLEEP}"       = "YES" \
-        -o "${SEND_PROWL}"       = "YES" \
-        -o "${SEND_CUSTOM}"      = "YES" \
-        -o "${SEND_MSTEAM}"        = "YES" \
-    \) -a -z "${curl}" ]
-    then
-    curl="$(which curl 2>/dev/null || command -v curl 2>/dev/null)"
-    if [ -z "${curl}" ]
-        then
-        error "Cannot find curl command in the system path. Disabling all curl based notifications."
-        SEND_PUSHOVER="NO"
-        SEND_PUSHBULLET="NO"
-        SEND_TELEGRAM="NO"
-        SEND_SLACK="NO"
-        SEND_MSTEAM="NO"
-        SEND_ROCKETCHAT="NO"
-        SEND_ALERTA="NO"
-        SEND_PD="NO"
-        SEND_FLOCK="NO"
-        SEND_DISCORD="NO"
-        SEND_TWILIO="NO"
-        SEND_HIPCHAT="NO"
-        SEND_MESSAGEBIRD="NO"
-        SEND_KAVENEGAR="NO"
-        SEND_KAFKA="NO"
-        SEND_FLEEP="NO"
-        SEND_PROWL="NO"
-        SEND_CUSTOM="NO"
-    fi
+#shellcheck disable=SC2153
+{ [ -z "${FLEEP_SERVER}" ] || [ -z "${FLEEP_SENDER}" ]; } && SEND_FLEEP="NO"
+
+if [ "${SEND_PUSHOVER}" = "YES" ] ||
+	[ "${SEND_SLACK}" = "YES" ] ||
+	[ "${SEND_ROCKETCHAT}" = "YES" ] ||
+	[ "${SEND_ALERTA}" = "YES" ] ||
+	[ "${SEND_PD}" = "YES" ] ||
+	[ "${SEND_FLOCK}" = "YES" ] ||
+	[ "${SEND_DISCORD}" = "YES" ] ||
+	[ "${SEND_HIPCHAT}" = "YES" ] ||
+	[ "${SEND_TWILIO}" = "YES" ] ||
+	[ "${SEND_MESSAGEBIRD}" = "YES" ] ||
+	[ "${SEND_KAVENEGAR}" = "YES" ] ||
+	[ "${SEND_TELEGRAM}" = "YES" ] ||
+	[ "${SEND_PUSHBULLET}" = "YES" ] ||
+	[ "${SEND_KAFKA}" = "YES" ] ||
+	[ "${SEND_FLEEP}" = "YES" ] ||
+	[ "${SEND_PROWL}" = "YES" ] ||
+	[ "${SEND_CUSTOM}" = "YES" ] ||
+	[ "${SEND_MSTEAM}" = "YES" ]; then
+	# if we need curl, check for the curl command
+	if [ -z "${curl}" ]; then
+		curl="$(command -v curl 2>/dev/null)"
+	fi
+	if [ -z "${curl}" ]; then
+		error "Cannot find curl command in the system path. Disabling all curl based notifications."
+		SEND_PUSHOVER="NO"
+		SEND_PUSHBULLET="NO"
+		SEND_TELEGRAM="NO"
+		SEND_SLACK="NO"
+		SEND_MSTEAM="NO"
+		SEND_ROCKETCHAT="NO"
+		SEND_ALERTA="NO"
+		SEND_PD="NO"
+		SEND_FLOCK="NO"
+		SEND_DISCORD="NO"
+		SEND_TWILIO="NO"
+		SEND_HIPCHAT="NO"
+		SEND_MESSAGEBIRD="NO"
+		SEND_KAVENEGAR="NO"
+		SEND_KAFKA="NO"
+		SEND_FLEEP="NO"
+		SEND_PROWL="NO"
+		SEND_CUSTOM="NO"
+	fi
 fi
 
 # if we need sendmail, check for the sendmail command
-if [ "${SEND_EMAIL}" = "YES" -a -z "${sendmail}" ]
-    then
-    sendmail="$(which sendmail 2>/dev/null || command -v sendmail 2>/dev/null)"
-    if [ -z "${sendmail}" ]
-        then
-        debug "Cannot find sendmail command in the system path. Disabling email notifications."
-        SEND_EMAIL="NO"
-    fi
+if [ "${SEND_EMAIL}" = "YES" ] && [ -z "${sendmail}" ]; then
+	sendmail="$(command -v sendmail 2>/dev/null)"
+	if [ -z "${sendmail}" ]; then
+		debug "Cannot find sendmail command in the system path. Disabling email notifications."
+		SEND_EMAIL="NO"
+	fi
 fi
 
 # if we need logger, check for the logger command
-if [ "${SEND_SYSLOG}" = "YES" -a -z "${logger}" ]
-    then
-    logger="$(which logger 2>/dev/null || command -v logger 2>/dev/null)"
-    if [ -z "${logger}" ]
-        then
-        debug "Cannot find logger command in the system path. Disabling syslog notifications."
-        SEND_SYSLOG="NO"
-    fi
+if [ "${SEND_SYSLOG}" = "YES" ] && [ -z "${logger}" ]; then
+	logger="$(command -v logger 2>/dev/null)"
+	if [ -z "${logger}" ]; then
+		debug "Cannot find logger command in the system path. Disabling syslog notifications."
+		SEND_SYSLOG="NO"
+	fi
 fi
 
 # if we need aws, check for the aws command
-if [ "${SEND_AWSSNS}" = "YES" -a -z "${aws}" ]
-    then
-    aws="$(which aws 2>/dev/null || command -v aws 2>/dev/null)"
-    if [ -z "${aws}" ]
-        then
-        debug "Cannot find aws command in the system path.  Disabling Amazon SNS notifications."
-        SEND_AWSSNS="NO"
-    fi
+if [ "${SEND_AWSSNS}" = "YES" ] && [ -z "${aws}" ]; then
+	aws="$(command -v aws 2>/dev/null)"
+	if [ -z "${aws}" ]; then
+		debug "Cannot find aws command in the system path.  Disabling Amazon SNS notifications."
+		SEND_AWSSNS="NO"
+	fi
 fi
 
 # -----------------------------------------------------------------------------
@@ -589,47 +566,48 @@ fi
 
 # netdata may call us with multiple roles, and roles may have multiple but
 # overlapping recipients - so, here we find the unique recipients.
-for method_name in ${method_names} ; do
-    send_var="SEND_${method_name^^}"
-    if [ ${!send_var} = "NO" ] ; then
-        continue
-    fi
-
-    declare -A arr_var=()
-
-    for x in ${roles//,/ } ; do
-        # the roles 'silent' and 'disabled' mean:
-        # don't send a notification for this role
-        [ "${x}" = "silent" -o "${x}" = "disabled" ] && continue
-
-        role_recipients="role_recipients_${method_name}[$x]"
-        default_recipient_var="DEFAULT_RECIPIENT_${method_name^^}"
-
-        a="${!role_recipients}"
-        [ -z "${a}" ] && a="${!default_recipient_var}"
-        for r in ${a//,/ } ; do
-            [ "${r}" != "disabled" ] && filter_recipient_by_criticality ${method_name} "${r}" && arr_var[${r/|*/}]="1"
-        done
-    done
-
-    # build the list of recipients
-    to_var="to_${method_name}"
-    declare to_${method_name}="${!arr_var[*]}"
-
-    [ -z "${!to_var}" ] && declare ${send_var}="NO"
+for method_name in ${method_names}; do
+	send_var="SEND_${method_name^^}"
+	if [ "${!send_var}" = "NO" ]; then
+		continue
+	fi
+
+	declare -A arr_var=()
+
+	for x in ${roles//,/ }; do
+		# the roles 'silent' and 'disabled' mean:
+		# don't send a notification for this role
+		if [ "${x}" = "silent" ] || [ "${x}" = "disabled" ]; then
+			continue
+		fi
+
+		role_recipients="role_recipients_${method_name}[$x]"
+		default_recipient_var="DEFAULT_RECIPIENT_${method_name^^}"
+
+		a="${!role_recipients}"
+		[ -z "${a}" ] && a="${!default_recipient_var}"
+		for r in ${a//,/ }; do
+			[ "${r}" != "disabled" ] && filter_recipient_by_criticality ${method_name} "${r}" && arr_var[${r/|*/}]="1"
+		done
+	done
+
+	# build the list of recipients
+	to_var="to_${method_name}"
+	declare to_${method_name}="${!arr_var[*]}"
+
+	[ -z "${!to_var}" ] && declare ${send_var}="NO"
 done
 
 # -----------------------------------------------------------------------------
 # handle fixup of the email recipient list.
 
 fix_to_email() {
-  to_email=
-  while [ ! -z "${1}" ]
-  do
-    [ ! -z "${to_email}" ] && to_email="${to_email}, "
-    to_email="${to_email}${1}"
-    shift 1
-  done
+	to_email=
+	while [ -n "${1}" ]; do
+		[ -n "${to_email}" ] && to_email="${to_email}, "
+		to_email="${to_email}${1}"
+		shift 1
+	done
 }
 
 # ${to_email} without quotes here
@@ -637,41 +615,45 @@ fix_to_email ${to_email}
 
 # -----------------------------------------------------------------------------
 # handle output if we're running in unit test mode
-if [ ${unittest} ] ; then
-    for method_name in ${method_names} ; do
-        to_var="to_${method_name}"
-        echo "results: ${method_name}: ${!to_var}"
-    done
-    exit 0
+if [ ${unittest} ]; then
+	for method_name in ${method_names}; do
+		to_var="to_${method_name}"
+		echo "results: ${method_name}: ${!to_var}"
+	done
+	exit 0
 fi
 
 # -----------------------------------------------------------------------------
 # check that we have at least a method enabled
-if [   "${SEND_EMAIL}"          != "YES" \
-    -a "${SEND_PUSHOVER}"       != "YES" \
-    -a "${SEND_TELEGRAM}"       != "YES" \
-    -a "${SEND_SLACK}"          != "YES" \
-    -a "${SEND_ROCKETCHAT}"     != "YES" \
-    -a "${SEND_ALERTA}"         != "YES" \
-    -a "${SEND_FLOCK}"          != "YES" \
-    -a "${SEND_DISCORD}"        != "YES" \
-    -a "${SEND_TWILIO}"         != "YES" \
-    -a "${SEND_HIPCHAT}"        != "YES" \
-    -a "${SEND_MESSAGEBIRD}"    != "YES" \
-    -a "${SEND_KAVENEGAR}"      != "YES" \
-    -a "${SEND_PUSHBULLET}"     != "YES" \
-    -a "${SEND_KAFKA}"          != "YES" \
-    -a "${SEND_PD}"             != "YES" \
-    -a "${SEND_FLEEP}"          != "YES" \
-    -a "${SEND_CUSTOM}"         != "YES" \
-    -a "${SEND_IRC}"            != "YES" \
-    -a "${SEND_AWSSNS}"         != "YES" \
-    -a "${SEND_PROWL}"          != "YES" \
-    -a "${SEND_SYSLOG}"         != "YES" \
-    -a "${SEND_MSTEAM}"         != "YES" \
-    ]
-    then
-    fatal "All notification methods are disabled. Not sending notification for host '${host}', chart '${chart}' to '${roles}' for '${name}' = '${value}' for status '${status}'."
+proceed=0
+for method in "${SEND_EMAIL}" \
+	"${SEND_PUSHOVER}" \
+	"${SEND_TELEGRAM}" \
+	"${SEND_SLACK}" \
+	"${SEND_ROCKETCHAT}" \
+	"${SEND_ALERTA}" \
+	"${SEND_FLOCK}" \
+	"${SEND_DISCORD}" \
+	"${SEND_TWILIO}" \
+	"${SEND_HIPCHAT}" \
+	"${SEND_MESSAGEBIRD}" \
+	"${SEND_KAVENEGAR}" \
+	"${SEND_PUSHBULLET}" \
+	"${SEND_KAFKA}" \
+	"${SEND_PD}" \
+	"${SEND_FLEEP}" \
+	"${SEND_CUSTOM}" \
+	"${SEND_IRC}" \
+	"${SEND_AWSSNS}" \
+	"${SEND_SYSLOG}" \
+	"${SEND_MSTEAM}"; do
+	if [ "${method}" == "YES" ]; then
+		proceed=1
+		break
+	fi
+done
+if [ "$proceed" -eq 0 ]; then
+	fatal "All notification methods are disabled. Not sending notification for host '${host}', chart '${chart}' to '${roles}' for '${name}' = '${value}' for status '${status}'."
 fi
 
 # -----------------------------------------------------------------------------
@@ -684,36 +666,35 @@ date=$(date --date=@${when} "${date_format}" 2>/dev/null)
 
 # ----------------------------------------------------------------------------
 # prepare some extra headers if we've been asked to thread e-mails
-if [ "${SEND_EMAIL}" == "YES" -a "${EMAIL_THREADING}" != "NO" ] ; then
-    email_thread_headers="In-Reply-To: <${chart}-${name}@${host}>\nReferences: <${chart}-${name}@${host}>"
+if [ "${SEND_EMAIL}" == "YES" ] && [ "${EMAIL_THREADING}" != "NO" ]; then
+	email_thread_headers="In-Reply-To: <${chart}-${name}@${host}>\\nReferences: <${chart}-${name}@${host}>"
 else
-    email_thread_headers=
+	email_thread_headers=
 fi
 
 # -----------------------------------------------------------------------------
 # function to URL encode a string
 
 urlencode() {
-    local string="${1}" strlen encoded pos c o
-
-    strlen=${#string}
-    for (( pos=0 ; pos<strlen ; pos++ ))
-    do
-        c=${string:${pos}:1}
-        case "${c}" in
-            [-_.~a-zA-Z0-9])
-                o="${c}"
-                ;;
-
-            *)
-                printf -v o '%%%02x' "'${c}"
-                ;;
-        esac
-        encoded+="${o}"
-    done
-
-    REPLY="${encoded}"
-    echo "${REPLY}"
+	local string="${1}" strlen encoded pos c o
+
+	strlen=${#string}
+	for ((pos = 0; pos < strlen; pos++)); do
+		c=${string:pos:1}
+		case "${c}" in
+		[-_.~a-zA-Z0-9])
+			o="${c}"
+			;;
+
+		*)
+			printf -v o '%%%02x' "'${c}"
+			;;
+		esac
+		encoded+="${o}"
+	done
+
+	REPLY="${encoded}"
+	echo "${REPLY}"
 }
 
 # -----------------------------------------------------------------------------
@@ -721,238 +702,217 @@ urlencode() {
 # using DAYS, MINUTES, SECONDS
 
 duration4human() {
-    local s="${1}" d=0 h=0 m=0 ds="day" hs="hour" ms="minute" ss="second" ret
-    d=$(( s / 86400 ))
-    s=$(( s - (d * 86400) ))
-    h=$(( s / 3600 ))
-    s=$(( s - (h * 3600) ))
-    m=$(( s / 60 ))
-    s=$(( s - (m * 60) ))
-
-    if [ ${d} -gt 0 ]
-    then
-        [ ${m} -ge 30 ] && h=$(( h + 1 ))
-        [ ${d} -gt 1 ] && ds="days"
-        [ ${h} -gt 1 ] && hs="hours"
-        if [ ${h} -gt 0 ]
-        then
-            ret="${d} ${ds} and ${h} ${hs}"
-        else
-            ret="${d} ${ds}"
-        fi
-    elif [ ${h} -gt 0 ]
-    then
-        [ ${s} -ge 30 ] && m=$(( m + 1 ))
-        [ ${h} -gt 1 ] && hs="hours"
-        [ ${m} -gt 1 ] && ms="minutes"
-        if [ ${m} -gt 0 ]
-        then
-            ret="${h} ${hs} and ${m} ${ms}"
-        else
-            ret="${h} ${hs}"
-        fi
-    elif [ ${m} -gt 0 ]
-    then
-        [ ${m} -gt 1 ] && ms="minutes"