all: sync with master; upd chlog

docker/healthcheck.sh

@@ -0,0 +1,89 @@
+#!/bin/sh
+
+# AdGuard Home Docker healthcheck script
+
+# Exit the script if a pipeline fails (-e), prevent accidental filename
+# expansion (-f), and consider undefined variables as errors (-u).
+set -e -f -u
+
+# Function error_exit is an echo wrapper that writes to stderr and stops the
+# script execution with code 1.
+error_exit() {
+	echo "$1" 1>&2
+
+	exit 1
+}
+
+agh_dir="/opt/adguardhome"
+readonly agh_dir
+
+filename="${agh_dir}/conf/AdGuardHome.yaml"
+readonly filename
+
+if ! [ -f "$filename" ]
+then
+    wget "http://127.0.0.1:3000" -O /dev/null -q || exit 1
+
+    exit 0
+fi
+
+help_dir="${agh_dir}/scripts"
+readonly help_dir
+
+# Parse web host
+
+web_url="$( awk -f "${help_dir}/web-bind.awk" "$filename" )"
+readonly web_url
+
+if [ "$web_url" = '' ]
+then
+    error_exit "no web bindings could be retrieved from $filename"
+fi
+
+# TODO(e.burkov):  Deal with 0 port.
+case "$web_url"
+in
+(*':0')
+    error_exit '0 in web port is not supported by healthcheck'
+    ;;
+(*)
+    # Go on.
+    ;;
+esac
+
+# Parse DNS hosts
+
+dns_hosts="$( awk -f "${help_dir}/dns-bind.awk" "$filename" )"
+readonly dns_hosts
+
+if [ "$dns_hosts" = '' ]
+then
+    error_exit "no DNS bindings could be retrieved from $filename"
+fi
+
+# TODO(e.burkov):  Deal with 0 port.
+case "$( echo "$dns_hosts" | head -n 1 )"
+in
+(*':0')
+    error_exit '0 in DNS port is not supported by healthcheck'
+    ;;
+(*)
+    # Go on.
+    ;;
+esac
+
+# Check
+
+# Skip SSL certificate validation since there is no guarantee the container
+# trusts the one used.  It should be safe to drop the SSL validation since the
+# current script intended to be used from inside the container and only checks
+# the endpoint availability, ignoring the content of the response.
+#
+# See https://github.com/AdguardTeam/AdGuardHome/issues/5642.
+wget --no-check-certificate "$web_url" -O /dev/null -q || exit 1
+
+echo "$dns_hosts" | while read -r host
+do
+    nslookup -type=a healthcheck.adguardhome.test. "$host" > /dev/null ||\
+        error_exit "nslookup failed for $host"
+done