unbound: rewrote healthcheck to be more detailed

unbound: added comments to rewritten healthcheck

data/Dockerfiles/unbound/Dockerfile

@@ -4,6 +4,8 @@ LABEL maintainer "The Infrastructure Company GmbH <info@servercow.de>"
 
 RUN apk add --update --no-cache \
 	curl \
+	bind-tools \
+	netcat-openbsd \
 	unbound \
 	bash \
 	openssl \
@@ -21,7 +23,7 @@ COPY docker-entrypoint.sh /docker-entrypoint.sh
 # healthcheck (nslookup)
 COPY healthcheck.sh /healthcheck.sh
 RUN chmod +x /healthcheck.sh
-HEALTHCHECK --interval=30s --timeout=10s CMD [ "/healthcheck.sh" ]
+HEALTHCHECK --interval=5s --timeout=10s CMD [ "/healthcheck.sh" ]
 
 ENTRYPOINT ["/docker-entrypoint.sh"]
 

data/Dockerfiles/unbound/healthcheck.sh

@@ -1,12 +1,89 @@
 #!/bin/bash
 
-nslookup mailcow.email 127.0.0.1 1> /dev/null
+# Declare log function for logfile inside container
+function log_to_file() {
+    echo "$(date +"%Y-%m-%d %H:%M:%S"): $1" > /var/log/healthcheck.log
+}
 
-if [ $? == 0 ]; then
-    echo "DNS resolution is working!"
-    exit 0
-else
-    echo "DNS resolution is not working correctly..."
-    echo "Maybe check your outbound firewall, as it needs to resolve DNS over TCP AND UDP!"
+# General Ping function to check general pingability
+function check_ping() {
+    declare -a ipstoping=("1.1.1.1" "8.8.8.8" "9.9.9.9")
+
+    for ip in "${ipstoping[@]}" ; do
+            ping -q -c 3 -w 5 "$ip"
+            if [ $? -ne 0 ]; then
+                log_to_file "Healthcheck: Couldn't ping $ip for 5 seconds... Gave up!"
+                log_to_file "Please check your internet connection or firewall rules to fix this error, because a simple ping test should always go through from the unbound container!"
+                return 1
+            fi
+    done
+
+    log_to_file "Healthcheck: Ping Checks WORKING properly!"
+    return 0
+}
+
+# General DNS Resolve Check against Unbound Resolver himself
+function check_dns() {
+    declare -a domains=("mailcow.email" "github.com" "hub.docker.com")
+
+    for domain in "${domains[@]}" ; do
+        for ((i=1; i<=3; i++)); do
+            dig +short +timeout=2 +tries=1 "$domain" @127.0.0.1 > /dev/null
+        if [ $? -ne 0 ]; then
+            log_to_file "Healthcheck: DNS Resolution Failed on $i attempt! Trying again..."
+            if [ $i -eq 3 ]; then
+                log_to_file "Healthcheck: DNS Resolution not possible after $i attempts... Gave up!"
+                log_to_file "Maybe check your outbound firewall, as it needs to resolve DNS over TCP AND UDP!"
+                return 1
+            fi
+        fi
+        done
+    done
+
+    log_to_file "Healthcheck: DNS Resolver WORKING properly!"
+    return 0
+    
+}
+
+# Simple Netcat Check to connect to common webports
+function check_netcat() {
+    declare -a domains=("mailcow.email" "github.com" "hub.docker.com")
+    declare -a ports=("80" "443")
+
+    for domain in "${domains[@]}" ; do
+        for port in "${ports[@]}" ; do
+            nc -z -w 2 $domain $port
+            if [ $? -ne 0 ]; then
+                log_to_file "Healthcheck: Could not reach $domain on Port $port... Gave up!"
+                log_to_file "Please check your internet connection or firewall rules to fix this error."
+                return 1
+            fi
+        done
+    done
+
+    log_to_file "Healthcheck: Netcat Checks WORKING properly!"
+    return 0
+
+}
+
+# run checks, if check is not returning 0 (return value if check is ok), healthcheck will exit with 1 (marked in docker as unhealthy)
+check_ping
+
+if [ $? -ne 0 ]; then
     exit 1
 fi
+
+check_dns
+
+if [ $? -ne 0 ]; then
+    exit 1
+fi
+
+check_netcat
+
+if [ $? -ne 0 ]; then
+    exit 1
+fi
+
+log_to_file "Healthcheck: ALL CHECKS WERE SUCCESSFUL! Unbound is healthy!"
+exit 0