From eb3be80286b1fe80c64f407cb5ac692767955abc Mon Sep 17 00:00:00 2001
From: DerLinkman <derlinkman@gmail.com>
Date: Wed, 11 Oct 2023 15:48:25 +0200
Subject: [PATCH] [Unbound] Added Healthcheck (nslookup)

---
 data/Dockerfiles/unbound/Dockerfile     |  5 +++++
 data/Dockerfiles/unbound/healthcheck.sh | 12 ++++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 data/Dockerfiles/unbound/healthcheck.sh

diff --git a/data/Dockerfiles/unbound/Dockerfile b/data/Dockerfiles/unbound/Dockerfile
index e853082d..b1909083 100644
--- a/data/Dockerfiles/unbound/Dockerfile
+++ b/data/Dockerfiles/unbound/Dockerfile
@@ -18,6 +18,11 @@ EXPOSE 53/udp 53/tcp
 
 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" ]
+
 ENTRYPOINT ["/docker-entrypoint.sh"]
 
 CMD ["/usr/sbin/unbound"]
diff --git a/data/Dockerfiles/unbound/healthcheck.sh b/data/Dockerfiles/unbound/healthcheck.sh
new file mode 100644
index 00000000..8c4508fb
--- /dev/null
+++ b/data/Dockerfiles/unbound/healthcheck.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+nslookup mailcow.email 127.0.0.1 1> /dev/null
+
+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!"
+    exit 1
+fi