failover script works, it's now ksh, btw.

1 files changed, 88 insertions, 0 deletions

diff --git a/frontends/scripts/dns-failover.ksh b/frontends/scripts/dns-failover.ksh
new file mode 100644
index 0000000..0be63bf
--- /dev/null
+++ b/frontends/scripts/dns-failover.ksh
@@ -0,0 +1,88 @@
+#!/bin/ksh
+
+ZONES_DIR=/var/nsd/zones/master/
+DEFAULT_MASTER=fishfinger.buetow.org
+DEFAULT_STANDBY=blowfish.buetow.org
+
+MASTER=$DEFAULT_MASTER
+STANDBY=$DEFAULT_STANDBY
+
+MASTER_A=$(host $MASTER | awk '/has address/ { print $(NF) }')
+MASTER_AAAA=$(host $MASTER | awk '/has IPv6 address/ { print $(NF) }')
+STANDBY_A=$(host $STANDBY | awk '/has address/ { print $(NF) }')
+STANDBY_AAAA=$(host $STANDBY | awk '/has IPv6 address/ { print $(NF) }')
+
+transform () {
+    sed -E '
+        /IN A .*; Enable failover/ {
+            /^mirror/! {
+                s/^(.*) 300 IN A (.*) ; (.*)/\1 300 IN A '$MASTER_A' ; \3/;
+            }
+            /^mirror/ {
+                s/^(.*) 300 IN A (.*) ; (.*)/\1 300 IN A '$STANDBY_A' ; \3/;
+            }
+        }
+        /IN AAAA .*; Enable failover/ {
+            /^mirror/! {
+                s/^(.*) 300 IN AAAA (.*) ; (.*)/\1 300 IN AAAA '$MASTER_AAAA' ; \3/;
+            }
+            /^mirror/ {
+                s/^(.*) 300 IN AAAA (.*) ; (.*)/\1 300 IN AAAA '$STANDBY_AAAA' ; \3/;
+            }
+        }
+        / ; serial/ {
+            s/^( +) ([0-9]+) .*; (.*)/\1 '"$(date +%s)"' ; \3/;
+        }
+    '
+}
+
+zone_is_ok () {
+    local zone=$1
+    local domain=${zone%.zone}
+
+    echo "Testing zone $zone (if no NS output, then doesn't work)"
+    dig $domain @localhost | grep "$domain.*IN.*NS"
+}
+
+failover_zone () {
+    local zone_file=$1
+    local zone=$(basename $zone_file)
+
+    cat $zone_file | transform > $zone_file.new.tmp 
+
+    grep -v ' ; serial' $zone_file.new.tmp > $zone_file.new.noserial.tmp
+    grep -v ' ; serial' $zone_file > $zone_file.old.noserial.tmp
+
+    if diff $zone_file.new.noserial.tmp $zone_file.old.noserial.tmp; then
+        echo "zone $zone_file hasn't changed"
+        rm $zone_file.*.tmp
+        return
+    fi
+
+    cp $zone_file $zone_file.bak
+    mv $zone_file.new.tmp $zone_file
+    rm $zone_file.*.tmp
+    nsd-control reload
+
+    if zone_is_ok $zone; then
+        if [ -f $zone_file.invalid ]; then
+            rm $zone_file.invalid
+        fi
+        echo "Failover of zone $zone completed"
+        return
+    fi
+
+    echo "Rolling back $zone_file changes"
+    cp $zone_file $zone_file.invalid
+    mv $zone_file.bak $zone_file
+    nsd-control reload
+    zone_is_ok $zone
+}
+
+main () {
+    for zone_file in $ZONES_DIR/*.zone; do
+        failover_zone $zone_file
+    done
+}
+
+main