diff --git a/test_pipeline.sh b/test_pipeline.sh
new file mode 100755
index 0000000..4c59470
--- /dev/null
+++ b/test_pipeline.sh
@@ -0,0 +1,69 @@
+#!/bin/sh
+
+set -eu
+
+INPUT=$(mktemp tmp.logstash.in.XXXXX)
+OUTPUT=$(mktemp tmp.logstash.out.XXXXX)
+PIPELINE=$(mktemp tmp.logstash.pipeline.XXXXX)
+
+echo Preparing input data
+echo "postfix/smtp[123]: 7EE668039: to=<admin@example.com>, relay=127.0.0.1[127.0.0.1]:2525, delay=3.6, delays=0.2/0.02/0.04/3.3, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 153053D)" > $INPUT
+
+echo Preparing pipeline config
+cat > $PIPELINE << EOF
+input {
+  file {
+    path => "/tmp/logstash.in"
+    start_position => beginning
+  }
+}
+filter {
+  dissect {
+    mapping => {
+      "message" => "%{program}[%{pid}]: %{message}"
+    }
+  }
+}
+EOF
+
+cat 50-filter-postfix.conf >> $PIPELINE
+
+cat >> $PIPELINE << EOF
+output {
+  file {
+    path => "/tmp/logstash.out"
+  }
+}
+EOF
+
+echo Starting logstash docker container
+CONTAINER_ID=$(docker run --rm --detach \
+  --volume ./${INPUT}:/tmp/logstash.in \
+  --volume ./${OUTPUT}:/tmp/logstash.out \
+  --volume ./postfix.grok:/etc/logstash/patterns.d/postfix.grok \
+  --volume ./${PIPELINE}:/usr/share/logstash/pipeline/pipeline.conf \
+  logstash:8.12.0 \
+  logstash -f /usr/share/logstash/pipeline/pipeline.conf)
+
+echo -n "Waiting for output from logstash "
+until test -s $OUTPUT; do
+  echo -n "."
+  sleep 2
+done
+echo
+
+docker stop --time 1 $CONTAINER_ID > /dev/null
+
+if test "$(jq .tags[0] $OUTPUT)" = '"_grok_postfix_success"'; then
+  echo Grok processing successful!
+  jq . $OUTPUT
+else
+  echo "Grok processing failed :<"
+  jq . $OUTPUT
+  exit 1
+fi
+
+echo Cleaning up
+rm -f $INPUT $OUTPUT $PIPELINE
+
+echo Done
\ No newline at end of file