Add basic docker integration test

Dockerfile

@@ -0,0 +1,19 @@
+FROM caddy:2.7-builder AS builder
+
+COPY ./fail2ban.go /src/caddy-fail2ban/
+COPY ./go.sum /src/caddy-fail2ban/
+COPY ./go.mod /src/caddy-fail2ban/
+RUN xcaddy build \
+    --with github.com/Javex/caddy-fail2ban=/src/caddy-fail2ban
+
+FROM caddy:2.7
+
+COPY --from=builder /usr/bin/caddy /usr/bin/caddy
+
+RUN apk update && apk add fail2ban curl bash
+RUN rm /etc/fail2ban/jail.d/alpine-ssh.conf
+COPY ./fail2ban/caddy-banfile.conf /etc/fail2ban/action.d/caddy-banfile.conf
+COPY ./test/caddy-test.local /etc/fail2ban/jail.d/caddy-test.local
+COPY ./test/caddy-fail2ban-test.sh /usr/local/bin/
+RUN chmod u+x /usr/local/bin/caddy-fail2ban-test.sh
+

README.md

@@ -36,4 +36,20 @@ Now in any of your jails if you want to block requests at the HTTP layer, you ca
 action = caddy-banfile[banfile_path="/etc/caddy/banned-ips"]
 ```
 
-The above path is the default so you can omit the `banfile_path` parameter if you like.
+The above path is the default so you can omit the `banfile_path` parameter if you like.
+
+## Running tests
+
+First run the go unit tests, then spin up a docker container to test the
+integration with fail2ban
+
+```
+go build -v ./...
+go test -v ./...
+
+sudo docker build . -t caddy-fail2ban
+sudo docker run --rm --name caddy-fail2ban --detach -v $PWD/test/Caddyfile:/etc/caddy/Caddyfile caddy-fail2ban
+sudo docker exec -it caddy-fail2ban /usr/local/bin/caddy-fail2ban-test.sh
+sudo docker logs caddy-fail2ban
+sudo docker stop caddy-fail2ban
+```

test/Caddyfile

@@ -0,0 +1,15 @@
+{
+	log {
+		level DEBUG
+	}
+}
+
+127.0.0.1:80 {
+	@banned {
+		fail2ban /srv/banned-ips
+	}
+	handle @banned {
+		abort
+	}
+	respond "ok"
+}

test/caddy-fail2ban-test.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+set -euo pipefail
+
+fail2ban-server
+sleep 1
+
+output=$(curl http://127.0.0.1)
+if [ "$output" != "ok" ]; then
+  echo "Expected 'ok' output, got '${output}'"
+  exit 1
+fi
+
+fail2ban-client set caddy_test banip 127.0.0.1
+
+set +e
+curl http://127.0.0.1
+curl_exit_code=$?
+set -e
+if [ $curl_exit_code -eq 0 ]; then
+  echo "Expected curl to exit with non-zero exit code, but it was successful";
+  exit 1
+fi
+
+echo "Success!"
+exit 0

test/caddy-test.local

@@ -0,0 +1,10 @@
+[caddy_test]
+backend = auto
+enabled = true
+port = 80,443
+protocol = tcp
+filter = bitwarden
+maxretry = 3
+bantime = 86400
+findtime = 43200
+action = caddy-banfile[banfile_path="/srv/banned-ips"]