diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..a262943
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,15 @@
+FROM alpine:latest
+
+RUN apk --no-cache add \
+  python3 \
+  py3-pip \
+  py3-yaml \
+  py3-click \
+  py3-dnspython \
+ && python3 -m pip install \
+  ovh \
+  schema
+
+COPY main.py /usr/local/bin/ovhddns
+COPY periodic.sh /usr/local/bin/ovhddns-periodic
+ENTRYPOINT [ "ovhddns-periodic" ]
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..8632ed8
--- /dev/null
+++ b/README.md
@@ -0,0 +1,20 @@
+# OVHDDNS
+
+Update a OVH subdomain to own IP.
+
+## Configuration file
+
+```yaml
+---
+ovh:
+  application_key: str
+  application_secret: str
+  consumer_key: str
+  endpoint: str
+zone: str; example: redxef.at
+subdomain: str; example: subdomain-xyz
+field_type: *Optional* str; example: 'A' or 'AAAA'
+logging: *Optional*
+  level: *Optional* str; default: :WARNING,ovhdns:INFO
+ttl: *Optional* int; default: None
+```
diff --git a/main.py b/main.py
index e523e92..24f9378 100755
--- a/main.py
+++ b/main.py
@@ -1,13 +1,11 @@
 #!/usr/bin/env python3
 
 import itertools
-import json
 import os
 import sys
 import logging
 
 import yaml
-import schema
 import click
 import ovh
 import dns.resolver
diff --git a/periodic.sh b/periodic.sh
new file mode 100755
index 0000000..de6b212
--- /dev/null
+++ b/periodic.sh
@@ -0,0 +1,31 @@
+#!/bin/sh
+
+pids=""
+
+run_prog() {
+    "$@" &
+    pids="$! $pids"
+}
+
+trap_sig() {
+    printf '%s' "$pids" | while IFS= read -r pid; do
+        echo "pid=$pid"
+        # shellcheck disable=2086
+        kill -s $1 $pid
+    done
+}
+
+trap 'trap_sig TERM' TERM
+
+# default to every 5 minutes
+DELAY="${OVHDDNS_INTERVAL_SECONDS:-300}"
+
+stdin_content="$(cat -)"
+
+while :; do
+    echo "$stdin_content" | ovhddns "$@"
+    run_prog sleep "$DELAY"
+    wait $pids
+    pids=
+done
+