diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..0793df8
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,14 @@
+FROM python
+MAINTAINER think@hotmail.de
+
+RUN pip install pyaml
+
+ADD bin /bin
+COPY compose_format /usr/local/lib/python3.5/site-packages/compose_format
+ADD features /
+ADD Dockerfile /
+ADD README.md /
+
+RUN chmod +x /bin/compose_format
+
+ENTRYPOINT python3 /bin/compose_format
diff --git a/README.md b/README.md
index a395c55..3c8ca2a 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 # compose_format
-Format docker compose files.
+
+Format docker-compose files.
 
 Note that this small utility is just valid until docker-compose has itself a format functionality.
 Currently docker-compose just support the "config" switch. Which joins multiple compose files and print them in a machine readable form.
@@ -11,10 +12,16 @@ Currently docker-compose just support the "config" switch. Which joins multiple
 Install it via:
 `pip3 install compose_format`
 
+After that use it like
+
+`compose_format compose-format.yml`
+this will print the formatted compose file to stdout.
+To let it replace the compose file add `--replace`.
+
 ### Via Docker
 
-After that use it like:
-`echo "docker-compose.yml" > docker run -t compose_format`
+Use it like:
+`cat docker-compose.yml | docker run -i funkwerk/compose_format`
 
 ## Features
  - Support for Version 2 and Version 1.
diff --git a/Rakefile b/Rakefile
index fa09c2e..edf6302 100644
--- a/Rakefile
+++ b/Rakefile
@@ -29,3 +29,7 @@ end
 task :generate do
   sh 'pandoc --from=markdown --to=rst --output=README.rst README.md'
 end
+
+task :docker do
+  sh 'docker build --tag=funkwerk/compose_format  .'
+end
diff --git a/bin/compose_format b/bin/compose_format
index 9894fa5..093638e 100755
--- a/bin/compose_format
+++ b/bin/compose_format
@@ -5,6 +5,7 @@ from compose_format import ComposeFormat
 if __name__ == '__main__':
 
     import argparse
+    import sys
 
     parser = argparse.ArgumentParser()
     parser.add_argument(
@@ -15,12 +16,17 @@ if __name__ == '__main__':
         help='ignore changes for return code', default=True)
     parser.add_argument('files', nargs=argparse.REMAINDER)
     args = parser.parse_args()
+    formatter = ComposeFormat()
+
     if len(args.files) == 0:
-        import sys
-        print('specify at least one file')
-        sys.exit(1)
+        assert args.replace is False, 'replace makes no sense when reading from stdin'
 
-    formatter = ComposeFormat()
+        data = sys.stdin.read()
+        formatted = formatter.format_string(data)
+        print(formatted)
+        if not args.ignore_changes:
+            if data != formatted:
+                sys.exit(1)
 
     for path in args.files:
         if not formatter.format(path, args.replace):
diff --git a/compose_format/__init__.py b/compose_format/__init__.py
index 1e0362a..4f2451a 100755
--- a/compose_format/__init__.py
+++ b/compose_format/__init__.py
@@ -25,6 +25,16 @@ def format(self, path, replace=False):
         with open(path, 'r') as file:
             data = file.read()
         original = data
+        formatted = self.format_string(data, replace=replace)
+
+        if replace:
+            with open(path, 'w') as file:
+                file.write(formatted)
+        else:
+            print(formatted)
+        return original == formatted
+
+    def format_string(self, data, replace=False):
         data = self.reorder(load(data))
 
         def is_legacy_version(data):
@@ -35,14 +45,7 @@ def is_legacy_version(data):
         vspacing = [1, 0] if is_legacy_version(data) else [0, 1, 0]
 
         formatted = pyaml.dump(data, vspacing=vspacing, indent=2, width=120, string_val_style='plain')
-        formatted = formatted.strip() + '\n'
-
-        if replace:
-            with open(path, 'w') as file:
-                file.write(formatted)
-        else:
-            print(formatted)
-        return original == formatted
+        return formatted.strip() + '\n'
 
     @staticmethod
     def reorder(data):
diff --git a/setup.py b/setup.py
index ef69d5e..96bfed1 100644
--- a/setup.py
+++ b/setup.py
@@ -7,8 +7,8 @@ def readme():
 
 setup(
     name='compose_format',
-    version='0.1.3',
-    description='format docker compose files',
+    version='0.1.4',
+    description='format docker-compose files',
     long_description=readme(),
     url='http://github.com/funkwerk/compose_format',
     author='Stefan Rohe',