diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..31931fa
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,5 @@
+__pycache__
+venv
+surprise.txt
+backend/static/main.js
+frontend/elm-stuff
diff --git a/Dockerfile b/Dockerfile
index b55c9d8..418e0aa 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,10 +1,19 @@
-FROM xxx
+FROM python:3-alpine
 
-# Install flask and elm
+ENV SURPRISE_ASSET_DIR=/assets
+ENV ELM_VERSION=0.19.1
+ENV PYTHONUNBUFFERED=1
 
-# Copy files
+COPY backend backend
+COPY frontend frontend
 
-# Compile elm
-
-# Run flask
+ADD https://github.com/elm/compiler/releases/download/$ELM_VERSION/binary-for-linux-64-bit.gz elm.gz
+RUN gunzip elm.gz && \
+    chmod +x elm && \
+    mv elm /bin/elm
+RUN cd frontend && \
+    elm make src/Main.elm --optimize --output=../backend/static/main.js
 
+WORKDIR backend
+RUN pip install -r requirements.pip
+ENTRYPOINT ["flask", "run", "-h", "0.0.0.0"]
diff --git a/README.md b/README.md
index cd5b4bf..bb7d703 100644
--- a/README.md
+++ b/README.md
@@ -2,5 +2,43 @@
 
 This is a web application for revealing a surprise at a given time.
 
+Two pages are served:
+
+ 1. `/` - The index page polls the backend every second and displays the image
+    asset corresponding to the state of the surprise with a countdown if applicable. 
+ 2. `/set-surprise` - Select and POST the surprise to the backend (password protected).
+
+The surprise can have the following states:
+
+  - `_null` - The surprise is not set.
+  - `_secret` - The surprise is set but not yet revealed.
+  - `<value>` - The surprise is set and revealed.
 
 
+## Configuration
+
+Environment variables:
+
+  - `SURPRISE_TITLE` - Page title
+  - `SURPRISE_STORE_FILE` - File name to store surprise value.
+  - `SURPRISE_SECRET` - Password for setting the surprise.
+  - `SURPRISE_ASSET_DIR` - Directory of image assets that corresponds to surprise
+    state/values. The set of possible surprise values are parsed from the basename
+    of the asset files. The `_null` and `_secret` states may be overridden.
+  - `SURPRISE_REVEAL_DATETIME` - Datetime for reveal.
+
+
+## Build
+
+```bash
+$ docker build -t surprise-countdown .
+```
+
+
+## Run gender reveal example
+
+```bash
+$ docker run -e SURPRISE_SECRET=hunter2 -p 5000:5000 -v $(pwd)/surprise-assets/gender-reveal:/assets:ro surprise-countdown
+```
+
+Then browse to [localhost:5000](localhost:5000).
diff --git a/frontend/src/Main.elm b/frontend/src/Main.elm
index 7cd6432..3c3a7f4 100644
--- a/frontend/src/Main.elm
+++ b/frontend/src/Main.elm
@@ -64,7 +64,7 @@ update msg model =
 
 subscriptions : Model -> Sub Msg
 subscriptions model =
-  Time.every 980 FetchSurprise
+  Time.every 1000 FetchSurprise
 
 
 -- VIEW