Dockerize Spectogram

.dockerignore

@@ -0,0 +1,8 @@
+.git
+.github
+data
+*.png
+coverage.*
+*.out
+spectogram
+spectrogram

.github/workflows/ci.yml

@@ -98,3 +98,12 @@ jobs:
 
       - name: Run tests
         run: go test ./... -v
+
+  docker:
+    name: Docker Build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Build image
+        run: docker build -t spectogram:ci .

Dockerfile

@@ -0,0 +1,23 @@
+FROM golang:1.24-alpine AS builder
+
+WORKDIR /src
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY cmd/ ./cmd/
+RUN CGO_ENABLED=0 go build -o /out/spectogram ./cmd/spectogram
+
+FROM python:3.11-alpine
+
+WORKDIR /app
+
+COPY --from=builder /out/spectogram /usr/local/bin/spectogram
+COPY web/ ./web/
+COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
+RUN chmod +x /usr/local/bin/docker-entrypoint.sh
+
+EXPOSE 8000
+
+ENTRYPOINT ["docker-entrypoint.sh"]
+CMD ["serve"]

README.md

@@ -73,6 +73,32 @@ http://localhost:8000/web
 
 You should now see an interactive, zoomable Plotly heatmap.
 
+## 🐳 Running with Docker
+
+A `Dockerfile` is included so you can run both steps without installing Go or Python locally. Build the image once:
+
+```bash
+docker build -t spectogram .
+```
+
+### Step 1. Generate the spectrogram data
+
+Mount a local directory containing your audio file to `/app/data`, and generate the output into it:
+
+```bash
+docker run --rm -v "$(pwd)":/app/data spectogram generate -in /app/data/audio.mp3 -out /app/data/spectrogram.png -json /app/data/spectrogram.json
+```
+
+### Step 2. View the Spectrogram
+
+Using the same mount, so the web viewer can find `spectrogram.json`:
+
+```bash
+docker run --rm -p 8000:8000 -v "$(pwd)":/app/data spectogram serve
+```
+
+Then open `http://localhost:8000/web` in your browser, same as the local workflow above.
+
 ## 🧠 How It Works?
 
 The `Go` script:
@@ -106,10 +132,12 @@ Unit and integration tests live alongside the code in `cmd/spectogram/main_test.
 ## 📁 Folder Structure
 
 ```
-.github/workflows/ - CI pipeline (build, vet, test)
+.github/workflows/  - CI pipeline (build, vet, test, Docker image build)
 cmd/spectogram/     - main Go application and tests (main.go, main_test.go)
 web/                - HTML viewer with Plotly
 data/               - generated spectrogram.json output (created automatically, not tracked in git)
+Dockerfile          - containerized build (Go binary + Python static file server)
+docker-entrypoint.sh - dispatches `generate` and `serve` container commands
 README.md           - this file
 go.mod              - Go module info
 ```

docker-entrypoint.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+set -e
+
+case "$1" in
+  generate)
+    shift
+    exec spectogram "$@"
+    ;;
+  serve)
+    exec python3 -m http.server 8000
+    ;;
+  *)
+    exec "$@"
+    ;;
+esac