A photo booth application for Raspberry Pi 5, built as Go microservices communicating over gRPC and packaged in containers.

Six services in a single Go module (github.com/chrischdi/gophotobooth):

Proto definitions live in proto/{core,ui,dslr}/. Generated *.pb.go files are not committed — run make generate to (re)create them.

Startup        → UI.ShowIdle()
Trigger()      → ShowCountdown(3) → sleep 1s
               → ShowCountdown(2) → sleep 1s
               → ShowCountdown(1) → sleep 1s
               → ShowSmile()
               → DSLR.TakePhoto() → write JPEG to --directory
               → UI.ShowImage()
               → sleep --post-capture-seconds   ← blocks next trigger
               → unlock (UI stays on last photo)

At most one workflow runs at a time (sync.Mutex.TryLock). A concurrent Trigger call returns codes.AlreadyExists.

The buzzer button is connected to the Raspberry Pi 5 via a simple RC debounce circuit:

• 3.3 V (Pin 1) is pulled high through R1 (4.7 kΩ) and R2 (1 kΩ) in series.
• GPIO 17 (Pin 11) is read by the buzzer service; it detects a falling edge when the button is pressed.
• C1 (100 nF) is placed between GPIO 17 and ground to filter switch bounce.
• The button connects the node between R1 and R2 to Ground (Pin 9).

The internal pull-up/pull-down resistors of the Raspberry Pi GPIO are not used; the external resistor network provides the pull-up and debounce filtering.

The pin name is configurable via the --pin flag on the buzzer binary (default: GPIO17).

• Go 1.26.1
• protoc + protoc-gen-go + protoc-gen-go-grpc (for proto regeneration)
• libgphoto2-dev and X11/OpenGL headers (for CGO binaries, only needed on the build host)
• golangci-lint

Install the protoc plugins:

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

make generate      # Regenerate *.pb.go from proto files
make build         # Build all binaries to bin/ (host arch)
make build-arm64   # Cross-compile for Raspberry Pi 5 (arm64)
make test          # go test ./...
make vet           # go vet ./...
make image         # Build all container images via podman

CGO-free services can always be built with CGO_ENABLED=0 go build ./cmd/<service>.

Edit the .proto file, then run:

make generate
# or
./proto/regen.sh

Never edit *.pb.go files by hand.

Use ctl stub servers to replace real hardware:

# 1. Stub UI (no display needed)
./bin/ctl ui-serve-dummy

# 2. Dummy DSLR (generates timestamp images)
./bin/ctl dslr-serve-dummy

# 3. Core
./bin/core --directory /tmp/photos

# 4. Trigger a workflow
./bin/ctl core-trigger

make package          # builds arm64 images + ctl binary, outputs dist/gophotobooth-arm64.tar.gz

On an x86_64 host this requires binfmt_misc support for aarch64:

docker run --privileged --rm docker.io/tonistiigi/binfmt --install arm64

Copy env.sample and fill in your values:

cp env.sample my.env
# Set at minimum:
#   GALLERY_BASE_URL   — public URL of the gallery (e.g. https://photos.example.com)
#   CLOUDFLARED_TOKEN  — Cloudflare Tunnel token
#   WIFI_SSID_1 / WIFI_PASSWORD_1 (and _2, _3, …) — WiFi networks to pre-configure

bash scripts/flash-raspberrypi-os.sh /dev/sdX \
    --package dist/gophotobooth-arm64.tar.gz \
    --env my.env \
    --hostname fotobox \
    --user pi raspberry

The script will:

1. Download the latest Raspberry Pi OS Lite (arm64) image
2. Flash it to the device
3. Resize partition 2 (ext4 root) to 32 GiB
4. Create partition 3 (exFAT, remaining space) for photo storage, mounted at /data
5. Inject a firstrun.service that runs install.sh on first boot
6. Write userconf.txt, enable SSH, and apply config.txt tweaks

Additional options:

Insert the SSD into the Raspberry Pi 5 and power it on. install.sh runs automatically via firstrun.service and sets up all services. Monitor progress over SSH:

journalctl -u firstrun -f

The gallery is exposed publicly through a Cloudflare Tunnel (no open ports on the Pi):

• cloudflare/cloudflared runs as photobooth-cloudflared.service
• Enabled by setting CLOUDFLARED_TOKEN in /etc/gophotobooth/env
• The tunnel token is obtained from Cloudflare Zero Trust → Networks → Tunnels
• In the tunnel's Public Hostnames tab, configure: photos.example.com → http://localhost:8080
• Set SSL/TLS mode to Full in the Cloudflare dashboard (tunnel leg is already encrypted)
• GALLERY_BASE_URL in the env file should be set to the public hostname (e.g. https://photos.example.com) so Core builds correct QR codes

golangci-lint run ./...

CI runs golangci-lint on every pull request. Fix all lint errors before merging.

Every PR must pass:

1. make generate — verify proto stubs are up to date
2. go vet ./...
3. golangci-lint run ./...
4. CGO_ENABLED=0 go build ./cmd/core ./cmd/buzzer ./cmd/gallery ./cmd/ctl
5. make test

CGO binaries (cmd/dslr, cmd/ui) are only built in CI if the runner has the required system libraries installed.