Shrink image size (650MB => 85MB) + add Go dependencies

Dockerfile

@@ -7,16 +7,24 @@ COPY assets /tmp/assets
 
 RUN npm install && npm run build-prod
 
-FROM golang:1.13
+FROM golang:1.13 as go-builder
 
 WORKDIR /go/src/app
 
-COPY main.go ./
+COPY main.go go.mod go.sum ./
 COPY static ./static
 
 COPY --from=node /tmp/static/bundle.js ./static/bundle.js
 
 RUN go get -d -v ./...
 RUN go install -v ./...
 
-CMD ["app"]
+FROM debian:buster-slim
+
+COPY --from=go-builder /go/bin/GoPubSub /usr/local/bin/gopubsub
+COPY --from=go-builder /go/src/app /go/src/app
+
+# Legacy config directory
+WORKDIR /go/src/app/
+
+CMD ["gopubsub"]

README.md

@@ -21,7 +21,7 @@ Following environment variables may be set:
 
 | Variable | Usage | Default value |
 |---|---|---|
-| `GOPUBSUB_CONFIG` | Config file path | `config.yaml` |
+| `GOPUBSUB_CONFIG` | Config file path | `/go/src/app/config.yaml` |
 | `GOPUBSUB_PORT` | Listening HTTP port | `8080` |
 | `GOPUBSUB_MAX_MESSAGES` | Only keep last _n_ messages per topic | `10` |
 | `GOOGLE_APPLICATION_CREDENTIALS` | Path to JSON credentials file | _none_ |

go.mod

@@ -0,0 +1,11 @@
+module github.com/ClickAndMortar/GoPubSub
+
+require (
+	cloud.google.com/go/pubsub v1.0.1
+	github.com/alexandrevicenzi/go-sse v0.0.0-20200117161408-7b23d5ff7420
+	github.com/gobuffalo/packr v1.30.1
+	google.golang.org/api v0.13.0 // indirect
+	gopkg.in/yaml.v2 v2.2.7
+)
+
+go 1.13