feat: Add Dockerfile to build and containerize the application

* Add basic Dockerfile
* Add build CI pipeline
* Some quick adaptations to the config file location

.woodpecker/build.yaml

@@ -0,0 +1,20 @@
+---
+when:
+  branch: main
+  path:
+    - Dockerfile
+    - .woodpecker/build.yaml
+
+variables:
+  - &buildx woodpeckerci/plugin-docker-buildx:4.2.0
+  - &buildx_settings
+    platforms: linux/amd64
+
+steps:
+  dryrun:
+    image: *buildx
+    settings:
+      <<: *buildx_settings
+      dry_run: true
+    when:
+      event: pull_request

Dockerfile

@@ -0,0 +1,25 @@
+# syntax=docker/dockerfile:1
+
+FROM golang:1.22.4 AS builder
+
+WORKDIR /app
+
+COPY go.mod go.sum main.go ./
+RUN go mod download
+RUN go build
+
+FROM gcr.io/distroless/base-debian12
+
+WORKDIR /
+
+COPY --from=builder /app/labtime /labtime
+
+# This is the port currently hardcoded in the application
+EXPOSE 2112
+
+# For now the config file path/name are hardcoded in the application
+VOLUME ["/config"]
+
+USER nonroot:nonroot
+
+ENTRYPOINT ["/labtime"]

main.go

@@ -89,7 +89,8 @@ func Ping(url string) (int, time.Duration, error) {
 func main() {
 
 	// Load config
-	config, err := NewConfig("config.yaml")
+    // TODO: Use a flag to specify the config file
+	config, err := NewConfig("config/config.yaml")
 	if err != nil {
 		log.Fatalf("Error loading config: %s", err)
 	}