feat: docker build

Signed-off-by: Sven Gerber <github@gerber.uno>

.github/workflows/release.yml

@@ -0,0 +1,50 @@
+# This workflow uses actions that are not certified by GitHub.
+# They are provided by a third-party and are governed by
+# separate terms of service, privacy policy, and support
+# documentation.
+
+# GitHub recommends pinning actions to a commit SHA.
+# To get a newer version, you will need to update the SHA.
+# You can also reference a tag or branch, but the action may change without warning.
+
+name: Create and publish a Docker image
+
+on:
+  push:
+    tags: [ '*' ]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@ad44023a93711e3deb337508980b4b5e9bcdc5dc
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -0,0 +1,11 @@
+FROM golang:1.20.1 as build
+WORKDIR /go/src/github.com/natrontech/alertmanager-uptime-kuma-push
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o alertmanager-uptime-kuma-push ./cmd/pusher
+
+FROM alpine:latest
+RUN apk --no-cache add ca-certificates
+WORKDIR /root/
+COPY --from=build /go/src/github.com/natrontech/alertmanager-uptime-kuma-push/alertmanager-uptime-kuma-push ./
+EXPOSE 8080
+CMD ["./alertmanager-uptime-kuma-push"]

cmd/pusher/pusher.go

@@ -34,5 +34,5 @@ func main() {
         return c.SendString("OK")
     })
 
-    app.Listen(":" + util.ListenPort)
+    app.Listen(":8080")
 }

internal/util/env.go

@@ -4,12 +4,10 @@ import (
 	"errors"
 	"os"
 	"net/url"
-	"log"
 )
 
 var (
 	UptimeKumaURL      string
-	ListenPort         string
 )
 
 // LoadEnv loads OS environment variables
@@ -31,10 +29,5 @@ func LoadEnv() error {
 		return errors.New("UPTIME_KUMA_URL has invalid scheme (http or https only)")
 	}
 
-	if ListenPort = os.Getenv("LISTEN_PORT"); ListenPort == "" {
-		ListenPort = "3000"
-		log.Println("LISTEN_PORT not set, defaulting to 3000")
-	}
-
 	return nil
 }