add docker image, workflow file

.dockerignore

@@ -0,0 +1,9 @@
+example.postalion.yml
+postalion.yml
+postalion
+
+LICENSE
+README.md
+.git
+.github
+

.github/workflows/docker-image.yml

@@ -0,0 +1,42 @@
+name: build and publish a Docker image
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+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@v4
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata 
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -0,0 +1,20 @@
+FROM golang:1.21-alpine AS build-stage
+
+WORKDIR /usr/src/app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+
+RUN go build -o /app/postalion
+
+COPY templates /app/templates
+
+VOLUME /app/templates
+
+WORKDIR /app
+
+EXPOSE 8080
+
+ENTRYPOINT ["/app/postalion"]

example.postalion.yml

@@ -0,0 +1,37 @@
+---
+mailAccounts:
+  test-account:
+    host: mail.example.com
+    port: 587
+    username: [email protected]
+    password: p@ssword
+    encryption: starttls
+forms:
+  test-form:
+    account: test-account
+    from: "Postalion <[email protected]>"
+    to: "Contact <[email protected]>"
+    honeypot: honeypot
+    replyTo:
+      format: "%s <%s>"
+      fields:
+        - name
+        - email
+    subjectField: subject
+    template: default
+    redirect: https://example.com/pages/contact-redirect
+    fields:
+      - name: name
+        label: Name
+        type: string
+      - name: email
+        label: Email
+        type: string
+      - name: subject
+        label: Subject
+        type: string
+      - name: file
+        label: File
+        type: file
+port: 8080
+templateDir: /app/data/templates

main.go

@@ -75,7 +75,7 @@ func initConfig() {
 	v.SetConfigName("postalion")
 	v.AddConfigPath(".")
 	v.AddConfigPath("/etc/postalion")
-	v.AddConfigPath("/data")
+	v.AddConfigPath("/app")
 	v.SetEnvPrefix("postalion")
 	v.AutomaticEnv()