Rebuild mailhog every time, using latest go version

Avoid potential vulns introduced by go

.github/workflows/docker-image.yml

@@ -21,21 +21,22 @@ jobs:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
-      - name: Create tags
-        id: create-tag
+      - name: Download latest MailHog release
         run: |
-          # Find latest release (same as "go install github.com/mailhog/MailHog@latest" in Dockerfile)
+          # Find latest release 
           VERSION="$( curl -s -H "Authorization: bearer ${{ secrets.GITHUB_TOKEN }}"  "https://api.github.com/repos/mailhog/mailhog/releases/latest" | jq -r '.tag_name')"
           VERSION_DATE="$VERSION-$(date +'%Y-%m-%d')"
           
           GHCR_IMAGE=ghcr.io/${{ github.repository_owner }}/mailhog
           TAGS="${GHCR_IMAGE}:latest,${GHCR_IMAGE}:${VERSION},${GHCR_IMAGE}:${VERSION_DATE}"
           echo "TAGS=${TAGS}" | tee -a $GITHUB_ENV
+          echo "VERSION=${VERSION}" | tee -a $GITHUB_ENV
       - name: Build and push
         id: docker_build
         uses: docker/build-push-action@v5
         with:
           context: .
+          build-args: VERSION=${{ env.VERSION }}
           push: true
           tags: ${{ env.TAGS }}
           labels: |

Dockerfile

@@ -1,15 +1,19 @@
-#
-# MailHog Dockerfile
-#
+FROM golang:1-alpine as builder
+ARG VERSION
 
-FROM golang:1.18-alpine as builder
+RUN apk --no-cache add make jq curl
+
+RUN mkdir -p /root/gocode
+ENV GOPATH=/root/gocode 
+
+WORKDIR $GOPATH/src/github.com/mailhog/MailHog
+RUN curl -L https://github.com/mailhog/MailHog/archive/refs/tags/${VERSION}.tar.gz | tar -xz --strip-components=1 
+
+ENV GO111MODULE="off"
+ENV CGO_ENABLED=0
+ENV GOOS=linux 
+RUN go build -ldflags "-X main.version=$VERSION" -o $GOPATH/bin/MailHog
 
-# Install MailHog:
-RUN apk --no-cache add --virtual build-dependencies \
-    git \
-  && mkdir -p /root/gocode \
-  && export GOPATH=/root/gocode \
-  && go install github.com/mailhog/MailHog@latest
 
 FROM alpine:3
 # Add mailhog user/group with uid/gid 1000.
@@ -26,4 +30,4 @@ WORKDIR /home/mailhog
 ENTRYPOINT ["MailHog"]
 
 # Expose the SMTP and HTTP ports:
-EXPOSE 1025 8025
+EXPOSE 1025 8025