optimize: Simplify and clean up Dockerfile (#8244)

Dockerfile.dapper

 ARG GOLANG=golang:1.20.10-alpine3.18
 FROM ${GOLANG}
 
-ARG http_proxy=$http_proxy
-ARG https_proxy=$https_proxy
-ARG no_proxy=$no_proxy
-ENV http_proxy=$http_proxy
-ENV https_proxy=$https_proxy
-ENV no_proxy=$no_proxy
+# Set proxy environment variables
+ARG http_proxy
+ARG https_proxy
+ARG no_proxy
+ENV http_proxy=${http_proxy} \
+    https_proxy=${https_proxy} \
+    no_proxy=${no_proxy}
 
-RUN apk -U --no-cache add bash git gcc musl-dev docker vim less file curl wget ca-certificates jq linux-headers \
-    zlib-dev tar zip squashfs-tools npm coreutils python3 py3-pip openssl-dev libffi-dev libseccomp libseccomp-dev \
-    libseccomp-static make libuv-static sqlite-dev sqlite-static libselinux libselinux-dev zlib-dev zlib-static \
-    zstd pigz alpine-sdk binutils-gold btrfs-progs-dev btrfs-progs-static gawk yq \
-    && \
-    if [ "$(go env GOARCH)" = "amd64" ]; then \
-    apk -U --no-cache add mingw-w64-gcc; \
-    fi
+# Install necessary packages
+RUN apk -U --no-cache add \
+    bash git gcc musl-dev docker vim less file curl wget ca-certificates jq linux-headers \
+    zlib-dev tar zip squashfs-tools npm coreutils python3 py3-pip openssl-dev libffi-dev libseccomp \
+    libseccomp-dev libseccomp-static make libuv-static sqlite-dev sqlite-static libselinux \
+    libselinux-dev zlib-dev zlib-static zstd pigz alpine-sdk binutils-gold btrfs-progs-dev \
+    btrfs-progs-static gawk yq \
+    && [ "$(go env GOARCH)" = "amd64" ] && apk -U --no-cache add mingw-w64-gcc || true
 
+# Install AWS CLI
 RUN python3 -m pip install awscli
 
-RUN TRIVY_VERSION="0.46.1" && \
-    if [ "$(go env GOARCH)" != "arm" ] && [ "$(go env GOARCH)" != "386" ]; then \
-        if [ "$(go env GOARCH)" = "arm64" ]; then \
-            # Turn arm64 into uppercase ARM64 for Trivy's download
-            TRIVY_ARCH=$(go env GOARCH | tr "[:lower:]" "[:upper:]") && \
-            wget --no-verbose "https://github.com/aquasecurity/trivy/releases/download/v${TRIVY_VERSION}/trivy_${TRIVY_VERSION}_Linux-${TRIVY_ARCH}.tar.gz" && \
-            tar -zxvf "trivy_${TRIVY_VERSION}_Linux-${TRIVY_ARCH}.tar.gz" && \
-            mv trivy /usr/local/bin; \
-        elif [ "$(go env GOARCH)" = "amd64" ]; then \
-            wget --no-verbose "https://github.com/aquasecurity/trivy/releases/download/v${TRIVY_VERSION}/trivy_${TRIVY_VERSION}_Linux-64bit.tar.gz" && \
-            tar -zxvf "trivy_${TRIVY_VERSION}_Linux-64bit.tar.gz" && \
-            mv trivy /usr/local/bin; \
-        elif [ "$(go env GOARCH)" = "s390x" ]; then \
-            wget --no-verbose "https://github.com/aquasecurity/trivy/releases/download/v${TRIVY_VERSION}/trivy_${TRIVY_VERSION}_Linux-s390x.tar.gz" && \
-            tar -zxvf "trivy_${TRIVY_VERSION}_Linux-s390x.tar.gz" && \
-            mv trivy /usr/local/bin; \
-        fi \
+# Install Trivy
+ENV TRIVY_VERSION="0.46.1"
+RUN case "$(go env GOARCH)" in \
+    arm64) TRIVY_ARCH="ARM64" ;; \
+    amd64) TRIVY_ARCH="64bit" ;; \
+    s390x) TRIVY_ARCH="s390x" ;; \
+    *) TRIVY_ARCH="" ;; \
+    esac
+RUN if [ -n "${TRIVY_ARCH}" ]; then \ 
+        wget --no-verbose "https://github.com/aquasecurity/trivy/releases/download/v${TRIVY_VERSION}/trivy_${TRIVY_VERSION}_Linux-${TRIVY_ARCH}.tar.gz" \
+        && tar -zxvf "trivy_${TRIVY_VERSION}_Linux-${TRIVY_ARCH}.tar.gz" \
+        && mv trivy /usr/local/bin; \
     fi
 
-# this works for both go 1.17 and 1.18
+# Install goimports
 RUN GOPROXY=direct go install golang.org/x/tools/cmd/goimports@gopls/v0.11.0
+
+# Cleanup
 RUN rm -rf /go/src /go/pkg
 
+# Install golangci-lint for amd64
 RUN if [ "$(go env GOARCH)" = "amd64" ]; then \
     curl -sL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s v1.51.2;  \
     fi
-
+    
+# Set SELINUX environment variable
 ARG SELINUX=true
-ENV SELINUX $SELINUX
+ENV SELINUX=${SELINUX}
 
-ENV DAPPER_RUN_ARGS --privileged -v k3s-cache:/go/src/github.com/k3s-io/k3s/.cache -v trivy-cache:/root/.cache/trivy
-ENV DAPPER_ENV REPO TAG DRONE_TAG IMAGE_NAME SKIP_VALIDATE SKIP_IMAGE SKIP_AIRGAP AWS_SECRET_ACCESS_KEY AWS_ACCESS_KEY_ID GITHUB_TOKEN GOLANG GOCOVER DEBUG
-ENV DAPPER_SOURCE /go/src/github.com/k3s-io/k3s/
-ENV DAPPER_OUTPUT ./bin ./dist ./build/out ./build/static ./pkg/static ./pkg/deploy
+# Set Dapper configuration variables
+ENV DAPPER_RUN_ARGS="--privileged -v k3s-cache:/go/src/github.com/k3s-io/k3s/.cache -v trivy-cache:/root/.cache/trivy" \
+    DAPPER_ENV="REPO TAG DRONE_TAG IMAGE_NAME SKIP_VALIDATE SKIP_IMAGE SKIP_AIRGAP AWS_SECRET_ACCESS_KEY AWS_ACCESS_KEY_ID GITHUB_TOKEN GOLANG GOCOVER DEBUG" \
+    DAPPER_SOURCE="/go/src/github.com/k3s-io/k3s/" \
+    DAPPER_OUTPUT="./bin ./dist ./build/out ./build/static ./pkg/static ./pkg/deploy" \
+    DAPPER_DOCKER_SOCKET=true \
+    HOME=${DAPPER_SOURCE} \
+    CROSS=true \
+    STATIC_BUILD=true
 
-ENV DAPPER_DOCKER_SOCKET true
-ENV HOME ${DAPPER_SOURCE}
-ENV CROSS true
-ENV STATIC_BUILD true
 WORKDIR ${DAPPER_SOURCE}
 
 ENTRYPOINT ["./scripts/entry.sh"]