refactor: Revise Dockerfile - Remove entrypoint.sh (#598)

* chore: Formatting

* chore: Formatting (fix indent)

* refactor: Remove entrypoint

* chore: Remove `entrypoint.sh` from `.goreleaser.yaml`

* tests: Replace `entrypoint.sh` script usage in `e2eentry.sh`

* Set default plugin argument from environment variable in main function and update Dockerfile to remove CMD instruction

* Add user and group setup for testing in Dockerfile and update e2e entry script

* Update cmd/sshpiperd/main.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update cmd/sshpiperd/main.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Remove test user and group creation from Dockerfile and move it to e2e entry script; update plugin argument handling in main function

* Update Dockerfile

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Skip empty plugin directory entries in main function

---------

Co-authored-by: Brennan Kinney <5098581+polarathene@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

.goreleaser.yaml

@@ -154,8 +154,6 @@ dockers:
     build_flag_templates:
       - "--platform=linux/amd64"
       - "--build-arg=EXTERNAL=1"
-    extra_files:
-      - entrypoint.sh
     skip_push: "{{ .Env.SKIP_PUSH }}"
   - image_templates:
       - "farmer1992/sshpiperd:v{{ .Version }}-arm64"
@@ -170,8 +168,6 @@ dockers:
     build_flag_templates:
       - "--platform=linux/arm64"
       - "--build-arg=EXTERNAL=1"
-    extra_files:
-      - entrypoint.sh
     skip_push: "{{ .Env.SKIP_PUSH }}"
   # full
   - image_templates:
@@ -182,8 +178,6 @@ dockers:
     build_flag_templates:
       - "--platform=linux/amd64"
       - "--build-arg=EXTERNAL=1"
-    extra_files:
-      - entrypoint.sh
     skip_push: "{{ .Env.SKIP_PUSH }}"
   - image_templates:
       - "farmer1992/sshpiperd:full-v{{ .Version }}-arm64"
@@ -194,8 +188,6 @@ dockers:
     build_flag_templates:
       - "--platform=linux/arm64"
       - "--build-arg=EXTERNAL=1"
-    extra_files:
-      - entrypoint.sh
     skip_push: "{{ .Env.SKIP_PUSH }}"
 docker_manifests:
   - name_template: "farmer1992/sshpiperd:v{{ .Version }}"

Dockerfile

@@ -1,12 +1,10 @@
-FROM docker.io/golang:1.24-bookworm as builder
-
+FROM docker.io/golang:1.24-bookworm AS builder
 ARG VER=devel
 ARG BUILDTAGS
 ARG EXTERNAL=0
-
 ENV CGO_ENABLED=0
-
 WORKDIR /src
+
 RUN \
   --mount=target=/src,type=bind,source=. \
   --mount=type=cache,target=/root/.cache/go-build \
@@ -22,13 +20,14 @@ RUN \
       go build -o /sshpiperd/plugins -tags "${BUILDTAGS}" ./plugin/... ./e2e/testplugin/...
     fi
 HEREDOC
-ADD entrypoint.sh /sshpiperd
 
-FROM builder as testrunner
+
+FROM builder AS testrunner
 COPY --from=farmer1992/openssh-static:V_9_8_P1 /usr/bin/ssh /usr/bin/ssh-9.8p1
 COPY --from=farmer1992/openssh-static:V_8_0_P1 /usr/bin/ssh /usr/bin/ssh-8.0p1
 
-FROM docker.io/busybox
+
+FROM docker.io/busybox AS sshpiperd
 ARG USERID=1000
 ARG GROUPID=1000
 RUN <<HEREDOC
@@ -43,7 +42,8 @@ HEREDOC
 COPY --from=builder --chown=${USERID} /sshpiperd/ /sshpiperd
 
 # Runtime setup:
+ENV SSHPIPERD_SERVER_KEY_GENERATE_MODE=notexist PLUGIN=workingdir
+ENTRYPOINT ["/sshpiperd/sshpiperd"]
+
 USER ${USERID}:${GROUPID}
 EXPOSE 2222
-
-ENTRYPOINT ["/sshpiperd/entrypoint.sh"]

cmd/sshpiperd/main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"path/filepath"
 	"runtime/debug"
 	"slices"
 	"time"
@@ -264,6 +265,46 @@ func main() {
 			var plugins []*plugin.GrpcPlugin
 
 			args := ctx.Args().Slice()
+
+			// If no command-line arguments are provided, fall back to the PLUGIN environment variable.
+			if len(args) == 0 {
+				pluginEnv := os.Getenv("PLUGIN")
+				if pluginEnv != "" {
+
+					exePath, err := os.Executable()
+					exeDir := ""
+					if err == nil {
+						exeDir = fmt.Sprintf("%s/", filepath.Dir(exePath))
+					}
+
+					pluginDirs := []string{
+						filepath.Join(exeDir, "plugins"),
+						os.Getenv("SSHPIPERD_PLUGIN_PATH"),
+					}
+
+					found := false
+
+					for _, dir := range pluginDirs {
+						if dir == "" {
+							continue
+						}
+						
+						pluginexe := filepath.Join(dir, pluginEnv)
+						if _, err := os.Stat(pluginexe); err == nil {
+							args = append(args, pluginexe)
+							found = true
+							break
+						}
+					}
+
+					if !found {
+						if path, err := exec.LookPath(pluginEnv); err == nil {
+							args = append(args, path)
+						}
+					}
+				}
+			}
+
 			remain := args
 
 			for len(remain) > 0 {

e2e/docker-compose.yml

@@ -101,6 +101,7 @@ services:
       - SSHPIPERD_E2E_TEST=1
       - SSHPIPERD_DEBUG=${SSHPIPERD_DEBUG}
       - SSHPIPERD_ALLOWED_PROXY_ADDRESSES=0.0.0.0/0
+      - SSHPIPERD_SERVER_KEY_GENERATE_MODE=notexist
       - DOCKER_API_VERSION=1.40
     build: 
       context: ../

e2e/e2eentry.sh

@@ -1,9 +1,6 @@
 #!/bin/bash
 set -x
 
-# use entrypoint.sh to generate the ssh_host_ed25519_key
-PLUGIN="dummy_badname/" bash /sshpiperd/entrypoint.sh 2>/dev/null
-
 groupadd -f testgroup && \
 useradd -m -G testgroup testgroupuser
 

entrypoint.sh

@@ -1,7 +0,0 @@
-#!/bin/sh
-set -eo pipefail
-
-PLUGIN=${PLUGIN:-workingdir}
-export SSHPIPERD_SERVER_KEY_GENERATE_MODE=${SSHPIPERD_SERVER_KEY_GENERATE_MODE:-notexist}
-
-exec /sshpiperd/sshpiperd "${@:-/sshpiperd/plugins/$PLUGIN}"