faster docker build

Dockerfile

@@ -2,21 +2,31 @@ FROM golang:1.18-stretch as builder
 
 ARG VER=devel
 
+ENV CGO_ENABLED=0
+
+# thanks to https://github.com/montanaflynn/golang-docker-cache
+RUN mkdir -p /cache/crypto
+COPY crypto /cache/crypto
+COPY go.mod go.sum /cache/
+WORKDIR /cache
+RUN go mod graph | awk '{if ($1 !~ "@") print $2}' | xargs go get
+
 RUN mkdir -p /out/plugins
 ADD . /src/
 WORKDIR /src
-RUN CGO_ENABLED=0 go build -o /out -ldflags "-X main.mainver=$VER" ./cmd/...
-RUN CGO_ENABLED=0 go build -o /out/plugins  -ldflags "-X main.mainver=$VER" ./plugin/...
+RUN go build -o /out -ldflags "-X main.mainver=$VER" ./cmd/...
+RUN go build -o /out/plugins  -ldflags "-X main.mainver=$VER" ./plugin/...
 
 FROM busybox
 LABEL maintainer="Boshi Lian<farmer1992@gmail.com>"
 
+COPY --from=ep76/openssh-static:latest /usr/bin/ssh-keygen /bin/ssh-keygen
 RUN mkdir /etc/ssh/
+RUN mkdir /sshpiperd
 
-ADD entrypoint.sh /
-COPY --from=builder /out/ /
-COPY --from=ep76/openssh-static:latest /usr/bin/ssh-keygen /ssh-keygen
+ADD entrypoint.sh /sshpiperd
+COPY --from=builder /out/ /sshpiperd
 EXPOSE 2222
 
-ENTRYPOINT ["/entrypoint.sh"]
-CMD ["/sshpiperd", "/plugins/workingdir"]
+ENTRYPOINT ["/sshpiperd/entrypoint.sh"]
+CMD ["/sshpiperd/sshpiperd", "/sshpiperd/plugins/workingdir"]

README.md

@@ -83,7 +83,7 @@ sudo ./out/sshpiperd --log-level=trace ./out/simplemath -- ./out/fixed --target
 
 Plugin list
 
- * [workingdir](plugin/workingdir/) 🔀: ask for working directory before login, demo purpose
+ * [workingdir](plugin/workingdir/) 🔀: `/home`-like directory to managed upstreams routing by sshpiped.
  * [azdevicecode](plugin/azdevicecode/) 🔒: ask user to enter [azure device code](https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-device-code) before login
  * [fixed](plugin/fixed/) 🔀: fixed targetting the dummy sshd server
  * [simplemath](plugin/simplemath/) 🔒: ask for very simple math question before login, demo purpose

entrypoint.sh

@@ -3,7 +3,7 @@ set -euo pipefail
 
 
 if [ ! -f /etc/ssh/ssh_host_rsa_key ];then
-    /ssh-keygen -t rsa -N '' -f /etc/ssh/ssh_host_rsa_key
+    ssh-keygen -t rsa -N '' -f /etc/ssh/ssh_host_rsa_key
 fi
 
 exec "$@"

plugin/workingdir/README.md

@@ -1,7 +1,7 @@
 # Working Directory plugin for sshpiperd
 
 `Working Dir` is a `/home`-like directory. 
-SSHPiperd read files from `workingdir/[username]/` to know upstream's configuration.
+sshpiperd read files from `workingdir/[username]/` to know upstream's configuration.
 
 e.g.