Add missing packages and improve shell selection in service script

Dockerfile

@@ -14,7 +14,9 @@ RUN apk update && apk upgrade && apk add --no-cache \
     nano \
     tmux \
     openssh-server \
-    iproute2
+    iproute2 \
+    shadow \
+    procps
 
 # Download ttyd
 RUN wget -O /usr/local/bin/ttyd https://github.com/tsl0922/ttyd/releases/download/1.7.7/ttyd.x86_64 && chmod +x /usr/local/bin/ttyd

service.ssh.sh

@@ -12,6 +12,20 @@ X11Forwarding no
 Subsystem sftp internal-sftp" > /etc/ssh/sshd_config
 fi
 
+if [ -z "$SET_SHELL" ]; then
+    SET_SHELL="/bin/bash"
+fi
+
+if [ "$SET_SHELL" = "zsh" ]; then
+    SET_SHELL="/bin/zsh"
+fi
+
+if [ "$SET_SHELL" = "fish" ]; then
+    SET_SHELL="/usr/bin/fish"
+fi
+
+chsh -s $SET_SHELL
+
 # Cloud image generates this file which prevents sshd from accepting passwords
 rm -f /etc/ssh/sshd_config.d/50-cloud-init.conf