Add ssh-keys core plugin

plugins/ssh-keys/functions

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+
+verify_ssh_key_file() {
+  declare desc="Test that public key is valid"
+  [[ -s ${DOKKU_ROOT}/.ssh/authorized_keys ]] || dokku_log_fail "No public keys found."
+  ssh-keygen -l -f "${DOKKU_ROOT}/.ssh/authorized_keys" &> /dev/null || dokku_log_fail "${DOKKU_ROOT}/.ssh/authorized_keys failed ssh-kegen check."
+}
+
+verify_ssh_key_exists() {
+  declare desc="Test that public key exists"
+  [[ -e ${DOKKU_ROOT}/.ssh/authorized_keys ]] || dokku_log_fail "No public keys found."
+}