Finally!

.woodpecker.yml

@@ -3,8 +3,7 @@ pipeline:
     image: machines/ssh
     commands: 
       - mkdir -p ~/.ssh 
-      - echo $SSH_KEY > ~/.ssh/id_rsa
+      - echo "$PRIVKEY $privkey" > ~/.ssh/id_rsa
       - chmod 700 ~/.ssh && chmod 600 ~/.ssh/id_rsa
-      - cat ~/.ssh/id_rsa
       - ssh websiteupdate@172.19.0.1 -p1813 -i ~/.ssh/id_rsa "cd /var/www/websitenew && git pull && git reset --hard origin/master"
-    secrets: [ ssh_key ]
+    secrets: [ privkey ]