Update stale env variable and switch back alpine

.drone.yml

@@ -9,7 +9,7 @@ steps:
   command: ["build"]
 
 - name: deploy
-  image: ubuntu:latest
+  image: alpine:latest
 
   environment:
     HOST:
@@ -17,7 +17,7 @@ steps:
     USER:
       from_secret: user
     SSH_KEY:
-      from_secret: rsync_key
+      from_secret: ssh_key
     SITE_PATH:
       from_secret: path
 
@@ -26,8 +26,8 @@ steps:
     - main
 
   commands:
-  - apt-get update
-  - apt-get install -y ssh rsync
+  - apk update
+  - apk add openssh rsync
   - eval $(ssh-agent -s)
   - mkdir -p ~/.ssh
   - echo "$SSH_KEY" > ~/.ssh/id_rsa