ci: try to use pipeline env

.drone.yml

@@ -3,12 +3,14 @@ kind: pipeline
 type: docker
 name: default
 
+environment:
+  DOCKER_REPO: glenux/service-dolibarr
 
 steps:
   - name: debug
     image: alpine
     environment:
-      DOCKER_REPO: glenux/service-dolibarr
+
     commands:
       - 'echo "Repository: $${DOCKER_REPO}"'
       - 'echo "Git commit: ${DRONE_COMMIT_SHA:0:8}"'
@@ -26,8 +28,8 @@ steps:
         from_secret: DOCKERHUB_USERNAME
       password:
         from_secret: DOCKERHUB_PASSWORD
-      cache_from: "${DOCKER_REPO}:latest_${DRONE_BRANCH/\\//-}"
-      repo: "${DOCKER_REPO}"
+      cache_from: "$${DOCKER_REPO}:latest_${DRONE_BRANCH/\\//-}"
+      repo: "$${DOCKER_REPO}"
       tags: "${DRONE_COMMIT_SHA:0:8}"
 
   - name: publish:commit_branch
@@ -41,7 +43,7 @@ steps:
       password:
         from_secret: DOCKERHUB_PASSWORD
       cache_from: "$${DOCKER_REPO}:latest_${DRONE_BRANCH/\\//-}"
-      repo: "${DOCKER_REPO}"
+      repo: "$${DOCKER_REPO}"
       tags: "latest_${DRONE_BRANCH/\\//-}"
     when:
       branch:
@@ -55,7 +57,7 @@ steps:
       username: "${DOCKERHUB_USERNAME}"
       password: "${DOCKERHUB_PASSWORD}"
       cache_from: "$${DOCKER_REPO}:latest_${DRONE_BRANCH/\\//-}"
-      repo: "${DOCKER_REPO}"
+      repo: "$${DOCKER_REPO}"
       tags: latest
     when:
       branch: