Add target to push to Docker Hub

.gitlab-ci.yml

@@ -40,6 +40,8 @@
   image:
     name: gcr.io/kaniko-project/executor:debug
     entrypoint: [""]
+  variables:
+    DOCKERHUB_IMAGE: hub.docker.com/ocamlpro/ocaml
   script:
   - |
     echo "{
@@ -47,7 +49,11 @@
         \"$CI_REGISTRY\": {
           \"username\":\"$CI_REGISTRY_USER\",
           \"password\":\"$CI_REGISTRY_PASSWORD\"
-    }}}
+        },
+        \"hub.docker.com\": {
+          \"auth\":\"$DOCKERHUB_AUTH\"
+        }
+    }}
     " > /kaniko/.docker/config.json
   - /kaniko/executor --cache=true
       --context=$CI_PROJECT_DIR
@@ -55,10 +61,14 @@
       --build-arg=OCAML_VERSION=$OCAML_VERSION
       --build-arg=LAST_REPO_UPDATE=$(date +%s)
       --destination=$CI_REGISTRY_IMAGE:${OCAML_VERSION}
+      --destination=$DOCKERHUB_IMAGE:${OCAML_VERSION}
       --destination=$CI_REGISTRY_IMAGE:${OCAML_VERSION%.*}
+      --destination=$DOCKERHUB_IMAGE:${OCAML_VERSION%.*}
       --destination=$CI_REGISTRY_IMAGE:${OCAML_VERSION%.*}-$(date +%F)
+      --destination=$DOCKERHUB_IMAGE:${OCAML_VERSION%.*}-$(date +%F)
       $(if [ "$OCAML_VERSION" = "$LATEST_OCAML_VERSION" ]; then
           echo "--destination=$CI_REGISTRY_IMAGE:latest";
+          echo "--destination=$DOCKERHUB_IMAGE:latest";
         fi)
   only:
     - master