feat: implement application cloning

Application cloning can be used to setup review applications based on an existing application. This is useful in CI/CD pipelines where a developer may wish to verify code in a custom environment without overwriting a shared staging environment.

docs/deployment/application-management.md

@@ -4,6 +4,7 @@
 
 ```
 apps                                           # List your apps
+apps:clone <old-app> <new-app>                 # Clone an app
 apps:create <app>                              # Create a new app
 apps:destroy <app>                             # Permanently destroy an app
 apps:rename <old-app> <new-app>                # Rename an app
@@ -112,3 +113,25 @@ Renaming node-js-app to io-js-app... done
 ```
 
 This will copy all of your app's contents into a new app directory with the name of your choice, delete your old app, then rebuild the new version of the app and deploy it. All of your config variables, including database urls, will be preserved.
+
+### Cloning an existing app
+
+> New as of 0.8.1
+
+You can clone an existing app using the `apps:clone` command.  Note that the application *must* have been deployed at least once, or the rename will not complete successfully:
+
+```shell
+dokku apps:clone node-js-app io-js-app
+```
+
+```
+Cloning node-js-app to io-js-app... done
+```
+
+This will copy all of your app's contents into a new app directory with the name of your choice and then rebuild the new version of the app and deploy it. All of your config variables, including database urls, will be preserved.
+
+By default, Dokku will deploy this new application, though you can skip the deploy by using the `--skip-deploy` flag:
+
+```shell
+dokku apps:clone --skip-deploy node-js-app io-js-app
+```

plugins/apps/commands

@@ -8,6 +8,7 @@ case "$1" in
       declare desc="return apps plugin help content"
       cat<<help_content
     apps, List your apps
+    apps:clone <old-app> <new-app>, Clone an app
     apps:create <app>, Create a new app
     apps:destroy <app>, Permanently destroy an app
     apps:rename <old-app> <new-app>, Rename an app

plugins/apps/subcommands/clone

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+source "$PLUGIN_AVAILABLE_PATH/apps/functions"
+source "$PLUGIN_AVAILABLE_PATH/ps/functions"
+
+apps_clone_cmd() {
+  declare desc="renames an app"
+  declare OLD_APP="$2" NEW_APP="$3"
+  local cmd="apps:rename"
+  local SKIP_REBUILD=false
+
+  if [[ "$2" == "--skip-deploy" ]]; then
+    SKIP_REBUILD=true
+    OLD_APP="$3"
+    NEW_APP="$4"
+  fi
+
+  [[ -z "$OLD_APP" ]] && dokku_log_fail "Please specify an app to run the command on"
+  [[ -d "$DOKKU_ROOT/$NEW_APP" ]] && dokku_log_fail "Name is already taken"
+  local NEW_CACHE_DIR="$DOKKU_ROOT/$NEW_APP/cache"
+
+  apps_create "$NEW_APP"
+  cp -a "$DOKKU_ROOT/$OLD_APP/." "$DOKKU_ROOT/$NEW_APP"
+
+  if [[ -d "$NEW_CACHE_DIR" ]] && ! rmdir "$NEW_CACHE_DIR"; then
+    docker run "$DOKKU_GLOBAL_RUN_ARGS" --rm -v "$NEW_CACHE_DIR:/cache" "dokku/$OLD_APP" chmod 777 -R /cache
+  fi
+  rm -rf "$NEW_CACHE_DIR"
+
+  [[ -f "$DOKKU_ROOT/$NEW_APP/URLS" ]] && sed -i -e "s/$OLD_APP/$NEW_APP/g" "$DOKKU_ROOT/$NEW_APP/URLS"
+  [[ -f "$DOKKU_ROOT/$NEW_APP/VHOST" ]] && sed -i -e "s/$OLD_APP/$NEW_APP/g" "$DOKKU_ROOT/$NEW_APP/VHOST"
+  [[ -f "$DOKKU_ROOT/$NEW_APP/hooks/pre-receive" ]] && sed -i -e "s/git-hook $OLD_APP/git-hook $NEW_APP/g" "$DOKKU_ROOT/$NEW_APP/hooks/pre-receive"
+  [[ "$SKIP_REBUILD" == "false" ]] || ps_rebuild "$NEW_APP"
+  plugn trigger post-app-clone "$OLD_APP" "$NEW_APP"
+  echo "Cloning $OLD_APP to $NEW_APP... done"
+}
+
+apps_clone_cmd "$@"

tests/unit/10_apps.bats

@@ -90,3 +90,36 @@ teardown () {
   echo "status: "$status
   assert_success
 }
+
+@test "(apps) apps:clone" {
+  deploy_app
+  run bash -c "dokku apps:clone $TEST_APP great-test-name"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run bash -c "dokku apps | grep $TEST_APP"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run bash -c "curl --silent --write-out '%{http_code}\n' `dokku url great-test-name` | grep 404"
+  echo "output: "$output
+  echo "status: "$status
+  assert_output ""
+  run bash -c "dokku --force apps:destroy great-test-name"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+
+  run bash -c "dokku apps:clone --skip-deploy $TEST_APP great-test-name"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run bash -c "curl --silent --write-out '%{http_code}\n' `dokku url great-test-name` | grep 404"
+  echo "output: "$output
+  echo "status: "$status
+  assert_failure
+  run bash -c "dokku --force apps:destroy great-test-name"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+}