Revamp link/unlink commands

Previously we were exporting `MONGO_URL` via the docker-args* hooks. This seems to confuse our users (since the env var is not displayed when calling `dokku config`) and in some cases it also seems that the env var is not correctly set. Another problem is if several services are linked to the same app and if they are exporting `MONGO_URL` as well. Then we don’t know what will be set. To resolve theses issues, this patch changes the way we manage the env vars. We use standard dokku commands (`config` and `docker-options`) so config is set on the linked application and can be reviewed by the user easily. We also handle the case where `MONGO_URL` is already set on the linked application. When it’s the case, we automatically generate another env var based on the following pattern: DOKKU_<service name>_<random unused color>_URL. For example, this can give: DOKKU_MONGO_BLACK_URL. Since naming is now handled automatically, the `alias` command has been removed. If the user wants to set a different env var on her app, it’s just a matter of using `dokku config:set` and pasting the wanted value. IP in DSN has been removed in favor of host name exported by docker in the container. This is more robust and simpler since the IP can change but the name will remain the same if the service container restarts for instance. With all those changes, a new command has been introduced: `promote`. The goal of this command is to easily set a service as the primary one when several are linked to an app. (see README for an example)
2015-09-22 18:13:57 +02:00
parent 9038ffc684
commit 5eed4378aa
18 changed files with 284 additions and 119 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 tests/dokku
 tests/fixtures
+tests/bin/plugn
--- a/README.md
+++ b/README.md
@@ -22,7 +22,6 @@ dokku plugin:install https://github.com/dokku/dokku-mongo.git mongo
 ## commands

 ```
-mongo:alias <name> <alias>     Set an alias for the docker link
 mongo:clone <name> <new-name>  Create container <new-name> then copy data from <name> into <new-name>
 mongo:connect <name>           Connect via telnet to a mongo service
 mongo:create <name>            Create a mongo service
@@ -34,6 +33,7 @@ mongo:info <name>              Print the connection information
 mongo:link <name> <app>        Link the mongo service to the app
 mongo:list                     List all mongo services
 mongo:logs <name> [-t]         Print the most recent log(s) for this service
+mongo:promote <name> <app>     Promote service <name> as MONGO_URL in <app>
 mongo:restart <name>           Graceful shutdown and restart of the mongo service container
 mongo:start <name>             Start a previously stopped mongo service
 mongo:stop <name>              Stop a running mongo service
@@ -57,8 +57,6 @@ dokku mongo:create lolipop
 # get connection information as follows
 dokku mongo:info lolipop

-# lets assume the ip of our mongo service is 172.17.0.1
-
 # a mongo service can be linked to a
 # container this will use native docker
 # links via the docker-options plugin
@@ -68,24 +66,42 @@ dokku mongo:link lolipop playground

 # the above will expose the following environment variables
 #
-#   MONGO_URL=mongo://l:PASSWORD@172.17.0.1:27017/lolipop
-#   MONGO_NAME=/lolipop/DATABASE
-#   MONGO_PORT=tcp://172.17.0.1:27017
-#   MONGO_PORT_27017_TCP=tcp://172.17.0.1:27017
-#   MONGO_PORT_27017_TCP_PROTO=tcp
-#   MONGO_PORT_27017_TCP_PORT=27017
-#   MONGO_PORT_27017_TCP_ADDR=172.17.0.1
+#   DOKKU_MONGO_LOLIPOP_NAME=/lolipop/DATABASE
+#   DOKKU_MONGO_LOLIPOP_PORT=tcp://172.17.0.1:27017
+#   DOKKU_MONGO_LOLIPOP_PORT_27017_TCP=tcp://172.17.0.1:27017
+#   DOKKU_MONGO_LOLIPOP_PORT_27017_TCP_PROTO=tcp
+#   DOKKU_MONGO_LOLIPOP_PORT_27017_TCP_PORT=27017
+#   DOKKU_MONGO_LOLIPOP_PORT_27017_TCP_ADDR=172.17.0.1
+#
+# and the following will be set on the linked application by default
+#
+#   MONGO_URL=mongodb://lolipop:SOME_PASSWORD@dokku-mongo-lolipop:27017/lolipop
+#
+# NOTE: the host exposed here only works internally in docker containers. If
+# you want your container to be reachable from outside, you should use `expose`.

-# you can examine the environment variables
-# using our 'playground' app's env command
-dokku run playground env
+# another service can be linked to your app
+dokku mongo:link other_service playground

-# you can customize the environment
-# variables through a custom docker link alias
-dokku mongo:alias lolipop MONGO_DATABASE
+# since DATABASE_URL is already in use, another environment variable will be
+# generated automatically
+#
+#   DOKKU_MONGO_BLUE_URL=mongodb://other_service:ANOTHER_PASSWORD@dokku-mongo-other-service:27017/other_service
+
+# you can then promote the new service to be the primary one
+# NOTE: this will restart your app
+dokku mongo:promote other_service playground
+
+# this will replace MONGO_URL with the url from other_service and generate
+# another environment variable to hold the previous value if necessary.
+# you could end up with the following for example:
+#
+#   MONGO_URL=mongodb://other_service:ANOTHER_PASSWORD@dokku-mongo-other-service:27017/other_service
+#   DOKKU_MONGO_BLUE_URL=mongodb://other_service:ANOTHER_PASSWORD@dokku-mongo-other-service:27017/other_service
+#   DOKKU_MONGO_SILVER_URL=mongodb://lolipop:SOME_PASSWORD@dokku-mongo-lolipop:27017/lolipop

 # you can also unlink a mongo service
-# NOTE: this will restart your app
+# NOTE: this will restart your app and unset related environment variables
 dokku mongo:unlink lolipop playground

 # you can tail logs for a particular service
--- a/17
+++ b/17
@@ -16,13 +16,6 @@ if [[ $1 == $PLUGIN_COMMAND_PREFIX:* ]]; then
 fi

 case "$1" in
-  $PLUGIN_COMMAND_PREFIX:alias)
-    [[ -z $2 ]] && dokku_log_fail "Please specify a name for the service"
-    [[ -z $3 ]] && dokku_log_fail "Please specify an alias for the service"
-    verify_service_name "$2"
-    service_set_alias "$2" "$3"
-    ;;
-
  $PLUGIN_COMMAND_PREFIX:create)
    [[ -z $2 ]] && dokku_log_fail "Please specify a name for the service"
    [[ ! -d "$PLUGIN_DATA_ROOT/$2" ]] || dokku_log_fail "$PLUGIN_SERVICE service $2 already exists"
@@ -205,9 +198,16 @@ case "$1" in
    service_port_unexpose "$2"
    ;;

+  $PLUGIN_COMMAND_PREFIX:promote)
+    [[ -z $2 ]] && dokku_log_fail "Please specify a name for the service"
+    [[ -z $3 ]] && dokku_log_fail "Please specify an app to run the command on"
+    verify_service_name "$2"
+    verify_app_name "$3"
+    promote "$2" "$3"
+    ;;
+
  help | $PLUGIN_COMMAND_PREFIX:help)
    HELP=$(cat<<EOF
-    $PLUGIN_COMMAND_PREFIX:alias <name> <alias>, Set an alias for the docker link
    $PLUGIN_COMMAND_PREFIX:create <name>, Create a $PLUGIN_SERVICE service
    $PLUGIN_COMMAND_PREFIX:destroy <name>, Delete the $PLUGIN_SERVICE service and stop its container if there are no links left
    $PLUGIN_COMMAND_PREFIX:link <name> <app>, Link the $PLUGIN_SERVICE service to the app
@@ -224,6 +224,7 @@ case "$1" in
    $PLUGIN_COMMAND_PREFIX:unexpose <name>, Unexpose a previously exposed $PLUGIN_SERVICE service
    $PLUGIN_COMMAND_PREFIX:start <name>, Start a previously stopped $PLUGIN_SERVICE service
    $PLUGIN_COMMAND_PREFIX:stop <name>, Stop a running $PLUGIN_SERVICE service
+    $PLUGIN_COMMAND_PREFIX:promote <name> <app>, Promote service <name> as ${PLUGIN_DEFAULT_ALIAS}_URL in <app>
 EOF
 )
    if [[ -n $DOKKU_API_VERSION ]]; then
--- a/1
+++ b/1
@@ -7,6 +7,7 @@ export PLUGIN_COMMAND_PREFIX="mongo"
 export PLUGIN_DATA_ROOT=$MONGO_ROOT
 export PLUGIN_DATASTORE_PORTS=(27017 27018 27019 28017)
 export PLUGIN_DEFAULT_ALIAS="MONGO"
+export PLUGIN_ALT_ALIAS="DOKKU_MONGO"
 export PLUGIN_IMAGE=$MONGO_IMAGE
 export PLUGIN_IMAGE_VERSION=$MONGO_IMAGE_VERSION
 export PLUGIN_SCHEME="mongodb"
--- a/1
+++ b/1
@@ -1 +0,0 @@
-docker-args-deploy
--- a/31
+++ b/31
@@ -1,31 +0,0 @@
-#!/usr/bin/env bash
-set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
-PLUGIN_BASE_PATH="$PLUGIN_PATH"
-if [[ -n $DOKKU_API_VERSION ]]; then
-  PLUGIN_BASE_PATH="$PLUGIN_ENABLED_PATH"
-fi
-source "$PLUGIN_BASE_PATH/common/functions"
-source "$(dirname "$0")/functions"
-source "$(dirname "$0")/config"
-
-STDIN=$(cat)
-APP="$1"
-
-output=""
-for i in $PLUGIN_DATA_ROOT/*; do
-  [[ -d $i ]] || continue
-  SERVICE=$(echo "$i" | cut -d'/' -f 7)
-  LINKS_FILE="$PLUGIN_DATA_ROOT/$SERVICE/LINKS"
-  ALIAS="$(service_alias "$SERVICE")"
-  SERVICE_URL="$(service_url "$SERVICE")"
-  if [[ -f "$LINKS_FILE" ]]; then
-    while read line; do
-      if [[ "$line" == "$APP" ]]; then
-        output="$output --link dokku.mongo.$SERVICE:$ALIAS --env ${ALIAS}_URL=$SERVICE_URL"
-        break
-      fi
-    done < "$LINKS_FILE"
-  fi
-done
-
-echo "$STDIN$output"
--- a/1
+++ b/1
@@ -1 +0,0 @@
-docker-args-deploy
--- a/107
+++ b/107
@@ -32,14 +32,8 @@ verify_service_name() {

 service_alias() {
  local SERVICE="$1"
-  local ALIAS_FILE="$PLUGIN_DATA_ROOT/$SERVICE/ALIAS"
-
-  verify_service_name "$1"
-  if [[ -f "$ALIAS_FILE" ]]; then
-    cat "$ALIAS_FILE"
-  else
-    echo "$PLUGIN_DEFAULT_ALIAS"
-  fi
+  local SERVICE_NAME=$(get_service_name "$SERVICE")
+  echo "$SERVICE_NAME" | tr ._ -
 }

 service_info() {
@@ -77,16 +71,44 @@ service_exposed_ports() {
 service_link() {
  local APP="$2"
  local SERVICE="$1"
+  local SERVICE_URL=$(service_url "$SERVICE")
+  local SERVICE_NAME=$(get_service_name "$SERVICE")
  local SERVICE_ROOT="$PLUGIN_DATA_ROOT/$SERVICE"
+  local EXISTING_CONFIG=$(dokku config "$APP")
+  local LINK=$(echo "$EXISTING_CONFIG" | grep "$SERVICE_URL" | cut -d: -f1) || true
+  local DEFAULT_ALIAS=$(echo "$EXISTING_CONFIG" | grep "${PLUGIN_DEFAULT_ALIAS}_URL") || true
+  local SERVICE_ALIAS=$(service_alias "$SERVICE")
  local LINKS_FILE="$SERVICE_ROOT/LINKS"

+  [[ -n $LINK ]] && dokku_log_fail "Already linked as $LINK"
  mkdir -p "$SERVICE_ROOT" || dokku_log_fail "Unable to create service directory"
  touch "$LINKS_FILE"
  echo "$APP" >> "$LINKS_FILE"
  sort "$LINKS_FILE" -u -o "$LINKS_FILE"

-  dokku_log_info1 "Restarting app $APP"
-  dokku ps:restart "$APP"
+  local ALIAS="$PLUGIN_DEFAULT_ALIAS"
+  if [[ -n $DEFAULT_ALIAS ]]; then
+    ALIAS=$(service_alternative_alias "$EXISTING_CONFIG")
+  fi
+  dokku docker-options:add "$APP" build,deploy,run "--link $SERVICE_NAME:$SERVICE_ALIAS"
+  dokku config:set "$APP" "${ALIAS}_URL=$SERVICE_URL"
+}
+
+service_alternative_alias() {
+  local EXISTING_CONFIG="$1"
+  local COLORS=(AQUA BLACK BLUE FUCHSIA GRAY GREEN LIME MAROON NAVY OLIVE PURPLE RED SILVER TEAL WHITE YELLOW)
+  local ALIAS;
+
+  while [[ -z $ALIAS ]]; do
+    local IDX=$((RANDOM % ${#COLORS[*]}))
+    local COLOR=${COLORS[IDX]}
+    ALIAS="${PLUGIN_ALT_ALIAS}_${COLOR}"
+    local IN_USE=$(echo "$EXISTING_CONFIG" | grep "${ALIAS}_URL")
+    if [[ -n $IN_USE ]]; then
+      unset ALIAS
+    fi
+  done
+  echo "$ALIAS"
 }

 service_logs() {
@@ -232,25 +254,25 @@ service_stop() {
 service_unlink() {
  local APP="$2"
  local SERVICE="$1"
-  local SERVICE_ROOT="$PLUGIN_DATA_ROOT/$SERVICE"
-  local LINKS_FILE="$SERVICE_ROOT/LINKS"
+  local SERVICE_URL=$(service_url "$SERVICE")
+  local SERVICE_NAME=$(get_service_name "$SERVICE")
+  local EXISTING_CONFIG=$(dokku config "$APP")
+  local SERVICE_ALIAS=$(service_alias "$SERVICE")
+  local LINK=($(echo "$EXISTING_CONFIG" | grep "$SERVICE_URL" | cut -d: -f1)) || true

-  mkdir -p "$SERVICE_ROOT" || dokku_log_fail "Unable to create service directory"
-  touch "$LINKS_FILE"
-  sed -i "/^$APP\$/d" "$LINKS_FILE"
-  sort "$LINKS_FILE" -u -o "$LINKS_FILE"
+  [[ -z ${LINK[*]} ]] && dokku_log_fail "Not linked to app $APP"
+  remove_from_links_file "$SERVICE" "$APP"

-  dokku_log_info1 "Restarting app $APP"
-  dokku ps:restart "$APP"
+  dokku docker-options:remove "$APP" build,deploy,run "--link $SERVICE_NAME:$SERVICE_ALIAS"
+  dokku config:unset "$APP" "${LINK[*]}"
 }

 service_url() {
  local SERVICE="$1"
  local SERVICE_ROOT="$PLUGIN_DATA_ROOT/$SERVICE"
-  local ID="$(cat "$SERVICE_ROOT/ID")"
-  local IP="$(get_container_ip "$ID")"
  local PASSWORD="$(cat "$SERVICE_ROOT/PASSWORD")"
-  echo "$PLUGIN_SCHEME://$SERVICE:$PASSWORD@$IP:${PLUGIN_DATASTORE_PORTS[0]}/$SERVICE"
+  local SERVICE_ALIAS="$(service_alias "$SERVICE")"
+  echo "$PLUGIN_SCHEME://$SERVICE:$PASSWORD@$SERVICE_ALIAS:${PLUGIN_DATASTORE_PORTS[0]}/$SERVICE"
 }

 is_container_status () {
@@ -275,3 +297,46 @@ service_version() {
  local SERVICE_NAME="$(get_service_name "$SERVICE")"
  docker inspect -f '{{.Config.Image}}' "$SERVICE_NAME"
 }
+
+get_url_from_config() {
+  local EXISTING_CONFIG="$1"
+  local CONFIG_VAR="$2"
+  echo "$EXISTING_CONFIG" | grep "$CONFIG_VAR" | sed "s/$CONFIG_VAR:\s*//"
+}
+
+promote() {
+  local SERVICE="$1"
+  local APP="$2"
+  local PLUGIN_DEFAULT_CONFIG_VAR="${PLUGIN_DEFAULT_ALIAS}_URL"
+  local EXISTING_CONFIG=$(dokku config "$APP")
+  local SERVICE_URL=$(service_url "$SERVICE")
+  local CONFIG_VARS=($(echo "$EXISTING_CONFIG" | grep "$SERVICE_URL" | cut -d: -f1)) || true
+  local PREVIOUS_DEFAULT_URL=$(get_url_from_config "$EXISTING_CONFIG" "$PLUGIN_DEFAULT_CONFIG_VAR")
+
+  [[ -z ${CONFIG_VARS[*]} ]] && dokku_log_fail "Not linked to app $APP"
+  [[ ${CONFIG_VARS[*]} =~ $PLUGIN_DEFAULT_CONFIG_VAR ]] && dokku_log_fail "Service $1 already promoted as $PLUGIN_DEFAULT_CONFIG_VAR"
+
+  local NEW_CONFIG_VARS=""
+  if [[ -n $PREVIOUS_DEFAULT_URL ]]; then
+    local PREVIOUS_ALIAS=$(echo "$EXISTING_CONFIG" | grep "$PREVIOUS_DEFAULT_URL" | grep -v "$PLUGIN_DEFAULT_CONFIG_VAR") || true
+    if [[ -z $PREVIOUS_ALIAS ]]; then
+      local ALIAS=$(service_alternative_alias "$EXISTING_CONFIG")
+      NEW_CONFIG_VARS+="${ALIAS}_URL=$PREVIOUS_DEFAULT_URL "
+    fi
+  fi
+  local PROMOTE_URL=$(get_url_from_config "$EXISTING_CONFIG" "${CONFIG_VARS[0]}")
+  NEW_CONFIG_VARS+="$PLUGIN_DEFAULT_CONFIG_VAR=$PROMOTE_URL"
+  dokku config:set "$APP" $NEW_CONFIG_VARS
+}
+
+remove_from_links_file() {
+  local SERVICE="$1"
+  local APP="$2"
+  local SERVICE_ROOT="$PLUGIN_DATA_ROOT/$SERVICE"
+  local LINKS_FILE="$SERVICE_ROOT/LINKS"
+
+  mkdir -p "$SERVICE_ROOT" || dokku_log_fail "Unable to create service directory"
+  touch "$LINKS_FILE"
+  sed -i "/^$APP\$/d" "$LINKS_FILE"
+  sort "$LINKS_FILE" -u -o "$LINKS_FILE"
+}
--- a/16
+++ b/16
@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+
+PLUGIN_BASE_PATH="$PLUGIN_PATH"
+if [[ -n $DOKKU_API_VERSION ]]; then
+  PLUGIN_BASE_PATH="$PLUGIN_ENABLED_PATH"
+fi
+source "$PLUGIN_BASE_PATH/common/functions"
+source "$(dirname "$0")/functions"
+source "$(dirname "$0")/config"
+
+APP="$1"
+for SERVICE in "$PLUGIN_DATA_ROOT"/*; do
+  remove_from_links_file "$(basename "$SERVICE")" "$APP"
+done
+exit 0
--- a/tests/bin/sudo
+++ b/tests/bin/sudo
@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+exit 0
--- a/tests/hook_pre_delete.bats
+++ b/tests/hook_pre_delete.bats
@@ -0,0 +1,20 @@
+#!/usr/bin/env bats
+load test_helper
+
+setup() {
+  dokku apps:create my_app >&2
+  dokku "$PLUGIN_COMMAND_PREFIX:create" l >&2
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app >&2
+}
+
+teardown() {
+  dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app >&2
+  dokku --force "$PLUGIN_COMMAND_PREFIX:destroy" l >&2
+  rm "$DOKKU_ROOT/my_app" -rf
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:hook:pre-delete) removes app from links file when destroying app" {
+  [[ -n $(< "$PLUGIN_DATA_ROOT/l/LINKS") ]]
+  dokku --force apps:destroy my_app
+  [[ -z $(< "$PLUGIN_DATA_ROOT/l/LINKS") ]]
+}
--- a/tests/service_alias.bats
+++ b/tests/service_alias.bats
@@ -1,32 +0,0 @@
-#!/usr/bin/env bats
-load test_helper
-
-setup() {
-  dokku "$PLUGIN_COMMAND_PREFIX:create" l >&2
-}
-
-teardown() {
-  dokku --force "$PLUGIN_COMMAND_PREFIX:destroy" l >&2
-}
-
-@test "($PLUGIN_COMMAND_PREFIX:alias) error when there are no arguments" {
-  run dokku "$PLUGIN_COMMAND_PREFIX:alias"
-  assert_contains "${lines[*]}" "Please specify a name for the service"
-}
-
-@test "($PLUGIN_COMMAND_PREFIX:alias) error when alias is missing" {
-  run dokku "$PLUGIN_COMMAND_PREFIX:alias" l
-  assert_contains "${lines[*]}" "Please specify an alias for the service"
-}
-
-@test "($PLUGIN_COMMAND_PREFIX:alias) error when service does not exist" {
-  run dokku "$PLUGIN_COMMAND_PREFIX:alias" not_existing_service MY_ALIAS
-  assert_contains "${lines[*]}" "service not_existing_service does not exist"
-}
-
-@test "($PLUGIN_COMMAND_PREFIX:alias) success" {
-  run dokku "$PLUGIN_COMMAND_PREFIX:alias" l MY_ALIAS
-  new_alias=$(cat "$PLUGIN_DATA_ROOT/l/ALIAS")
-  [[ $new_alias == "MY_ALIAS" ]]
-}
-
--- a/tests/service_info.bats
+++ b/tests/service_info.bats
@@ -22,5 +22,13 @@ teardown() {
@test "($PLUGIN_COMMAND_PREFIX:info) success" {
  run dokku "$PLUGIN_COMMAND_PREFIX:info" l
  password="$(cat "$PLUGIN_DATA_ROOT/l/PASSWORD")"
-  assert_contains "${lines[*]}" "DSN: mongodb://l:$password@172.17.0.34:27017/l"
+  assert_contains "${lines[*]}" "DSN: mongodb://l:$password@dokku-mongo-l:27017/l"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:info) replaces underscores by dash in hostname" {
+  dokku "$PLUGIN_COMMAND_PREFIX:create" test_with_underscores
+  run dokku "$PLUGIN_COMMAND_PREFIX:info" test_with_underscores
+  password="$(cat "$PLUGIN_DATA_ROOT/test_with_underscores/PASSWORD")"
+  assert_contains "${lines[*]}" "DSN: mongodb://test_with_underscores:$password@dokku-mongo-test-with-underscores:27017/test_with_underscores"
+  dokku --force "$PLUGIN_COMMAND_PREFIX:destroy" test_with_underscores
 }
--- a/tests/service_link.bats
+++ b/tests/service_link.bats
@@ -31,8 +31,31 @@ teardown() {
  assert_contains "${lines[*]}" "service not_existing_service does not exist"
 }

-@test "($PLUGIN_COMMAND_PREFIX:link) success" {
+@test "($PLUGIN_COMMAND_PREFIX:link) error when the service is already linked to app" {
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app
  run dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app
-  links=$(cat "$PLUGIN_DATA_ROOT/l/LINKS")
-  assert_equal "$links" "my_app"
+  assert_contains "${lines[*]}" "Already linked as MONGO_URL"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:link) exports MONGO_URL to app" {
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app
+  url=$(dokku config:get my_app MONGO_URL)
+  password="$(cat "$PLUGIN_DATA_ROOT/l/PASSWORD")"
+  assert_contains "$url" "mongodb://l:$password@dokku-mongo-l:27017/l"
+  dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:link) generates an alternate config url when MONGO_URL already in use" {
+  dokku config:set my_app MONGO_URL=mongodb://user:pass@host:27017/db
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app
+  run dokku config my_app
+  assert_contains "${lines[*]}" "DOKKU_MONGO_"
+  dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:link) links to app with docker-options" {
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app
+  run dokku docker-options my_app
+  assert_contains "${lines[*]}" "--link dokku.mongo.l:dokku-mongo-l"
+  dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app
 }
--- a/tests/service_promote.bats
+++ b/tests/service_promote.bats
@@ -0,0 +1,55 @@
+#!/usr/bin/env bats
+load test_helper
+
+setup() {
+  dokku "$PLUGIN_COMMAND_PREFIX:create" l >&2
+  dokku apps:create my_app >&2
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app
+}
+
+teardown() {
+  dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app
+  dokku --force "$PLUGIN_COMMAND_PREFIX:destroy" l >&2
+  rm "$DOKKU_ROOT/my_app" -rf
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:promote) error when there are no arguments" {
+  run dokku "$PLUGIN_COMMAND_PREFIX:promote"
+  assert_contains "${lines[*]}" "Please specify a name for the service"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:promote) error when the app argument is missing" {
+  run dokku "$PLUGIN_COMMAND_PREFIX:promote" l
+  assert_contains "${lines[*]}" "Please specify an app to run the command on"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:promote) error when the app does not exist" {
+  run dokku "$PLUGIN_COMMAND_PREFIX:promote" l not_existing_app
+  assert_contains "${lines[*]}" "App not_existing_app does not exist"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:promote) error when the service does not exist" {
+  run dokku "$PLUGIN_COMMAND_PREFIX:promote" not_existing_service my_app
+  assert_contains "${lines[*]}" "service not_existing_service does not exist"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:promote) error when the service is already promoted" {
+  run dokku "$PLUGIN_COMMAND_PREFIX:promote" l my_app
+  assert_contains "${lines[*]}" "already promoted as MONGO_URL"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:promote) changes MONGO_URL" {
+  password="$(cat "$PLUGIN_DATA_ROOT/l/PASSWORD")"
+  dokku config:set my_app "MONGO_URL=mongodb://u:p@host:27017/db" "DOKKU_MONGO_BLUE_URL=mongodb://l:$password@dokku-mongo-l:27017/l"
+  dokku "$PLUGIN_COMMAND_PREFIX:promote" l my_app
+  url=$(dokku config:get my_app MONGO_URL)
+  assert_equal "$url" "mongodb://l:$password@dokku-mongo-l:27017/l"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:promote) creates new config url when needed" {
+  password="$(cat "$PLUGIN_DATA_ROOT/l/PASSWORD")"
+  dokku config:set my_app "MONGO_URL=mongodb://u:p@host:27017/db" "DOKKU_MONGO_BLUE_URL=mongodb://l:$password@dokku-mongo-l:27017/l"
+  dokku "$PLUGIN_COMMAND_PREFIX:promote" l my_app
+  run dokku config my_app
+  assert_contains "${lines[*]}" "DOKKU_MONGO_"
+}
--- a/tests/service_unlink.bats
+++ b/tests/service_unlink.bats
@@ -31,9 +31,21 @@ teardown() {
  assert_contains "${lines[*]}" "service not_existing_service does not exist"
 }

-@test "($PLUGIN_COMMAND_PREFIX:unlink) success" {
-  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app >&2
+@test "($PLUGIN_COMMAND_PREFIX:unlink) error when service not linked to app" {
  run dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app
-  links=$(cat "$PLUGIN_DATA_ROOT/l/LINKS")
-  assert_equal "$links" ""
+  assert_contains "${lines[*]}" "Not linked to app my_app"
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:unlink) removes link from docker-options" {
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app >&2
+  dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app
+  options=$(dokku docker-options my_app)
+  assert_equal "$options" ""
+}
+
+@test "($PLUGIN_COMMAND_PREFIX:unlink) unsets config url from app" {
+  dokku "$PLUGIN_COMMAND_PREFIX:link" l my_app >&2
+  dokku "$PLUGIN_COMMAND_PREFIX:unlink" l my_app
+  config=$(dokku config:get my_app MONGO_URL)
+  assert_equal "$config" ""
 }
--- a/tests/setup.sh
+++ b/tests/setup.sh
@@ -1,6 +1,8 @@
 #!/usr/bin/env bash
 source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/test_helper.bash"

+BIN_STUBS="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/bin"
+
 if [[ ! -d $DOKKU_ROOT ]]; then
  git clone https://github.com/progrium/dokku.git $DOKKU_ROOT > /dev/null
 fi
@@ -13,3 +15,10 @@ cd -
 rm -rf $DOKKU_ROOT/plugins/service
 mkdir -p $DOKKU_ROOT/plugins/service
 find ./ -maxdepth 1 -type f -exec cp '{}' $DOKKU_ROOT/plugins/service \;
+
+if [[ ! -f $BIN_STUBS/plugn ]]; then
+  wget -O- "$PLUGN_URL" | tar xzf - -C "$BIN_STUBS"
+  plugn init
+  ln -s "$DOKKU_ROOT"/plugins/* "$DOKKU_ROOT"/plugins/available
+  ln -s "$DOKKU_ROOT"/plugins/* "$DOKKU_ROOT"/plugins/enabled
+fi
--- a/tests/test_helper.bash
+++ b/tests/test_helper.bash
@@ -10,6 +10,7 @@ export PLUGIN_AVAILABLE_PATH="$PLUGIN_PATH"
 export PLUGIN_CORE_AVAILABLE_PATH="$PLUGIN_PATH"
 export MONGO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/fixtures"
 export PLUGIN_DATA_ROOT="$MONGO_ROOT"
+export PLUGN_URL="https://github.com/progrium/plugn/releases/download/v0.1.0/plugn_0.1.0_linux_x86_64.tgz"

 mkdir -p "$PLUGIN_DATA_ROOT"
 rm -rf "${PLUGIN_DATA_ROOT:?}"/*