add switches to prevent .env and .env.dist files

tere is a flaw w/ docker run - or at least it could be seen as flaw - as
while following the docs for --env-file automatic handling on .env.dist
and .env files it came to the attention that the .env.dist file not
setting any values will not as documented only set the variable if it is
exported but also - and that came by surprise - if not exported, the
variable is set to an empty string despite of the lack of the quality sign.

refs:

- docker/for-linux#284

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to Pipelines will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [unreleased]
+### Added
+- Add `--no-dot-env-files` and `--no-dot-env-dot-dist` flags to
+  not pass `.env.dist` and `.env` files to docker as
+  `--env-file` arguments
+
 ## [0.0.14] - 2018-04-18
 ### Added
 - Tag script to make releases
@@ -78,7 +84,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [0.0.5] - 2018-01-29
 ### Added
-- Docker environment variables options: `-e`, `--env` for 
+- Docker environment variables options: `-e`, `--env` for
   variables and `--env-file` for files
 - Composer "ci" script to integrate continuously
 - `--no-keep` option to never keep containers, even on error

bitbucket-pipelines.yml

@@ -78,3 +78,9 @@ pipelines:
           script:
             - lib/pipelines/environment.sh
             - env
+    printenv:
+        - step:
+            image: busybox
+            name: print environemnt variables
+            script:
+              - printenv

src/Utility/App.php

@@ -4,7 +4,6 @@
 
 namespace Ktomk\Pipelines\Utility;
 
-use Exception;
 use InvalidArgumentException;
 use Ktomk\Pipelines\Cli\Args;
 use Ktomk\Pipelines\Cli\ArgsException;
@@ -219,10 +218,19 @@ private function parseEnv(array $inherit, $reference, $workingDir)
 
         $env = Env::create($inherit);
         $env->addReference($reference);
-        $env->collectFiles(array(
-            $workingDir . '/.env.dist',
-            $workingDir . '/.env',
-        ));
+
+        $noDotEnvFiles = $args->hasOption('no-dot-env-files');
+        $noDotEnvDotDist = $args->hasOption('no-dot-env-dot-dist');
+
+        if (false === $noDotEnvFiles) {
+            $filesToCollect = array();
+            if (false === $noDotEnvDotDist) {
+                $filesToCollect[] = $workingDir . '/.env.dist';
+            }
+            $filesToCollect[] = $workingDir . '/.env';
+            $env->collectFiles($filesToCollect);
+        }
+
         $env->collect($args, array('e', 'env', 'env-file'));
 
         return $env;

src/Utility/Help.php

@@ -43,6 +43,7 @@ public function showUsage()
                  [--[no-|error-]keep] [--prefix <prefix>]
                  [--basename <basename>]
                  [[-e | --env] <variable>] [--env-file <path>]
+                 [--no-dot-env-files] [--no-dot-env-dot-dist]
                  [--file <path>] [--dry-run] [--no-run] [--list]
                  [--deploy mount | copy ] [--show] [--images]
                  [--pipeline <id>] [--trigger <ref>] [--verbatim]
@@ -80,6 +81,10 @@ public function showHelp()
                           for the docker container
     --env-file <path>     pass variables from environment file
                           to the docker container
+    --no-dot-env-files    do not pass .env.dist and .env files
+                          as environment files to docker
+    --no-dot-env-dot-dist dot not pass .env.dist as environment
+                          file to docker
     --file <path>         path to the pipelines file, overrides
                           looking up the <basename> file from
                           the current working directory