Inject same env variables when building container and exec command

src/main/java/com/cloudbees/jenkins/plugins/docker_build_env/BuiltInContainer.java

@@ -27,6 +27,7 @@ public class BuiltInContainer implements BuildBadgeAction, EnvironmentContributi
     private final transient Docker docker;
     private List<Integer> ports = new ArrayList<Integer>();
     private Map<String,String> volumes = new HashMap<String,String>();
+    private EnvVars envVars;
 
     public BuiltInContainer(Docker docker) {
         this.docker = docker;
@@ -84,6 +85,14 @@ public void buildEnvVars(AbstractBuild<?, ?> build, EnvVars env) {
         }
     }
 
+    public EnvVars getEnvVars() {
+        return envVars;
+    }
+
+    public void setEnvVars(EnvVars envVars) {
+        this.envVars = envVars;
+    }
+
     public void bindMount(String path) {
         volumes.put(path, path);
     }

src/main/java/com/cloudbees/jenkins/plugins/docker_build_env/DockerBuildWrapper.java

@@ -191,6 +191,8 @@ private String startBuildContainer(BuiltInContainer runInContainer, AbstractBuil
         try {
             EnvVars environment = buildContainerEnvironment(build, listener);
 
+            runInContainer.setEnvVars(environment);
+
             String workdir = build.getWorkspace().getRemote();
 
             Map<String, String> links = new HashMap<String, String>();

src/main/java/com/cloudbees/jenkins/plugins/docker_build_env/DockerDecoratedLauncher.java

@@ -56,16 +56,9 @@ public Proc launch(ProcStarter starter) throws IOException {
     private EnvVars buildContainerEnvironment() throws IOException, InterruptedException {
 
         if (this.env == null) {
-            this.env = runInContainer.getDocker().getEnv(runInContainer.container, launcher);
+            this.env = runInContainer.getEnvVars();
         }
-        EnvVars environment = new EnvVars(env);
-
-        // Let BuildWrapper customize environment, including PATH
-        for (Environment e : build.getEnvironments()) {
-            e.buildEnvVars(environment);
-        }
-
-        return environment;
+        return new EnvVars(env);
     }
 
 }