diff --git a/Dockerfile b/Dockerfile
index 233338b..82ce4b8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,13 @@
 FROM alpine:3
 
+# Labels.
+LABEL org.opencontainers.image.authors='peter.zmilczak@gmail.com' \
+      org.opencontainers.image.url='https://github.com/logchange/valhalla' \
+      org.opencontainers.image.documentation='https://github.com/logchange/valhalla/blob/master/README.md' \
+      org.opencontainers.image.source='https://github.com/logchange/valhalla' \
+      org.opencontainers.image.vendor='The logchange Community' \
+      org.opencontainers.image.licenses='Apache-2.0'
+
 RUN apk --update --no-cache add  \
     bash  \
     git  \
diff --git a/README.md b/README.md
index 0784c3e..0a33983 100644
--- a/README.md
+++ b/README.md
@@ -40,10 +40,10 @@ commit_before_release: # define actions which have to happen before release and
   username: Test1234 # git config username
   email: test-valhalla@logchange.dev # git config email
   msg: Releasing version {VERSION} # commit message, you can use string predefined variables
-  before: # list of bash commands, you can use string predefined variables
+  before: # list of bash commands, you can use string predefined variables, custom variables or system environment variables!
     - echo "test" > some_file4.md
     - mkdir -p changelog/v{VERSION}
-    - echo "Super release description for tests" > changelog/v{VERSION}/version_summary.md
+    - echo "Super release description for tests generated at {CI_COMMIT_TIMESTAMP}" > changelog/v{VERSION}/version_summary.md
 # definition of release which will be created
 release:
   description:
@@ -128,6 +128,14 @@ which will be overriden in child `valhalla.yml`.**
 | `VERSION`        | value extracted from branch name, for `release-1.2.14` it will be `1.2.14` |
 | `VALHALLA_TOKEN` | token passed to CI runner which execute this job                           |
 
+### 🐛 Environment variables
+
+Valhalla allows you to use any variable defined in your environment system, it is useful f.e when you
+are using GitLab CI/CD and you want to use [GitLab CI/CD predefined variables](https://docs.gitlab.com/ee/ci/variables/predefined_variables.html)
+in your `valhalla.yml`.
+
+**Use `{}` to evaluate variable to value f.e. `{HOME}`**
+
 ### 🦊 .gitlab-ci.yml
 
 - if using GitLab workflows
@@ -136,16 +144,23 @@ which will be overriden in child `valhalla.yml`.**
 
 ```yml
 
+# Modify your workflow rules to include rule to start pipeline for branch starting with name 
+# release- and exclude commits with VALHALLA SKIP (when valhalla commits files we don't want to start pipeline again)
 workflows:
+  # .... your standard workflows here
   - if: $CI_COMMIT_BRANCH =~ /^release-*/ && $CI_COMMIT_TITLE !~ /.*VALHALLA SKIP.*/
   
 # add new stage
 stages:
+  # .... your standard stages here
   - release
   
 valhalla_release:
   stage: release
-  image: logchange/valhalla:1.2.1
+  image: logchange/valhalla:1.3.0
+  # Prevent from fetching artifacts because it is a problem during committing all files (git add .)
+  # https://docs.gitlab.com/ee/ci/jobs/job_artifacts.html#prevent-a-job-from-fetching-artifacts
+  dependencies: []
   rules:
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"
       when: never
@@ -158,7 +173,12 @@ valhalla_release:
 ```
 ### 🚧 .gitignore
 
-Add to your `.gitignore` following rules, please create issue if valhalla commits to much files!
+Add to your `.gitignore` following rules, please create issue if valhalla commits to many files!
+(For GitLab CI/CD add `dependencies: []` which will prevent from committing generated files)
+
+It is important to modify your `.gitignore` when valhalla during `commit_before_release` or 
+`commit_after_release` phase generates files which you don't want to commit (f.e. maven release plugin or 
+maven version plugin generates `pom.xml` backup - for mvn version you can also use `-DgenerateBackupPoms=false`)
 
 ```
 ### Valhalla ###
diff --git a/test/extends/resolver_test.py b/test/extends/resolver_test.py
new file mode 100644
index 0000000..72430dd
--- /dev/null
+++ b/test/extends/resolver_test.py
@@ -0,0 +1,42 @@
+import os
+import unittest
+from unittest.mock import patch
+
+from valhalla.common.resolver import resolve, init_str_resolver, init_str_resolver_custom_variables
+
+
+class TestStringResolver(unittest.TestCase):
+
+    def test_resolve_predefined(self):
+        # given:
+        init_str_resolver("1.0", "token123")
+        init_str_resolver_custom_variables({"CUSTOM_VAR": "value123"})
+
+        # when:
+        resolved_string = resolve("Testing {VERSION}")
+
+        # then:
+        self.assertEqual("Testing 1.0", resolved_string)
+
+    def test_resolve_custom_variables(self):
+        # given:
+        init_str_resolver("1.0", "token123")
+        init_str_resolver_custom_variables({"CUSTOM_VAR": "value123"})
+
+        # when:
+        resolved_string = resolve("Testing {CUSTOM_VAR}")
+
+        # then:
+        self.assertEqual("Testing value123", resolved_string)
+
+    @patch.dict(os.environ, {"ENV_VAR": "env_value123"})
+    def test_resolve_from_env(self):
+        # given:
+        init_str_resolver("1.0", "token123")
+        init_str_resolver_custom_variables({"CUSTOM_VAR": "value123"})
+
+        # when:
+        resolved_string = resolve("Testing {ENV_VAR}")
+
+        # then:
+        self.assertEqual("Testing env_value123", resolved_string)
diff --git a/valhalla/common/resolver.py b/valhalla/common/resolver.py
index a11bed7..84fd310 100644
--- a/valhalla/common/resolver.py
+++ b/valhalla/common/resolver.py
@@ -1,3 +1,5 @@
+import os
+
 from valhalla.common.logger import info, error
 
 VERSION = "not_set"
@@ -21,20 +23,40 @@ def init_str_resolver_custom_variables(variables: dict):
 
 
 def resolve(string: str):
-    global VERSION
-    global VALHALLA_TOKEN
-    global CUSTOM_VARIABLES_DICT
-
     if VERSION == "not_set":
         error("There was no init_str_resolver(...) call in the code, so resolving strings does not work!")
         error("There is bug in valhalla! Please report it here: https://github.com/logchange/valhalla/issues")
         exit(1)
 
+    string = __resolve_predefined(string)
+    string = __resolve_custom_variables(string)
+    string = __resolve_from_env(string)
+
+    info("String resolving output: " + string)
+    return string
+
+
+def __resolve_predefined(string: str):
+    global VERSION
+    global VALHALLA_TOKEN
+
     string = string.replace("{VERSION}", VERSION)
     string = string.replace("{VALHALLA_TOKEN}", VALHALLA_TOKEN)
 
+    return string
+
+
+def __resolve_custom_variables(string: str):
+    global CUSTOM_VARIABLES_DICT
+
     for key, value in CUSTOM_VARIABLES_DICT.items():
         string = string.replace("{" + key + "}", value)
 
-    info("String resolving output: " + string)
+    return string
+
+
+def __resolve_from_env(string: str):
+    # Iterating over each environment variable
+    for env_var in os.environ:
+        string = string.replace('{' + env_var + '}', os.environ.get(env_var, ''))
     return string