diff --git a/.gitignore b/.gitignore
index 35eb97f..79fdf95 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,6 @@ inventories/*
 !inventories/.gitkeep
 site.yml
 vapid-private-key.pem
+
+library/__pycache__/
+library/*.pyc
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 0000000..86c1774
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,13 @@
+---
+image: python:3.7.6-slim-buster
+
+stages:
+- test
+
+test:
+  stage: test
+  before_script:
+  - apt-get update && apt-get install make
+  - pip install ansible==2.9.6
+  script:
+  - make test_modules_unit
diff --git a/Makefile b/Makefile
index 73a27b1..b0abff3 100644
--- a/Makefile
+++ b/Makefile
@@ -24,3 +24,6 @@ vapid_private_key: $(VAPID_PRIVATE_KEY_FILE)
 vapid_public_key: $(VAPID_PRIVATE_KEY_FILE)
 	@echo -e "\n\nVapid public key:"
 	@openssl ec -in $(VAPID_PRIVATE_KEY_FILE) -pubout -outform DER 2> /dev/null | tail -c 65 | base64 | tr '/+' '_-' | tr -d '=' | tr -d '\n'
+
+test_modules_unit:
+	@find ./library -mindepth 1 -maxdepth 1 -type f -name test_*.py | xargs python3
diff --git a/library/compare_semantic_versions.py b/library/compare_semantic_versions.py
new file mode 100644
index 0000000..39a4413
--- /dev/null
+++ b/library/compare_semantic_versions.py
@@ -0,0 +1,162 @@
+#!/usr/bin/python3
+# -*- coding: utf-8 -*-
+
+# Copyright: (c) 2020, Daniel Anglin <d.n.i.anglin@gmail.com>
+# The MIT License (see LICENSE or https://mit-license.org)
+
+ANSIBLE_METADATA = {
+  'metadata_version': '1.1',
+  'supported_by': 'community',
+  'status': ['preview']
+}
+
+DOCUMENTATION = '''
+---
+module: compare_semantic_versions
+
+short_description: Compares two semantic version values.
+
+description:
+- This module compares two semantic versions and outputs whether the change is an upgrade, a downgrade or no change.
+- The values must use valid semantic versioning in order for a successful comparison.
+
+version_added: "2.9.5"
+
+author: Daniel Anglin (@dananglin)
+
+options:
+  new_version:
+    description:
+    - The semantic version of the new software.
+    required: true
+    type: string
+  old_version:
+    description:
+    - The semantic version of the old software.
+    required: true
+    type: string
+'''
+
+EXAMPLES = '''
+- name: Simple comparison between two semantic versions.
+  compare_semantic_versions:
+    old_version: "1.7.10"
+    new_version: "1.8.0"
+  register: output1
+
+- debug:
+    msg: "{{ output1.result }}"
+
+- name: Semantic versions with the 'v' prefix are supported.
+  compare_semantic_versions:
+    old_version: "1.6.7"
+    new_version: "v3.5.9"
+  register: output2
+
+- debug:
+    msg: "{{ output2.result }}"
+
+- name: Semantic versions without minor and/or patch versions are supported.
+  compare_semantic_versions:
+    old_version: "v1.100.3"
+    new_version: "v2"
+  register: output3
+
+- debug:
+    msg: "{{ output3.result }}"
+'''
+
+RETURN = '''
+result:
+  description:
+  - The result of the comparison between the two semantic versions.
+  - The value "upgrade" is returned if the new version is higher than the old version.
+  - The value "downgrade" is returned if the new version is lower than the old version.
+  - The value "noVersionChange" is returned if the new version equals the old version.
+  returned: On success
+  type: string
+  sample: upgrade
+'''
+
+from ansible.module_utils.basic import AnsibleModule
+
+UPGRADE = "upgrade"
+DOWNGRADE = "downgrade"
+NO_VERSION_CHANGE = "noVersionChange"
+MAJOR = "major"
+MINOR = "minor"
+PATCH = "patch"
+MAX_VERSION_COMPONENTS = 3
+
+def process(semVer):
+    if semVer.startswith('v'):
+        semVer = semVer[1:]
+
+    semVerArr = semVer.split(".")
+
+    if len(semVerArr) > MAX_VERSION_COMPONENTS:
+        raise ValueError("invalid number of version components in semantic version '{}'.".format(semVer))
+
+    if len(semVerArr) < MAX_VERSION_COMPONENTS:
+        diff = MAX_VERSION_COMPONENTS - len(semVerArr)
+        for i in range(diff):
+            semVerArr.append('0')
+
+    try:
+        semVerMap = {
+                MAJOR: int(semVerArr[0]),
+                MINOR: int(semVerArr[1]),
+                PATCH: int(semVerArr[2])
+        }
+    except ValueError as e:
+        raise ValueError("unable to parse an int for semantic version '{}' due to invalid format. ({})".format(semVer, str(e)))
+
+    return semVerMap
+
+def compare_versions(old, new):
+    try:
+        oldSemVerMap = process(old)
+        newSemVerMap = process(new)
+    except:
+        raise
+
+    versions = [MAJOR, MINOR, PATCH]
+
+    for v in range(len(versions)):
+        if newSemVerMap[versions[v]] > oldSemVerMap[versions[v]]:
+            return UPGRADE
+        elif newSemVerMap[versions[v]] < oldSemVerMap[versions[v]]:
+            return DOWNGRADE
+
+    return NO_VERSION_CHANGE
+
+def run_module():
+    module_args = dict(
+        new_version = dict(type='str', required=True),
+        old_version = dict(type='str', required=True)
+    )
+
+    module = AnsibleModule(
+        argument_spec=module_args,
+        supports_check_mode=True
+    )
+
+    output = dict(
+        changed=False,
+        result=''
+    )
+
+    try:
+        result = compare_versions(module.params['old_version'], module.params['new_version'])
+    except ValueError as e:
+        module.fail_json(msg="Unable to compare semantic versions: {}".format(str(e)), **output)
+
+    output['result'] = result
+
+    module.exit_json(**output)
+
+def main():
+    run_module()
+
+if __name__ == '__main__':
+    main()
diff --git a/library/test_compare_semantic_versions.py b/library/test_compare_semantic_versions.py
new file mode 100644
index 0000000..8fda93a
--- /dev/null
+++ b/library/test_compare_semantic_versions.py
@@ -0,0 +1,33 @@
+#!/usr/bin/python3
+# -*- coding: utf-8 -*-
+
+# Copyright: (c) 2020, Daniel Anglin <d.n.i.anglin@gmail.com>
+# The MIT License (see LICENSE or https://mit-license.org)
+
+import unittest as u
+import compare_semantic_versions as c
+
+class TestCompareSemanticVersions(u.TestCase):
+    def test_compare_versions_results(self):
+        self.assertEqual(c.compare_versions("2.3.0", "3.0.0"), c.UPGRADE)
+        self.assertEqual(c.compare_versions("2.4.0", "2.3.0"), c.DOWNGRADE)
+        self.assertEqual(c.compare_versions("1.2.2", "1.2.3"), c.UPGRADE)
+        self.assertEqual(c.compare_versions("v2", "2.0.0"), c.NO_VERSION_CHANGE)
+        self.assertEqual(c.compare_versions("1.4.0", "v1.4"), c.NO_VERSION_CHANGE)
+        self.assertEqual(c.compare_versions("12.24.1", "v12.25.6"), c.UPGRADE)
+
+    def test_compare_versions_exceptions(self):
+        with self.assertRaises(ValueError) as ctx:
+            c.compare_versions("1.2.3.4", "1.2.3")
+        self.assertEqual("invalid number of version components in semantic version '1.2.3.4'.", str(ctx.exception))
+
+        with self.assertRaises(ValueError) as ctx:
+            c.compare_versions("10.3.1", "11..3")
+        self.assertRegex(str(ctx.exception), r'^unable to parse an int for semantic version \'11..3\' due to invalid format\..*$')
+
+        with self.assertRaises(ValueError) as ctx:
+            c.compare_versions("10.FOUR.8", "10.4.8")
+        self.assertRegex(str(ctx.exception), r'^unable to parse an int for semantic version \'10.FOUR.8\' due to invalid format\..*$')
+
+if __name__ == '__main__':
+    u.main()
diff --git a/roles/pleroma-main/tasks/main.yml b/roles/pleroma-main/tasks/main.yml
index ac13200..ce27373 100644
--- a/roles/pleroma-main/tasks/main.yml
+++ b/roles/pleroma-main/tasks/main.yml
@@ -37,10 +37,37 @@
   - "{{ pleroma_static_dir }}/static"
   - "{{ pleroma_static_dir }}/static/themes"
 
-- name: Ensuring that the release build of pleroma is downloaded.
+- name: Checking if Pleroma is already installed.
+  stat:
+    path: "{{ pleroma_user.home }}/bin/pleroma"
+  register: pleroma_bin
+
+- debug:
+    msg: "Pleroma is currently installed."
+    verbosity: 0
+  when: pleroma_bin.stat.isreg is defined
+
+- debug:
+    msg: "Pleroma does not appear to be installed. It will be downloaded and installed."
+    verbosity: 0
+  when: pleroma_bin.stat.isreg is not defined
+
+- name: Registering the 'enable_pleroma_download' flag.
+  set_fact:
+    enable_pleroma_download: true
+  when: (pleroma_bin.stat.isreg is not defined) or
+        (enable_pleroma_upgrade | default(False))
+
+- name: Registering the 'enable_pleroma_installation' flag.
+  set_fact:
+    enable_pleroma_installation: true
+  when: pleroma_bin.stat.isreg is not defined
+
+- name: Ensuring that the stable release build of pleroma is downloaded.
   get_url:
     url: "{{ pleroma_download_url }}"
     dest: "{{ pleroma_download_dest }}"
+  when: enable_pleroma_download | default(False)
 
 - name: Unzipping the release build of pleroma.
   unarchive:
@@ -49,12 +76,71 @@
     dest: /tmp
     owner: "{{ pleroma_user.name }}"
     group: "{{ pleroma_user.group }}"
+  when: enable_pleroma_download | default(False)
+
+- name: Registering the installed version of Pleroma.
+  shell: "{{ pleroma_user.home }}/bin/pleroma version | awk '{print $2}'"
+  register: pleroma_installed_version
+  when: enable_pleroma_upgrade | default(False)
+
+- debug:
+    msg: "Version {{ pleroma_installed_version.stdout }} is installed."
+    verbosity: 0
+  when: enable_pleroma_upgrade | default(False)
+
+- name: Registering the downloaded version of Pleroma.
+  shell: /tmp/release/bin/pleroma version | awk '{print $2}'
+  register: pleroma_downloaded_version
+  when: enable_pleroma_upgrade | default(False)
+
+- debug:
+    msg: "Version {{ pleroma_downloaded_version.stdout }} is downloaded."
+    verbosity: 0
+  when: enable_pleroma_upgrade | default(False)
+
+- name: Comparing the installed and downloaded versions of Pleroma.
+  compare_semantic_versions:
+    old_version: "{{ pleroma_installed_version.stdout }}"
+    new_version: "{{ pleroma_downloaded_version.stdout }}"
+  register: comparison
+  when: enable_pleroma_upgrade | default(False)
+
+- fail:
+    msg: "This playbook does not currently support downgrading Pleroma."
+  when: comparison.result is defined and comparison.result == "downgrade"
+
+- debug:
+    msg: "Pleroma is already installed at the target version {{ pleroma_downloaded_version.stdout }}."
+    verbosity: 0
+  when: comparison.result is defined and comparison.result == "noVersionChange"
+
+- debug:
+    msg: "Pleroma will be upgraded to version {{ pleroma_downloaded_version.stdout }}."
+    verbosity: 0
+  when: comparison.result is defined and comparison.result == "upgrade"
+
+- name: Registering the 'enable_pleroma_installation' flag for the upgrade.
+  set_fact:
+    enable_pleroma_installation: true
+  when: comparison.result is defined and comparison.result == "upgrade"
+
+- name: Ensuring that the Pleroma service is stopped.
+  service:
+    name: pleroma
+    state: stopped
+  when: comparison.result is defined and comparison.result == "upgrade"
+
+- name: Ensuring that the previous version of Pleroma is uninstalled.
+  shell: |
+    find {{ pleroma_user.home }} -mindepth 1 -maxdepth 1 | xargs -I dir rm -rf dir
+  when: comparison.result is defined and comparison.result == "upgrade"
 
 - name: Ensuring that Pleroma is installed.
   shell: |
     find /tmp/release/ -mindepth 1 -maxdepth 1 | xargs -I dir mv dir {{ pleroma_user.home }}
   args:
     creates: "{{ pleroma_user.home }}/bin/pleroma"
+  when: enable_pleroma_installation is defined
 
 - name: Ensuring the configuration file is set.
   template:
@@ -71,6 +157,7 @@
     - migrate
   environment:
     PATH: "{{ ansible_env.PATH }}:/opt/pleroma/bin"
+  when: enable_pleroma_installation is defined
 
 - name: Ensuring that folder permissions are set properly in /opt/pleroma.
   shell: |
@@ -103,7 +190,7 @@
     group: "{{ pleroma_user.group }}"
     mode: '0400'
 
-- name: Setting up the Pleroma service.
+- name: Ensuring that the pleroma init file is installed.
   copy:
     src: "{{ pleroma_user.home }}/installation/init.d/pleroma"
     dest: /etc/init.d/pleroma
@@ -116,7 +203,7 @@
   service:
     name: pleroma
     enabled: yes
-    state: restarted
+    state: started
 
 - name: Cleaning up
   file: