diff --git a/.env.example b/.env.example
index 3cc72910f..2fe0ecf11 100644
--- a/.env.example
+++ b/.env.example
@@ -1,5 +1,5 @@
 # Mysql
-MYSQL_ROOT_PASSWORD=toor
+MYSQL_ROOT_PASSWORD=root
 MYSQL_DATABASE=rmt
 MYSQL_USER=rmt
 MYSQL_PASSWORD=rmt
diff --git a/.github/workflows/lint-unit.yml b/.github/workflows/lint-unit.yml
index a7ac0ac8b..af293bcb2 100644
--- a/.github/workflows/lint-unit.yml
+++ b/.github/workflows/lint-unit.yml
@@ -28,8 +28,6 @@ jobs:
       # Only use 2 workers, gh actions seems to kill jobs when we use more
       max-parallel: 2
       matrix:
-        # we need to test the Ruby versions of the products we release RMT for,
-        # those are: SLE15 (2.5.8, 2.5.9)
         ruby-version: ['3.4.8']
 
     services:
@@ -76,7 +74,7 @@ jobs:
 
       - name: Prepare database
         run: |
-          bundle exec rails db:drop db:create db:migrate
+          bundle exec rails db:drop db:create db:schema:load
 
       - name: Run core tests
         run: |
diff --git a/.rubocop.yml b/.rubocop.yml
index 49bf40e2d..708b7df14 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -9,7 +9,7 @@ inherit_mode:
     - Exclude
 
 AllCops:
-  TargetRubyVersion: 2.5
+  TargetRubyVersion: 3.1
   SuggestExtensions: false
   NewCops: enable
   Exclude:
@@ -21,7 +21,10 @@ AllCops:
     - tmp/**/*
     - lib/locale/*
     - package/**/*
+    - ci/Dockerfile
 
+Style/HashSyntax:
+  EnforcedShorthandSyntax: never
 
 Style/TrailingUnderscoreVariable:
   Enabled: false
diff --git a/Dockerfile b/Dockerfile
index 243a46df6..8c9051ce4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,26 +1,22 @@
-FROM opensuse/leap:15.6
+FROM registry.opensuse.org/opensuse/leap:16.0
 
-RUN zypper --non-interactive install --no-recommends \
-        timezone wget gcc-c++ libffi-devel git-core zlib-devel \
-        libxml2-devel libxslt-devel cron libmariadb-devel mariadb-client sqlite3-devel \
-        vim ruby2.5 ruby2.5-devel ruby2.5-rubygem-bundler SUSEConnect jq bzip2 gzip && \
-    zypper --non-interactive install -t pattern devel_basis && \
-    update-alternatives --install /usr/bin/bundle bundle /usr/bin/bundle.ruby2.5 5 && \
-    update-alternatives --install /usr/bin/bundler bundler /usr/bin/bundler.ruby2.5 5
+RUN zypper --non-interactive install --no-recommends ruby3.4 ruby3.4-devel
+
+RUN zypper --non-interactive install libffi-devel libmysqlclient-devel libxml2-devel \
+                        libxslt-devel rpmbuild systemd gzip tar bzip2 nodejs sqlite-devel \
+                        make chrpath fdupes gcc libcurl-devel libyaml-devel
 
 WORKDIR /srv/www/rmt/
 
-COPY Gemfile* /srv/www/rmt/
+COPY Gemfile Gemfile.lock /srv/www/rmt/
 
-RUN bundle.ruby2.5 config build.nokogiri --use-system-libraries && \
-    bundle install
+RUN bundle install
 
 COPY . /srv/www/rmt/
 
-RUN mkdir /srv/www/rmt/public/repo 
+RUN mkdir /srv/www/rmt/public/repo
 
-RUN sed -i 's/#!\/usr\/bin\/env ruby/#!\/usr\/bin\/ruby.ruby2.5/g' /srv/www/rmt/bin/rmt-cli && \
-    ln -s /srv/www/rmt/bin/rmt-cli /usr/bin && \
+RUN ln -s /srv/www/rmt/bin/rmt-cli /usr/bin && \
     mkdir /var/lib/rmt/ && \
     groupadd -r nginx && \
     useradd -g nginx -s /bin/false -r -c "user for RMT" _rmt && \
diff --git a/Gemfile.lock b/Gemfile.lock
index 3a19908b8..04a18694c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -559,4 +559,4 @@ RUBY VERSION
    ruby 3.4.8p72
 
 BUNDLED WITH
-   2.6.3
+   2.6.7
diff --git a/ci/Dockerfile b/ci/Dockerfile
index 14e3319ef..97e10e025 100644
--- a/ci/Dockerfile
+++ b/ci/Dockerfile
@@ -1,15 +1,36 @@
-#!BuildTag: rmt-ci-container
+#!BuildTag: rmt-ci-container-ruby3.4
 #!UseOBSRepositories
-FROM opensuse/leap:15.5
+FROM opensuse/tumbleweed
 
-RUN zypper --non-interactive in make chrpath fdupes gcc libcurl-devel libffi-devel libmysqlclient-devel \
-                                libxml2-devel libxslt-devel nodejs sqlite-devel ruby2.5-rubygem-ronn    \
-                                rpmbuild systemd gzip tar bzip2 vim curl wget ruby2.5 ruby2.5-devel     \
-                                ruby2.5-rubygem-bundler
+RUN zypper --non-interactive install --no-recommends ruby3.4 ruby3.4-devel
 
-# Set default bundler to the required version. This way we can easily update ruby in case required
-RUN update-alternatives --install /usr/bin/bundle bundle /usr/bin/bundle.ruby2.5 5 && \
-    update-alternatives --install /usr/bin/bundler bundler /usr/bin/bundler.ruby2.5 5
+RUN zypper --non-interactive install libffi-devel libmysqlclient-devel libxml2-devel \
+                        libxslt-devel rpmbuild systemd gzip tar bzip2 nodejs sqlite-devel \
+                        make chrpath fdupes gcc libcurl-devel libyaml-devel
+
+RUN rm /usr/bin/ruby /usr/bin/gem
+
+RUN update-alternatives --install /usr/bin/gem gem /usr/bin/gem.ruby3.4 1
+RUN update-alternatives --install /usr/bin/gem gem /usr/bin/gem.ruby4.0 2
+RUN update-alternatives --install /usr/bin/ruby ruby /usr/bin/ruby.ruby3.4 1
+RUN update-alternatives --install /usr/bin/ruby ruby /usr/bin/ruby.ruby4.0 2
+
+RUN update-alternatives --set ruby /usr/bin/ruby.ruby3.4 && \
+    update-alternatives --set gem /usr/bin/gem.ruby3.4 && \
+    update-alternatives --set bundle /usr/bin/bundle.ruby.ruby3.4 && \
+    update-alternatives --set bundler /usr/bin/bundler.ruby.ruby3.4 && \
+    update-alternatives --set racc /usr/bin/racc.ruby.ruby3.4 && \
+    update-alternatives --set rake /usr/bin/rake.ruby.ruby3.4 && \
+    update-alternatives --set rbs /usr/bin/rbs.ruby.ruby3.4 && \
+    update-alternatives --set rdoc /usr/bin/rdoc.ruby.ruby3.4 && \
+    update-alternatives --set ri /usr/bin/ri.ruby.ruby3.4 && \
+    update-alternatives --set typeprof /usr/bin/typeprof.ruby.ruby3.4 && \
+    update-alternatives --set rdbg /usr/bin/rdbg.ruby.ruby3.4 && \
+    update-alternatives --set syntax_suggest /usr/bin/syntax_suggest.ruby.ruby3.4
+
+# HACK: Manually set default macros for ruby builds
+RUN sed -i -e 's/4\.[0-9]/3\.4/g' -e 's/4[0-9]/34/g' /usr/lib/rpm/macros.d/macros.suse-ruby4.0-default && \
+    cp /usr/lib/rpm/macros.d/macros.suse-ruby4.0-default /usr/lib/rpm/macros.d/macros.suse-ruby3.4-default
 
 RUN mkdir /usr/src/rmt-server
 WORKDIR /usr/src/rmt-server
diff --git a/ci/Dockerfile.ruby3 b/ci/Dockerfile.ruby3
deleted file mode 100644
index 97e10e025..000000000
--- a/ci/Dockerfile.ruby3
+++ /dev/null
@@ -1,36 +0,0 @@
-#!BuildTag: rmt-ci-container-ruby3.4
-#!UseOBSRepositories
-FROM opensuse/tumbleweed
-
-RUN zypper --non-interactive install --no-recommends ruby3.4 ruby3.4-devel
-
-RUN zypper --non-interactive install libffi-devel libmysqlclient-devel libxml2-devel \
-                        libxslt-devel rpmbuild systemd gzip tar bzip2 nodejs sqlite-devel \
-                        make chrpath fdupes gcc libcurl-devel libyaml-devel
-
-RUN rm /usr/bin/ruby /usr/bin/gem
-
-RUN update-alternatives --install /usr/bin/gem gem /usr/bin/gem.ruby3.4 1
-RUN update-alternatives --install /usr/bin/gem gem /usr/bin/gem.ruby4.0 2
-RUN update-alternatives --install /usr/bin/ruby ruby /usr/bin/ruby.ruby3.4 1
-RUN update-alternatives --install /usr/bin/ruby ruby /usr/bin/ruby.ruby4.0 2
-
-RUN update-alternatives --set ruby /usr/bin/ruby.ruby3.4 && \
-    update-alternatives --set gem /usr/bin/gem.ruby3.4 && \
-    update-alternatives --set bundle /usr/bin/bundle.ruby.ruby3.4 && \
-    update-alternatives --set bundler /usr/bin/bundler.ruby.ruby3.4 && \
-    update-alternatives --set racc /usr/bin/racc.ruby.ruby3.4 && \
-    update-alternatives --set rake /usr/bin/rake.ruby.ruby3.4 && \
-    update-alternatives --set rbs /usr/bin/rbs.ruby.ruby3.4 && \
-    update-alternatives --set rdoc /usr/bin/rdoc.ruby.ruby3.4 && \
-    update-alternatives --set ri /usr/bin/ri.ruby.ruby3.4 && \
-    update-alternatives --set typeprof /usr/bin/typeprof.ruby.ruby3.4 && \
-    update-alternatives --set rdbg /usr/bin/rdbg.ruby.ruby3.4 && \
-    update-alternatives --set syntax_suggest /usr/bin/syntax_suggest.ruby.ruby3.4
-
-# HACK: Manually set default macros for ruby builds
-RUN sed -i -e 's/4\.[0-9]/3\.4/g' -e 's/4[0-9]/34/g' /usr/lib/rpm/macros.d/macros.suse-ruby4.0-default && \
-    cp /usr/lib/rpm/macros.d/macros.suse-ruby4.0-default /usr/lib/rpm/macros.d/macros.suse-ruby3.4-default
-
-RUN mkdir /usr/src/rmt-server
-WORKDIR /usr/src/rmt-server
diff --git a/docker-compose.yml b/docker-compose.yml
index 912cb5299..6d295fe30 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,6 +1,6 @@
 services:
   db:
-    image: registry.suse.com/suse/mariadb:10.11
+    image: registry.suse.com/suse/mariadb:11.8
     restart: unless-stopped
     volumes:
       - mariadb:/var/lib/mysql
@@ -19,7 +19,7 @@ services:
     command: bundle exec rails runner /srv/www/rmt/bin/compose-init.rb
 
   nginx:
-    image: nginx:1.14
+    image: nginx:1.27.2
     volumes:
       - ./public:/var/www/
       - ./nginx/default.conf:/tmp/default.template
diff --git a/engines/scc_proxy/lib/scc_proxy/engine.rb b/engines/scc_proxy/lib/scc_proxy/engine.rb
index 510495c30..8f34edcaa 100644
--- a/engines/scc_proxy/lib/scc_proxy/engine.rb
+++ b/engines/scc_proxy/lib/scc_proxy/engine.rb
@@ -18,7 +18,7 @@
   Net::HTTPHeaderSyntaxError,
   Net::ProtocolError,
   Net::OpenTimeout,
-  Net::HTTPServerException,
+  Net::HTTPClientException,
   Net::HTTPFatalError,
   OpenSSL::SSL::SSLError,
   Errno::EHOSTUNREACH,
@@ -333,7 +333,7 @@ def status_code(error_message)
 
         def has_no_regcode?(auth_header)
           auth_header ||= '='
-          auth_header = auth_header[(auth_header.index('=') + 1)..-1]
+          auth_header = auth_header[(auth_header.index('=') + 1)..]
           auth_header.empty?
         end
       end
diff --git a/lib/rmt/mirror/debian.rb b/lib/rmt/mirror/debian.rb
index 51b48c5f7..81a355a72 100644
--- a/lib/rmt/mirror/debian.rb
+++ b/lib/rmt/mirror/debian.rb
@@ -5,8 +5,8 @@ class RMT::Mirror::Debian < RMT::Mirror::Base
   SIGNATURE_FILE_NAME = 'Release.gpg'.freeze
   KEY_FILE_NAME = 'Release.key'.freeze
   INRELEASE_FILE_NAME = 'InRelease'.freeze
-  NESTED_REPOSITORY_REGEX = %r{/dists/.*/$}.freeze
-  PACKAGE_INDEX_FILE_NAME = /Packages\.(gz|xz)/.freeze
+  NESTED_REPOSITORY_REGEX = %r{/dists/.*/$}
+  PACKAGE_INDEX_FILE_NAME = /Packages\.(gz|xz)/
 
 
   def mirror_implementation
diff --git a/spec/lib/rmt/file_validator_spec.rb b/spec/lib/rmt/file_validator_spec.rb
index 4fe6653a0..92219ed61 100644
--- a/spec/lib/rmt/file_validator_spec.rb
+++ b/spec/lib/rmt/file_validator_spec.rb
@@ -332,14 +332,14 @@ def initialize(deep_verify)
 
     shared_examples 'invalid files on disk' do
       it 'removes invalid files from the disk' do
-        previous_state = invalid_files.map { |f| [f[:file].local_path, true] }.to_h
-        expected_state = invalid_files.map { |f| [f[:file].local_path, false] }.to_h
+        previous_state = invalid_files.to_h { |f| [f[:file].local_path, true] }
+        expected_state = invalid_files.to_h { |f| [f[:file].local_path, false] }
 
         expect { find_valid_files_by_checksum }
           .to change {
-            invalid_files.map do |f|
+            invalid_files.to_h do |f|
               [f[:file].local_path, File.exist?(f[:file].local_path)]
-            end.to_h
+            end
           }.from(previous_state).to(expected_state)
       end
     end