Installing Redmine on Ubuntu 18.04

Redmine is a flexible project management web application written in Ruby on Rails. It is designed to help teams collaborate on projects, track issues, and manage tasks efficiently.

Here are the steps to install Redmine on Ubuntu 18.04:

1. Update the system packages:

   sudo apt update

2. Install the required dependencies:

   sudo apt install -y build-essential mariadb-server libmariadb-dev zlib1g-dev libxml2-dev libxslt1-dev imagemagick libmagickwand-dev libcurl4-openssl-dev libssl-dev libyaml-dev libffi-dev libgdbm-dev libreadline-dev libncurses5-dev libffi-dev libgdbm5 libgdbm-dev libsqlite3-dev

3. Install Ruby using rbenv:
   1. Install dependencies for rbenv:

      sudo apt install -y libssl-dev libreadline-dev zlib1g-dev

   2. Clone rbenv repository from GitHub and set it up:

      git clone https://github.com/rbenv/rbenv.git ~/.rbenv
      cd ~/.rbenv && src/configure && make -C src

   3. Add rbenv to the PATH:

      echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
      echo 'eval "$(rbenv init -)"' >> ~/.bashrc
      source ~/.bashrc

   4. Install the ruby-build plugin:

      git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build

   5. Install Ruby:

      rbenv install 2.6.5
      rbenv global 2.6.5

4. Install Bundler and Rails:

   gem install bundler
   gem install rails -v 5.2.4.3

5. Download and extract the latest stable version of Redmine:

   wget https://www.redmine.org/releases/redmine-4.1.1.tar.gz
   tar -xvf redmine-4.1.1.tar.gz

6. Move the extracted Redmine directory to /opt:

   sudo mv redmine-4.1.1 /opt/redmine

7. Create a database and database user for Redmine:

   sudo mysql
   CREATE DATABASE redmine CHARACTER SET utf8mb4;
   CREATE USER 'redmine'@'localhost' IDENTIFIED BY 'password';
   GRANT ALL PRIVILEGES ON redmine.* TO 'redmine'@'localhost';
   FLUSH PRIVILEGES;
   EXIT;

8. Copy the default configuration:

   cd /opt/redmine/config
   cp database.yml.example database.yml
   cp configuration.yml.example configuration.yml

9. Edit database configuration:

   nano database.yml

   Set the database adapter, database name, database username, and password as per your database configuration.

10. Install required gems:

    cd /opt/redmine
    bundle install --without development test

11. Run the database migration:

    bundle exec rake db:migrate

12. Generate a secret key for session management:

    bundle exec rake generate_secret_token

13. Precompile assets:

    RAILS_ENV=production bundle exec rake assets:precompile

14. Start a Redmine server:

    bundle exec rails server -e production

Redmine should now be accessible on http://localhost:3000. You can log in using the default administrator credentials (username: admin, password: admin) and start configuring your projects.