Install GeoServer on cloud server with Ubuntu 20.04

deploy-geoserver

# Install GeoServer on cloud server
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## 1. Install Java JDK

    apt install openjdk-11-jdk
    
You can check the installation using `$ java -version`. Now you can see something like this:

    openjdk version "11.0.7" 2020-04-14
    OpenJDK Runtime Environment (build 11.0.7+10-post-Ubuntu-3ubuntu1)
    OpenJDK 64-Bit Server VM (build 11.0.7+10-post-Ubuntu-3ubuntu1, mixed mode, sharing)    
  
## 2. Install and configure Tomcat
### 2.1 Create the tomcat user and its folder

    useradd -m -U -d /opt/tomcat -s /bin/false tomcat
  
### 2.2 Download Tomcat

    wget http://mirror.nohup.it/apache/tomcat/tomcat-9/v9.0.37/bin/apache-tomcat-9.0.37.tar.gz -O apache-tomcat-9.0.37.tar.gz
  
Find the latest version of tomcat from the link belove ad use it
http://mirror.nohup.it/apache/tomcat/tomcat-9/

### 2.3 Uncompress the archive

    tar -xf apache-tomcat-9.0.37.tar.gz -C /opt/tomcat/

Then create a symbolik link to have more control on over versions and updates

    ln -s /opt/tomcat/apache-tomcat-9.0.37 /opt/tomcat/latest

### 2.4 Assign to tomcat's user the Tomcat folder and make executable the shell scripts

    chown -R tomcat: /opt/tomcat
    sh -c 'chmod +x /opt/tomcat/latest/bin/*.sh'
    
### 2.5 Setting up the automatic restart of the webserver
Open tomcat.service

    nano /etc/systemd/system/tomcat.service
    
Paste the text belove:

    [Unit]
    Description=Tomcat 9 servlet container
    After=network.target

    [Service]
    Type=forking

    User=tomcat
    Group=tomcat

    Environment="JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64"
    Environment="JAVA_OPTS=-Djava.security.egd=file:///dev/urandom -Djava.awt.headless=true"

    Environment="CATALINA_BASE=/opt/tomcat/latest"
    Environment="CATALINA_HOME=/opt/tomcat/latest"
    Environment="CATALINA_PID=/opt/tomcat/latest/temp/tomcat.pid"
    Environment="CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC"

    ExecStart=/opt/tomcat/latest/bin/startup.sh
    ExecStop=/opt/tomcat/latest/bin/shutdown.sh

    [Install]
    WantedBy=multi-user.target

Reload the services

    systemctl daemon-reload
    
Enable Tomcat

    systemctl enable --now tomcat
    
Check service status

    systemctl status tomcat
    
Now you are be able to stop, start and restart tomcat
    
    systemctl stop tomcat
    systemctl start tomcat
    systemctl restart tomcat
    
## 3. Configure Nginx Proxy for Tomcat
### 3.1 Install Nginx

    apt install nginx -y
    
### 3.2 Create a new virtual host configuration file for Tomcat

    nano /etc/nginx/sites-available/tomcat.conf
    
Add the following lines:

    server {
      listen 80;

      server_name    example.com www.example.com;
      access_log /var/log/nginx/tomcat-access.log;
      error_log /var/log/nginx/tomcat-error.log;

      location / {
            proxy_set_header X-Forwarded-Host $host;
            proxy_set_header X-Forwarded-Server $host;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_pass http://127.0.0.1:8080/;
      }
    }

Then enable virtual host file and restart Nginx

    ln -s /etc/nginx/sites-available/tomcat.conf /etc/nginx/sites-enabled/
    systemctl restart nginx

Now, you can access your Tomcat web interface using the URL http://example.com.

## 4. Install Geoserver
### 4.1. Download GeoServer

    mkdir Downloads 
    cd Downloads/
    wget http://sourceforge.net/projects/geoserver/files/GeoServer/2.17.1/geoserver-2.17.1-war.zip
    apt install unzip
    unzip geoserver-2.17.1-war.zip
    
### 4.2 Move GeoServer inside Tomcat

    mv geoserver.war /opt/tomcat/apache-tomcat-9.0.37/webapps
    
### 4.3 Restart Tomcat and access to GeoServer

    systemctl restart tomcat
    
You can log-in into GeoServer using the link belove: example.com/geoserver

Default access data:

user -> admin <br>
password -> geoserver

## 5. Allow CORS Origin

Edit `$CATALINA_HOME/conf/web.xml` adding this rows:

    <filter>
      <filter-name>CorsFilter</filter-name>
      <filter-class>org.apache.catalina.filters.CorsFilter</filter-class>
      <init-param>
        <param-name>cors.allowed.origins</param-name>
        <param-value>*</param-value>
      </init-param>
    </filter>
    <filter-mapping>
      <filter-name>CorsFilter</filter-name>
      <url-pattern>/*</url-pattern>
    </filter-mapping>

Save the file and restart tomcat.

## 6. Generate certificate for HTTPS [OPTIONAL]

If you want you can use https using a certificate. You can use the wizard of [*certbot*](https://certbot.eff.org/) to do this in a few steps.
At the end you must setup the [*CSRF Protection*](https://docs.geoserver.org/latest/en/user/security/webadmin/csrf.html)