By default, the Exhibitor HTTP service is open to any client that can reach port 8181 on a master node. This page describes a method for protecting the Exhibitor service from unauthorized access. Once enabled, HTTP clients must access Exhibitor through Admin Router; thus applying the Admin Router access control policy to the Exhibitor service.
The strategy for securing Exhibitor is mutual TLS authentication. In order to secure Exhibitor you must first create a unique root CA certificate. This CA certificate is used to sign various end entity certificates for the Admin Router and Exhibitor services. Creating a public key infrastructure that outputs PEM and Java KeyStore formatted artifacts is not a trivial task. To make this processes easier, a simple tool has been created for producing the necessary files.
Using the tool
Download the script from the GitHub release page and run it:
curl -LsO https://github.com/mesosphere/exhibitor-tls-artifacts-gen/releases/download/v0.4.0/exhibitor-tls-artifacts chmod +x exhibitor-tls-artifacts ./exhibitor-tls-artifacts --help
The expected output is shown below:
Usage: exhibitor-tls-artifacts [OPTIONS] [NODES]... Generates Admin Router and Exhibitor TLS artifacts. NODES should consist of a space separated list of master IP addresses. See /mesosphere/dcos/1.13/security/ent/tls-ssl/exhibitor/ Options: -d, --output-directory TEXT Directory to put artifacts in. This output_directory must not exist. --help Show this message and exit.
Generating the artifacts
To generate the TLS artifacts, run the tool with the master node IP addresses as positional arguments. Use the IP addresses found in the
master_list field of the DC/OS configuration file, config.yml. If this file is not available, running
/opt/mesosphere/bin/detect_ip on each master node will produce the correct address.
As an example, if your master nodes are
10.192.0.2, 10.192.0.3, 10.192.0.4, invoke the script using:
./exhibitor-tls-artifacts 10.192.0.2 10.192.0.3 10.192.0.4
The above command will create a directory called
artifacts (which must not exist prior to running the command) in the current directory. Under
artifacts you will find root-cert.pem and truststore.jks. These files contain the root CA certificate in PEM and java keystore format. The
artifacts directory will also contain 3 sub-directories,
10.192.0.4. Each containing the following files:
client-cert.pem client-key.pem clientstore.jks root-cert.pem serverstore.jks truststore.jks
These directories contain all necessary files for securing each Exhibitor node.
Installing the artifacts
Copy the contents of each node’s artifact directory to
/var/lib/dcos/exhibitor-tls-artifacts to the appropriate master.
scp -r artifacts/10.192.0.2 firstname.lastname@example.org:/var/lib/dcos/exhibitor-tls-artifacts scp -r artifacts/10.192.0.3 email@example.com:/var/lib/dcos/exhibitor-tls-artifacts scp -r artifacts/10.192.0.4 firstname.lastname@example.org:/var/lib/dcos/exhibitor-tls-artifacts
Restarting the services
Exhibitor and Master Admin Router must be restarted on all nodes. After all files have been copied, run the following commands on all master nodes.
systemctl restart dcos-exhibitor.service systemctl restart dcos-adminrouter.service
systemd unit scripts will detect the presence of the artifacts and set ownership and permissions accordingly.
Deploying a new cluster
Generate the artifacts and copy the files to the master servers before installing DC/OS.