Installing Rancher Server


Rancher is deployed as a set of Docker containers. Running Rancher is as simple as launching two containers. One container as the management server and another container on a node as an agent.

Note: You can get all help options for the Rancher server container by running docker run rancher/server --help.

Requirements

  • Any modern Linux distribution with a supported version of Docker. RancherOS, Ubuntu, RHEL/CentOS 7 are more heavily tested.
    • For RHEL/CentOS, the default storage driver, i.e. devicemapper using loopback, is not recommended by Docker. Please refer to the Docker documentation on how to change it.
  • 1GB RAM
  • MySQL server should have a max_connections setting > 150
    • MYSQL Configuration Requirements
      • Option 1: Run with Antelope with default of COMPACT
      • Option 2: Run MySQL 5.7 with Barracuda where the default ROW_FORMAT is Dynamic

Note: Currently, Docker for Mac is not supported in Rancher.

Rancher Server Tags

Rancher server has 2 different tags. For each major release tag, we will provide documentation for the specific version.

  • rancher/server:latest tag will be our latest development builds. These builds will have been validated through our CI automation framework. These releases are not meant for deployment in production.
  • rancher/server:stable tag will be our latest stable release builds. This tag is the version that we recommend for production.

Please do not use any release with a rc{n} suffix. These rc builds are meant for the Rancher team to test out builds.

Launching Rancher Server - Single Container (non-HA)

On the Linux machine with Docker installed, the command to start a single instance of Rancher is simple.

$ sudo docker run -d --restart=unless-stopped -p 8080:8080 rancher/server

Rancher UI

The UI and API will be available on the exposed port 8080. After the docker image is downloaded, it will take a minute or two before Rancher has successfully started and is available to view.

Navigate to the following URL: http://<SERVER_IP>:8080. The <SERVER_IP> is the public IP address of the host that is running Rancher server.

Once the UI is up and running, you can start by adding hosts or select a container orchestration from the Infrastructure catalog. By default, if a different container orchestration type is not selected, the environment will be using cattle. After the hosts are added into Rancher, you can start adding services or launch templates from the Rancher catalog.

Launching Rancher Server - Single Container - External Database

Instead of using the internal database that comes with Rancher server, you can start Rancher server pointing to an external database. The command would be the same, but appending in additional arguments to direct how to connect to your external database.

Note: Your database, name and user of the database will already need to be created, but no schemas will need to be created. Rancher will automatically create all the schemas related to Rancher.

Here is an example of a SQL command to create a database and users.

> CREATE DATABASE IF NOT EXISTS cattle COLLATE = 'utf8_general_ci' CHARACTER SET = 'utf8';
> GRANT ALL ON cattle.* TO 'cattle'@'%' IDENTIFIED BY 'cattle';
> GRANT ALL ON cattle.* TO 'cattle'@'localhost' IDENTIFIED BY 'cattle';

To start Rancher connecting to an external database, you pass in additional arguments as part of the command for the container.

$ sudo docker run -d --restart=unless-stopped -p 8080:8080 rancher/server \
    --db-host myhost.example.com --db-port 3306 --db-user username --db-pass password --db-name cattle

Most of the options to pass in also have default values and are not required. Only the location of the MySQL server is required.

--db-host               IP or hostname of MySQL server
--db-port               port of MySQL server (default: 3306)
--db-user               username for MySQL login (default: cattle)
--db-pass               password for MySQL login (default: cattle)
--db-name               MySQL database name to use (default: cattle)


Note: In previous versions of Rancher server, we had connected to an external database using environment variables, those environment variables will continue to work, but Rancher recommends using the arguments instead.

Launching Rancher Server - Single Container - Bind Mount MySQL Volume

If you would like to persist the database inside your container to a volume on your host, launch Rancher server by bind mounting the MySQL volume.

$ sudo docker run -d -v <host_vol>:/var/lib/mysql --restart=unless-stopped -p 8080:8080 rancher/server

With this command, the database will persist on the host. If you have an existing Rancher container and would like to bind mount the MySQL volume, the instructions are located in our upgrading documentation.

Launching Rancher Server - Full Active/Active HA

Running Rancher server in High Availability (HA) is as easy as running Rancher server using an external database, exposing an additional port, and adding in an additional argument to the command for the external load balancer.

Requirements for HA

  • HA Nodes:
    • Any modern Linux distribution with a supported version of Docker. RancherOS, Ubuntu, RHEL/CentOS 7 are more heavily tested.
    • For RHEL/CentOS, the default storage driver, i.e. devicemapper using loopback, is not recommended by Docker. Please refer to the Docker documentation on how to change it.
    • Port that needs to be opened between nodes: 9345
    • 1GB RAM
  • MySQL database
    • At least 1 GB RAM
    • 50 connections per Rancher server node (e.g. A 3 node setup will need to support at least 150 connections)
    • MYSQL Configuration Requirements
      • Option 1: Run with Antelope with default of COMPACT
      • Option 2: Run MySQL 5.7 with Barracuda where the default ROW_FORMAT is Dynamic
  • External Load Balancer
    • Port that needs to be opened between nodes and external load balancer: 8080

Note: Currently, Docker for Mac is not supported in Rancher.

Recommendations for Larger Deployments

  • Each Rancher server node should have a 4 GB or 8 GB heap size, which requires having at least 8 GB or 16 GB of RAM
  • MySQL database should have fast disks
  • For true HA, a replicated MySQL database with proper backups is recommended. Using Galera and forcing writes to a single node, due to transaction locks, would be an alternative.
  1. On each of your nodes that you want to add into the HA setup, run the following command:

    # Launch on each node in your HA cluster
    $ docker run -d --restart=unless-stopped -p 8080:8080 -p 9345:9345 rancher/server \
         --db-host myhost.example.com --db-port 3306 --db-user username --db-pass password --db-name cattle \
         --advertise-address <IP_of_the_Node>
    

    For each node, the <IP_of_the_Node> will be unique to each node, as it will be the IP of each specific node that is being added into the HA setup.

    If you change -p 8080:8080 to expose a different port, then you would also add --advertise-http-port to match the same port as part of the command.

    Note: You can get the help for the commands by running docker run rancher/server --help

  2. Configure an external load balancer that will balance traffic on ports 80 and 443 across a pool of nodes that will be running Rancher server and target the nodes on port 8080. Your load balancer must support websockets and forwarded-for headers, in order for Rancher to function properly. See SSL settings page for example configuration settings.

Notes on the Rancher Server Nodes in HA

If the IP of your Rancher server node changes, your node will no longer be part of the Rancher HA cluster. You must stop the old Rancher server container using the incorrect IP for --advertise-address and start a new Rancher server with the correct IP for --advertise-address.

Running Rancher Server Behind an Application Load Balancer (ALB) in AWS

We recommend using an Application Load Balancer (ALB) in AWS over using an Elastic Load Balancer (ELB). With an ALB, you will only need to direct the traffic to the advertised port (--advertise-http-port), which is by default 8080.

Running Rancher Server Behind an Elastic Load Balancer (ELB) in AWS

If you choose to use an ELB, you will need to enable proxy protocol mode. By default, ELB is enabled in HTTP/HTTPS mode, which does not support websockets. Since Rancher uses websockets, ELB must be configured specifically in order for Rancher’s websockets to work.

Configuration Requirements for Elastic Load Balancer (ELB)

$ aws elb create-load-balancer-policy --load-balancer-name <LB_NAME> --policy-name <POLICY_NAME> --policy-type-name ProxyProtocolPolicyType --policy-attributes AttributeName=ProxyProtocol,AttributeValue=true
$ aws elb set-load-balancer-policies-for-backend-server --load-balancer-name <LB_NAME> --instance-port 81 --policy-names <POLICY_NAME>
$ aws elb set-load-balancer-policies-for-backend-server --load-balancer-name <LB_NAME> --instance-port 444 --policy-names <POLICY_NAME>
$ aws elb set-load-balancer-policies-for-backend-server --load-balancer-name <LB_NAME> --instance-port 8080 --policy-names <POLICY_NAME>
  • Health check can be configured to use HTTP:8080 using /ping as your path.

Note: If you are using a self signed certificate, please read more about how to configure your ELB in AWS under our SSL section.

Enabling Active Directory or OpenLDAP for TLS

In order to enable Active Directory or OpenLDAP for Rancher server with TLS, the Rancher server container will need to be started with the LDAP certificate, provided by your LDAP setup. On the Linux machine that you want to launch Rancher server on, save the certificate.

Start Rancher by bind mounting the volume that has the certificate. The certificate must be called ca.crt inside the container.

$ sudo docker run -d --restart=unless-stopped -p 8080:8080 \
  -v /some/dir/cert.crt:/var/lib/rancher/etc/ssl/ca.crt rancher/server

You can check that the ca.crt was passed to Rancher server container successfully by checking the logs of the rancher server container.

$ docker logs <SERVER_CONTAINER_ID>

In the beginning of the logs, there will be confirmation that the certificate was added correctly.

Adding ca.crt to Certs.
Updating certificates in /etc/ssl/certs... 1 added, 0 removed; done.
Running hooks in /etc/ca-certificates/update.d....done.
Certificate was added to keystore

Launching Rancher Server behind an HTTP proxy

In order to set up an HTTP proxy, the Docker daemon will need to be modified to point to the proxy. Before starting Rancher server, edit the /etc/default/docker file to point to your proxy and restart Docker.

$ sudo vi /etc/default/docker

In the file, edit the #export http_proxy="http://127.0.0.1:3128/" to have it point to your proxy. Save your changes and then restart docker. Restarting Docker is different on every OS.

Note: If you are running Docker with systemd, please follow Docker’s instructions on how to configure the HTTP proxy.

In order for the Rancher catalog to load, the proxy will need to be configured and Rancher server will need to be launched with environment variables to pass in the proxy information.

$ sudo docker run -d \
    -e http_proxy=<proxyURL> \
    -e https_proxy=<proxyURL> \
    -e no_proxy="localhost,127.0.0.1" \
    -e NO_PROXY="localhost,127.0.0.1" \
    --restart=unless-stopped -p 8080:8080 rancher/server

If the Rancher catalog will not be used, run the Rancher server command as you normally would.

When adding hosts to Rancher, there is no additional requirements behind an HTTP proxy.