Teleport
Server Access Getting Started Guide
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- Version 16.x
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Teleport SSH Server Access Demo
Length: 06:45
You can protect a server with Teleport by running the Teleport SSH Service on the server and enrolling it in your Teleport cluster. Once the server has joined your cluster, the Teleport RBAC system enforces secure access to the server, and administrators can identify security threats using the Teleport audit log.
The Teleport SSH Service opens a reverse SSH tunnel to the Teleport Proxy Service, and SSH client traffic uses this tunnel to connect to a server. This setup is similar to the bastion pattern.
This guides shows you how to:
- Enroll a server in your Teleport cluster.
- SSH into a server using Teleport.
- Inspect server resources in the cluster using Teleport commands.
You can use Teleport to enable secure access to a Kubernetes node. To do so, modify your node's machine image to install and run the Teleport SSH Service as per the instructions in this guide. Do not run the SSH Service as a Kubernetes pod, as there is no guarantee that the SSH Service pod is running on a server that a user intends to access.
Prerequisites
-
A running Teleport cluster version 16.4.6 or above. If you want to get started with Teleport, sign up for a free trial or set up a demo environment.
-
The
tctl
admin tool andtsh
client tool.Visit Installation for instructions on downloading
tctl
andtsh
.
- One host running a Linux environment (such as Ubuntu 20.04, CentOS 8.0, or Debian 10). This will serve as a Teleport Node.
- To check that you can connect to your Teleport cluster, sign in with
tsh login
, then verify that you can runtctl
commands using your current credentials. For example:If you can connect to the cluster and run thetsh login --proxy=teleport.example.com --user=[email protected]tctl statusCluster teleport.example.com
Version 16.4.6
CA pin sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678
tctl status
command, you can use your current credentials to run subsequenttctl
commands from your workstation. If you host your own Teleport cluster, you can also runtctl
commands on the computer that hosts the Teleport Auth Service for full permissions.
When running Teleport in production, you should adhere to the following best practices to avoid security incidents:
- Avoid using
sudo
in production environments unless it's necessary. - Create new, non-root, users and use test instances for experimenting with Teleport.
- Run Teleport's services as a non-root user unless required. Only the SSH
Service requires root access. Note that you will need root permissions (or
the
CAP_NET_BIND_SERVICE
capability) to make Teleport listen on a port numbered <1024
(e.g.443
). - Follow the principle of least privilege. Don't give users
permissive roles when more a restrictive role will do.
For example, don't assign users the built-in
access,editor
roles, which give them permissions to access and edit all cluster resources. Instead, define roles with the minimum required permissions for each user and configure access requests to provide temporary elevated permissions. - When you enroll Teleport resources—for example, new databases or applications—you
should save the invitation token to a file.
If you enter the token directly on the command line, a malicious user could view
it by running the
history
command on a compromised system.
You should note that these practices aren't necessarily reflected in the examples used in documentation. Examples in the documentation are primarily intended for demonstration and for development environments.
Step 1/4. Install Teleport on your Linux host
-
Your Linux host will be a private resource. Open port 22 so you can initially access, configure, and provision your instance.
We'll configure and launch our instance, then demonstrate how to use the
tsh
tool and Teleport in SSH mode. -
On the host where you will run the Teleport SSH Service, follow the instructions for your environment to install Teleport.
Install Teleport on your Linux server:
-
Assign edition to one of the following, depending on your Teleport edition:
Edition Value Teleport Enterprise Cloud cloud
Teleport Enterprise (Self-Hosted) enterprise
Teleport Community Edition oss
-
Get the version of Teleport to install. If you have automatic agent updates enabled in your cluster, query the latest Teleport version that is compatible with the updater:
TELEPORT_DOMAIN=example.teleport.comTELEPORT_VERSION="$(curl https://$TELEPORT_DOMAIN/v1/webapi/automaticupgrades/channel/default/version | sed 's/v//')"Otherwise, get the version of your Teleport cluster:
TELEPORT_DOMAIN=example.teleport.comTELEPORT_VERSION="$(curl https://$TELEPORT_DOMAIN/v1/webapi/ping | jq -r '.server_version')" -
Install Teleport on your Linux server:
curl https://cdn.teleport.dev/install-v16.4.6.sh | bash -s ${TELEPORT_VERSION} editionThe installation script detects the package manager on your Linux server and uses it to install Teleport binaries. To customize your installation, learn about the Teleport package repositories in the installation guide.
Next, we'll create a join token so you can start the Teleport SSH Service and add it to your cluster.
-
Step 2/4. Add a server to the cluster
Create a join token
On your local workstation, create a join token so you can add the server to your Teleport cluster:
Let's save the token to a filetctl tokens add --type=node --format=text > token.file
--type=node
specifies that the Teleport process will act and join as an SSH
server.
> token.file
indicates that you'd like to save the output to a file name token.file
.
This helps to minimize the direct sharing of tokens even when they are dynamically generated.
Join your server to the cluster
On your server, save token.file
to an appropriate, secure, directory you have
the rights and access to read. Next, generate a configuration file enabling
Teleport's SSH Service.
Change tele.example.com
to the address of your Teleport Proxy Service. Assign
the --token
flag to the path where you saved token.file
.
Generate config
sudo teleport node configure \ --output=file:///etc/teleport.yaml \ --token=/path/to/token.file \ --proxy=tele.example.com:443
Change mytenant.teleport.sh
to your Teleport Cloud tenant address. Assign the
--token
flag to the path where you saved token.file
.
Generate config
sudo teleport node configure \ --output=file:///etc/teleport.yaml \ --token=/path/to/token.file \ --proxy=mytenant.teleport.sh:443
The teleport node configure
command above placed a configuration file at
/etc/teleport.yaml
. The last step is to start Teleport, pointing it at this
configuration:
Configure the Teleport SSH Service to start automatically when the host boots up by creating a systemd service for it. The instructions depend on how you installed the Teleport SSH Service.
On the host where you will run the Teleport SSH Service, enable and start Teleport:
sudo systemctl enable teleportsudo systemctl start teleport
On the host where you will run the Teleport SSH Service, create a systemd service configuration for Teleport, enable the Teleport service, and start Teleport:
sudo teleport install systemd -o /etc/systemd/system/teleport.servicesudo systemctl enable teleportsudo systemctl start teleport
You can check the status of the Teleport SSH Service with systemctl status teleport
and view its logs with journalctl -fu teleport
.
Access the Web UI
Run the following command to create a local user that can access the Teleport Web UI:
tctl users add myuser --roles=editor,access --logins=root,ubuntu,ec2-user
This will generate an initial login link where you can create a password and set
up multi-factor authentication for myuser
.
We've only given myuser
the roles editor
and access
according to the
Principle of Least Privilege.
You should now be able to view your server in the Teleport Web UI after
logging in as myuser
:
Step 3/4. SSH into the server
Now that we've got our cluster up and running, let's see how easy it is to connect to our server.
We can use tsh
to SSH into the cluster:
Log in to the cluster
On your local machine, log in to your cluster through tsh
, assigning the
--proxy
flag to the address of your Teleport Proxy Service:
Log in through tsh
tsh login --proxy=tele.example.com --user=myuser
On your local machine, log in to your cluster through tsh
, assigning the
--proxy
flag to the address of your Teleport Cloud tenant:
Log in through tsh
tsh login --proxy=mytenant.teleport.sh:443 --user=myuser
You'll be prompted to supply the password and second factor we set up previously.
myuser
will now see something similar to:
> Profile URL: https://tele.example.com:443
Logged in as: myuser
Cluster: tele.example.com
Roles: access, editor
Logins: root, ubuntu, ec2-user
Kubernetes: disabled
Valid until: 2021-04-30 06:39:13 -0500 CDT [valid for 12h0m0s]
Extensions: permit-agent-forwarding, permit-port-forwarding, permit-pty
In this example, myuser
is now logged into the tele.example.com
cluster
through Teleport SSH.
> Profile URL: https://mytenant.teleport.sh:443
Logged in as: myuser
Cluster: mytenant.teleport.sh
Roles: access, editor
Logins: root, ubuntu, ec2-user
Kubernetes: disabled
Valid until: 2021-04-30 06:39:13 -0500 CDT [valid for 12h0m0s]
Extensions: permit-agent-forwarding, permit-port-forwarding, permit-pty
In this example, myuser
is now logged into the mytenant.teleport.sh
cluster through Teleport SSH.
Display cluster resources
myuser
can now execute the following to find the cluster's server names,
which are used for establishing SSH connections:
Display cluster resources
tsh ls
In this example, the bastion host is located on the bottom line below:
Node Name Address Labels
---------------- -------------- --------------------------------------
ip-172-31-35-170 ⟵ Tunnel
ip-172-31-41-144 127.0.0.1:3022 env=example, hostname=ip-172-31-41-144
Connect to a server
myuser
can SSH into the bastion host server by running the following command locally:
Use tsh to ssh into a server
tsh ssh root@ip-172-31-41-144
Now, they can:
- Connect to other servers in the cluster by using the appropriate IP address in
the
tsh ssh
command. - Traverse the Linux file system.
- Execute desired commands.
All commands executed by myuser
are recorded and can be replayed in the
Teleport Web UI.
The tsh ssh
command allows users to do anything they could if they were to SSH
into a server using a third-party tool. Compare the two equivalent commands:
tsh ssh root@ip-172-31-41-144
To use the ssh
client generate a SSH configuration file and postfix
the cluster name after the node name.
tsh config > ssh_config_teleportssh -F ssh_config_teleport [email protected]
Step 4/4. Use tsh and the unified resource catalog to introspect the cluster
Now, myuser
has the ability to SSH into other servers within the cluster,
traverse the Linux file system, and execute commands.
- They have visibility into all resources within the cluster due to their defined and assigned roles.
- They can also quickly view any server or grouping of servers that have been assigned a particular label.
Display the unified resource catalog
Execute the following command within your bastion host console:
List servers
tctl nodes ls
This displays the unified resource catalog with all queried resources in one view:
Nodename UUID Address Labels
---------------- ------------------------------------ -------------- -------------------------------------
ip-172-31-35-170 4980899c-d260-414f-9aea-874feef71747
ip-172-31-41-144 f3d2a65f-3fa7-451d-b516-68d189ff9ae5 127.0.0.1:3022 env=example,hostname=ip-172-31-41-144
Note the "Labels" column on the farthest side. myuser
can query all
resources with a shared label using the command:
Query all servers with a label
tsh ls env=example
Customized labels can be defined in your teleport.yaml
configuration file or
during server creation.
This is a convenient feature that allows for more advanced queries. If an IP address changes, for example, an admin can quickly find the current server with that label since it remains unchanged.
Run commands on all servers with a label
myuser
can also execute commands on all servers that share a label, vastly
simplifying repeated operations. For example, the following command will execute
the ls
command on each server and display the results in your terminal:
Run the ls command on all servers with a label
tsh ssh root@env=example ls
Optional: Harden your server
We previously configured our Linux instance to leave port 22
open to easily
configure and install Teleport. Feel free to compare Teleport SSH to your usual
ssh
commands.
To harden your Teleport server:
- Close port
22
on your private Linux instance now that your Teleport server is configured and running. - For self-hosted deployments, optionally close port
22
on your Proxy Service host. - You'll be able to fully connect to the private instance and, for self-hosted
deployments, the Proxy Service host, using
tsh ssh
.
Conclusion
To recap, this guide described:
- How to set up and add an SSH server to a cluster.
- Connect to the cluster using
tsh
to manage and introspect resources.
Feel free to shut down, clean up, and delete your resources, or use them in further Getting Started exercises.
Next steps
- While this guide shows you how to create a local user in order to access a server, you can also enable Teleport users to authenticate through a single sign-on provider. Read the documentation to learn more.
- Learn more about Teleport
tsh
through the reference documentation. - For a complete list of ports used by Teleport, read the Networking Guide.
Resources
- Setting Up an SSH Bastion Host
- Announcing Teleport SSH Server
- How to SSH properly
- Consider whether OpenSSH or Teleport SSH is right for you.
- Labels