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Introduction
1 - What is Talos?
Talos is a container optimized Linux distro; a reimagining of Linux for distributed systems such as Kubernetes. Designed to be as minimal as possible while still maintaining practicality. For these reasons, Talos has a number of features unique to it:
- it is immutable
- it is atomic
- it is ephemeral
- it is minimal
- it is secure by default
- it is managed via a single declarative configuration file and gRPC API
Talos can be deployed on container, cloud, virtualized, and bare metal platforms.
Why Talos
In having less, Talos offers more. Security. Efficiency. Resiliency. Consistency.
All of these areas are improved simply by having less.
2 - Quickstart
The easiest way to try Talos is by using the CLI (talosctl
) to create a cluster on a machine with docker
installed.
Prerequisites
talosctl
Download talosctl
:
curl -Lo /usr/local/bin/talosctl https://github.com/talos-systems/talos/releases/latest/download/talosctl-$(uname -s | tr "[:upper:]" "[:lower:]")-amd64
chmod +x /usr/local/bin/talosctl
kubectl
Download kubectl
via one of methods outlined in the documentation.
Create the Cluster
Now run the following:
talosctl cluster create
Verify that you can reach Kubernetes:
$ kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
talos-default-master-1 Ready master 115s v1.20.2 10.5.0.2 <none> Talos (v0.11.0) <host kernel> containerd://1.4.3
talos-default-worker-1 Ready <none> 115s v1.20.2 10.5.0.3 <none> Talos (v0.11.0) <host kernel> containerd://1.4.3
Destroy the Cluster
When you are all done, remove the cluster:
talosctl cluster destroy
3 - Getting Started
This document will walk you through installing a full Talos Cluster. You may wish to read through the Quickstart first, to quickly create a local virtual cluster on your workstation.
Regardless of where you run Talos, you will find that there is a pattern to deploying it.
In general you will need to:
- acquire the installation image
- decide on the endpoint for Kubernetes
- optionally create a load balancer
- configure Talos
- configure
talosctl
- bootstrap Kubernetes
Prerequisites
talosctl
The talosctl
tool provides a CLI tool which interfaces with the Talos API in
an easy manner.
It also includes a number of useful tools for creating and managing your clusters.
You should install talosctl
before continuing:
curl -Lo /usr/local/bin/talosctl https://github.com/talos-systems/talos/releases/latest/download/talosctl-$(uname -s | tr "[:upper:]" "[:lower:]")-amd64
chmod +x /usr/local/bin/talosctl
Acquire the installation image
The easiest way to install Talos is to use the ISO image.
The latest ISO image can be found on the Github Releases page:
- X86: https://github.com/siderolabs/talos/releases/download/v0.11.0/talos-amd64.iso
- ARM64: https://github.com/siderolabs/talos/releases/download/v0.11.0/talos-arm64.iso
For self-built media and network booting, you can use the kernel and initramfs:
- X86: https://github.com/siderolabs/talos/releases/download/v0.11.0/boot-amd64.tar.gz
- ARM64: https://github.com/siderolabs/talos/releases/download/v0.11.0/boot-ard64.tar.gz
When booted from the ISO, Talos will run in RAM, and it will not install itself until it is provided a configuration. Thus, it is safe to boot the ISO onto any machine.
Alternative Booting
If you wish to use a different boot mechanism (such as network boot or a custom ISO), there are a number of required kernel parameters.
Please see the kernel docs for more information.
Decide the Kubernetes Endpoint
In order to configure Kubernetes and bootstrap the cluster, Talos needs to know what the endpoint (DNS name or IP address) of the Kubernetes API Server will be.
The endpoint should be the fully-qualified HTTP(S) URL for the Kubernetes API Server, which (by default) runs on port 6443 using HTTPS.
Thus, the format of the endpoint may be something like:
https://192.168.0.10:6443
https://kube.mycluster.mydomain.com:6443
https://[2001:db8:1234::80]:6443
Because the Kubernetes controlplane is meant to be supplied in a high availability manner, we must also choose how to bind it to the servers themselves. There are three common ways to do this.
Dedicated Load-balancer
If you are using a cloud provider or have your own load-balancer available (such as HAProxy, nginx reverse proxy, or an F5 load-balancer), using a dedicated load balancer is a natural choice. Just create an appropriate frontend matching the endpoint, and point the backends at each of the addresses of the Talos controlplane nodes.
This is convenient if a load-balancer is available, but don’t worry if that is not the case.
Layer 2 Shared IP
Talos has integrated support for serving Kubernetes from a shared (sometimes called “virtual”) IP address. This method relies on OSI Layer 2 connectivity between controlplane Talos nodes.
In this case, we may choose an IP address on the same subnet as the Talos controlplane nodes which is not otherwise assigned to any machine. For instance, if your controlplane node IPs are:
- 192.168.0.10
- 192.168.0.11
- 192.168.0.12
You could choose the ip 192.168.0.15
as your shared IP address.
Just make sure that 192.168.0.15
is not used by any other machine and that your DHCP
will not serve it to any other machine.
Once chosen, form the full HTTPS URL from this IP:
https://192.168.0.15:6443
You are also free to set a DNS record to this IP address instead, but you will
still need to use the IP address to set up the shared IP
(machine.network.interfaces[].vip.ip
) inside the Talos
configuration.
For more information about using a shared IP, see the related Guide
DNS records
If neither of the other methods work for you, you can instead use DNS records to provide a measure of redundancy. In this case, you would add multiple A or AAAA records for a DNS name.
For instance, you could add:
kube.cluster1.mydomain.com IN A 192.168.0.10
kube.cluster1.mydomain.com IN A 192.168.0.11
kube.cluster1.mydomain.com IN A 192.168.0.12
Then, your endpoint would be:
https://kube.cluster1.mydomain.com:6443
Decide how to access the Talos API
Since Talos is entirely API-driven, it is important to know how you are going to access that API. Talos comes with a number of mechanisms to make that easier.
Controlplane nodes can proxy requests for worker nodes. This means that you only need access to the controlplane nodes in order to access the rest of the network. This is useful for security (your worker nodes do not need to have public IPs or be otherwise connected to the Internet), and it also makes working with highly-variable clusters easier, since you only need to know the controlplane nodes in advance.
Even better, the talosctl
tool will automatically load balance and fail over
between all of your controlplane nodes, so long as it is informed of each of the
controlplane node IPs.
That does, of course, present the problem that you need to know how to talk to the controlplane nodes. In some environments, it is easy to be able to forecast, prescribe, or discover the controlplane node IP addresses. For others, though, even the controlplane nodes are dynamic, unpredictable, and undiscoverable.
The dynamic options above for the Kubernetes API endpoint also apply to the
Talos API endpoints.
The difference is that the Talos API runs on port 50000/tcp
.
Whichever way you wish to access the Talos API, be sure to note the IP(s) or
hostname(s) so that you can configure your talosctl
tool’s endpoints
below.
Configure Talos
When Talos boots without a configuration, such as when using the Talos ISO, it enters a limited maintenance mode and waits for a configuration to be provided.
Alternatively, the Talos installer can be booted with the talos.config
kernel
commandline argument set to an HTTP(s) URL from which it should receive its
configuration.
In cases where a PXE server can be available, this is much more efficient than
manually configuring each node.
If you do use this method, just note that Talos does require a number of other
kernel commandline parameters.
See the required kernel parameters for more information.
In either case, we need to generate the configuration which is to be provided.
Luckily, the talosctl
tool comes with a configuration generator for exactly
this purpose.
talosctl gen config "cluster-name" "cluster-endpoint"
Here, cluster-name
is an arbitrary name for the cluster which will be used
in your local client configuration as a label.
It does not affect anything in the cluster itself.
It is arbitrary, but it should be unique in the configuration on your local workstation.
The cluster-endpoint
is where you insert the Kubernetes Endpoint you
selected from above.
This is the Kubernetes API URL, and it should be a complete URL, with https://
and port, if not 443
.
The default port is 6443
, so the port is almost always required.
When you run this command, you will receive a number of files in your current directory:
controlplane.yaml
join.yaml
talosconfig
The three .yaml
files are what we call Machine Configs.
They are installed onto the Talos servers to act as their complete configuration,
describing everything from what disk Talos should be installed to, to what
sysctls to set, to what network settings it should have.
In the case of the controlplane.yaml
, it even describes how Talos should form its Kubernetes cluster.
The talosconfig
file (which is also YAML) is your local client configuration
file.
Controlplane, Init, and Join
The three types of Machine Configs correspond to the three roles of Talos nodes. For our purposes, you can ignore the Init type. It is a legacy type which will go away eventually. Its purpose was to self-bootstrap. Instead, we now use an API call to bootstrap the cluster, which is much more robust.
That leaves us with Controlplane and Join.
The Controlplane Machine Config describes the configuration of a Talos server on which the Kubernetes Controlplane should run. The Join Machine Config describes everything else: workload servers.
The main difference between Controlplane Machine Config files and Join Machine Config files is that the former contains information about how to form the Kubernetes cluster.
Templates
The generated files can be thought of as templates.
Individual machines may need specific settings (for instance, each may have a
different static IP address).
When different files are needed for machines of the same type, simply
copy the source template (controlplane.yaml
or join.yaml
) and make whatever
modifications need to be done.
For instance, if you had three controlplane nodes and three worker nodes, you may do something like this:
for i in $(seq 0 2); do
cp controlplane.yaml cp$i.yaml
end
for i in $(seq 0 2); do
cp join.yaml w$i.yaml
end
In cases where there is no special configuration needed, you may use the same file for each machine of the same type.
Apply Configuration
After you have generated each machine’s Machine Config, you need to load them into the mahines themselves. For that, you need to know their IP addresses.
If you have access to the console or console logs of the machines, you can read them to find the IP address(es). Talos will print them out during the boot process:
[ 4.605369] [talos] task loadConfig (1/1): this machine is reachable at:
[ 4.607358] [talos] task loadConfig (1/1): 192.168.0.2
[ 4.608766] [talos] task loadConfig (1/1): server certificate fingerprint:
[ 4.611106] [talos] task loadConfig (1/1): xA9a1t2dMxB0NJ0qH1pDzilWbA3+DK/DjVbFaJBYheE=
[ 4.613822] [talos] task loadConfig (1/1):
[ 4.614985] [talos] task loadConfig (1/1): upload configuration using talosctl:
[ 4.616978] [talos] task loadConfig (1/1): talosctl apply-config --insecure --nodes 192.168.0.2 --file <config.yaml>
[ 4.620168] [talos] task loadConfig (1/1): or apply configuration using talosctl interactive installer:
[ 4.623046] [talos] task loadConfig (1/1): talosctl apply-config --insecure --nodes 192.168.0.2 --interactive
[ 4.626365] [talos] task loadConfig (1/1): optionally with node fingerprint check:
[ 4.628692] [talos] task loadConfig (1/1): talosctl apply-config --insecure --nodes 192.168.0.2 --cert-fingerprint 'xA9a1t2dMxB0NJ0qH1pDzilWbA3+DK/DjVbFaJBYheE=' --file <config.yaml>
If you do not have console access, the IP address may also be discoverable from your DHCP server.
Once you have the IP address, you can then apply the correct configuration.
talosctl apply-config --insecure \
--nodes 192.168.0.2 \
--file cp0.yaml
The insecure flag is necessary at this point because the PKI infrastructure has not yet been made available to the node. Note that the connection will be encrypted, it is just unauthenticated.
If you have console access, though, you can extract the server certificate fingerprint and use it for an additional layer of validation:
talosctl apply-config --insecure \
--nodes 192.168.0.2 \
--cert-fingerprint xA9a1t2dMxB0NJ0qH1pDzilWbA3+DK/DjVbFaJBYheE= \
--file cp0.yaml
Using the fingerprint allows you to be sure you are sending the configuration to the right machine, but it is completely optional.
After the configuration is applied to a node, it will reboot.
You may repeat this process for each of the nodes in your cluster.
Configure your talosctl client
Now that the nodes are running Talos with its full PKI security suite, you need
to use that PKI to talk to the machines.
That means configuring your client, and that is what that talosconfig
file is for.
Endpoints
Endpoints are the communication endpoints to which the client directly talks. These can be load balancers, DNS hostnames, a list of IPs, etc. In general, it is recommended that these point to the set of control plane nodes, either directly or through a reverse proxy or load balancer.
Each endpoint will automatically proxy requests destined to another node through it, so it is not necessary to change the endpoint configuration just because you wish to talk to a different node within the cluster.
Endpoints do, however, need to be members of the same Talos cluster as the target node, because these proxied connections reply on certificate-based authentication.
We need to set the endpoints
in your talosconfig
.
talosctl
will automatically load balance and fail over among the endpoints,
so no external load balancer or DNS abstraction is required
(though you are free to use them, if desired).
As an example, if the IP addresses of our controlplane nodes are:
- 192.168.0.2
- 192.168.0.3
- 192.168.0.4
We would set those in the talosconfig
with:
talosctl --talosconfig=./talosconfig \
config endpoint 192.168.0.2 192.168.0.3 192.168.0.4
Nodes
The node is the target node on which you wish to perform the API call.
Keep in mind, when specifying nodes that their IPs and/or hostnames are as seen by the endpoint servers, not as from the client. This is because all connections are proxied first through the endpoints.
Some people also like to set a default set of nodes in the talosconfig
.
This can be done in the same manner, replacing endpoint
with node
.
If you do this, however, know that you could easily reboot the wrong machine
by forgetting to declare the right one explicitly.
Worse, if you set several nodes as defaults, you could, with one talosctl upgrade
command upgrade your whole cluster all at the same time.
It’s a powerful tool, and with that comes great responsibility.
The author of this document does not set a default node.
You may simply provide -n
or --nodes
to any talosctl
command to
supply the node or (comma-delimited) nodes on which you wish to perform the
operation.
Supplying the commandline parameter will override any default nodes
in the configuration file.
To verify default node(s) you’re currently configured to use, you can run:
$ talosctl version
Client:
...
Server:
NODE: <node>
...
For a more in-depth discussion of Endpoints and Nodes, please see talosctl.
Default configuration file
You can reference which configuration file to use directly with the --talosconfig
parameter:
talosctl --talosconfig=./talosconfig \
--nodes 192.168.0.2 version
However, talosctl
comes with tooling to help you integrate and merge this
configuration into the default talosctl
configuration file.
This is done with the merge
option.
talosctl config merge ./talosconfig
This will merge your new talosconfig
into the default configuration file
($XDG_CONFIG_HOME/talos/config.yaml
), creating it if necessary.
Like Kubernetes, the talosconfig
configuration files has multiple “contexts”
which correspond to multiple clusters.
The <cluster-name>
you chose above will be used as the context name.
Kubernetes Bootstrap
All of your machines are configured, and your talosctl
client is set up.
Now, you are ready to bootstrap your Kubernetes cluster.
If that sounds daunting, you haven’t used Talos before.
Bootstrapping your Kubernetes cluster with Talos is as simple as:
talosctl bootstrap --nodes 192.168.0.2
The IP there can be any of your controlplanes (or the loadbalancer, if you have one). It should only be issued once.
At this point, Talos will form an etcd
cluster, generate all of the core
Kubernetes assets, and start the Kubernetes controlplane components.
After a few moments, you will be able to download your Kubernetes client configuration and get started:
talosctl kubeconfig
Running this command will add (merge) you new cluster into you local Kubernetes
configuration in the same way as talosctl config merge
merged the Talos client
configuration into your local Talos client configuration file.
If you would prefer for the configuration to not be merged into your default Kubernetes configuration file, simple tell it a filename:
talosctl kubeconfig alternative-kubeconfig
If all goes well, you should now be able to connect to Kubernetes and see your nodes:
kubectl get nodes
4 - System Requirements
Minimum Requirements
Role | Memory | Cores |
---|---|---|
Init/Control Plane | 2GB | 2 |
Worker | 1GB | 1 |
Recommended
Role | Memory | Cores |
---|---|---|
Init/Control Plane | 4GB | 4 |
Worker | 2GB | 2 |
These requirements are similar to that of kubernetes.
5 - What's New in Talos 0.11
Networking Configuration
Talos networking configuration was completely rewritten to be based on controllers
and resources.
There are no changes to the machine configuration, but any update to .machine.network
can now
be applied in immediate mode (without a reboot).
Talos should be setting up network configuration much faster on boot now, not blocking on DHCP for unconfigured
interfaces and skipping the reset network step.
Talos API RBAC
Limited RBAC support in Talos API is now enabled by default for Talos 0.11.
Default talosconfig
has os:admin
role embedded in the certificate so that all the APIs are available.
Certificates with reduced set of roles can be created with talosctl config new
command.
When upgrading from Talos 0.10, RBAC is not enabled by default.
Before enabling RBAC, generate talosconfig
with os:admin
role first to make sure that administrator still has access to the cluster when RBAC is enabled.
List of available roles:
os:admin
role enables every Talos APIos:reader
role limits access to read-only APIs which do not return sensitive dataos:etcd:backup
role only allowstalosctl etcd snapshot
API call (for etcd backup automation)
Default to Bootstrap workflow
The init.yaml
is no longer an output of talosctl gen config
.
We now encourage using the bootstrap API, instead of init
node types, as we
intend on deprecating this machine type in the future.
The init.yaml
and controlplane.yaml
machine configs are identical with the
exception of the machine type.
Users can use a modified controlplane.yaml
with the machine type set to
init
if they would like to avoid using the bootstrap API.
Component Updates
- containerd was updated to 1.5.2
- Linux kernel was updated to 5.10.45
- Kubernetes was updated to 1.21.2
- etcd was updated to 3.4.16
CoreDNS
Added the flag cluster.coreDNS.disabled
to coreDNS deployment during the cluster bootstrap.
Legacy BIOS Support
Added an option to the machine.install
section of the machine config that can enable marking MBR partition bootable
for the machines that have legacy BIOS which does not support GPT partitioning scheme.
Multi-arch Installer
Talos installer image (for any arch) now contains artifacts for both amd64
and arm64
architecture.
This means that e.g. images for arm64 SBCs can be generated on amd64 host.