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Using Calico with a secure etcd cluster

Calico supports insecure and TLS/certificate-enabled etcd clusters.

Etcd with client and server verification

To use TLS-enabled etcd, the following environment variables need to be set before running any calicoctl command:

  • ETCD_AUTHORITY: The <hostname>:<port_number> pair representing the access point to the cluster. Default: 127.0.0.1:2379
    • NOTE: When running Etcd with TLS enabled, the address of the ETCD_AUTHORITY must be a hostname value, NOT an IP address, such as etcd-host:2379.
  • ETCD_SCHEME: The http or https protocol used by the etcd datastore. Default: http
  • ETCD_CA_CERT_FILE: The full path to the CA certificate file for the Certificate Authority that signed the etcd server key/certificate pair.
  • ETCD_CERT_FILE: The full path to the client certificate file for accessing the etcd cluster.
  • ETCD_KEY_FILE: The full path to the client key file for accessing the etcd cluster.

For example:

export ETCD_AUTHORITY=hostname:2379
export ETCD_SCHEME=https
export ETCD_CA_CERT_FILE=/path/to/ca.pem
export ETCD_CERT_FILE=/path/to/server.pem
export ETCD_KEY_FILE=/path/to/server-key.pem

NOTE: The file extensions are not important, the files just need to exist and be readable.

You can create self-signed certificates using the calico-containers Makefile:

make ssl-certs

This will create the CA certificate, a client certificate/key pair, and a server certificate/key pair located at:

/path/to/calico-containers/certs/ca.pem
/path/to/calico-containers/certs/client.pem
/path/to/calico-containers/certs/client-key.pem
/path/to/calico-containers/certs/server.pem
/path/to/calico-containers/certs/server-key.pem

Commands that require root

Some commands are required to be run as root. The user’s environment variables specified above will not be recognized by the root user, so the variables must be passed into the Calico command.

For example, to run calicoctl node, you would call something like this:

sudo ETCD_SCHEME=https ETCD_KEY_FILE=/path/to/client.key \
     ETCD_CA_CERT_FILE=/path/to/ca.crt ETCD_CERT_FILE=/path/to/client.crt \
     ETCD_AUTHORITY=hostname:2379 calicoctl node

Alternatively, if you have previously defined/exported your environment variables, you can run sudo with the -E flag to pass in your environment:

sudo -E calicoctl node

Here’s a list of commands that must be run as root:

  • calicoctl node
  • calicoctl node stop
  • calicoctl node remove
  • calicoctl container add
  • calicoctl container remove
  • calicoctl container ip add
  • calicoctl container ip remove

See the calicoctl reference guide for details on specific calicoctl commands.

Calico as a Docker network plugin

If you are using Calico as a Docker network plugin, the Docker daemon requires a KV store for its inbuilt multi-host networking support. In our tutorials recommend using etcd for this KV store so that you can have a single store used by both Docker and Calico.

To run Docker daemon with TLS-enabled etcd, supply the following additional command line options to the Docker daemon.

 --cluster-store-opt kv.cacertfile=/path/to/ca.crt
 --cluster-store-opt kv.certfile=/path/to/cert.crt
 --cluster-store-opt kv.keyfile=/path/to/key.pem