How to expose LXD to the network¶

By default, LXD can be used only by local users through a Unix socket and is not accessible over the network.

To expose LXD to the network, you must configure it to listen to addresses other than the local Unix socket. To do so, set the core.https_address server configuration option.

For example, allow access to the LXD server on port 8443:

lxc config set core.https_address :8443

lxc query --request PATCH /1.0 --data '{
  "config": {
    "core.https_address": ":8443"
  }
}'

Note

The UI requires LXD to be exposed to the network. Therefore, you must use the CLI or API to originally expose LXD to the network.

Once you have access to the UI, you can use it to update the setting. However, be careful when changing the configured value, because using an invalid value might cause you to lose access to the UI.

Go to Settings and edit the value for core.https_address.

To allow access through a specific IP address, use ip addr to find an available address and then set it. For example:

user@host:~$ ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever2: enp5s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000 link/ether 00:16:3e:e3:f3:3f brd ff:ff:ff:ff:ff:ff inet 10.68.216.12/24 metric 100 brd 10.68.216.255 scope global dynamic enp5s0 valid_lft 3028sec preferred_lft 3028sec inet6 fd42:e819:7a51:5a7b:216:3eff:fee3:f33f/64 scope global mngtmpaddr noprefixroute valid_lft forever preferred_lft forever inet6 fe80::216:3eff:fee3:f33f/64 scope link valid_lft forever preferred_lft forever3: lxdbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 00:16:3e:8d:f3:72 brd ff:ff:ff:ff:ff:ff inet 10.64.82.1/24 scope global lxdbr0 valid_lft forever preferred_lft forever inet6 fd42:f4ab:4399:e6eb::1/64 scope global valid_lft forever preferred_lft forever

user@host:~$ lxc config set core.https_address 10.68.216.12

All remote clients can then connect to LXD and access any image that is marked for public use.

Authenticate with the LXD server¶

To be able to access the remote API, clients must authenticate with the LXD server. There are several authentication methods; see Remote API authentication for detailed information.

The recommended method is to add the client’s TLS certificate to the server’s trust store through a trust token.

See How to access the LXD web UI for instructions on how to authenticate with the LXD server using the UI. To authenticate a CLI or API client using a trust token, complete the following steps:

On the server, generate a trust token.
To generate a trust token, enter the following command on the server:
lxc config trust add
Enter the name of the client that you want to add. The command generates and prints a token that can be used to add the client certificate.
To generate a trust token, send a POST request to the /1.0/certificates endpoint:
lxc query --request POST /1.0/certificates --data '{ "name": "<client_name>", "token": true, "type": "client" }'
See POST /1.0/certificates for more information.

The return value of this query contains an operation that has the information that is required to generate the trust token:
{ "class": "token", ... "metadata": { "addresses": [ "<server_address>" ], "fingerprint": "<fingerprint>", ... "secret": "<secret>" }, ... }
Use this information to generate the trust token:
echo -n '{"client_name":"<client_name>","fingerprint":"<fingerprint>",'\ '"addresses":["<server_address>"],'\ '"secret":"<secret>","expires_at":"0001-01-01T00:00:00Z"}' | base64 -w0
Authenticate the client.
On the client, add the server with the following command:
lxc remote add <remote_name> <token>
Note

If your LXD server is behind NAT, you must specify its external public address when adding it as a remote for a client:
lxc remote add <name> <IP_address>
When you are prompted for the admin password, specify the generated token.

When generating the token on the server, LXD includes a list of IP addresses that the client can use to access the server. However, if the server is behind NAT, these addresses might be local addresses that the client cannot connect to. In this case, you must specify the external address manually.
On the client, generate a certificate to use for the connection:
openssl req -x509 -newkey rsa:2048 -keyout "<keyfile_name>" -nodes \ -out "<crtfile_name>" -subj "/CN=<client_name>"
Then send a POST request to the /1.0/certificates?public endpoint to authenticate:
curl -k -s --key "<keyfile_name>" --cert "<crtfile_name>" \ -X POST https://<server_address>/1.0/certificates \ --data '{ "password": "<trust_token>" }'
See POST /1.0/certificates?public for more information.

See Remote API authentication for detailed information and other authentication methods.