How to configure Prosody IM for communication between two computers using DNSmasq

Question

I install Prosody IM sucessfull and work with it in localhost. Now, I have two computers connected by a crossover cable with fix IP address (I check it, sent a ping). In one of this computers are installed Jabber server and in both, the client based on xmpp.

But, this clients cannot resolve the name of my server even if it are in the same host. For example, if I have a virtual host 'lti.loc', my client (based on aioxmpp) when trying to connect show this error:

ioxmpp.errors.MultiOSError: failed to connect to XMPP domain 'lti.loc': multiple errors: [Errno -2] Name or service not known

Have one tool or manner to set this service in SRV records only for local network?

UPDATE: I found a tool called dnsmasq, and now I working in configurate this properly. If someone know more about this configuration, please answer.

Answer 1

I found a solution:

First, it's need to install dnsmasq.

After, it's important to disable the resolution of names of the system. In Ubuntu based systems the commands are:

$ sudo systemctl disable systemd-resolved

$ sudo systemctl stop systemd-resolved

Let's configurate the dnsmasq config file to locate the Prosody server. The command to open the file is:

$ sudo gedit /etc/dnsmasq.conf

The configuration example is:

local=/localnet/

address=/lti.loc/192.168.1.1
srv-host=_xmpp-client._tcp.lti.loc,lti.loc,5222
srv-host=_xmpp-server._tcp.lti.loc,lti.loc,5269

Finally, start the dnsmasq with the command:

$ sudo systemctl start dnsmasq

Some applications require SSL to connect to Prosody. Prosody have commands to generate this automatically. The final Prosody config file /etc/prosody/prosody.cfg.lua seems like this:

    -- Prosody Example Configuration File

    modules_enabled = {
    -- Generally required
        "roster"; -- Allow users to have a roster. Recommended ;)
        "saslauth"; -- Authentication for clients and servers. Recommended if you want to log in.
        "tls"; -- Add support for secure TLS on c2s/s2s connections
        "dialback"; -- s2s dialback support
        "disco"; -- Service discovery

    -- Not essential, but recommended
        "carbons"; -- Keep multiple clients in sync
        "pep"; -- Enables users to publish their mood, activity, playing music and more
        "private"; -- Private XML storage (for room bookmarks, etc.)
        "blocklist"; -- Allow users to block communications with other users
        "vcard"; -- Allow users to set vCards

    -- Nice to have
        "version"; -- Replies to server version requests
        "uptime"; -- Report how long server has been running
        "time"; -- Let others know the time here on this server
        "ping"; -- Replies to XMPP pings with pongs
        "register"; -- Allow users to register on this server using a client and change passwords
        --"mam"; -- Store messages in an archive and allow users to access it
        --"smacks"; -- Stream manager
    -- Admin interfaces
        "admin_adhoc"; -- Allows administration via an XMPP client that supports ad-hoc commands
        --"admin_telnet"; -- Opens telnet console interface on localhost port 5582

    -- HTTP modules
        -- "bosh"; -- Enable BOSH clients, aka "Jabber over HTTP"
        --"websocket"; -- XMPP over WebSockets
        --"http_files"; -- Serve static files from a directory over HTTP

    -- Other specific functionality
        --"limits"; -- Enable bandwidth limiting for XMPP connections
        --"groups"; -- Shared roster support
        --"server_contact_info"; -- Publish contact information for this service
        --"announce"; -- Send announcement to all online users
        --"welcome"; -- Welcome users who register accounts
        --"watchregistrations"; -- Alert admins of registrations
        --"motd"; -- Send a message to users when they log in
        --"legacyauth"; -- Legacy authentication. Only used by some old clients and bots.
        --"proxy65"; -- Enables a file transfer proxy service which clients behind NAT can use
}

-- These modules are auto-loaded, but should you want
-- to disable them then uncomment them here:
modules_disabled = {
    -- "offline"; -- Store offline messages
    -- "c2s"; -- Handle client connections
    -- "s2s"; -- Handle server-to-server connections
    -- "posix"; -- POSIX functionality, sends server to background, enables syslog, etc.
}

-- Disable account creation by default, for security
-- For more information see https://prosody.im/doc/creating_accounts
allow_registration = true

-- Force clients to use encrypted connections? This option will
-- prevent clients from authenticating unless they are using encryption.

c2s_require_encryption = false

-- Force servers to use encrypted connections? This option will
-- prevent servers from authenticating unless they are using encryption.
-- Note that this is different from authentication

s2s_require_encryption = false


-- Force certificate authentication for server-to-server connections?
-- This provides ideal security, but requires servers you communicate
-- with to support encryption AND present valid, trusted certificates.
-- NOTE: Your version of LuaSec must support certificate verification!
-- For more information see https://prosody.im/doc/s2s#security

s2s_secure_auth = false

allow_unencrypted_plain_auth = false
disable_sasl_mechanisms = { "DIGEST-MD5" }

-- Some servers have invalid or self-signed certificates. You can list
-- remote domains here that will not be required to authenticate using
-- certificates. They will be authenticated using DNS instead, even
-- when s2s_secure_auth is enabled.

--s2s_insecure_domains = { "insecure.example" }

-- Even if you leave s2s_secure_auth disabled, you can still require valid
-- certificates for some domains by specifying a list here.

--s2s_secure_domains = { "jabber.org" }

-- Select the authentication backend to use. The 'internal' providers
-- use Prosody's configured data storage to store the authentication data.
-- To allow Prosody to offer secure authentication mechanisms to clients, the
-- default provider stores passwords in plaintext. If you do not trust your
-- server please see https://prosody.im/doc/modules/mod_auth_internal_hashed
-- for information about using the hashed backend.

authentication = "internal_hashed"

-- Select the storage backend to use. By default Prosody uses flat files
-- in its configured data directory, but it also supports more backends
-- through modules. An "sql" backend is included by default, but requires
-- additional dependencies. See https://prosody.im/doc/storage for more info.

--storage = "sql" -- Default is "internal"

-- For the "sql" backend, you can uncomment *one* of the below to configure:
--sql = { driver = "SQLite3", database = "prosody.sqlite" } -- Default. 'database' is the filename.
--sql = { driver = "MySQL", database = "prosody", username = "prosody", password = "secret", host = "localhost" }
--sql = { driver = "PostgreSQL", database = "prosody", username = "prosody", password = "secret", host = "localhost" }


-- Archiving configuration
-- If mod_mam is enabled, Prosody will store a copy of every message. This
-- is used to synchronize conversations between multiple clients, even if
-- they are offline. This setting controls how long Prosody will keep
-- messages in the archive before removing them.

archive_expires_after = "1w" -- Remove archived messages after 1 week

-- You can also configure messages to be stored in-memory only. For more
-- archiving options, see https://prosody.im/doc/modules/mod_mam

-- Logging configuration
-- For advanced logging see https://prosody.im/doc/logging
log = {
    info = "prosody.log"; -- Change 'info' to 'debug' for verbose logging
    error = "prosody.err";
    -- "*syslog"; -- Uncomment this for logging to syslog
    -- "*console"; -- Log to the console, useful for debugging with daemonize=false
}

-- Uncomment to enable statistics
-- For more info see https://prosody.im/doc/statistics
-- statistics = "internal"

-- Certificates
-- Every virtual host and component needs a certificate so that clients and
-- servers can securely verify its identity. Prosody will automatically load
-- certificates/keys from the directory specified here.
-- For more information, including how to use 'prosodyctl' to auto-import certificates
-- (from e.g. Let's Encrypt) see https://prosody.im/doc/certificates

-- Location of directory to find certificates in (relative to main config file):
--certificates = "certs"

----------- Virtual hosts -----------
-- You need to add a VirtualHost entry for each domain you wish Prosody to serve.
-- Settings under each VirtualHost entry apply *only* to that host.

pidfile = "prosody.pid" -- stores prosody.pid in the current directory

VirtualHost "lti.loc"

ssl = {
    key = "/var/lib/prosody/lti.loc.key";
    certificate = "/var/lib/prosody/lti.loc.crt";
}

Finally, it's important correct setup the hosts in /etc/host/!