Hi,
I have used Home Assistant for some months now and love it. I moved to a house with a garage around 60 meters away without able to extend my WiFi to. I then added a 4G router and a Pi and control the garage door with zwave and some zigbee sensors in the garage. These two systems are today totally isolated from each other but I want to be able to control everything in the home assistant instance in the house.
When searching how to connect two HA instance it recommends MQTT eventstreams but also some new thing using Websockets, https://github.com/lukas-hetzenecker/home-assistant-remote.
The HA in the garage is connection to my home network with openvpn so both are able to connect each other directly with ping over an encrypted connection.
I can only find some forum post for both these solutions with dates 6-12 months ago so I am wondering what is the preferred way to connect two instances today?
I’d be interested to hear current best practice also.
I’ve a separate garage (on same LAN after some external cabling) which has a separate instance of hassio on a Pi3B to manage a few zwave switches.
At the moment i’m using command line switches, which gives an unsatisfying delay before the new state is shown when toggling them in the UI.
Same here, been trying to incorporate my remote HA controlling an irigation system in another city to my home HA. I gave a shot to the home-assistant-remote you mentioned but i couldnt get it to work.
Currently i have both RPis in the same network and trying to figure it out before i install it there.
I posted here in order to get some help but i’d love to hear what the alternatives are.
My guess would be to use MQTT but that’s just a guess.
As Bosborne said above, I imagine the easiest way will be a cloud based MQTT platform (whether you are comfortable with this is another question).
With this you could in theory control another Hass install globally as long as they both set up with the same broker info.
Question out of ignorance. Why cloud based? I assume they can talk to each other directly.
If not some sort of VPN might be a secure option.
I would still want to try the remote component.
MQTT sounds like a solution but why mess with a cloud broker if they can connect directly.
There’s some relevant discussion here.
Fair enough. I am a newbie and have not messed with MQTT. I am still learning but browse over the discussions to discern the usefulness of all the smart home puzzle pieces.
I just discerned the meaning of “discern” 
I used to say if you’re not learning, you’re not living. 
I’ve never used them but they seem to be suggested as the go-to solution:
I used the mqtt options for a few months and i didn’t work well. The remote_assistant custom component works great and it populate your entities automatically. Check this post:
Is the principal issue here the underlying access between n+1 instances or also the HA control plane?
What are the other requirements for having two instances linked?
To create automations for components that HA instances are independently aware of can be done in numerous was without having the instances in a mirrored state, the UI can be unified, and recorder/history can be kept in sync without MQTT State/Eventstream by choosing to use a database back end that HA supports and then bilaterally replicating changes or simply configuring a single instance of the chosen back end and having n+1 instances write to the same database (I’m presuming that will work, just throwing out a suggestion).
In terms of connectivity, I would strongly recommend anyone looking for the easiest way to have “like I’m actually at home” remote access or create a simple, lightweight, easy to configure, software-defined overlay network for interconnectivity to consider using Zero Tier (zerotier.com).
It’s a piece of cake to configure, affords granular traffic flow control and enables you to bridge two otherwise disparate layer 2 (switched) network segments together so they appear as a single homogeneous LAN.
Literally everything, from the most heavily scripted or over-engineering unsophisticated user UI VPN wizard to one-click VPN configurations on devices like Fortinet’s Fortigate are still orders of magnitude more difficult to configure than zerotier.com, far less flexible, and have a heavy tax on resources in many cases.