MVP Web Access
While you can access the interface using > http://localhost:8000 And if you know the local IP address of your Raspberry Pi, you can access it from other computers on your network. This does not allow you to remotely connect to your MVP outside your local network. That takes a bit more work, and a knowledge of your local network and router. The following assumes you are setting things up at home, your home has internet service, and you have access to your home router. I have a Linksys router, and will use it as an example of what to do. To access your MVP from outside your local network requires three things:
- The ability to find your home IP address
- A static network IP address for your Raspberry Pi
- Port forwarding for CouchDB and your server
It is unlikely that you have a static IP address for your home, it is an expensive service of most internet providers that few people are willing to pay for. Since many people are not on the internet all the time, and there are a lot of customers sharing a limited number if IP addresses; most internet providers give out temporary IP addresses as needed. This is known as the DHCP protocol. This means your IP address will change over time. On my router (Security/Apps and Gaming/DDNS) it lists my current IP address. With this address, I could reach my router from anywhere on the web - but it could change at any time. To get around this, you need a DDNS service. This is a company that lets you create a web/host name (ie. OpenAgBloom.ddns.net), and they take care of tracking what IP address is assigned to it at any time. My router knows of several companies that provide this service (some for free). In my case I am using NO-IP.com. I tell my router the name of the company, my login and password, and my host name. Every time my IP address changes my router sends a message to NO-IP.com telling them my new IP address. Now, every time someone types OpenAgBloom.ddns.com into their browser, they get routed to the service which looks up the current IP address, and sends them on their way to my router. Notice I say they go to my router, nobody outside of my local/private network knows that I have a Raspberry Pi connected up as my MVP. This is where you have to tell your router how to send people to your MVP.
Just as your internet provider changes your router's IP address, so too your home router hands out local IP addresses as people connect and disconnect from your home LAN. What you want to do is tell your router to reserve an IP address for your Raspberry Pi, and always give it to your Pi when it connects to the network. On my Linksys this is found under Connectivity/Local Network, there I find a button that says "DHCP Reservation". On this page you will see other information on this page, such as the starting IP address the router will use, how many addresses it will manage, and how long it will let a device keep an address before it frees that address for someone else to use. If you click on "DHCP Reservation" you will see a list of devices that have reserved addresses (if any), and a list of connected devices for which you can reserve an address. Find your Raspberry in the list and select it, then save the reservation. Sometimes my Raspberry doesn't always reconnect properly, but usually it connects reliable and is where I expect it.
The last step is telling the router how to forward people outside your LAN to your Raspberry. All internet requests go to a "port", an address that is listening for requests to service them; if none is provided, things usually default to port 80 which is the standard for HTTP requests. If your router is set up correctly (with security), it will refuse to answer any requests from outside your LAN. This port number is where your Raspberry knows that "5984" means a request for the CouchDB, and "8000" is the MVP (using the Python server). Port forwarding is where you tell your router that if a request comes in for port "8000" it should know to forward that request to your Raspberry Pi. On my Linksys (Security/Apps and Gaming/Single Port Forwarding) there is a table of port numbers (as requested from an outside call) that map to internal IP addresses and port numbers. I am not doing any fancy port switching (setting up two MVPs, both with CouchDB on 5984), so my external port numbers are the same as the internal. Specify both protocols, and enable the forwarding. For the MVP you need two ports (5984 for CouchDB and 8000 for the server) and will create two forwarding entries in the table. Save the results and you should be able to connect to your MVP from anywhere on the web.
NOTE: In release III we are doing away with the Python server (port 8000) and offering Caddy as an optional server. Caddy is simpler, and offers way more options that the basic Python server. In addition, Caddy is capable of providing HTTPS security. If you are using Caddy, instead of port 8000, you will need to forward both port 80 (inbound) and port 443 (outbound). See the Caddy wiki entry for details.
You are opening up your Raspberry Pi to the web, which also means you are potentially opening up your home LAN as well. The server only handles HTTP requests, so there is little damage a hacker can do here, but CouchDB is configured as an "Admin Party" and anyone who can delete your data and cause other trouble. This is probably a very low risk, but it is a risk and I have done my | due diligence. At a minimum, change your Raspberry Pi password. Also, back up your SD card on a regular basis (Reminder to self - you need to do this).
2018/05/31 webbhm