Add some notes on deployment

deployment.md

@@ -0,0 +1,51 @@
+Deploying on an AWS EC2 server
+==============================
+
+Instance setup
+--------------
+On an EC2 server running Ubuntu 20.04, follow the instructions at
+https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-neo4j-on-ubuntu-20-04
+and do
+
+```
+sudo apt-get update
+sudo apt-get install apt-transport-https ca-certificates curl software-properties-common
+curl -fsSL https://debian.neo4j.com/neotechnology.gpg.key | sudo apt-key add -
+sudo add-apt-repository "deb https://debian.neo4j.com stable 4.1"
+sudo apt-get install neo4j
+```
+
+In the config file, update the following lines:
+Set the default database to indra:
+```
+dbms.default_database=indra
+```
+EC2 instances have small default root volumes so it makes sense to move
+neo4j's data folder to some other mounted volume e.g.,
+```
+dbms.directories.data=/data/neo4j/data
+```
+To accept non-local connections, set
+```
+dbms.default_listen_address=0.0.0.0
+```
+
+Now run `import.sh` to fill up the database with content and then start
+the service with
+```
+sudo neo4j start
+```
+
+In terms of authentication, one simple way to set up a custom password
+initially is to connect to the neo4j browser and do it via the web UI.
+
+Networking setup
+----------------
+To communicate with neo4j directly from outside, the 7687 port (by default)
+needs to be exposed for bolt protocol connections. To avoid exposing the
+instance to the outside world directly, it makes sense to set up a load
+balancer. Only network load balancers support bolt so that has to be used,
+ideally with an IP-based target group that points to the private IP of the
+given EC2 instance. The instance's security group can then just allow
+incoming connections on port 7687 to the private IP (range) of the load
+balancer.