Oxen Observer OMG block explorer

Block explorer using Oxen 8+ LMQ RPC interface that does everything through RPC requests. Sexy, awesome, safe.

Prerequisite packages

sudo apt install build-essential pkg-config libsodium-dev libzmq3-dev python3-dev python3-flask python3-babel python3-pygments

Building and running

Quick and dirty setup instructions for now:

git submodule update --init --recursive
cd pylokimq
mkdir build
cd build
cmake ..
make -j6
cd ../..
ln -s pylokimq/build/pylokimq/pylokimq.cpython-*.so .

(Note that we require a very recent python3-jinja package (2.11+), which may not be installed by the above.)

You'll also need to run oxend with --lmq-local-control ipc:///path/to/loki-observer/mainnet.sock.

Running in debug mode

To run it in debug mode (production requires setting up a WSGI server, see below):

FLASK_APP=observer flask run --reload --debugger

This mode seems to be a bit flakey, though -- reloading, in particular, seems to break things and make it just silently exit after a while.

Setting up for production with uwsgi-emperor:

Do all of the above, but instead of running it with flask, set up uwsgi-emperor as follows:

apt install uwsgi-emperor uwsgi-plugin-python3

in /etc/uwsgi-emperor/emperor.ini add configuration of:

# vassals directory
emperor = /etc/uwsgi-emperor/vassals
cap = setgid,setuid
emperor-tyrant = true

Create a "vassal" config for loki-observer, /etc/uwsgi-emperor/vassals/loki-observer.ini, containing:

[uwsgi]
chdir = /path/to/loki-observer
socket = mainnet.wsgi
plugins = python3,logfile
processes = 4
manage-script-name = true
mount = /=mainnet:app

logger = file:logfile=/path/to/loki-observer/mainnet.log

Set ownership of this user to whatever use you want it to run as, and set the group to _loki (so that it can open the oxend unix socket):

chown MYUSERNAME:_loki /etc/uwsgi-emperor/vassals/loki-observer.ini

In the loki-observer/mainnet.py, set:

config.oxend_rpc = 'ipc:///var/lib/loki/oxend.sock'

and finally, proxy requests from the webserver to the wsgi socket. For Apache I do this with:

# Allow access to static files (e.g. .css and .js):
<Directory /path/to/loki-observer/static>
    Require all granted
</Directory>
DocumentRoot /home/jagerman/src/loki-observer/static

# Proxy everything else via the uwsgi socket:
ProxyPassMatch "^/[^/]*\.(?:css|js)(?:$|\?)" !
ProxyPass / unix:/path/to/loki-observer/mainnet.wsgi|uwsgi://uwsgi-mainnet-observer/

(you will probably need to a2enmod proxy_uwsgi to enable the Apache modules that make that work).

That should be it: restart apache2 and uwsgi-emperor and you should be good to go. If you want to make uwsgi restart (for example because you are changing things) then it is sufficient to touch /etc/uwsgi-emperor/vassals/loki-observer.ini to trigger a reload (you do not have to restart the apache2/uwsgi-emperor layers).

If you want to set up a testnet or devnet observer the procedure is essentially the same, but using testnet.py or devnet.py pointing to a oxend.sock from a testnet or devnet oxend.