Commit graph

6 commits

Author SHA1 Message Date
William Carroll
e223adfec5 Begin work on YNAB client
After reading these docs
https://api.youneedabudget.com/v1#/Transactions/createTransaction I successfully
made a request to post a transaction to my YNAB account. Hastily created a
client.go that doesn't contain much at the moment.
2020-02-10 23:24:33 +00:00
William Carroll
44dca4a188 Move authorization logic into separate package
Relocated the logic for authorizing clients into a separate package that the
tokens server now depends on. Moving this helped me separate concerns. I removed
a few top-level variables and tried to write more pure versions of the
authorization functions to avoid leaking Monzo-specific details.
2020-02-10 10:06:40 +00:00
William Carroll
64654d1d6d Create gopkgs directory for golang libs
- Created a gopkgs directory and registered it with default.nix's readTree
- Moved monzo_ynab/utils -> gopkgs
- Consumed utils.go in main.go
- Renamed monzo_ynab -> job
2020-02-10 10:06:40 +00:00
William Carroll
7f8a5176ce Create server for managing Monzo credentials
I created a server to manage my access and refresh tokens. This server exposes a
larger API than it needs to at the moment, but that should change. The goal is
to expose a GET at /token to retrieve a valid access token. The server should
take care of refreshing tokens before they expire and getting entirely new
tokens, should they become so stale that I need to re-authorize my application.

A lot of my development of this project has been clumsy. I'm new to Go; I didn't
understand OAuth2.0; I'm learning concurrent programming (outside of the context
of comfortable Elixir/Erlang).

My habits for writing programs in compiled languages feels amateurish. I find
myself dropping log.Println's all over the source code when I should be using
proper debugging tools like Delve and properly logging with things like
httputil.Dump{Request,Response}.

The application right now is in a transitional state. There is still plenty of
code in main.go that belongs in tokens.go. For instance, the client
authorization code belongs in the tokens server.

Another question I haven't answered is where is the monzo client that I can use
to make function calls like `monzo.Transactions` or `monzo.Accounts`?

The benefit of having a tokens server is that it allows me to maintain state of
the tokens while I'm developing. This way, I can stop and start main.go without
disturbing the state of the access tokens. Of course this isn't the primary
benefit, which is to abstract over the OAuth details and expose an API
that gives me an access token whenever I request one.

The first benefit that I listed could and perhaps should be solved by
introducing some simple persistence. I'd like to write the access tokens to disk
when I shutdown the tokens server and read them from disk when I start the
tokens server. This will come. I could have done this before introducing the
tokens server, and it would have saved me a few hours I think.

Where has my time gone? Mostly I've been re-authorizing my client
unnecessarily. This process is expensive because it opens a web browser, asks me
to enter my email address, sends me an email, I then click the link in that
email. Overall this takes maybe 1-3 minutes in total. Before my tokens server
existed, however, I was doing this about 10-20 times per hour. It's a little
disappointing that I didn't rectify this earlier. I'd like to remain vigilant
and avoid making similar workflow mistakes as I move ahead.
2020-02-10 10:06:40 +00:00
William Carroll
4f63b99cee Support YNAB personal-access-token
Define my YNAB personal access token as an environment variable. Prefix Monzo
environment variables with "monzo_" to more easily differentiate between Monzo
credentials and YNAB credentials.
2020-02-07 21:30:24 +00:00
William Carroll
fafabc6e4a Support OAuth 2.0 login flow for Monzo API
After some toil and lots of learning, monzo_ynab is receiving access and refresh
tokens from Monzo. I can now use these tokens to fetch my transactions from the
past 24 hours and then forward them along to YNAB.

If YNAB's API requires OAuth 2.0 login flow for authorization, I should be able
to set that up in about an hour, which would be much faster than it took me to
setup the login flow for Monzo. Learning can be a powerful thing.

See the TODOs scattered around for a general idea of some (but not all) of the
work that remains.

TL;DR
- Package monzo_ynab with buildGo
- Move some utility functions to sibling packages
- Add a README with a project overview, installation instructions, and a brief
  note about my ideas for deployment

Note: I have some outstanding questions about how to manage state in Go. Should
I use channels? Should I use a library? Are top-level variables enough? Answers
to some or all of these questions and more coming soon...
2020-02-05 23:33:23 +00:00