Entries posted in January 2020

Once upon a time I wrote an email client, in a combination of C++ and Lua.

Later I realized it was flawed, and because I hadn't realized that writing email clients is hard I decided to write it anew (again in C++ and Lua).

Nowadays I do realize how hard writing email clients is, so I'm not going to do that again. But still .. but still ..

I was doing some mail-searching recently and realized I wanted to write something that processed all the messages in a Maildir folder. Imagine I wanted to run:

 message-dump ~/Maildir/people-foo/ ~/Maildir/people-bar/  \
     --format '${flags} ${filename} ${subject}'

As this required access to (arbitrary) headers I had to read, parse, and process each message. It was slow, but it wasn't that slow. The second time I ran it, even after adjusting the format-string, it was nice and fast because buffer-caches rock.

Anyway after that I wanted to write a script to dump the list of folders (because I store them recursively so ls -1 ~/Maildir wasn't enough):

 maildir-dump --format '${unread}/${total} ${path}'

I guess you can see where this is going now! If you have the following three primitives, you have a mail-client (albeit read-only)

• List "folders"
• List "messages"
• List a single message.

So I hacked up a simple client that would have a sub-command for each one of these tasks. I figured somebody else could actually use that, be a little retro, be a little cool, pretend they were using MH. Of course I'd have to write something horrid as a bash-script to prove it worked - probably using dialog to drive it.

And then I got interested. The end result is a single golang binary that will either:

• List maildirs, with a cute format string.
• List messages, with a cute format string.
• List a single message, decoding the RFC2047 headers, showing text/plain, etc.
• AND ALSO USE ITSELF TO PROVIDE A GUI

And now I wonder, am I crazy? Is writing an email client hard? I can't remember

• Current user-interface:
  • https://asciinema.org/a/FXjgOsnwjVu0lB5znx8EwRVWF
• Current source code:
  • https://github.com/skx/maildir-utils

Probably best to forget the GUI exists. Probably best to keep it a couple of standalone sub-commands for "scripting email stuff".

But still .. but still ..

Tags: email, golang, maildir, maildir-utils | 4 comments

myrepos is an excellent tool for applying git operations to multiple repositories, and I use it extensively.

Given a configuration file like this:

..

[github.com/skx/asql]
checkout = git clone [email protected]:skx/asql.git

[github.com/skx/bookmarks.public]
checkout = git clone [email protected]:skx/bookmarks.public.git

[github.com/skx/Buffalo-220-NAS]
checkout = git clone [email protected]:skx/Buffalo-220-NAS.git

[github.com/skx/calibre-plugins]
checkout = git clone [email protected]:skx/calibre-plugins.git

...

You can clone all the repositories with one command:

mr -j5 --config .mrconfig.github checkout

Then pull/update them them easily:

mr -j5 --config .mrconfig.github update

It works with git repositories, mercurial, and more. (The -j5 argument means to run five jobs in parallel. Much speed, many fast. Big wow.)

I wrote a simple golang utility to use the github API to generate a suitable configuration including:

• All your personal repositories.
• All the repositories which belong to organizations you're a member of.

Currently it only supports github, but I'll update to include self-hosted and API-compatible services such as gitbucket. Is there any interest in such a tool? Or have you all written your own already?

(I have the feeling I've written this tool in Perl, Ruby, and even using curl a time or two already. This time I'll do it properly and publish it to save effort next time!)

Tags: github, golang, mr, myrepos | 2 comments

myrepos is an excellent tool for applying git operations to multiple repositories, and I use it extensively.

I've written several scripts to dump remote repository-lists into a suitable configuration format, and hopefully I've done that for the last time.

github2mr correctly handles:

• Exporting projects from Github.com
• Exporting projects from (self-hosted installations of) Github Enterprise.
• Exporting projects from (self-hosted installations of) Gitbucket.

If it can handle Gogs, Gitea, etc, then I'd love to know, otherwise patches are equally welcome!

Tags: github, github2mr, golang, mr, myrepos | No comments

After 10+ years I'm in the process of retiring my mail-host. In the future I'll no longer be running exim4/dovecot/similar, and handling my own mail. Instead it'll all go to a (paid) Google account.

It feels like the end of an era, as it means a lot of my daily life will not be spent inside a single host no longer will I run:

ssh [email protected]

I'm still within my Gsuite trial, but I've mostly finished importing my vast mail archive, via mbsync.

The only outstanding thing I need is some scripting for the mail. Since my mail has been self-hosted I've evolved a large and complex procmail configuration file which sorted incoming messages into Maildir folders.

Having a quick look around last night I couldn't find anything similar for the brave new world of Google Mail. So I hacked up a quick script which will automatically add labels to new messages that don't have any.

Finding messages which are new/unread and which don't have labels is a matter of searching for:

is:unread -has:userlabels

From there adding labels is pretty simple, if you decide what you want. For the moment I'm keeping it simple:

• If a message comes from "Bob Smith" <[email protected]>
  • I add the label "bob.smith".
  • I add the label "example.com".

Both labels will be created if they don't already exist, and the actual coding part was pretty simple. To be more complex/flexible I would probably need to integrate a scripting language (oh, I have one of those), and let the user decide what to do for each message.

The biggest annoyance is setting up the Google project, and all the OAUTH magic. I've documented briefly what I did but I don't actually know if anybody else could run the damn thing - there's just too much "magic" involved in these APIs.

Anyway procmail-lite for gmail. Job done.

Tags: dovecot, exim, gmail, golang, gsuite, maildir, procmail | 5 comments

So recently I talked about how I was moving my email to a paid GSuite account, that process has now completed.

To recap I've been paying approximately €65/month for a dedicated host from Hetzner:

• 2 x 2Tb drives.
• 32Gb RAM.
• 8-core CPU.

To be honest the server itself has been fine, but the invoice is a little horrific regardless:

• SB31 - €26.05
• Additional subnet /27 - €26.89

I'm actually paying more for the IP addresses than for the server! Anyway I was running a bunch of virtual machines on this host:

• mail
  • Exim4 + Dovecot + SSH
  • I'd SSH to this host, daily, to read mail with my console-based mail-client, etc.
• www
  • Hosted websites.
  • Each different host would run an instance of lighttpd, serving on localhost:XXX running under a dedicated UID.
  • Then Apache would proxy to the right one, and handle SSL.
• master
  • Puppet server, and VPN-host.
• git
  • Self-hosted gitbucket git-server.
• ..
  • Bunch more servers, nine total.

My plan is to basically cut down and kill 99% of these servers, and now I've made the initial pass:

I've now bought three virtual machines, and juggled stuff around upon them. I now have:

• debian - €3.00/month
  • This hosts the read-only copy of https://debian-administration.org, which I still didn't want to kill.
• dns - €3.00/month
  • This hosts my commercial DNS thing
  • Admin overhead is essentially zero.
  • Profit is essentially non-zero :)
• shell - €6.00/month
  • The few dynamic sites I maintain were moved here, all running as www-data behind Apache. Meh.
  • This is where I run cron-jobs to invoke rss2email, my google mail filtering hack.
  • This is also a VPN-provider, providing a secure link to my home desktop, and the other servers.

The end result is that my hosting bill has gone down from being around €50/month to about €20/month (€6/month for gsuite hosting), and I have far fewer hosts to maintain, update, manage, and otherwise care about.

Since I'm all cloudy-now I have backups via the provider, as well as those maintained by rsync.net. I'll need to rebuild the shell host over the next few weeks as I mostly shuffled stuff around in-place in an adhoc fashion, but the two other boxes were deployed entirely via Ansible, and Deployr. I made the decision early on that these hosts should be trivial to relocate and they have been!

All static-sites such as my blog, my vanity site and similar have been moved to netlify. I lose the ability to view access-logs, but I'd already removed analytics because I just don't care,. I've also lost the ability to have custom 404-pages, etc. But the fact that I don't have to maintain a host just to serve static pages is great. I was considering using AWS to host these sites (i.e. S3) but chose against it in the end as it is a bit complex if you want to use cloudfront/cloudflare to avoid bandwidth-based billing surprises.

I dropped MX records from a bunch of domains, so now I only receive email at steve.fi, steve.org.uk, and to a lesser extent dns-api.com. That goes to Google. Migrating to GSuite was pretty painless although there was a surprise: I figured I'd setup a single user, then use aliases to handle the mail such that:

• debian@example -> steve
• facebook@example -> steve
• webmaster@example -> steve

All told I have about 90 distinct local-parts configured in my old Exim setup. Turns out that Gsuite has a limit of like 20 aliases per-user. Happily you can achieve the same effect with address maps. If you add an address map you can have about 4000 distinct local-parts, and reject anything else. (I can't think of anything worse than having wildcard handling; I've been hit by too many bounce-attacks in the past!)

Oh, and I guess for completeness I should say I also have a single off-site box hosted by Scaleway for €5/month. This runs monitoring via overseer and notification via purppura. Monitoring includes testing that websites are up, that responses contain a specific piece of text, DNS records resolve to expected values, SSL certificates haven't expired, & etc.

Monitoring is worth paying for. I'd be tempted to charge people to use it, but I suspect nobody would pay. It's a cute setup and very flexible and reliable. I've been pondering adding a scripting language to the notification - since at the moment it alerts me via Pushover, Email, and SMS-messages. Perhaps I should just settle on one! Having a scripting language would allow me to use different mechanisms for different services, and severities.

Then again maybe I should just pay for pingdom, or similar? I have about 250 tests which run every two minutes. That usually exceeds most services free/cheap offerings..

Tags: aws, debian, debian-administration, gmail, google, hetzner, hosting, netlify, pingdom, s3, servers | 3 comments