I'd just use Evernote and use Zapier or IFTTT to back up entries to gdrive/dropbox etc. Fairly decent app functionality across iOS/Android/Windows/Chrome OS/Mac OS. Great build in tagging, ok searchability and even with a free account you'll still be able to add the occasional photo or small PDF relevant to your entry.

I have my Google calendar and Automatic driving history dump to Evernote in appropriate notebooks. The weather also gets added to my Google calendar so gets recorded for each day. Everything gets backed up to my gdrive too as spreadsheets.

Similarly, call logs also get backed up to my gdrive via IFTTT and I use 3 different apps to back up my SMS every 3 days which get filed a few different places.

A text file?

I tend to just write stuff grouped by category into a text file, with timestamp tags (today is 180717). Nothing i tried was more comfortable and portable than that.

Standard search function of text editors take care of tags and searching. Picking a text editor is great customization.

There's org-mode in emacs. I've got mine setup so that hitting `C-x d` opens up a calendar with today as default selected. I press Enter and it visits ~/org/diary/2018-07-16.org, creating it if it doesn't exist.

You may like hugo and markdown for journaling.

Personally I settled running wordpress in a lxc container in my roofspace. The little hp dual-core box runs wordpress, gitlab and a plex media server.

I think sometimes lightweight and simple becomes a pain.

I'll recommend Zero AM (https://www.roastedbytes.com/zeroam/)

This looks pretty good, unfortunately it's windows only.

A notebook and a pen.

Try workflowy. Not so customizable, but it is easy to make it hierarchical, so things don't get too cluttered. It also handles links well.

Single line shell script:

(date ; cat) > ~/.notes