Original post is here: eklausmeier.goip.de
1. Web-server log. This blog logs the following information about a visitor. Below is an example from my web-server log file:
72.54.201.201|15/Oct/2023:06:01:06 +0200|200|14170|GET /blog/2021/05-30-generate-rss-from-markdown HTTP/2.0|https://www.google.com/|Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Mobile Safari/537.36|eklausmeier.goip.de:443|on
The data items are separated by a vertical bar (|). Below table shows the data items, which are stored in the web-server log.
| Nr. | Data item | Example |
|---|---|---|
| 1 | IP address | 72.54.201.201 |
| 2 | Date+time | 15/Oct/2023:06:01:06 +0200 |
| 3 | HTTP status code | 200 |
| 4 | Transfered bytes | 14170 |
| 5 | Fetched URL with method | GET /blog/2021/05-30-generate-rss-from-markdown HTTP/2.0 |
| 6 | Referrer | https://www.google.com/ |
| 8 | User agent | Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Mobile Safari/537.36 |
| 8 | Target server+port | eklausmeier.goip.de:443 |
| 9 | https on? | on |
This information in the log files is used to do the following:
- Adapt
robot.txtfile - Possibly block IP addresses in case of abuse
- Adapt Perl script
accesslogFilter, see Filtering Bots and Crawlers from Access.log - Count the number of views of blog posts
This information is not sold, nor given to anyone else.
2. JavaScript. Some blog posts make use of JavaScript. The most notable JavaScript libraries are given below.
| Nr. | Library | Purpose |
|---|---|---|
| 1 | MathJax | Math symbol rendering |
| 2 | Mermaid | Graphs, like flowcharts, block diagrams, etc. |
| 3 | Markmap | Mindmap diagrams |
| 4 | no name | gallery images |
3. Cookies. This blog does not use cookies, so no cookies are stored on your computer. Nevertheless, this blog embeds some YouTube videos, Twitter tweets, etc. These embeds do store cookies. The third-party embeds also use JavaScript. The privacy policies of those companies can be found here.
| Company | Privacy policy |
|---|---|
| Google YouTube | https://www.youtube.com/howyoutubeworks/user-settings/privacy/ |
| https://twitter.com/en/privacy | |
| TikTok | https://www.tiktok.com/legal/page/eea/privacy-policy/en |
| Vimeo | https://vimeo.com/privacy |
| CodePen | https://blog.codepen.io/documentation/privacy-policy/ |
4. Fonts. This blog uses Google fonts. Therefore Google "knows" that you have fetched fonts for a web-site. In Privacy and Data Collection Google states:
When end users visit a website that embeds Google Fonts, their browsers send HTTP requests to the Google Fonts Web API. The Google Fonts Web API serves the Google Fonts Cascading Style Sheets (CSS) and subsequently the font files specified in the CSS to the users. Such HTTP requests include (1) the IP address used by the respective user to access the Internet, (2) the requested URL on the Google server, and (3) HTTP headers including the user agent describing the website visitors’ Internet browser and operating system versions as well as the referer (i.e. the webpage on which the Google font is to be displayed).
Furthermore:
For clarity, Google does not use any information collected by Google Fonts to create profiles of end users or for targeted advertising.
5. Usage statistics. I generate usage statistics for this blog using the web-server log files. See for example "Statistics of this Blog: Crossed 120.000 Views". For this I use the Perl script blogurlcnt.