posts/2021-12-05-mathyd-easy-tex-to-svg.md: fix typos, add safe public url options

1 files changed, 17 insertions, 7 deletions

diff --git a/content/posts/2021-12-05-mathyd-easy-tex-to-svg.md b/content/posts/2021-12-05-mathyd-easy-tex-to-svg.md
index 040be71..5e64743 100644
--- a/content/posts/2021-12-05-mathyd-easy-tex-to-svg.md
+++ b/content/posts/2021-12-05-mathyd-easy-tex-to-svg.md
@@ -49,7 +49,9 @@ docker run --rm -d -e MATHYD_HMAC_KEY="2dhXA3HTmfEMq2d5" -p 3000:3000 pablotron/
   reusing the key from the examples above.
 * Don't expose [Mathyd][] via a publicly-accessible [URL][]; it does
   not support [TLS][] and [MathJax][] may use a lot of memory for large
-  input files.
+  input files.  If you really do want to do this, then you'll need to
+  proxy the [Mathyd][] endpoint behind [Apache][] or [nginx][] on an
+  authenticated, [TLS][]-encrypted [URL][].
 
 ### Technical Details
 
@@ -57,15 +59,18 @@ Under the hood, [Mathyd][] is just:
 1. a [container][] running an [Express][] [HTTP][] daemon that exposes a
    single endpoint that accepts a `PUT` request containing:
 
-   * A [JSON][]-encoded body of input parameters 
+   * A [JSON][]-encoded body of input parameters.
    * A hex-encoded, [SHA-256 HMAC][hmac] of the body and the [HMAC][]
      secret key in the `x-mathyd-hmac-sha256` header.
 
    The endpoint does the following:
 
-   1. Verifies the body [HMAC][]
-   2. Converts the input [TeX][] to [SVG][] (via [MathJax][])
-   3. Returns a [JSON][] response containing the generated [SVG][]
+   1. Verifies the body [HMAC][].
+   2. Parses the [JSON][] body and extracts the input parameters,
+      including the source [TeX][].
+   3. Converts the input [TeX][] to [SVG][] (via [MathJax][]).
+   4. Returns a [JSON][]-encoded response containing the generated
+      [SVG][].
 
 2. A command-line client, written in [Ruby][], which:
    1. Reads [TeX][] from standard input and serializes it as [JSON][].
@@ -88,8 +93,9 @@ I prefer [SVGs][svg] over bitmap images whenever possible because:
 * [SVGs][svg] scale to any screen size and resolution.  This is
   particularly useful for [responsive design][].
 * [SVGs][svg] are supported by all modern browsers, including mobile
-  browsers. (Fun fact: even the [animated logo for this page][logo] is
-  an [SVG][]).
+  browsers.
+
+Fun fact: even the [animated logo for this page][logo] is an [SVG][].
 
 ### Links
 
@@ -135,3 +141,7 @@ check out [Mathy][] instead.
   "Responsive web design."
 [tls]: https://en.wikipedia.org/wiki/Transport_Layer_Security
   "Transport Layer Security"
+[apache]: https://apache.org/
+  "Apache web server"
+[nginx]: https://www.nginx.com/
+  "nginx web server"