Stretchyfile is a stretchy Caddyfile flavour. It is designed to simplify complex use-cases, by extending how variables and conditions function in Caddyfile.
$port = 80
$ports = 80,443
$domain = example.com
$domains = example.com,example.org
$:{port} {
respond "Hello, world!"
}
$:{ports} {
respond "Hello, world!"
}
${domain} {
respond "Hello, world!"
}
${domains} {
respond "Hello, world!"
}
${domain}:{port} {
respond "Hello, world!"
}
${domain}:{ports} {
respond "Hello, world!"
}
${domains}:{port} {
respond "Hello, world!"
}
${domains}:{ports} {
respond "Hello, world!"
}
${domain}:{ports} {
if (host beta.example.com) {
respond "Hello, world!"
} else {
respond "Goodbye, world!"
}
}
:80 {
respond "Hello, world!"
}
:80, :443 {
respond "Hello, world!"
}
example.com {
respond "Hello, world!"
}
example.com, example.org {
respond "Hello, world!"
}
example.com:80 {
respond "Hello, world!"
}
example.com:80, example.com:443 {
respond "Hello, world!"
}
example.com:80, example.org:80 {
respond "Hello, world!"
}
example.com:80, example.org:80, example.com:443, example.org:443 {
respond "Hello, world!"
}
example.com:80, example.com:443 {
@condition0 {
host beta.example.com
}
handle @condition0 {
respond "Hello, world!"
}
@condition1 {
not {
host beta.example.com
}
}
handle @condition1 {
respond "Goodbye, world!"
}
}
The syntax of Stretchyfile is very similar to Caddyfile's syntax. In fact, you can input a raw Caddyfile and it will output the exact same Caddyfile. Any line of code that uses Stretchyfile-specific code, must start with a $, otherwise it'll be skipped over.
You can declare a variable at any point within your code. At the top, in the middle, wherever.
Here's how you set a variable:
$port = 80
To use a variable, you need to add a $ at the start of the line where you want to use the variable. You then insert the variable name wrapped with {}.
Here's a real-world example of how you would use a variable:
$port = 80
$example.com:{port} {
respond "Hello, world!"
}
You are free to use variables for any value. The only exception is ports. It is crucial that if you want to save a port to a variable, you do not include a :. This is important for mapping array variables which are explained further down.
Do not do this:
$port = :80
$example.com{port} {
respond "Hello, world!"
}
Array's are why I made Stretchyfile. For sites with a more complicated setup, arrays are a life-saver.
Here's an example of the problem I'm trying to solve:
example.com:80, example.com:443, *.example.com:80, *.example.com:443, example.org:80, example.org:443, *.example.org:80, *.example.org:443 {
respond "Hello, world!"
}
And the worst part is, this is a common setup. If you have multiple domains, use multiple ports, or have many subdomains, I am sure your Caddyfile is a mess (like mine).
Here's how the above example looks with Stretchyfile:
$domains = example.com,example.org,*.example.com,*.example.org
$ports = 80,443
${domains}:{ports} {
respond "Hello, world!"
}
Simple, right?
Here's another way you can do it:
$domains = example.com,example.org
$ports = 80,443
${domains}:{ports}, *.{domains}:{ports} {
respond "Hello, world!"
}
And another way:
$tlds = .com,.org
$ports = 80,443
$example{tlds}:{ports}, *.example{tlds}:{ports} {
respond "Hello, world!"
}
And another (yes, you can concat arrays):
$domains = example.com,example.org
$domains = {domains},*.{domains}
$ports = 80,443
${domains}:{ports} {
respond "Hello, world!"
}
Caddyfile's if statements are great, but they can be a bit of a pain to use. Stretchyfile makes them a bit easier to use. Conditions are identical to Caddyfile's conditions. Though defining the if statement is a bit different. Stretchyfile uses a more uniform approach to if/else statements, matching the syntax of most programming languages.
Let's say you have example.com, and you want to route beta.example.com to a different server block. Here's how you would do it in Caddyfile:
*.example.com {
@beta {
host beta.example.com
}
handle @beta {
respond "Hello, world!"
}
@not_beta {
not {
host beta.example.com
}
}
handle @not_beta {
respond "Hello, world!"
}
}
The syntax is a bit difficult to remember, and it's a bit of a pain to write. Here's how you would do it in Stretchyfile:
*.example.com {
if (host beta.example.com) {
respond "Hello, world!"
} else {
respond "Hello, world!"
}
}
A lot simpler, right? You can also use variables in your conditions:
$ports = 80, 443
$*.example.com:{ports} {
if (host beta.example.com) {
respond "Hello, world!"
} else {
respond "Hello, world!"
}
}
Have multiple conditions? Easy, just use && like any other programming language:
*.example.com {
if (host beta.example.com && cookie beta) {
respond "Hello, world!"
} else {
respond "Hello, world!"
}
}
Here is the Caddyfile equivalent:
*.example.com {
@beta {
host beta.example.com
cookie beta
}
handle @beta {
respond "Hello, world!"
}
@not_beta {
not {
host beta.example.com
cookie beta
}
}
handle @not_beta {
respond "Hello, world!"
}
}
Using Stretchyfile is super simple. Clone this repo, or copy stretchy.py to your machine.
If stretchy.py is in your Caddy directory, simply run:
python3 stretchy.py
Otherwise, you can specify your path name:
python3 stretchy.py /etc/caddy/Stretchyfile
I have extensively tested this for my use-cases, but it is impossible for me to have caught every edge case. If your Stretchyfile isn't being transpiled properly, you can add a -V argument to the end to see what the transpiler is doing step-by-step to hopefully troubleshoot your issue. You can also optionally set -V comment to insert logs as comments in the Caddyfile instead of printing.