use figment and try to make an "upgradeable firewall"

Cargo.lock

@@ -219,6 +219,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "atomic"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a89cbf775b137e9b968e67227ef7f775587cde3fd31b0d8599dbd0f598a48340"
+dependencies = [
+ "bytemuck",
+]
+
 [[package]]
 name = "atomic-waker"
 version = "1.1.2"
@@ -409,6 +418,12 @@ version = "3.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "46c5e41b57b8bba42a04676d81cb89e9ee8e859a1a66f80a5a72e1cb76b34d43"
 
+[[package]]
+name = "bytemuck"
+version = "1.23.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c76a5792e44e4abe34d3abf15636779261d45a7450612059293d1d2cfc63422"
+
 [[package]]
 name = "byteorder"
 version = "1.5.0"
@@ -1429,6 +1444,19 @@ version = "0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "28dea519a9695b9977216879a3ebfddf92f1c08c05d984f8996aecd6ecdc811d"
 
+[[package]]
+name = "figment"
+version = "0.10.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8cb01cd46b0cf372153850f4c6c272d9cbea2da513e07538405148f95bd789f3"
+dependencies = [
+ "atomic",
+ "pear",
+ "serde",
+ "uncased",
+ "version_check",
+]
+
 [[package]]
 name = "filetime"
 version = "0.2.25"
@@ -1751,6 +1779,7 @@ dependencies = [
  "dyn-clone",
  "email_address",
  "env_logger",
+ "figment",
  "fqdn",
  "futures-util",
  "harmony_macros",
@@ -2416,6 +2445,12 @@ version = "2.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f4c7245a08504955605670dbf141fceab975f15ca21570696aebe9d2e71576bd"
 
+[[package]]
+name = "inlinable_string"
+version = "0.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8fae54786f62fb2918dcfae3d568594e50eb9b5c25bf04371af6fe7516452fb"
+
 [[package]]
 name = "inout"
 version = "0.1.4"
@@ -3237,6 +3272,29 @@ dependencies = [
  "hmac",
 ]
 
+[[package]]
+name = "pear"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bdeeaa00ce488657faba8ebf44ab9361f9365a97bd39ffb8a60663f57ff4b467"
+dependencies = [
+ "inlinable_string",
+ "pear_codegen",
+ "yansi",
+]
+
+[[package]]
+name = "pear_codegen"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4bab5b985dc082b345f812b7df84e1bef27e7207b39e448439ba8bd69c93f147"
+dependencies = [
+ "proc-macro2",
+ "proc-macro2-diagnostics",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "pem"
 version = "3.0.5"
@@ -3499,6 +3557,19 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "proc-macro2-diagnostics"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af066a9c399a26e020ada66a034357a868728e72cd426f3adcd35f80d88d88c8"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "version_check",
+ "yansi",
+]
+
 [[package]]
 name = "punycode"
 version = "0.4.1"
@@ -5141,6 +5212,15 @@ version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2896d95c02a80c6d6a5d6e953d479f5ddf2dfdb6a244441010e373ac0fb88971"
 
+[[package]]
+name = "uncased"
+version = "0.9.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1b88fcfe09e89d3866a5c11019378088af2d24c3fbd4f0543f96b479ec90697"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.18"