docs: cross compile

CROSS_COMPILE.md

@@ -0,0 +1,13 @@
+Install docker:
+
+$ sudo apt install docker
+$ sudo usermod -aG docker $USER
+
+Then log out and back in.
+
+$ sudo systemctl start docker
+
+$ cargo install cross
+$ cross build --release --features tls_vendored --target armv7-unknown-linux-musleabihf
+
+The cross-compiled binary is at target/armv7-unknown-linux-musleabihf/release/conduit

Cargo.lock

@@ -1136,6 +1136,15 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77af24da69f9d9341038eba93a073b1fdaaa1b788221b00a69bce9e762cb32de"
 
+[[package]]
+name = "openssl-src"
+version = "111.12.0+1.1.1h"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "858a4132194f8570a7ee9eb8629e85b23cbc4565f2d4a162e87556e5956abf61"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "openssl-sys"
 version = "0.9.58"
@@ -1145,6 +1154,7 @@ dependencies = [
  "autocfg",
  "cc",
  "libc",
+ "openssl-src",
  "pkg-config",
  "vcpkg",
 ]

Cargo.toml

@@ -62,6 +62,7 @@ trust-dns-resolver = "0.19.5"
 [features]
 default = ["conduit_bin"]
 conduit_bin = [] # TODO: add rocket to this when it is optional
+tls_vendored = ["reqwest/native-tls-vendored"]
 
 [[bin]]
 name = "conduit"