ref(feat-33): TLS support for Spin.

The `spin-cli` now supports the `tls-key` and `tls-crt` options, e.g.
```spin up -tls-key <path/to/key> -tls-crt <path/to/crt> ...```

For convenience, the following environment variables can be set in lieu of
their respective flags.

```
SPIN_TLS_CRT=<path/to/crt>
SPIN_TLS_KEY=<path/to/key>
```

NOTE: Explicitly set flags take precedence over the environment.

```
export RUST_LOG=spin_engine=info,spin_http,wact=info
export SPIN_TLS_CRT=crates/http/tests/local.crt.pem
export SPIN_TLS_KEY=crates/http/tests/local.key.pem
spin up --app templates/spin-http/spin.toml
curl -k https://127.0.0.1:3000/test/hello
```

Signed-off-by: Brian Hardock <brian.hardock@fermyon.com>
Co-authored-by: Michelle Dhanani <michelle@fermyon.com>
Signed-off-by: Brian Hardock <brian.hardock@fermyon.com>

Makefile

@@ -1,4 +1,5 @@
 LOG_LEVEL ?= spin=trace
+CERT_NAME ?= local
 
 .PHONY: build
 build:
@@ -9,3 +10,10 @@ test:
 	RUST_LOG=$(LOG_LEVEL) cargo test --all -- --nocapture
 	cargo clippy --all-targets --all-features -- -D warnings
 	cargo fmt --all -- --check
+
+# simple convenience for developing with TLS
+.PHONY: tls
+tls: ${CERT_NAME}.crt.pem
+
+$(CERT_NAME).crt.pem:
+	openssl req -newkey rsa:2048 -nodes -keyout $(CERT_NAME).key.pem -x509 -days 365 -out $(CERT_NAME).crt.pem

crates/http/Cargo.toml

@@ -13,13 +13,18 @@ async-trait = "0.1"
 bytes = "1.1"
 ctrlc = "3.2.1"
 futures = "0.3"
+futures-util = "0.3.8"
 http = "0.2"
 hyper = { version = "0.14", features = [ "full" ] }
+hyper-rustls = { version = "0.23.0" }
 indexmap = "1.6"
 serde = { version = "1.0", features = [ "derive" ] }
 spin-config = { path = "../config" }
 spin-engine = { path = "../engine" }
+tls-listener = { version = "0.4.0", features = ["rustls", "hyper-h1", "hyper-h2"] }
 tokio = { version = "1.10", features = [ "full" ] }
+tokio-rustls = { version = "0.23.2" }
+rustls-pemfile = "0.3.0"
 tracing = { version = "0.1", features = [ "log" ] }
 tracing-futures = "0.2"
 tracing-subscriber = { version = "0.3.7", features = [ "env-filter" ] }