server: implement healthcheck

Cargo.lock

@@ -2138,6 +2138,7 @@ dependencies = [
  "opaque-ke",
  "orion",
  "rand 0.8.5",
+ "reqwest",
  "rustls 0.20.6",
  "rustls-pemfile",
  "sea-query",
@@ -2162,6 +2163,7 @@ dependencies = [
  "tracing-log",
  "tracing-subscriber",
  "uuid",
+ "webpki-roots 0.21.1",
 ]
 
 [[package]]
@@ -3018,9 +3020,9 @@ dependencies = [
 
 [[package]]
 name = "reqwest"
-version = "0.11.11"
+version = "0.11.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b75aa69a3f06bbcc66ede33af2af253c6f7a86b1ca0033f60c580a27074fbf92"
+checksum = "431949c384f4e2ae07605ccaa56d1d9d2ecdb5cadd4f9577ccfab29f2e5149fc"
 dependencies = [
  "base64",
  "bytes",
@@ -3034,9 +3036,9 @@ dependencies = [
  "hyper-rustls",
  "ipnet",
  "js-sys",
- "lazy_static",
  "log",
  "mime",
+ "once_cell",
  "percent-encoding",
  "pin-project-lite",
  "rustls 0.20.6",