[HEALTH] Extract health endpoint definition into blockscout-health crate

libs/Cargo.toml

@@ -4,6 +4,7 @@ members = [
     "blockscout-auth",
     "blockscout-client/crate",
     "blockscout-db",
+    "blockscout-service-health",
     "blockscout-service-launcher",
     "display-bytes",
     "env-collector",

libs/blockscout-service-health/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "blockscout-service-health"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+actix-web = "4"
+actix-prost = { git = "https://github.com/blockscout/actix-prost" }
+actix-prost-macros = { git = "https://github.com/blockscout/actix-prost" }
+prost = "0.11"
+serde = { version = "1", features = ["derive"] }
+serde_with = { version = "3", features = ["hex", "base64"] }
+tonic = "0.8"
+
+[build-dependencies]
+actix-prost-build = { git = "https://github.com/blockscout/actix-prost" }
+tonic-build = "0.8"
+prost-build = "0.11"

libs/blockscout-service-health/build.rs

@@ -0,0 +1,44 @@
+use actix_prost_build::{ActixGenerator, GeneratorList};
+use prost_build::{Config, ServiceGenerator};
+use std::path::Path;
+
+// custom function to include custom generator
+fn compile(
+    protos: &[impl AsRef<Path>],
+    includes: &[impl AsRef<Path>],
+    generator: Box<dyn ServiceGenerator>,
+) -> Result<(), Box<dyn std::error::Error>> {
+    let mut config = Config::new();
+    config
+        .service_generator(generator)
+        .compile_well_known_types()
+        .protoc_arg("--openapiv2_out=swagger")
+        .protoc_arg("--openapiv2_opt")
+        .protoc_arg("grpc_api_configuration=proto/api_config_http.yaml,output_format=yaml,allow_merge=true,merge_file_name=health")
+        .bytes(["."])
+        .type_attribute(".", "#[actix_prost_macros::serde]")
+        .field_attribute(
+            ".grpc.health.v1.HealthCheckRequest.service",
+            "#[serde(default)]"
+        );
+    config.compile_protos(protos, includes)?;
+    Ok(())
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // We need to rebuild proto lib only if any of proto definitions
+    // (or corresponding http mapping) has been changed.
+    println!("cargo:rerun-if-changed=proto/");
+
+    std::fs::create_dir_all("./swagger").unwrap();
+    let gens = Box::new(GeneratorList::new(vec![
+        tonic_build::configure().service_generator(),
+        Box::new(ActixGenerator::new("proto/api_config_http.yaml").unwrap()),
+    ]));
+    compile(
+        &["../../proto/health/v1/health.proto"],
+        &["../../proto", "proto"],
+        gens,
+    )?;
+    Ok(())
+}

libs/blockscout-service-health/proto/api_config_http.yaml

@@ -0,0 +1,7 @@
+type: google.api.Service
+config_version: 3
+
+http:
+  rules:
+    - selector: grpc.health.v1.Health.Check
+      get: /health

libs/blockscout-service-health/src/lib.rs

@@ -0,0 +1,7 @@
+pub mod grpc {
+    pub mod health {
+        pub mod v1 {
+            include!(concat!(env!("OUT_DIR"), "/grpc.health.v1.rs"));
+        }
+    }
+}

libs/blockscout-service-health/swagger/health.swagger.yaml

@@ -0,0 +1,74 @@
+swagger: "2.0"
+info:
+  title: health/v1/health.proto
+  version: version not set
+tags:
+  - name: Health
+consumes:
+  - application/json
+produces:
+  - application/json
+paths:
+  /health:
+    get:
+      summary: |-
+        Check gets the health of the specified service. If the requested service
+        is unknown, the call will fail with status NOT_FOUND. If the caller does
+        not specify a service name, the server should respond with its overall
+        health status.
+      description: |-
+        Clients should set a deadline when calling Check, and can declare the
+        server unhealthy if they do not receive a timely response.
+
+        Check implementations should be idempotent and side effect free.
+      operationId: Health_Check
+      responses:
+        "200":
+          description: A successful response.
+          schema:
+            $ref: '#/definitions/v1HealthCheckResponse'
+        default:
+          description: An unexpected error response.
+          schema:
+            $ref: '#/definitions/rpcStatus'
+      parameters:
+        - name: service
+          in: query
+          required: false
+          type: string
+      tags:
+        - Health
+definitions:
+  HealthCheckResponseServingStatus:
+    type: string
+    enum:
+      - UNKNOWN
+      - SERVING
+      - NOT_SERVING
+      - SERVICE_UNKNOWN
+    default: UNKNOWN
+    description: ' - SERVICE_UNKNOWN: Used only by the Watch method.'
+  protobufAny:
+    type: object
+    properties:
+      '@type':
+        type: string
+    additionalProperties: {}
+  rpcStatus:
+    type: object
+    properties:
+      code:
+        type: integer
+        format: int32
+      message:
+        type: string
+      details:
+        type: array
+        items:
+          type: object
+          $ref: '#/definitions/protobufAny'
+  v1HealthCheckResponse:
+    type: object
+    properties:
+      status:
+        $ref: '#/definitions/HealthCheckResponseServingStatus'