Pairing fixes (#155)

- Add ca-cert package to Docker image
- Add debugging tools to Docker image
- Add error source to snap_name lookup call
- Add Makefile command for building Docker container from folder (I kept
getting it wrong)

Makefile

@@ -2,6 +2,10 @@
 build:
 	@cargo build --release
 
+.PHONY: docker-build
+docker-build:
+	@docker build -f docker/prod/Dockerfile .
+
 .PHONY: up
 up:
 	@docker-compose up

docker/prod/Dockerfile

@@ -1,9 +1,15 @@
 FROM ubuntu:latest
 
-RUN DEBIAN_FRONTEND=noninteractive apt-get update && apt-get upgrade -y && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get install -y \
+    ca-certificates \
+    libssl-dev \
+    jq \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app
 COPY target/release/ratings /app/ratings
 
 EXPOSE 443
 ENTRYPOINT ["/app/ratings"]
+

src/grpc/app.rs

@@ -11,7 +11,7 @@ use crate::{
     ratings::{get_snap_name, Rating},
     Context,
 };
-use std::sync::Arc;
+use std::{error::Error, sync::Arc};
 use tonic::{Request, Response, Status};
 use tracing::error;
 
@@ -52,7 +52,16 @@ impl App for RatingService {
                     &self.ctx.http_client,
                 )
                 .await
-                .map_err(|_| Status::unknown("Internal server error"))?;
+                .map_err(|e| {
+                    let mut err = &e as &dyn Error;
+                    let mut error = format!("{err}");
+                    while let Some(src) = err.source() {
+                        error.push_str(&format!("\n\nCaused by: {src}"));
+                        err = src;
+                    }
+                    error!(%error, "unable to fetch snap name");
+                    Status::unknown("Internal server error")
+                })?;
 
                 Ok(Response::new(GetRatingResponse {
                     rating: Some(PbRating {