Enable the example in CI + add some comment about difference to sslmode

Author: weiznich

.github/workflows/ci.yml

@@ -115,6 +115,9 @@ jobs:
 
       - name: Test diesel_async
         run: cargo +${{ matrix.rust }} test --manifest-path Cargo.toml --no-default-features --features "${{ matrix.backend }} deadpool bb8 mobc"
+      - name: Run examples
+        if: matrix.backend == 'postgres'
+        run: cargo +${{ matrix.rust }} check --manifest-path examples/postgres/pooled-with-rustls
 
   rustfmt_and_clippy:
     name: Check rustfmt style && run clippy

Cargo.toml

@@ -51,3 +51,9 @@ rustdoc-args = ["--cfg", "doc_cfg"]
 
 [patch.crates-io]
 diesel = { git = "https://github.com/diesel-rs/diesel", rev = "b878fed" }
+
+[workspace]
+members = [
+        ".",
+        "examples/postgres/pooled-with-rustls"
+]

examples/postgres/pooled-with-rustls/Cargo.toml

@@ -6,8 +6,8 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-diesel = { version = "2.0.3", default-features = false, features = ["postgres"] }
-diesel-async = { version = "0.2.0", features = ["bb8", "postgres"] }
+diesel = { version = "2.0.2", default-features = false, features = ["postgres"] }
+diesel-async = { version = "0.2.0", path = "../../../", features = ["bb8", "postgres"] }
 futures-util = "0.3.21"
 rustls = "0.20.8"
 rustls-native-certs = "0.6.2"

examples/postgres/pooled-with-rustls/src/main.rs

@@ -17,6 +17,12 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         establish_connection,
     );
     // From that connection we can then create a pool, here given with some example settings.
+    //
+    // This creates a TLS configuration that's equivalent to `libpq'` `sslmode=verify-full`, which
+    // means this will check whether the provided certificate is valid for the given database host.
+    //
+    // `libpq` does not perform these checks by default (https://www.postgresql.org/docs/current/libpq-connect.html)
+    // If you hit a TLS error while conneting to the database double check your certificates
     let pool = Pool::builder()
         .max_size(10)
         .min_idle(Some(5))