feat: support standard Postgres env vars for db connection

Support DATABASE_URL, PGHOST, PGPORT, PGUSER, PGPASSWORD, PGDATABASE
environment variables for configuring the database connection. Env vars
take highest priority, overriding CLI args, LSP settings, and config file
values.

Closes #302

Author: psteinroe

crates/pgls_configuration/src/database.rs

@@ -73,9 +73,7 @@ impl PartialDatabaseConfiguration {
     pub fn from_env() -> Option<Self> {
         let database_url = std::env::var("DATABASE_URL").ok();
         let pghost = std::env::var("PGHOST").ok();
-        let pgport = std::env::var("PGPORT")
-            .ok()
-            .and_then(|p| p.parse().ok());
+        let pgport = std::env::var("PGPORT").ok().and_then(|p| p.parse().ok());
         let pguser = std::env::var("PGUSER").ok();
         let pgpassword = std::env::var("PGPASSWORD").ok();
         let pgdatabase = std::env::var("PGDATABASE").ok();

crates/pgls_env/src/lib.rs

@@ -76,18 +76,9 @@ impl PgLSEnv {
                 "DATABASE_URL",
                 "A connection string that encodes the full database connection setup.",
             ),
-            pghost: PgLSEnvVariable::new(
-                "PGHOST",
-                "The host of the database server.",
-            ),
-            pgport: PgLSEnvVariable::new(
-                "PGPORT",
-                "The port of the database server.",
-            ),
-            pguser: PgLSEnvVariable::new(
-                "PGUSER",
-                "The username to connect to the database.",
-            ),
+            pghost: PgLSEnvVariable::new("PGHOST", "The host of the database server."),
+            pgport: PgLSEnvVariable::new("PGPORT", "The port of the database server."),
+            pguser: PgLSEnvVariable::new("PGUSER", "The username to connect to the database."),
             pgpassword: PgLSEnvVariable::new(
                 "PGPASSWORD",
                 "The password to connect to the database.",

docs/codegen/src/env_variables.rs

@@ -39,6 +39,43 @@ pub fn generate_env_variables(docs_dir: &Path) -> Result<()> {
         env.pgls_config_path.description()
     )?;
 
+    writeln!(
+        content,
+        "### `{}`\n\n {}\n",
+        env.database_url.name(),
+        env.database_url.description()
+    )?;
+    writeln!(
+        content,
+        "### `{}`\n\n {}\n",
+        env.pghost.name(),
+        env.pghost.description()
+    )?;
+    writeln!(
+        content,
+        "### `{}`\n\n {}\n",
+        env.pgport.name(),
+        env.pgport.description()
+    )?;
+    writeln!(
+        content,
+        "### `{}`\n\n {}\n",
+        env.pguser.name(),
+        env.pguser.description()
+    )?;
+    writeln!(
+        content,
+        "### `{}`\n\n {}\n",
+        env.pgpassword.name(),
+        env.pgpassword.description()
+    )?;
+    writeln!(
+        content,
+        "### `{}`\n\n {}\n",
+        env.pgdatabase.name(),
+        env.pgdatabase.description()
+    )?;
+
     writeln!(
         content,
         "### `{}`\n\n {}\n",

docs/reference/env_variables.md

@@ -19,6 +19,30 @@
 
  A path to the configuration file
 
+### `DATABASE_URL`
+
+ A connection string that encodes the full database connection setup.
+
+### `PGHOST`
+
+ The host of the database server.
+
+### `PGPORT`
+
+ The port of the database server.
+
+### `PGUSER`
+
+ The username to connect to the database.
+
+### `PGPASSWORD`
+
+ The password to connect to the database.
+
+### `PGDATABASE`
+
+ The name of the database to connect to.
+
 ### `PGT_LOG_PATH`
 
  The directory where the Daemon logs will be saved. Deprecated, use PGLS_LOG_PATH instead.