Change SPK_REQUEST_PRIORITY_ORDER to use spk config

Pull the default value for this, if any, from the spk config file.
Remove custom env var name in lieu of using the standard method of
setting config settings via env vars.

Signed-off-by: J Robert Ray <jrray@jrray.org>

.site/spi/spk.toml

@@ -6,6 +6,7 @@ username_override_var = "GITLAB_USER_LOGIN"
 
 [solver]
 build_key_name_order = "gcc,python"
+request_priority_order = "*platform*"
 
 [statsd]
 host = "statsd.k8s.spimageworks.com"

crates/spk-config/src/config.rs

@@ -75,6 +75,10 @@ pub struct Solver {
     /// Comma-separated list of option names to promote to the front of the
     /// build key order.
     pub build_key_name_order: String,
+
+    /// Comma-separated list of option names to promote to the front of the
+    /// resolve order.
+    pub request_priority_order: String,
 }
 
 #[derive(Clone, Default, Debug, Deserialize, Serialize)]

crates/spk-solve/crates/graph/Cargo.toml

@@ -6,10 +6,11 @@ version = { workspace = true }
 
 [features]
 migration-to-components = [
-	"spk-solve-package-iterator/migration-to-components",
-	"spk-solve-solution/migration-to-components",
-	"spk-schema/migration-to-components",
-	"spk-storage/migration-to-components",
+    "spk-config/migration-to-components",
+    "spk-solve-package-iterator/migration-to-components",
+    "spk-solve-solution/migration-to-components",
+    "spk-schema/migration-to-components",
+    "spk-storage/migration-to-components",
 ]
 
 [dependencies]
@@ -25,6 +26,7 @@ once_cell = { workspace = true }
 priority-queue = "1.2"
 serde_json = { workspace = true }
 spfs = { path = "../../../spfs" }
+spk-config = { path = "../../../spk-config" }
 spk-solve-package-iterator = { path = "../package-iterator" }
 spk-solve-solution = { path = "../solution" }
 spk-schema = { path = "../../../spk-schema" }

crates/spk-solve/crates/graph/src/graph.rs

@@ -4,7 +4,6 @@
 
 use std::collections::hash_map::{DefaultHasher, Entry};
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet, VecDeque};
-use std::ffi::OsString;
 use std::hash::{Hash, Hasher};
 use std::iter::FromIterator;
 use std::sync::atomic::{AtomicU64, Ordering};
@@ -48,9 +47,9 @@ const BRANCH_ALREADY_ATTEMPTED: &str = "Branch already attempted";
 /// front of the request list.
 static REQUESTS_PRIORITY_ORDER: Lazy<PromotionPatterns> = Lazy::new(|| {
     PromotionPatterns::new(
-        std::env::var_os("SPK_REQUEST_PRIORITY_ORDER")
-            .unwrap_or_else(|| OsString::from("*platform*"))
-            .to_string_lossy()
+        spk_config::get_config()
+            .map(|c| c.solver.request_priority_order.clone())
+            .unwrap_or_else(|_| "".to_string())
             .as_ref(),
     )
 });