Pass 1 of pulling traefik config into functions

server/lib/traefik/rule.ts

@@ -0,0 +1,71 @@
+/**
+ * Build the Host()/HostRegexp() Traefik rule for a resource's domain.
+ * Wildcard resources match any single subdomain via HostRegexp.
+ */
+export function buildHostRule(
+    fullDomain: string,
+    wildcard?: boolean | null
+): string {
+    if (wildcard && fullDomain.startsWith("*.")) {
+        // Convert *.foo.bar.com -> HostRegexp(`^[^.]+\.foo\.bar\.com$`)
+        const escaped = fullDomain.slice(2).replace(/\./g, "\\.");
+        return `HostRegexp(\`^[^.]+\\.${escaped}$\`)`;
+    }
+    return `Host(\`${fullDomain}\`)`;
+}
+
+/**
+ * Append a path-matching clause to a Traefik rule based on the resource's
+ * configured path and pathMatchType.
+ */
+export function appendPathMatch(
+    rule: string,
+    path: string | null | undefined,
+    pathMatchType: string | null | undefined
+): string {
+    if (!path || !pathMatchType) return rule;
+
+    let p = path;
+    if (!p.startsWith("/")) {
+        p = `/${p}`;
+    }
+
+    if (pathMatchType === "exact") {
+        return `${rule} && Path(\`${p}\`)`;
+    } else if (pathMatchType === "prefix") {
+        return `${rule} && PathPrefix(\`${p}\`)`;
+    } else if (pathMatchType === "regex") {
+        return `${rule} && PathRegexp(\`${path}\`)`; // this is the raw path because it's a regex
+    }
+    return rule;
+}
+
+/**
+ * Compute the router priority for a resource, favoring an explicit override
+ * and otherwise deriving it from the path match specificity.
+ */
+export function computeRoutePriority(
+    priority: number | null | undefined,
+    path: string | null | undefined,
+    pathMatchType: string | null | undefined
+): number {
+    if (priority && priority != 100) {
+        return priority;
+    }
+
+    let p = 100;
+    if (path && pathMatchType) {
+        p += 10;
+        if (pathMatchType === "exact") {
+            p += 5;
+        } else if (pathMatchType === "prefix") {
+            p += 3;
+        } else if (pathMatchType === "regex") {
+            p += 2;
+        }
+        if (path === "/") {
+            p = 1; // lowest for catch-all
+        }
+    }
+    return p;
+}