Refactor nginx path resolution with improved regex and fallback

Updated regex patterns for extracting nginx configuration paths and added fallback mechanisms for determining paths on different operating systems. Improved error handling and logging for better debugging.

Author: enwikuna

internal/nginx/resolve_path.go

@@ -1,6 +1,7 @@
 package nginx
 
 import (
+	"os"
 	"path/filepath"
 	"regexp"
 	"runtime"
@@ -57,64 +58,104 @@ func GetPrefix() string {
 	return nginxPrefix
 }
 
-// GetConfPath returns the path of the nginx configuration file
+// GetConfPath returns the nginx configuration directory (e.g. "/etc/nginx").
+// It tries to derive it from `nginx -V --conf-path=...`.
+// If parsing fails, it falls back to a reasonable default instead of returning "".
 func GetConfPath(dir ...string) (confPath string) {
-	if settings.NginxSettings.ConfigDir == "" {
-		out := getNginxV()
-		r, _ := regexp.Compile("--conf-path=(.*)/(.*.conf)")
-		match := r.FindStringSubmatch(out)
-		if len(match) < 1 {
-			logger.Error("nginx.GetConfPath len(match) < 1")
-			return ""
-		}
-		confPath = match[1]
-	} else {
-		confPath = settings.NginxSettings.ConfigDir
-	}
-
-	confPath = resolvePath(confPath)
-
-	joined := filepath.Clean(filepath.Join(confPath, filepath.Join(dir...)))
-	if !helper.IsUnderDirectory(joined, confPath) {
-		return confPath
-	}
-	return joined
+    if settings.NginxSettings.ConfigDir == "" {
+        out := getNginxV()
+        r, _ := regexp.Compile(`--conf-path=([^\s]+)`)
+        match := r.FindStringSubmatch(out)
+		
+        if len(match) > 1 {
+            fullConf := match[1]
+            confPath = filepath.Dir(fullConf)
+        } else {
+            if runtime.GOOS == "windows" {
+                confPath = GetPrefix()
+            } else {
+                confPath = "/etc/nginx"
+            }
+			
+            logger.Debug("nginx.GetConfPath fallback used", "base", confPath)
+        }
+    } else {
+        confPath = settings.NginxSettings.ConfigDir
+    }
+
+    confPath = resolvePath(confPath)
+
+    joined := filepath.Clean(filepath.Join(confPath, filepath.Join(dir...)))
+    if !helper.IsUnderDirectory(joined, confPath) {
+        return confPath
+    }
+    return joined
 }
 
-// GetConfEntryPath returns the path of the nginx configuration file
+// GetConfEntryPath returns the absolute path to the main nginx.conf.
+// It prefers the value from `nginx -V --conf-path=...`.
+// If that can't be parsed, it falls back to "<confDir>/nginx.conf".
 func GetConfEntryPath() (path string) {
-	if settings.NginxSettings.ConfigPath == "" {
-		out := getNginxV()
-		r, _ := regexp.Compile("--conf-path=(.*.conf)")
-		match := r.FindStringSubmatch(out)
-		if len(match) < 1 {
-			logger.Error("nginx.GetConfEntryPath len(match) < 1")
-			return ""
-		}
-		path = match[1]
-	} else {
-		path = settings.NginxSettings.ConfigPath
-	}
-
-	return resolvePath(path)
+    if settings.NginxSettings.ConfigPath == "" {
+        out := getNginxV()
+        r, _ := regexp.Compile(`--conf-path=([^\s]+)`)
+        match := r.FindStringSubmatch(out)
+
+        if len(match) > 1 {
+            path = match[1]
+        } else {
+            baseDir := GetConfPath()
+			
+            if baseDir != "" {
+                path = filepath.Join(baseDir, "nginx.conf")
+            } else {
+                logger.Error("nginx.GetConfEntryPath: cannot determine nginx.conf path")
+                path = ""
+            }
+        }
+    } else {
+        path = settings.NginxSettings.ConfigPath
+    }
+
+    return resolvePath(path)
 }
 
-// GetPIDPath returns the path of the nginx PID file
+// GetPIDPath returns the nginx master process PID file path.
+// We try to read it from `nginx -V --pid-path=...`.
+// If that fails (which often happens in container images), we probe common
+// locations like /run/nginx.pid and /var/run/nginx.pid instead of just failing.
 func GetPIDPath() (path string) {
-	if settings.NginxSettings.PIDPath == "" {
-		out := getNginxV()
-		r, _ := regexp.Compile("--pid-path=(.*.pid)")
-		match := r.FindStringSubmatch(out)
-		if len(match) < 1 {
-			logger.Error("pid path not found in nginx -V output")
-			return ""
-		}
-		path = match[1]
-	} else {
-		path = settings.NginxSettings.PIDPath
-	}
-
-	return resolvePath(path)
+    if settings.NginxSettings.PIDPath == "" {
+        out := getNginxV()
+        r, _ := regexp.Compile(`--pid-path=([^\s]+)`)
+        match := r.FindStringSubmatch(out)
+
+        if len(match) > 1 {
+            path = match[1]
+        } else {
+            candidates := []string{
+                "/var/run/nginx.pid",
+                "/run/nginx.pid",
+            }
+
+            for _, c := range candidates {
+                if _, err := os.Stat(c); err == nil {
+                    logger.Debug("GetPIDPath fallback hit", "path", c)
+                    path = c
+                    break
+                }
+            }
+
+            if path == "" {
+                logger.Error("GetPIDPath: could not determine PID path")
+                return ""
+            }
+        }
+    } else {
+        path = settings.NginxSettings.PIDPath
+    }
+
+    return resolvePath(path)
 }
 
 // GetSbinPath returns the path of the nginx executable