fix(docker): Enhanced base image extraction logic from Dockerfile

changelog.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 2024-11-17 - 4.1.37 - fix(docker)
+Enhanced base image extraction logic from Dockerfile
+
+- Improved dockerBaseImage to accurately extract base images considering ARG variables.
+- Added support for parsing Dockerfile content without external libraries.
+- Enhanced error handling for missing FROM instructions.
+
 ## 2024-11-17 - 4.1.36 - fix(docker)
 Improve logging for Dockerfile build order with base image details.
 

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@ship.zone/npmci',
-  version: '4.1.36',
+  version: '4.1.37',
   description: 'A tool to streamline Node.js and Docker workflows within CI environments, particularly GitLab CI, providing various CI/CD utilities.'
 }

ts/manager.docker/mod.classes.dockerfile.ts

@@ -102,8 +102,11 @@ export class Dockerfile {
 
     // Log the sorted order
     sortedDockerfiles.forEach((dockerfile, index) => {
-      logger.log('info', `Build order ${index + 1}: ${dockerfile.cleanTag}
-      with base image ${dockerfile.baseImage}`);
+      logger.log(
+        'info',
+        `Build order ${index + 1}: ${dockerfile.cleanTag}
+      with base image ${dockerfile.baseImage}`
+      );
     });
 
     return sortedDockerfiles;
@@ -171,12 +174,62 @@ export class Dockerfile {
   }
 
   /**
-   * returns the docker base image for a Dockerfile
+   * Extracts the base image from a Dockerfile content without using external libraries.
+   * @param dockerfileContentArg The content of the Dockerfile as a string.
+   * @returns The base image specified in the first FROM instruction.
    */
   public static dockerBaseImage(dockerfileContentArg: string): string {
-    const baseImageRegex = /FROM\s([a-zA-z0-9\/\-\:]*)\n?/;
-    const regexResultArray = baseImageRegex.exec(dockerfileContentArg);
-    return regexResultArray[1];
+    const lines = dockerfileContentArg.split(/\r?\n/);
+    const args: { [key: string]: string } = {};
+
+    for (const line of lines) {
+      const trimmedLine = line.trim();
+
+      // Skip empty lines and comments
+      if (trimmedLine === '' || trimmedLine.startsWith('#')) {
+        continue;
+      }
+
+      // Match ARG instructions
+      const argMatch = trimmedLine.match(/^ARG\s+([^\s=]+)(?:=(.*))?$/i);
+      if (argMatch) {
+        const argName = argMatch[1];
+        const argValue = argMatch[2] !== undefined ? argMatch[2] : process.env[argName] || '';
+        args[argName] = argValue;
+        continue;
+      }
+
+      // Match FROM instructions
+      const fromMatch = trimmedLine.match(/^FROM\s+(.+?)(?:\s+AS\s+[^\s]+)?$/i);
+      if (fromMatch) {
+        let baseImage = fromMatch[1].trim();
+
+        // Substitute variables in the base image name
+        baseImage = Dockerfile.substituteVariables(baseImage, args);
+
+        return baseImage;
+      }
+    }
+
+    throw new Error('No FROM instruction found in Dockerfile');
+  }
+
+  /**
+   * Substitutes variables in a string, supporting default values like ${VAR:-default}.
+   * @param str The string containing variables.
+   * @param vars The object containing variable values.
+   * @returns The string with variables substituted.
+   */
+  private static substituteVariables(str: string, vars: { [key: string]: string }): string {
+    return str.replace(/\${([^}:]+)(:-([^}]+))?}/g, (_, varName, __, defaultValue) => {
+      if (vars[varName] !== undefined) {
+        return vars[varName];
+      } else if (defaultValue !== undefined) {
+        return defaultValue;
+      } else {
+        return '';
+      }
+    });
   }
 
   /**