fix: add ruby pathresolver and validator

Author: sriram-mv

aws_lambda_builders/exceptions.py

@@ -18,7 +18,7 @@ class UnsupportedManifestError(LambdaBuilderError):
 class MisMatchRuntimeError(LambdaBuilderError):
     MESSAGE = "{language} executable found in your path does not " \
               "match runtime. " \
-              "\n Expected version: {required_runtime}, Found version: {found_runtime}. " \
+              "\n Expected version: {required_runtime}, Found version: {runtime_path}. " \
               "\n Possibly related: https://github.com/awslabs/aws-lambda-builders/issues/30"
 
 

aws_lambda_builders/workflows/python_pip/validator.py

@@ -1,5 +1,5 @@
 """
-Supported Runtimes and their validations.
+Python Runtime Validation
 """
 
 import logging

aws_lambda_builders/workflows/ruby_bundler/path_resolver.py

@@ -0,0 +1,25 @@
+"""
+Ruby Path Resolver that looks for the executable by runtime first, before proceeding to 'ruby' in PATH.
+"""
+
+from whichcraft import which
+
+
+class RubyPathResolver(object):
+
+    def __init__(self, runtime):
+        self.language = 'ruby'
+        self.runtime = runtime
+        self.executables = [self.runtime, self.language]
+
+    def _which(self):
+        for executable in self.executables:
+            path = which(executable)
+            if path:
+                return path
+        raise ValueError("Path resolution for runtime: {} of language: "
+                         "{} was not successful".format(self.runtime, self.language))
+
+    @property
+    def path(self):
+        return self._which()

aws_lambda_builders/workflows/ruby_bundler/validator.py

@@ -0,0 +1,61 @@
+"""
+Supported Runtimes and their validations.
+"""
+
+import logging
+import os
+import subprocess
+
+from aws_lambda_builders.exceptions import MisMatchRuntimeError
+
+LOG = logging.getLogger(__name__)
+
+
+class RubyRuntimeValidator(object):
+    SUPPORTED_RUNTIMES = [
+        "ruby2.5"
+    ]
+
+    def __init__(self, runtime, runtime_path):
+        self.language = "ruby"
+        self.runtime = runtime
+        self.runtime_path = runtime_path
+
+    def has_runtime(self):
+        """
+        Checks if the runtime is supported.
+        :param string runtime: Runtime to check
+        :return bool: True, if the runtime is supported.
+        """
+        return self.runtime in self.SUPPORTED_RUNTIMES
+
+    def validate_runtime(self):
+        """
+        Checks if the language supplied matches the required lambda runtime
+        :param string runtime_path: runtime to check eg: /usr/bin/python3.6
+        :raises MisMatchRuntimeError: Version mismatch of the language vs the required runtime
+        """
+        if not self.has_runtime():
+            LOG.warning("'%s' runtime is not "
+                        "a supported runtime", self.runtime_path)
+            return
+        cmd = self._validate_ruby(self.runtime_path)
+
+        p = subprocess.Popen(cmd,
+                             cwd=os.getcwd(),
+                             stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        p.communicate()
+        if p.returncode != 0:
+            raise MisMatchRuntimeError(language=self.language,
+                                       required_runtime=self.runtime,
+                                       runtime_path=self.runtime_path)
+
+    def _validate_ruby(self, runtime_path):
+        major, minor = self.runtime.replace(self.language, "").split('.')
+        cmd = [
+            runtime_path,
+            "-e",
+            "unless RUBY_VERSION.match(/{major}\.{minor}\.\d/); exit(1); end".format(
+                major=major,
+                minor=minor)]
+        return cmd

aws_lambda_builders/workflows/ruby_bundler/workflow.py

@@ -4,6 +4,8 @@
 
 from aws_lambda_builders.workflow import BaseWorkflow, Capability
 from aws_lambda_builders.actions import CopySourceAction
+from aws_lambda_builders.workflows.ruby_bundler.path_resolver import RubyPathResolver
+from aws_lambda_builders.workflows.ruby_bundler.validator import RubyRuntimeValidator
 from .actions import RubyBundlerInstallAction, RubyBundlerVendorAction
 from .utils import OSUtils
 from .bundler import SubprocessBundler
@@ -53,3 +55,9 @@ def __init__(self,
             bundle_install,
             bundle_deployment,
         ]
+
+    def get_executable(self):
+        return RubyPathResolver(runtime=self.runtime).path
+
+    def get_validator(self):
+        return RubyRuntimeValidator(runtime=self.runtime, runtime_path=self.get_executable())