WIP: Validating config in docs

api/CONTRIBUTING.md

@@ -26,6 +26,12 @@ The documentation can be built locally in the root of https://github.com/envoypr
 docs/build.sh
 ```
 
+To skip configuration examples validation:
+
+```
+SPHINX_SKIP_CONFIG_VALIDATION=true docs/build.sh
+```
+
 Or to use a hermetic Docker container:
 
 ```

docs/README.md

@@ -4,7 +4,13 @@
 ./docs/build.sh
 ```
 
-The output can be found in `generated/docs`.
+The output can be found in `generated/docs`. By default configuration examples are going to be validated during build. 
+To disable validation, set `SPHINX_SKIP_CONFIG_VALIDATION` environment variable to `true`:
+
+```bash
+SPHINX_SKIP_CONFIG_VALIDATION=true docs/build.sh
+```
+
 
 # How the Envoy website and docs are updated
 

docs/_ext/validating_code_block.py

@@ -0,0 +1,62 @@
+from typing import List
+from docutils import nodes
+from docutils.parsers.rst import Directive
+from docutils.parsers.rst import directives
+from sphinx.application import Sphinx
+from sphinx.util.docutils import SphinxDirective
+from sphinx.directives.code import CodeBlock
+from sphinx.errors import ExtensionError
+
+import os
+import subprocess
+
+
+class ValidatingCodeBlock(CodeBlock):
+  """A directive that provides protobuf yaml formatting and validation.
+
+    'type-name' option is required and expected to conain full Envoy API type.
+    An ExtensionError is raised on validation failure.
+    Validation will be skipped if SPHINX_SKIP_CONFIG_VALIDATION environment variable is set.
+    """
+  has_content = True
+  required_arguments = CodeBlock.required_arguments
+  optional_arguments = CodeBlock.optional_arguments
+  final_argument_whitespace = CodeBlock.final_argument_whitespace
+  option_spec = {
+      'type-name': directives.unchanged,
+  }
+  option_spec.update(CodeBlock.option_spec)
+  skip_validation = (os.getenv('SPHINX_SKIP_CONFIG_VALIDATION') or 'false').lower() == 'true'
+
+  def run(self):
+    source, line = self.state_machine.get_source_and_line(self.lineno)
+    # built-in directives.unchanged_required option validator produces a confusing error message
+    if self.options.get('type-name') == None:
+      raise ExtensionError("Expected type name in: {0} line: {1}".format(source, line))
+
+    if not ValidatingCodeBlock.skip_validation:
+      args = [
+          'bazel-bin/tools/config_validation/validate_fragment',
+          self.options.get('type-name'), '-s', '\n'.join(self.content)
+      ]
+      completed = subprocess.run(args,
+                                 stdout=subprocess.PIPE,
+                                 stderr=subprocess.PIPE,
+                                 encoding='utf-8')
+      if completed.returncode != 0:
+        raise ExtensionError(
+            "Failed config validation for type: '{0}' in: {1} line: {2}:\n {3}".format(
+                self.options.get('type-name'), source, line, completed.stderr))
+
+    self.options.pop('type-name', None)
+    return list(CodeBlock.run(self))
+
+
+def setup(app):
+  app.add_directive("validated-code-block", ValidatingCodeBlock)
+
+  return {
+      'version': '0.1',
+      'parallel_read_safe': True,
+      'parallel_write_safe': True,
+  }

docs/build.sh

@@ -1,5 +1,8 @@
 #!/usr/bin/env bash
 
+# set SPHINX_SKIP_CONFIG_VALIDATION environment variable to true to skip 
+# validation of configuration examples
+
 . tools/shell_utils.sh
 
 set -e
@@ -126,6 +129,9 @@ cp -f "${CONFIGS_DIR}"/google-vrp/envoy-edge.yaml "${GENERATED_RST_DIR}"/configu
 
 rsync -rav  $API_DIR/diagrams "${GENERATED_RST_DIR}/api-docs"
 
-rsync -av "${SCRIPT_DIR}"/root/ "${SCRIPT_DIR}"/conf.py "${GENERATED_RST_DIR}"
+rsync -av "${SCRIPT_DIR}"/root/ "${SCRIPT_DIR}"/conf.py "${SCRIPT_DIR}"/_ext "${GENERATED_RST_DIR}"
+
+# To speed up validate_fragment invocations in validating_code_block 
+bazel build ${BAZEL_BUILD_OPTIONS} //tools/config_validation:validate_fragment
 
 sphinx-build -W --keep-going -b html "${GENERATED_RST_DIR}" "${DOCS_OUTPUT_DIR}"

docs/conf.py

@@ -67,7 +67,13 @@ def setup(app):
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = ['sphinxcontrib.httpdomain', 'sphinx.ext.extlinks', 'sphinx.ext.ifconfig']
+
+sys.path.append(os.path.abspath("./_ext"))
+
+extensions = [
+    'sphinxcontrib.httpdomain', 'sphinx.ext.extlinks', 'sphinx.ext.ifconfig',
+    'validating_code_block'
+]
 extlinks = {
     'repo': ('https://github.com/envoyproxy/envoy/blob/{}/%s'.format(blob_sha), ''),
     'api': ('https://github.com/envoyproxy/envoy/blob/{}/api/%s'.format(blob_sha), ''),

docs/root/configuration/operations/runtime.rst

@@ -24,7 +24,8 @@ runtime <envoy_v3_api_msg_config.bootstrap.v3.LayeredRuntime>` bootstrap configu
 layering. Runtime settings in later layers override earlier layers. A typical configuration might
 be:
 
-.. code-block:: yaml
+.. validated-code-block:: yaml
+  :type-name: envoy.config.bootstrap.v3.LayeredRuntime
 
   layers:
   - name: static_layer_0

docs/root/configuration/overview/examples.rst

@@ -9,7 +9,8 @@ Static
 
 A minimal fully static bootstrap config is provided below:
 
-.. code-block:: yaml
+.. validated-code-block:: yaml
+  :type-name: envoy.config.bootstrap.v3.Bootstrap
 
   admin:
     access_log_path: /tmp/admin_access.log
@@ -61,7 +62,8 @@ discovery <arch_overview_dynamic_config_eds>` via an
 :ref:`EDS<envoy_v3_api_file_envoy/service/endpoint/v3/eds.proto>` gRPC management server listening
 on 127.0.0.1:5678 is provided below:
 
-.. code-block:: yaml
+.. validated-code-block:: yaml
+  :type-name: envoy.config.bootstrap.v3.Bootstrap
 
   admin:
     access_log_path: /tmp/admin_access.log
@@ -100,8 +102,8 @@ on 127.0.0.1:5678 is provided below:
           api_config_source:
             api_type: GRPC
             grpc_services:
-              envoy_grpc:
-                cluster_name: xds_cluster
+              - envoy_grpc:
+                  cluster_name: xds_cluster
     - name: xds_cluster
       connect_timeout: 0.25s
       type: STATIC
@@ -159,7 +161,8 @@ A fully dynamic bootstrap configuration, in which all resources other than
 those belonging to the management server are discovered via xDS is provided
 below:
 
-.. code-block:: yaml
+.. validated-code-block:: yaml
+  :type-name: envoy.config.bootstrap.v3.Bootstrap
 
   admin:
     access_log_path: /tmp/admin_access.log
@@ -171,14 +174,14 @@ below:
       api_config_source:
         api_type: GRPC
         grpc_services:
-          envoy_grpc:
-            cluster_name: xds_cluster
+          - envoy_grpc:
+              cluster_name: xds_cluster
     cds_config:
       api_config_source:
         api_type: GRPC
         grpc_services:
-          envoy_grpc:
-            cluster_name: xds_cluster
+          - envoy_grpc:
+              cluster_name: xds_cluster
 
   static_resources:
     clusters:
@@ -226,8 +229,8 @@ The management server could respond to LDS requests with:
               api_config_source:
                 api_type: GRPC
                 grpc_services:
-                  envoy_grpc:
-                    cluster_name: xds_cluster
+                  - envoy_grpc:
+                      cluster_name: xds_cluster
           http_filters:
           - name: envoy.filters.http.router
 
@@ -262,8 +265,8 @@ The management server could respond to CDS requests with:
         api_config_source:
           api_type: GRPC
           grpc_services:
-            envoy_grpc:
-              cluster_name: xds_cluster
+            - envoy_grpc:
+                cluster_name: xds_cluster
 
 The management server could respond to EDS requests with:
 

tools/config_validation/validate_fragment.py

@@ -19,6 +19,8 @@
 
 from bazel_tools.tools.python.runfiles import runfiles
 
+import argparse
+
 
 def ValidateFragment(type_name, fragment):
   """Validate a dictionary representing a JSON/YAML fragment against an Envoy API proto3 type.
@@ -50,7 +52,21 @@ def ValidateFragment(type_name, fragment):
   json_format.Parse(json_fragment, msg, descriptor_pool=pool)
 
 
+def ParseArgs():
+  parser = argparse.ArgumentParser(
+      description='Validate a YAML fragment against an Envoy API proto3 type.')
+  parser.add_argument(
+      'message_type',
+      help='a string providing the type name, e.g. envoy.config.bootstrap.v3.Bootstrap.')
+  parser.add_argument('fragment_path', nargs='?', help='Path to a YAML configuration fragment.')
+  parser.add_argument('-s', required=False, help='YAML configuration fragment.')
+
+  return parser.parse_args()
+
+
 if __name__ == '__main__':
-  type_name, yaml_path = sys.argv[1:]
-  ValidateFragment(type_name, yaml.load(pathlib.Path(yaml_path).read_text(),
-                                        Loader=yaml.FullLoader))
+  parsed_args = ParseArgs()
+  message_type = parsed_args.message_type
+  content = parsed_args.s if (parsed_args.fragment_path is None) else pathlib.Path(
+      parsed_args.fragment_path).read_text()
+  ValidateFragment(message_type, yaml.load(content, Loader=yaml.FullLoader))