[kotlin-server] --library=ktor (barebones implementation) (#7412)

* [tools] Make sed in new.sh more cross-platform

The -r option passed to sed is a GNU sed option for extended regex
evaluation. The -E option evaluates the same option, and is part of the
POSIX standard, meaning this option is available in GNU sed as well as
Apple's BSD variant.

This commit removes the need for users to install gnu-sed on Mac.

* [ktor] Initial ktor (kotlin-server)

This adds a very barebones implementation for a ktor server generator.

This supports metrics and typed locations. All endpoins are stubbed to
return HTTP/1.1 501 Not Implemented.

* [ktor] Initial sample

* [ktor] Adding options for select feature installs

Options available:

* featureAutoHead
* featureConditionalHeaders
* featureHSTS
* featureCORS
* featureCompression

* [ktor] Start of auth functionality

* [ktor] API key auth placeholder

* Add basic support for oauth2 configurations

ktor doesn't seem to explicitly accept oauth flow properties in its
configuration object. This may be a blocker for 'implicit' flow
definitions.

* Added example response objects

* [ktor] Route for apis with bodies, some cleanup

ktor locations are only supported for routes with path/query parameters.
Routes with body or file parameters must be declared with traditional
route api.

This commit also includes lambdas for simplifying processing in
library-based server generator code. As an example, ktor requires
lowercase http methods while spring (a potential future generator)
would require an uppercase such as HttpMethod.GET. It doesn't make sense
to modify these in the operations post-process method because that
format wouldn't be universally desirable.

The lambdas included in the KotlinServerCodegen:
* lowercase: converts all text to lowercase
* uppercase: converts all text to UPPERCASE
* titlecase: converts words (with configurable delim) to Title Case
* indented|indented_8|indented_12|indented_16: these helpers apply the
  same desired indent to all lines of an included fragment's text.

* Fix some javadoc issues in lambda classes

* Update kotlin-server-petstore.bat

Change `kotlin` to `kotlin-server`

* Fix javadoc error messages in CI

bin/kotlin-server-petstore.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+
+SCRIPT="$0"
+
+while [ -h "$SCRIPT" ] ; do
+  ls=$(ls -ld "$SCRIPT")
+  link=$(expr "$ls" : '.*-> \(.*\)$')
+  if expr "$link" : '/.*' > /dev/null; then
+    SCRIPT="$link"
+  else
+    SCRIPT=$(dirname "$SCRIPT")/"$link"
+  fi
+done
+
+if [ ! -d "${APP_DIR}" ]; then
+  APP_DIR=$(dirname "$SCRIPT")/..
+  APP_DIR=$(cd "${APP_DIR}"; pwd)
+fi
+
+executable="./modules/swagger-codegen-cli/target/swagger-codegen-cli.jar"
+
+if [ ! -f "$executable" ]
+then
+  mvn clean package
+fi
+
+# if you've executed sbt assembly previously it will use that instead.
+export JAVA_OPTS="${JAVA_OPTS} -XX:MaxPermSize=256M -Xmx1024M -DloggerPath=conf/log4j.properties -DdebugSupportingFiles=true"
+ags="generate -i modules/swagger-codegen/src/test/resources/2_0/petstore.yaml -t modules/swagger-codegen/src/main/resources/kotlin-server -l kotlin-server --library=ktor -o samples/server/petstore/kotlin-server/ktor $@"
+
+java ${JAVA_OPTS} -jar ${executable} ${ags}

bin/windows/kotlin-server-petstore.bat

@@ -0,0 +1,10 @@
+set executable=.\modules\swagger-codegen-cli\target\swagger-codegen-cli.jar
+
+If Not Exist %executable% (
+  mvn clean package
+)
+
+REM set JAVA_OPTS=%JAVA_OPTS% -Xmx1024M -DloggerPath=conf/log4j.properties
+set ags=generate  --artifact-id "kotlin-petstore-server" -i modules\swagger-codegen\src\test\resources\2_0\petstore.yaml -l kotlin-server --library=ktor -o samples\server\petstore\kotlin
+
+java %JAVA_OPTS% -jar %executable% %ags%

modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenConstants.java

@@ -194,12 +194,15 @@ public static enum ENUM_PROPERTY_NAMING_TYPE {camelCase, PascalCase, snake_case,
     public static final String EXCLUDE_TESTS_DESC = "Specifies that no tests are to be generated.";
 
     // Not user-configurable. System provided for use in templates.
+
+    public static final String GENERATE_APIS = "generateApis";
     public static final String GENERATE_API_DOCS = "generateApiDocs";
 
     public static final String GENERATE_API_TESTS = "generateApiTests";
     public static final String GENERATE_API_TESTS_DESC = "Specifies that api tests are to be generated.";
 
     // Not user-configurable. System provided for use in templates.
+    public static final String GENERATE_MODELS = "generateModels";
     public static final String GENERATE_MODEL_DOCS = "generateModelDocs";
 
     public static final String GENERATE_MODEL_TESTS = "generateModelTests";

modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultGenerator.java

@@ -157,6 +157,9 @@ private void configureGeneratorProperties() {
         config.additionalProperties().put(CodegenConstants.GENERATE_API_DOCS, generateApiDocumentation);
         config.additionalProperties().put(CodegenConstants.GENERATE_MODEL_DOCS, generateModelDocumentation);
 
+        config.additionalProperties().put(CodegenConstants.GENERATE_APIS, generateApis);
+        config.additionalProperties().put(CodegenConstants.GENERATE_MODELS, generateModels);
+
         if (!generateApiTests && !generateModelTests) {
             config.additionalProperties().put(CodegenConstants.EXCLUDE_TESTS, true);
         }

modules/swagger-codegen/src/main/java/io/swagger/codegen/InlineModelResolver.java

@@ -434,7 +434,7 @@ public Model modelFromProperty(MapProperty object, @SuppressWarnings("unused") S
      *
      * @param ref new property name
      * @param property Property
-     * @return
+     * @return {@link Property} A constructed Swagger property
      */
     public Property makeRefProperty(String ref, Property property) {
         RefProperty newProperty = new RefProperty(ref);