Warm the user when upgrading (#115)

Author: stilvoid

python/rpdk/go/codegen.py

@@ -12,14 +12,23 @@
 from rpdk.core.jsonutils.resolver import resolve_models
 from rpdk.core.plugin_base import LanguagePlugin
 
+from . import __version__
 from .resolver import translate_type
 from .utils import safe_reserved, validate_path
+from .version import check_version
 
 LOG = logging.getLogger(__name__)
 
 OPERATIONS = ("Create", "Read", "Update", "Delete", "List")
 EXECUTABLE = "cfn-cli"
 
+LANGUAGE = "go"
+
+DEFAULT_SETTINGS = {
+    "protocolVersion": "1.0",
+    "pluginVersion": __version__,
+}
+
 
 class GoExecutableNotFoundError(SysExitRecommendedError):
     pass
@@ -121,6 +130,7 @@ def _init_settings(self, project):
         project.runtime = self.RUNTIME
         project.entrypoint = self.ENTRY_POINT.format(self.import_path)
         project.test_entrypoint = self.TEST_ENTRY_POINT.format(self.import_path)
+        project.settings.update(DEFAULT_SETTINGS)
 
     def init_handlers(self, project, src):
         LOG.debug("Writing stub handlers")
@@ -172,6 +182,23 @@ def generate(self, project):
             except (FileNotFoundError, CalledProcessError) as e:
                 raise DownstreamError("go fmt failed") from e
 
+        # Update settings as needed
+        need_to_write = False
+        for key, new in DEFAULT_SETTINGS.items():
+            old = project.settings.get(key)
+
+            if project.settings.get(key) != new:
+                LOG.debug(f"{key} version change from {old} to {new}")
+                project.settings[key] = new
+                need_to_write = True
+
+                if key == "pluginVersion":
+                    # Display any upgrade messages
+                    print(*check_version(old), sep="\n")
+
+        if need_to_write:
+            project._write_settings(LANGUAGE)
+
     @staticmethod
     def pre_package(project):
         # zip the Go build output - it's all needed to execute correctly

python/rpdk/go/version.py

@@ -0,0 +1,45 @@
+"""
+The version package contains warning messages that should be displayed
+to a Go plugin user when upgrading from an older version of the plugin
+"""
+
+import semver
+
+"""
+If there are breaking changes that need to be communicated to a user,
+add them to this dict. For readability, an opening and closing newline
+is recommended for each warning message
+"""
+WARNINGS = {
+    # FIXME: Version number to be finalised
+    semver.VersionInfo(
+        0, 1, 3
+    ): """
+Generated models no longer use the types exported in the encoding package.
+Your model's fields have been regenerated using standard pointer types (*string, *int, etc) as used in the AWS Go SDK.
+The AWS SDK has helper functions that you can use to get and set your model's values.
+
+Make the following changes to your handler code as needed:
+
+* Replace `encoding.New{Type}` with `aws.{Type}`
+* Replace `model.{field}.Value()` with `aws.{Type}Value(model.{field})`
+
+Where {Type} is either String, Bool, Int, or Float64 and {field} is any field within your generated model.
+""",
+}
+
+
+def check_version(current_version):
+    """
+    check_version compares the user's current plugin version with each
+    version in WARNINGS and returns any appropriate messages
+    """
+
+    if current_version is not None:
+        current_version = semver.VersionInfo.parse(current_version)
+
+    return [
+        f"Change message for Go plugin v{version}:" + WARNINGS[version]
+        for version in sorted(WARNINGS.keys())
+        if current_version is None or current_version < version
+    ]

setup.py

@@ -36,7 +36,7 @@ def find_version(*file_paths):
     # package_data -> use MANIFEST.in instead
     include_package_data=True,
     zip_safe=True,
-    install_requires=["cloudformation-cli>=0.1,<0.2"],
+    install_requires=["cloudformation-cli>=0.1,<0.2", "semver>=2.9.0",],
     python_requires=">=3.6",
     entry_points={"rpdk.v1.languages": ["go = rpdk.go.codegen:GoLanguagePlugin"]},
     license="Apache License 2.0",