release: trigger release processes when release workflow succeeded (#47)

GitHub: GH-43

In this PR, we set up how release flow is triggered from webhook
requests.

---------

Co-authored-by: Horimoto Yasuhiro <[email protected]>

Author: otegami

ansible/files/home/deployer/webhook/lib/deployer/app.rb

@@ -14,7 +14,9 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+require "json"
 require "openssl"
+require_relative "payload"
 require_relative "response"
 
 module Deployer
@@ -29,23 +31,70 @@ def call(env)
     private
 
     def process(request, response)
-      unless request.post?
-        response.set(:method_not_allowed, "must POST")
-        return
-      end
-
-      unless valid_signature?(request)
-        response.set(:unauthorized, "Authorization failed")
-        return
+      begin
+        unless request.post?
+          raise RequestError.new(:method_not_allowed, "must POST")
+        end
+        verify_signature!(request)
+        payload = parse_body!(request)
+        process_payload!(payload)
+      rescue RequestError => request_error
+        response.set(request_error.status, request_error.message)
+      rescue => e
+        response.set(:internal_server_error, e.message)
       end
     end
 
-    def valid_signature?(request)
+    def verify_signature!(request)
       hmac_sha256 = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new("sha256"),
                                             ENV["SECRET_TOKEN"],
                                             request.body.read)
       signature = "sha256=#{hmac_sha256}"
-      Rack::Utils.secure_compare(signature, request.env["HTTP_X_HUB_SIGNATURE_256"])
+      unless Rack::Utils.secure_compare(signature, request.env["HTTP_X_HUB_SIGNATURE_256"])
+        raise RequestError.new(:unauthorized, "Authorization failed")
+      end
+    end
+
+    def parse_body!(request)
+      unless request.media_type == "application/json"
+        raise RequestError.new(:bad_request, "invalid payload format")
+      end
+
+      body = request.body.read
+      if body.nil?
+        raise RequestError.new(:bad_request, "request body is missing")
+      end
+
+      begin
+        raw_payload = JSON.parse(body)
+      rescue JSON::ParserError
+        raise RequestError.new(:bad_request, "invalid JSON format: <#{$!.message}>")
+      end
+
+      metadata = {
+        "x-github-event" => request.env["HTTP_X_GITHUB_EVENT"]
+      }
+      Payload.new(raw_payload, metadata)
+    end
+
+    def process_payload!(payload)
+      case payload.event_name
+      when "ping"
+        # Do nothing because this is a kind of healthcheck.
+        nil
+      when "workflow_run"
+        return unless payload.released?
+        deploy(payload)
+      else
+        raise RequestError.new(:bad_request, "Unsupported event: <#{payload.event_name}>")
+      end
+    end
+
+    def deploy(payload)
+      Thread.new do
+        # TODO: call rake tasks for sign packages.
+        # TODO: write down the errors into log files.
+      end
     end
   end
 end

ansible/files/home/deployer/webhook/lib/deployer/error.rb

@@ -0,0 +1,29 @@
+# Copyright (C) 2024  Horimoto Yasuhiro <[email protected]>
+# Copyright (C) 2024  Takuya Kodama <[email protected]>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+module Deployer
+  class Error < StandardError
+  end
+
+  class RequestError < Error
+    attr_reader :status, :message
+
+    def initialize(status, message)
+      @status = status
+      @message = message
+    end
+  end
+end

ansible/files/home/deployer/webhook/lib/deployer/payload.rb

@@ -0,0 +1,73 @@
+# Copyright (C) 2010-2019  Sutou Kouhei <[email protected]>
+# Copyright (C) 2015  Kenji Okimoto <[email protected]>
+# Copyright (C) 2024  Takuya Kodama <[email protected]>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+module Deployer
+  class Payload
+    RELEASE_WORKFLOWS = ["Package", "CMake"].freeze
+
+    def initialize(data, metadata={})
+      @data = data
+      @metadata = metadata
+    end
+
+    def [](key)
+      @data.dig(*key.split("."))
+    end
+
+    def event_name
+      @metadata["x-github-event"]
+    end
+
+    def workflow_name
+      self["workflow_run.name"]
+    end
+
+    def workflow_succeeded?
+      self["workflow_run.conclusion"] == "success"
+    end
+
+    def branch
+      self["workflow_run.head_branch"]
+    end
+
+    def version
+      return unless workflow_tag?
+      branch.delete_prefix("v")
+    end
+
+    def released?
+      RELEASE_WORKFLOWS.include?(workflow_name) &&
+      workflow_tag? &&
+      workflow_succeeded?
+    end
+
+    def repository_owner
+      self["repository.owner.login"]
+    end
+
+    def repository_name
+      self["repository.name"]
+    end
+
+    private
+
+    def workflow_tag?
+      return false unless branch
+      branch.match?(/\Av\d+(\.\d+){1,2}\z/)
+    end
+  end
+end