release: add Rack application skeleton for automatic deployment (#45)

GitHub: GH-43

In this PR, we set up a Rack application skeleton for automatic
deployment using webhook.
At the following PRs, we will implement the logic of automatic sign as
first steps.

### Call webhook

```console
$ cd ansible/files/home/deployer/webhook
$ gem install rackup
$ bundle install
$ rackup &
$ curl localhost:9292
127.0.0.1 - - [10/Dec/2024:16:33:28 +0900] "GET / HTTP/1.1" 200 - 0.0001
Hello deployer
```

ansible/files/home/deployer/webhook/.gitignore

@@ -0,0 +1,16 @@
+# 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/>.
+
+/Gemfile.lock

ansible/files/home/deployer/webhook/Gemfile

@@ -0,0 +1,18 @@
+# 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/>.
+
+source "https://rubygems.org"
+
+gem "rack"

ansible/files/home/deployer/webhook/config.ru

@@ -0,0 +1,18 @@
+# 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/>.
+
+require_relative "lib/deployer"
+
+run Deployer::App.new

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

@@ -0,0 +1,16 @@
+# 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/>.
+
+require_relative "deployer/app"

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

@@ -0,0 +1,22 @@
+# 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 App
+    def call(env)
+      [200, {}, ["Hello deployer"]]
+    end
+  end
+end