Add Schema validator (#176)

* Add schema validation for dip.yml configuration

* Add option to skip validation with env variable

* Remove schema validation references and unused schema file

* Add schema validation instructions for VSCode in README.md

* Add schema validation for dip.yml using ajv

* Remove schema service from docker-compose.yml and dip.yml validation

* Add development dependency on public_suffix gem

* Add public_suffix as dependency in gemspec

* Add comment about public_suffix version compatibility

* Update public_suffix dependency version upper bound

README.md

@@ -472,6 +472,27 @@ services:
     user: "1000:1000"
 ```
 
+### dip validate
+
+Validates your dip.yml configuration against the JSON schema. The schema validation helps ensure your configuration is correct and follows the expected format.
+
+```sh
+dip validate
+```
+
+The validator will check:
+
+- Required properties are present
+- Property types are correct
+- Values match expected patterns
+- No unknown properties are used
+
+If validation fails, you'll get detailed error messages indicating what needs to be fixed.
+
+You can skip validation by setting `DIP_SKIP_VALIDATION` environment variable.
+
+Add `# yaml-language-server: $schema=https://raw.githubusercontent.com/bibendi/dip/refs/heads/master/schema.json` to the top of your dip.yml to get schema validation in VSCode. Read more about [YAML Language Server](https://github.com/redhat-developer/vscode-yaml?tab=readme-ov-file#associating-schemas).
+
 ## Changelog
 
 https://github.com/bibendi/dip/releases

dip.gemspec

@@ -27,14 +27,18 @@ Gem::Specification.new do |spec|
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
-  spec.files = Dir.glob("lib/**/*") + Dir.glob("exe/*") + %w[LICENSE.txt README.md]
+  spec.files = Dir.glob("lib/**/*") + Dir.glob("exe/*") + %w[LICENSE.txt README.md schema.json]
   spec.bindir = "exe"
   spec.executables = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
   spec.required_ruby_version = ">= 2.7"
 
   spec.add_dependency "thor", ">= 0.20", "< 2"
+  spec.add_dependency "json-schema", "~> 5"
+  # public_suffix >= 6.0 requires Ruby >= 3.0, so we need to specify an upper bound
+  # to maintain compatibility with Ruby 2.7
+  spec.add_dependency "public_suffix", ">= 2.0.2", "< 6.0"
 
   spec.add_development_dependency "bundler", ">= 1.15"
   spec.add_development_dependency "pry-byebug", "~> 3"

dip.yml

@@ -1,3 +1,5 @@
+# yaml-language-server: $schema=./schema.json
+
 version: '7'
 
 compose:

examples/dip.yml

@@ -0,0 +1,131 @@
+version: '8.1.0'
+
+environment:
+  RAILS_ENV: development
+  NODE_ENV: development
+  DATABASE_URL: postgres://user:password@db:5432/myapp_development
+  REDIS_URL: redis://redis:6379/0
+  PORT: ${PORT:-3000}
+  APP_PORT: ${PORT:-3000}
+
+compose:
+  files:
+    - docker-compose.yml
+    - docker-compose.override.yml
+  project_name: myapp_project
+  command: docker compose
+
+interaction:
+  rails:
+    description: Run Rails commands
+    service: web
+    command: bundle exec rails
+    default_args: server -p 3000 -b 0.0.0.0
+    environment:
+      RAILS_LOG_TO_STDOUT: "true"
+    compose:
+      method: run
+      compose_method: up
+      run_options:
+        - service-ports
+        - rm
+      profiles:
+        - web
+        - development
+    shell: true
+    entrypoint: /docker-entrypoint.sh
+    runner: docker_compose
+    subcommands:
+      console:
+        description: Start Rails console
+        command: console
+      routes:
+        description: Show Rails routes
+        command: routes
+      db:
+        description: Database related commands
+        subcommands:
+          migrate:
+            description: Run database migrations
+            command: db:migrate
+          seed:
+            description: Seed the database
+            command: db:seed
+
+  npm:
+    description: Run npm commands
+    service: frontend
+    command: npm
+    compose:
+      method: run
+      profiles:
+        - frontend
+
+  psql:
+    description: Connect to PostgreSQL database
+    service: db
+    command: psql -h db -U user myapp_development
+    compose:
+      method: run
+    environment:
+      PGPASSWORD: password
+
+  rspec:
+    description: Run RSpec tests
+    service: web
+    command: bundle exec rspec
+    environment:
+      RAILS_ENV: test
+    compose:
+      method: run
+      run_options:
+        - rm
+      profiles:
+        - test
+
+  shell:
+    description: Start a shell in the web container
+    service: web
+    command: /bin/bash
+    compose:
+      method: run
+      run_options:
+        - rm
+
+  k8s:
+    description: Run kubectl commands
+    command: kubectl
+    runner: kubectl
+    entrypoint: kubectl
+    shell: false
+
+  brakeman:
+    description: Check brakeman sast
+    command: docker run another-image ...
+
+  rake:
+    description: Run Rake tasks
+    service: web
+    command: bundle exec rake
+
+provision:
+  - dip compose down --volumes
+  - dip compose build
+  - dip rails db:create
+  - dip rails db:migrate
+  - dip rails db:seed
+  - dip npm install
+  - dip validate
+
+kubectl:
+  namespace: myapp-development
+
+modules:
+  - production
+
+infra:
+  redis:
+    git: https://github.com/mycompany/redis-config.git
+    ref: main
+  elasticsearch:
+    path: ./infra/elasticsearch

lib/dip/cli.rb

@@ -5,7 +5,7 @@
 
 module Dip
   class CLI < Thor
-    TOP_LEVEL_COMMANDS = %w[help version ls compose up stop down run provision ssh infra console].freeze
+    TOP_LEVEL_COMMANDS = %w[help version ls compose up stop down run provision ssh infra console validate]
 
     class << self
       # Hackery. Take the run method away from Thor so that we can redefine it.
@@ -117,6 +117,15 @@ def provision
       end
     end
 
+    desc "validate", "Validate the dip.yml file against the schema"
+    def validate
+      Dip.config.validate
+      puts "dip.yml is valid"
+    rescue Dip::Error => e
+      warn "Validation failed: #{e.message}"
+      exit 1
+    end
+
     require_relative "cli/ssh"
     desc "ssh", "ssh-agent container commands"
     subcommand :ssh, Dip::CLI::SSH

lib/dip/config.rb

@@ -3,6 +3,7 @@
 require "yaml"
 require "erb"
 require "pathname"
+require "json-schema"
 
 require "dip/version"
 require "dip/ext/hash"
@@ -112,6 +113,24 @@ def to_h
       end
     end
 
+    def validate
+      raise Dip::Error, "Config file path is not set" if file_path.nil?
+      raise Dip::Error, "Config file not found: #{file_path}" unless File.exist?(file_path)
+
+      schema_path = File.join(File.dirname(__FILE__), "../../schema.json")
+      raise Dip::Error, "Schema file not found: #{schema_path}" unless File.exist?(schema_path)
+
+      data = YAML.load_file(file_path)
+      schema = JSON.parse(File.read(schema_path))
+      JSON::Validator.validate!(schema, data)
+    rescue Psych::SyntaxError => e
+      raise Dip::Error, "Invalid YAML syntax in config file: #{e.message}"
+    rescue JSON::Schema::ValidationError => e
+      data_display = data ? data.to_yaml.gsub("\n", "\n  ") : "nil"
+      error_message = "Schema validation failed: #{e.message}\nInput data:\n  #{data_display}"
+      raise Dip::Error, error_message
+    end
+
     private
 
     attr_reader :work_dir
@@ -129,8 +148,8 @@ def config
 
       unless Gem::Version.new(Dip::VERSION) >= Gem::Version.new(config.fetch(:version))
         raise VersionMismatchError, "Your dip version is `#{Dip::VERSION}`, " \
-                                    "but config requires minimum version `#{config[:version]}`. " \
-                                    "Please upgrade your dip!"
+                                   "but config requires minimum version `#{config[:version]}`. " \
+                                   "Please upgrade your dip!"
       end
 
       base_config = {}
@@ -155,6 +174,12 @@ def config
       base_config.deep_merge!(self.class.load_yaml(override_finder.file_path)) if override_finder.exist?
 
       @config = CONFIG_DEFAULTS.merge(base_config)
+
+      unless ENV.key?("DIP_SKIP_VALIDATION")
+        validate
+      end
+
+      @config
     end
 
     def config_missing_error(config_key)