Add cb logout command.

These changes add a new command and action called `logout`. The purpose
of these are to allow a user to clear all credentials from their system
which has the effect of logging them out of the system.  To do this, we
remove both the stored credentials/API key. As well, we remove the
cached token regardless of whether or not it is expired.

In the case that none of the above items exist on the system, the effect
is the same as a no-op.

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- `cb logout` to logout a user from the CLI.
+
 
 ## [2.1.0] - 2022-06-03
 ### Added

src/cb/cacheable.cr

@@ -22,15 +22,21 @@ module CB::Cacheable
     end
 
     def fetch?(key)
+      token = fetch key
+
+      return nil unless token
+      return nil if Time.local > token.expires_at
+
+      token
+    end
+
+    def fetch(key)
       begin
         token = from_json File.read(file_path(key))
       rescue File::Error | JSON::ParseException
         return nil
       end
 
-      return nil unless token
-      return nil if Time.local > token.expires_at
-
       token
     end
 
@@ -49,4 +55,8 @@ module CB::Cacheable
     end
     self
   end
+
+  def delete
+    File.delete(self.class.file_path(key))
+  end
 end

src/cb/completion.cr

@@ -87,6 +87,7 @@ class CB::Completion
       "--help\tShow help and usage",
       "version\tShow version information",
       "login\tStore API key",
+      "logout\tRemove stored API key and token",
       "token\tGet current API token",
       "list\tList clusters",
       "team\tManage teams",
@@ -111,7 +112,7 @@ class CB::Completion
     if @client
       options
     else
-      options.first 3
+      options.first 4
     end
   end
 

src/cb/creds.cr

@@ -34,4 +34,9 @@ struct CB::Creds
   def delete
     File.delete CONFIG/host
   end
+
+  def self.delete(host)
+    creds = for_host host
+    creds.delete unless creds.nil?
+  end
 end

src/cb/logout.cr

@@ -0,0 +1,11 @@
+require "./action"
+
+module CB
+  class Logout < Action
+    def run
+      host = CB::HOST
+      Creds.delete(host)
+      Token.delete(host)
+    end
+  end
+end

src/cb/token.cr

@@ -41,6 +41,11 @@ struct CB::Token
     fetch? host
   end
 
+  def self.delete(host)
+    token = fetch host
+    token.delete unless token.nil?
+  end
+
   def expires_at : Time
     Time.unix expires
   end

src/cli.cr

@@ -55,6 +55,11 @@ op = OptionParser.new do |parser|
     action = CB::Login.new
   end
 
+  parser.on("logout", "Remove stored API key and tokens") do
+    parser.banner = "cb logout"
+    action = CB::Logout.new
+  end
+
   parser.on("list", "List clusters") do
     parser.banner = "cb list"
     set_action List