Add recipe for installing `Alertmanager`.

cookbooks/prometheus/alertmanager_install.rb

@@ -0,0 +1,57 @@
+alertmanager_url = ''
+alertmanager_bin = ''
+
+vtag             = ''
+tag              = ''
+
+# Calculate the Download URL:
+begin
+  require 'net/http'
+
+  uri = URI.parse('https://github.com/prometheus/alertmanager/releases/latest')
+
+  Timeout.timeout(3) do
+    response = Net::HTTP.get_response(uri)
+
+    vtag = $1 if response.body =~ %r{tag\/(v\d+\.\d+\.\d+)}
+    tag = vtag.sub(/^v/, '')
+
+    alertmanager_bin = "#{node['alertmanager']['prefix']}#{tag}#{node['alertmanager']['postfix']}"
+
+    alertmanager_url = "#{node['alertmanager']['url']}/#{vtag}/#{alertmanager_bin}"
+  end
+rescue
+  # Abort the chef client process:
+  raise 'Cannot connect to http://github.com.'
+end
+
+
+# バージョン確認して、アップデート必要かどうか確認
+result = run_command("alertmanager --version 2>&1 | grep #{tag}", error: false)
+if result.exit_status != 0
+  # Download:
+  TMP = "/tmp/#{alertmanager_bin}"
+
+  execute "wget #{alertmanager_url} -O #{TMP}"
+
+  # Install:
+  directory node['alertmanager']['storage'] do
+    owner 'root'
+    group 'root'
+    mode '755'
+  end
+
+  execute "tar zxf #{TMP} -C #{node['alertmanager']['storage']} --strip-components 1"
+
+  # Change Owner and Permissions:
+  file "#{node['alertmanager']['storage']}alertmanager" do
+    owner 'root'
+    group 'root'
+    mode  '755'
+  end
+
+  # Create Link
+  link "#{node['alertmanager']['location']}alertmanager" do
+    to "#{node['alertmanager']['storage']}alertmanager"
+  end
+end