1 files changed, 96 insertions, 0 deletions
diff --git a/lib/shell_utils.rb b/lib/shell_utils.rb
new file mode 100644
index 0000000..5ce8959
--- /dev/null
+++ b/lib/shell_utils.rb
@@ -0,0 +1,96 @@
+# GOV.UK Mini Environment Admin
+# Copyright © 2018  Christopher Baines <mail@cbaines.net>
+#
+# This file is part of the GOV.UK Mini Environment Admin.
+#
+# The GOV.UK Mini Environment Admin is free software: you can
+# redistribute it and/or modify it under the terms of the GNU Affero
+# General Public License as published by the Free Software Foundation,
+# either version 3 of the License, or (at your option) any later
+# version.
+#
+# The GOV.UK Mini Environment Admin 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public
+# License along with the GOV.UK Mini Environment Admin.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+require 'open3'
+require 'shellwords'
+
+module ShellUtils
+  def run_command(*command, run_remotely_on_host: nil)
+    if run_remotely_on_host
+      command = command.map do |arg|
+        Shellwords.escape(arg)
+      end
+
+      command = [
+        'ssh',
+        run_remotely_on_host,
+        *command
+      ]
+    end
+
+    logger.debug("#{self.class}: Running command #{command.join(' ')}")
+
+    Open3.popen2e(*command) do |_stdin, stdout_and_stderr, wait_thr|
+      logger.info("#{self.class}: commmand running, pid #{wait_thr.pid}")
+
+      output = []
+      stdout_and_stderr.each_line do |line|
+        logger.debug(self.class) { line.chomp }
+        output << line
+      end
+
+      exit_status = wait_thr.value
+      unless exit_status == 0
+        logger.error(self.class) { "failed, exit status #{exit_status}" }
+
+        raise "Running #{command.join(' ')} failed:\n\n#{output.join}\n"
+      end
+
+      output
+    end
+  end
+
+  def read_json_file(filename, from_remote_host: nil)
+    if from_remote_host
+      command = [
+        'ssh',
+        from_remote_host,
+        'cat',
+        filename
+      ]
+
+      stdout_str, status = Open3.capture2(*command)
+
+      unless status.exitstatus == 0
+        logger.error(self.class) { "failed, exit status #{exit_status}" }
+
+        raise "Running #{command.join(' ')} failed:\n\n#{output.join}\n"
+      end
+
+      JSON.parse(stdout_str)
+    else
+      JSON.parse(File.read(filename))
+    end
+  end
+
+  def hash_to_arguments(hash)
+    hash.flat_map do |(key, value)|
+      transformed_key = key.to_s.tr('_', '-')
+
+      if value == true
+        ["--#{transformed_key}"]
+      elsif value.kind_of?(Array)
+        value.map { |x| "--#{transformed_key}=#{x}" }
+      else
+        ["--#{transformed_key}=#{value}"]
+      end
+    end
+  end
+end