show the Mail-in-a-Box version in the control panel and a button to ping the MiaB website for the latest version

fixes #441

management/daemon.py

@@ -340,6 +340,24 @@ def web_update():
 
 # System
 
+@app.route('/system/version', methods=["GET"])
+@authorized_personnel_only
+def system_version():
+	from status_checks import what_version_is_this
+	try:
+		return what_version_is_this(env)
+	except Exception as e:
+		return (str(e), 500)
+
+@app.route('/system/latest-upstream-version', methods=["POST"])
+@authorized_personnel_only
+def system_latest_upstream_version():
+	from status_checks import get_latest_miab_version
+	try:
+		return get_latest_miab_version()
+	except Exception as e:
+		return (str(e), 500)
+
 @app.route('/system/status', methods=["POST"])
 @authorized_personnel_only
 def system_status():

management/status_checks.py

@@ -789,6 +789,20 @@ def list_apt_updates(apt_update=True):
 
 	return pkgs
 
+def what_version_is_this(env):
+	# This function runs `git describe` on the Mail-in-a-Box installation directory.
+	# Git may not be installed and Mail-in-a-Box may not have been cloned from github,
+	# so this function may raise all sorts of exceptions.
+	miab_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+	tag = shell("check_output", ["/usr/bin/git", "describe"], env={"GIT_DIR": os.path.join(miab_dir, '.git')}).strip()
+	return tag
+
+def get_latest_miab_version():
+	# This pings https://mailinabox.email/bootstrap.sh and extracts the tag named in
+	# the script to determine the current product version.
+	import urllib.request
+	return re.search(b'TAG=(.*)', urllib.request.urlopen("https://mailinabox.email/bootstrap.sh?ping=1").read()).group(1).decode("utf8")
+
 def run_and_output_changes(env, pool, send_via_email):
 	import json
 	from difflib import SequenceMatcher
@@ -969,3 +983,6 @@ if __name__ == "__main__":
 		if cert_status != "OK":
 			sys.exit(1)
 		sys.exit(0)
+
+	elif sys.argv[1] == "--version":
+		print(what_version_is_this(env))

management/templates/index.html

@@ -114,6 +114,7 @@
             </li>
             <li><a href="#sync_guide" onclick="return show_panel(this);">Contacts/Calendar</a></li>
             <li><a href="#web" onclick="return show_panel(this);">Web</a></li>
+            <li><a href="#version" onclick="return show_panel(this);">Version</a></li>
           </ul>
           <ul class="nav navbar-nav navbar-right">
             <li><a href="#" onclick="do_logout(); return false;" style="color: white">Log out?</a></li>
@@ -167,6 +168,10 @@
       {% include "ssl.html" %}
       </div>
 
+      <div id="panel_version" class="admin_panel">
+      {% include "version.html" %}
+      </div>
+
       <hr>
 
       <footer>