Show commit hash in IDE

The IDE will show the version it is running.

This value is the output of
    git describe --tags

Heroku doesn't keep the git repository data, so we need to cache the
result during the Travis build for Heroku to use.

Signed-off-by: Jadon Fowler <jadonflower@gmail.com>

Author: phase

.travis.yml

@@ -7,6 +7,7 @@ before_script:
 - git clone https://github.com/felix-lang/fbuild.git
 script:
 - fbuild/fbuild-light && build/tst
+- git describe --tags --always >> version.txt
 addons:
   apt:
     packages:
@@ -15,6 +16,7 @@ deploy:
   provider: heroku
   api_key:
     secure: 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
+  skip_cleanup: true
   app: o-lang
   on:
     repo: phase/o

ide.py

@@ -1,14 +1,22 @@
 #!/usr/bin/env python
 # NOTE: pass -d to this to print debugging info when the server crashes.
 from flask import Flask, render_template, url_for, request
-from subprocess import Popen, PIPE, check_call
+from subprocess import Popen, PIPE, check_call, check_output
 import sys, os, string, glob, logging, pathlib
 
 app = Flask(__name__)
 
 app.logger.addHandler(logging.StreamHandler(sys.stdout))
 app.logger.setLevel(logging.ERROR)
 
+# Git commit hash for easy version checking
+version = ""
+if os.path.isfile("version.txt"):
+    with open("version.txt", "r") as f:
+        version = f.readline().strip()
+else:
+    version = check_output(["git", "describe", "--tags", "--always"]).decode("utf-8")
+
 def compileO():
     r = check_call(['make', 'ide'])
     print("o-ide: " + "".join(glob.glob("oide*")))
@@ -38,12 +46,12 @@ def index():
         #Output to IDE
         if p.returncode:
             print('Output:', output, 'error:', error)
-            return render_template('error.html', code=code, input=input, error=error)
+            return render_template('error.html', version=version, code=code, input=input, error=error)
         else:
             print('Output:', output, 'stack:', error)
-            return render_template('code.html', code=code, input=input, output=output, stack=error or '[]')
+            return render_template('code.html', version=version, code=code, input=input, output=output, stack=error or '[]')
     else:
-        return render_template('primary.html')
+        return render_template('primary.html', version=version)
 
 @app.route('/link/')
 @app.route('/link/<code>/')

templates/primary.html

@@ -11,7 +11,9 @@
   <div class="col-xs-6">
     <h1><a href="https://github.com/phase/o">O</a> Language IDE</h1>
     <p>You can find documentation for the O Programming Language at <a href="https://o.readthedocs.org">o.readthedocs.org</a>.
-       The GitHub repository is located at <a href="https://github.com/phase/o">github.com/phase/o</a>.</p>
+       The GitHub repository is located at <a href="https://github.com/phase/o">github.com/phase/o</a>.<br/><br/>
+       Current Version: <b>{{ version }}</b>
+    </p>
     <br/>
     <p id="byteCount">0 bytes and 0 chars long.</p>
     <p>Code</p>