Tentatively store certutil

Commit to repository, even though not yet used.  It is likely to
be renamed.  The purpose is to help generate an appropriate self signed
cert for https including all the ip addresses as subject alternative
names so that names or addresses may be used with installers that
have had the cert injected.

confluent_server/bin/confluentcertutil.py

@@ -0,0 +1,50 @@
+import shutil
+import socket
+import subprocess
+import tempfile
+
+def get_openssl_conf_location():
+    # CentOS/RHAT
+    return '/etc/pki/tls/openssl.cnf'
+
+def get_ip_addresses():
+    lines = subprocess.check_output('ip addr'.split(' '))
+    for line in lines.split('\n'):
+        if line.startswith('    inet6 '):
+            line = line.replace('    inet6 ', '').split('/')[0]
+            if line.startswith('fe80::'):
+                continue
+            if line == '::1':
+                continue
+        elif line.startswith('    inet '):
+            line = line.replace('    inet ', '').split('/')[0]
+            if line == '127.0.0.1':
+                continue
+            if line.startswith('169.254.'):
+                continue
+        else:
+            continue
+        yield line
+
+def create_certificate():
+    shortname = socket.gethostname().split('.')[0]
+    longname = socket.getfqdn()
+    subprocess.check_call(
+        'openssl ecparam -name secp384r1 -genkey -out privkey.pem'.split(' '))
+    san = ['IP:{0}'.format(x) for x in get_ip_addresses()]
+    san.append('DNS:{0}'.format(shortname))
+    san.append('DNS:{0}'.format(longname))
+    san = ','.join(san)
+    sslcfg = get_openssl_conf_location()
+    tmpconfig = tempfile.mktemp()
+    shutil.copy2(sslcfg, tmpconfig)
+    with open(tmpconfig, 'a') as cfgfile:
+        cfgfile.write('\n[SAN]\nsubjectAltName={0}'.format(san))
+    subprocess.check_call(
+        'openssl req -new -x509 -key privkey.pem -days 7300 -out cert.pem '
+        '-subj /CN={0} -extensions SAN '
+        '-config {1}'.format(longname, tmpconfig).split(' ')
+    )
+
+if __name__ == '__main__':
+    create_certificate()