fix: always use python3 for the installer

This actually breaks compatability since now we drop python2 support completely, but it's worth it to fix the weird issues with trying to support both versions.

Closes #3740
Closes #3752
Refs #3717

contrib/dokku-installer.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import cgi
 import json
@@ -16,12 +16,29 @@ import threading
 
 VERSION = 'v0.19.2'
 
+def bytes_to_string(b):
+    if type(b) == bytes:
+        encoding = sys.stdout.encoding
+        if encoding is None:
+            encoding = 'utf-8'
+        b = b.decode(encoding)
+    b = b.strip()
+    return b
+
+
+def string_to_bytes(s):
+    if type(s) == str:
+        encoding = sys.stdout.encoding
+        if encoding is None:
+            encoding = 'utf-8'
+        s = s.encode(encoding)
+    return s
+
+
 hostname = ''
 try:
     command = "bash -c '[[ $(dig +short $HOSTNAME) ]] && echo $HOSTNAME || wget -q -O - icanhazip.com'"
-    hostname = subprocess.check_output(command, shell=True)
-    if ':' in hostname:
-        hostname = ''
+    hostname = bytes_to_string(subprocess.check_output(command, shell=True))
 except subprocess.CalledProcessError:
     pass
 
@@ -37,14 +54,14 @@ admin_keys = []
 if os.path.isfile(key_file):
     try:
         command = "cat {0}".format(key_file)
-        admin_keys = subprocess.check_output(command, shell=True).strip().split("\n")
+        admin_keys = bytes_to_string(subprocess.check_output(command, shell=True)).strip().split("\n")
     except subprocess.CalledProcessError:
         pass
 
 ufw_display = 'block'
 try:
     command = "sudo ufw status"
-    ufw_output = subprocess.check_output(command, shell=True).strip()
+    ufw_output = bytes_to_string(subprocess.check_output(command, shell=True).strip())
     if "inactive" in ufw_output:
         ufw_display = 'none'
 except subprocess.CalledProcessError:
@@ -55,7 +72,7 @@ nginx_dir = '/etc/nginx'
 nginx_init = '/etc/init.d/nginx'
 try:
     command = "test -x /usr/bin/openresty"
-    subprocess.check_output(command, shell=True).strip()
+    subprocess.check_output(command, shell=True)
     nginx_dir = '/usr/local/openresty/nginx/conf'
     nginx_init = '/etc/init.d/openresty'
 except subprocess.CalledProcessError:
@@ -84,8 +101,8 @@ def check_boot():
             f.write("[Install]\n")
             f.write("WantedBy=multi-user.target\n")
             f.write("WantedBy=graphical.target\n")
-    if os.path.exists(nginx_dir):
-        with open('{0}/dokku-installer.conf'.format(nginx_dir), 'w') as f:
+    if os.path.exists(nginx_conf_dir):
+        with open('{0}/dokku-installer.conf'.format(nginx_conf_dir), 'w') as f:
             f.write("upstream dokku-installer { server 127.0.0.1:2000; }\n")
             f.write("server {\n")
             f.write("  listen      80;\n")
@@ -99,6 +116,13 @@ def check_boot():
 
 
 class GetHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+    def write_content(self, content):
+        try:
+            self.wfile.write(content)
+        except TypeError:
+            self.wfile.write(string_to_bytes(content))
+
+
     def do_GET(self):
         content = PAGE.replace('{VERSION}', VERSION)
         content = content.replace('{UFW_DISPLAY}', ufw_display)
@@ -107,7 +131,7 @@ class GetHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
         content = content.replace('{ADMIN_KEYS}', "\n".join(admin_keys))
         self.send_response(200)
         self.end_headers()
-        self.wfile.write(content)
+        self.write_content(content)
 
     def do_POST(self):
         if self.path not in ['/setup', '/setup/']:
@@ -148,7 +172,10 @@ class GetHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
             user = user + str(index)
             command = ['sshcommand', 'acl-add', 'dokku', user]
             proc = subprocess.Popen(command, stdin=subprocess.PIPE)
-            proc.stdin.write(key)
+            try:
+                proc.stdin.write(key)
+            except TypeError:
+                proc.stdin.write(string_to_bytes(key))
             proc.stdin.close()
             proc.wait()
 
@@ -161,9 +188,11 @@ class GetHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
         if 'selfdestruct' in sys.argv:
             DeleteInstallerThread()
 
+        content = json.dumps({'status': 'ok'})
+
         self.send_response(200)
         self.end_headers()
-        self.wfile.write(json.dumps({'status': 'ok'}))
+        self.write_content(content)
 
     def web_admin_user_exists(self):
         return self.user_exists('web-admin(\d+)')

debian/control

@@ -5,7 +5,7 @@ Priority: optional
 Architecture: amd64
 Depends: locales, git, curl, man-db, netcat, sshcommand (>= 0.6.0), gliderlabs-sigil, docker-engine-cs (>= 1.13.0) | docker-engine (>= 1.13.0) | docker-io (>= 1.13.0) | docker.io (>= 1.13.0) | docker-ce (>= 1.13.0) | docker-ee (>= 1.13.0), net-tools, software-properties-common, procfile-util, python-software-properties | python3-software-properties, rsyslog, dos2unix, jq
 Recommends: herokuish (>= 0.3.4), parallel, dokku-update
-Pre-Depends: nginx (>= 1.8.0) | openresty, dnsutils, cgroupfs-mount | cgroup-lite, plugn (>= 0.3.0), sudo, python | python2.7 | python3, debconf
+Pre-Depends: nginx (>= 1.8.0) | openresty, dnsutils, cgroupfs-mount | cgroup-lite, plugn (>= 0.3.0), sudo, python3, debconf
 Maintainer: Jose Diaz-Gonzalez <dokku@josediazgonzalez.com>
 Description: Docker-powered PaaS that helps build and manage the lifecycle of applications
  Dokku is an extensible, open source Platform as a Service