I have an application that I wish to deploy on path: www.example.com/foo
I have another application that I want to deploy on path: www.example.com/bar
My load balancer currently doesn't support that.
How do I accomplish that? I read about path_beg but I can't seem to grasp it correctly. Is there an example that I can follow?
It's pretty straightforward.
frontend main-frontend
mode http
bind :80
use_backend foo-backend if { path_beg /foo }
use_backend bar-backend if { path_beg /bar }
Then you'd need to declare 2 backends, named "foo-backend" and "bar-backend" pointing to the servers and ports where those apps are listening (could be different servers, or just different ports on the same back-end servers). The names of the backends don't have to have "foo" and "bar" in them, as long as they match the names in the "use_backend" statements.
With this setup, the back-end servers need to be expecting the /foo or /bar at the beginning of the incoming path, because the entire request-path will be forwarded.
It is possible for haproxy to rewrite the path to scrub those out, but that configuration is rather more advanced.
Related
I wrote a Flask web application for a system that our company uses. However, we have another web application, which is running on Node.JS. The "problem" is that my colleague writes everything on node, while I write everything in Python.
We want to implement both applications on one webpage - for example:
My application will run on example.com/assistant
His application will run on example.com/app1 and example.com/app2
How can we do this? Can we somehow implement the templates that I use with his templates and vice-versa?
Thank you in advance!
V
Serving different apps from the same domain
You can use haproxy for directing requests to specific service based on ACL rules.
You could use path_beg rule, to direct any request beginning with specific path to be directed to corresponding server. See example below.
/etc/haproxy/haproxy.cfg
# only relevant part of the config file
# assumes all apps are on one machine
frontend http-in
bind *:80
acl py_app1 path_beg /assistant
acl node_app1 path_beg /app1
acl node_app2 path_beg /app2
default_backend main_servers
backend py_app1
server flask_app 127.0.0.1:5000
backend node_app1
server nodejs1 127.0.0.1:4001
backend node_app2
server nodejs2 127.0.0.1:4002
backend main_servers
server other1 127.0.0.1:3000 # nginx, apache, or whatever
Sharing template code between apps
This would be harder, as you would need to both agree on some kind of format, which needs to be language and framework-agnostic, and probably logic-less.
Mustache claims to be "framework-agnostic way to render logic-free views". I used it sparringly a few years ago so this one is first that came to mind, however you should do more research on this, maybe there is some better fit.
Python implementation
JS implementation
The problem would be to actually keep the templates always in sync with apps, and not break functionality of the views. If a template changes then you would need to test all apps that use this template file. Also, you probably will block one another from updating your apps at different times, because if one of you change the template files, then you must come to a consensus, update all relevant apps, and deploy them at one time.
I just hosted my website on the digital ocean by following below link.
https://www.digitalocean.com/community/tutorials/how-to-set-up-django-with-postgres-nginx-and-gunicorn-on-ubuntu-18-04
It works like a charm.
But i also want to host multiple site on the single drop let. I've no idea that how to host multiple site on the single droplet. Does name matters while creating gunicorn service file and socket file. I mean do I need to create separate service and socket file for separate project and also do i need to create separate sock file for separate project.
You can run as much as resources (RAM, Disk space) you have. For this, there is some tips i list them below:
Have separate virtualenvs for each site, inside its project folder.
Manage Database names to prevent conflicts
Don't use port 8000 and reserve it for tests.
Create separate systemd service for each project. (remember to use separate name for each service)
Therefore you should create separate socket for each site.
First start with 1 worker per site, to lower your resources costs.
Create separate nginx block for each site you have.
with these tips you can have multiple sites in an single droplet easily.
Yes you just have to create separate *.service and *.socket files for each project.
And just don't forget to change all strings in this tutorial from
gunicorn.service
gunicorn.socket
to
your_new_project.service
your_new_project.socket
when I had similar question this answer from DO website helped me.
You just have to change the project name and server_name when doing the "Configure Nginx to Proxy Pass to Gunicorn" part. If done correctly, after you restart nginx both websites will work.
I have a website (which running in Amazon EC2 Instance) running Python Bottle application with CherryPy as its front end web server.
Now I need to add another website with a different domain name already registered. To reduce the cost, I want to utilize the existing website host to do that.
Obviously, virtual host is the solution.
I know Apache mod_wsgi could play the trick. But I don't want to replace CherryPy.
I've googled a a lot, there are some articles showing how to make virtual hosts on CherryPy, but they all assume Cherrypy as Web Sever + Web application, Not CherrPy as Web server and Bottle as Application.
How to use CherrPy as Web server and Bottle as Application to support multiple virtual hosts?
As you mentioned, use VirtualHost. In the example cherrypy.Application instances are used, but any WSGI callable (e. g. Bottle app) will do.
perhaps you can simply put nginx as reverse proxy and configure it to send the traffic to the two domains to the right upstream (the cherryPy webserver).
Another idea would be to use Nginx (http://wiki.nginx.org/Main) with uWsgi(http://projects.unbit.it/uwsgi/) & (uWsgi-python) plug-in
uWsgi has a module named emperor that you can link vhosts(vassals) in, sort of.
i'm a newbie at this myself, so not necessarily an answer but rather a suggestion to check it out.
just a heads up, uWsgi and Nginx can be a hassle to get it to work, depending on your linux distro. Does work nicely with bottle, tested it myself.
hope it helps
jwalker's answer is pretty clear. In case any CherryPy newbie need whole script for reference, I post one below.
import cherrypy
from bottle import Bottle
import os
app1 = Bottle()
app2 = Bottle()
#app1.route('/')
def homePage():
return "========= home1 ==============="
#app2.route('/')
def homePage_2():
return "========= home2 ==============="
vhost = cherrypy._cpwsgi.VirtualHost(None,
domains={
'www.domain1.com': app1,
'www.domain2.com': app2,
}
)
cherrypy.tree.graft(vhost)
cherrypy.config.update({
'server.socket_host': '192.168.1.4',
'server.socket_port': 80,
})
cherrypy.engine.start()
cherrypy.engine.block()
you could make www.domain1.com and www.domain1.com point to one IP adress of you server, so it servers for 2 domain in one Web Server.
I'm using reverse proxy with Nginx.
When I POST a file to the Nginx, it seems that it will store the whole file in local and forward it to the backend server after received the whole file.
Is there a way to make Nginx receive & forward data synchronously？
It's already answered negatively from this SO link: nginx files upload streaming with proxy_pass
The answer of the above question was from one of the guys who is maintaining nginx code base. So you can forget it for now.
If it's really important to not transporting files twice, you may try nginx upload module if you have control over your upstream server. http://wiki.nginx.org/HttpUploadModule.
You mean streaming. Yeah, you probably want to play with proxy_buffering, proxy_store and/or proxy_temp_file_write_size:
http://wiki.nginx.org/HttpProxyModule#proxy_store
http://wiki.nginx.org/HttpProxyModule#proxy_buffering
http://wiki.nginx.org/HttpProxyModule#proxy_temp_file_write_size
Side note: since nginx is single-threaded, then you really want to use that feature (otherwise one upload may block entire server for quite a long time).
We have a hosting setup where we have one top level domain, and we host web applications under subpaths. For instance:
/projects -> Plone
/interal -> Tomcat
etc
In this scenario we need a way to tell the web application at the back end what its base path is, so that it can correctly generate links to its views and static content. For the examples above this is fine.
We have just started using Pyramid, served by Waitress, but so far we've not figure out how to do this. Is there a clean way to configure this base path in Waitress, or is there a more flexible application server that we can use that will support Pyramid?
Everything in WSGI is relative to the current request. You just have to have your environ setup properly (usually by your WSGI server).
For example your web application will know it is mounted at subpath /projects if request.environ['SCRIPT_NAME'] == '/projects'. If you want your application to be agnostic to its mount point, you can simply code it up as if it serves a view at /foo/bar. Then you mount your application on /projects via some middleware which can mutate the environ properly (mod_wsgi and some other servers should be able to do this for you automatically). Now when the incoming URL is /projects/foo/bar the environ['SCRIPT_NAME'] == '/projects' and environ['PATH_INFO'] == '/foo/bar', and your app can focus on the relative path.
In Pyramid this would boil down to an extra step in your ini where you add the prefix middleware to your WSGI stack. The middleware handles mutating the PATH_INFO and SCRIPT_NAME keys in the environ for you.
[app:myapp]
use = egg:myapp
# ...
[filter:proxy-prefix]
use = egg:PasteDeploy#prefix
prefix = /projects
[pipeline:main]
pipeline =
proxy-prefix
myapp
In my pyramid app, in the .ini config files (production and development) I'm doing something like this:
filter-with = urlprefix
[filter:urlprefix]
use = egg:PasteDeploy#prefix
prefix = /mysubfolder
I think it probably accomplishes the same as Michael's answer above; I'm still relatively new to Pyramid as well and am going off of recipes like you. But the end result is that it creates a base URL of /mysubfolder from my root and the rest of the app is relative to that. This is running under pserve locally and I think nginix on my web host.
repoze.vhm should work just fine for your use case.
I think it won't work if you want to use the virtual root feature. I.e a subpath of your proxied web app (https://hidden.tld/root/ should appear as https://example.com/ )
For exposing your app at a subpath of an external domain repoze.vhm works just fine. IMO the best thing about it is, that you don't need to put any subpath config or whatsoever into your web app deployment. This allows you to change the url to whatever you want on the proxy, or even expose the same app instance on multiple domain names and/or subpaths.