I'm running a classic style application in Sinatra and I would like to obtain a URL which the application is bound to. For example, if I start it in a development environment I would expect to get: http://localhost:4567/ while in production environment this would point to: http://example.com/
I know it is possible to retrieve it from the request. However, I need it in configuration block. How to do it?
Use the bind host and bind port method:
set :bind, 'example.com'
set :port, 80
should work.
taken from here. at the beginning of the page you can find how to implement them in you app (just copy it in front of your gets)
Related
When I set \p 8080 I can have calls to http://localhost:8080/ to interact with kdb+.
How can I do it for this url:
http://localhost:8080/somepath
?
The use case if for my app that send HTTP requests to the kdb process to get data from the DB. For react reasons that are out of scope here (see this) I can't use http://localhost:8080/.
By default the root server for the q webserver is located in a folder called html under your QHOME folder.
If you had a html document called mydoc.html then you could place it at, for instance,
$QHOME/html/example/mydoc.html
and reach it by calling
http://localhost:8080/example/mydoc.html
There is some info here: https://code.kx.com/q/kb/custom-web/
We let the golem package automatically create a Dockerfile for us and can run the docker image and see the app at the root directory: http://localhost:3838/?...
But we would like the app to appear in a subdirectory like http://localhost:3838/myApp/v1/?... so that we can set up the necessary proxying for Apache and have this and other apps all available from a single server.
We can manually edit the Dockerfile to copy a shiny-server.conf file with the following information:
# Define a server that listens on port 3838
server {
listen 3838;
# Define a location at the base URL
location /myApp/v1/ {
# Host the directory of Shiny Apps stored in this directory
site_dir /srv/shiny-server;
# Log all Shiny output to files in this directory
log_dir /var/log/shiny-server;
}
}
The above solution feels like a hack and we are hoping there is functionality inside of golem that will allow us to set the subdirectory at which the app will appear.
Unfortunately there is no way to include an nginx configuration inside the Dockerfile programmatically: {golem} tries to help with the creation of the file, but some things still need to be done manually.
Also, note that {golem} doesn't create a Dockerfile with a shiny server in it, it creates a standalone docker image that launches the app, so there is no shiny server running, just an R process. {shiny} being what it is, there is no way to natively run it on a given path, it's always at the root, on a port.
That being said, what you can do is either edit the dockerfile so that it also bundle nginx (or any other load balancer), so that you can serve the app on a path, or serve your application on another port, using the port argument of add_dockerfile(): that might be easier to configure it with you Apache proxy.
Colin
This is kind of a weird complicated question.
Context:
I have a bunch of docker containers that need to be routed to from haproxy dynamically. They are each running on different ports on the machine, and are stored in environment variables like this:
a=9873
b=9874
c=9875
These are available to the haproxy server. The request path that comes in will be in the form like this example:
/api/a/action
From that, the taks is as follows:
The /api needs to be removed from the path.
The /a refers to the service, so the environment variable for a needs to be retrieved to get the port of the server
The request needs to be routed to localhost:9873/a/action where the port, 9873, is the environment variable that is the value from the path in the beginning (after removing /api) and then the path is simply appended onto the request (which is the /a/action that remains after removing the /api.
My current config looks like this:
backend api
reqrep ^([^\ ]*\ /)api[/]?(.*) \1\2
server api_server localhost:9871
All this config is doing is removing the /api from the path of the request and sending it to a static port, 9871. *I need this port to be the value held by the environment variable of the same name as the first element in the path (the /a above) and the rest (passing the remaining path) is already working.*
I also would like to be able to get the environment variable of the name prefix_a, where the path will have the name /a, but I need to prepend one common prefix prefix_ to get the environment variable. This can be a separate question or search though, unless it's simple to just put that into the solution.
Please let me know if I can clarify or give more information that might help solve the problem.
(I've done a heck a lot of googling. Here are some related urls but not quite the answer I need:
https://gist.github.com/meineerde/8bea63e64fc47f9a67c0
Dynamic routing to backend based on context path in HAProxy
How can I set up HAProxy to a backend based on a value in the url?
Haproxy route and rewrite based on URI path
haproxy: get the host name
https://serverfault.com/questions/818937/haproxy-is-giving-me-problems-with-regex-replace-is-this-a-bug-or-am-i-doing-so
https://serverfault.com/questions/668025/how-to-use-environment-variable-in-haproxy
http://cbonte.github.io/haproxy-dconv/1.9/configuration.html#7.2
How do I set a dynamic variable in HAProxy?
use environment variables in haproxy
I'm trying to set up a loadbalancer that would redirect to specific version of an application certein users. So far i was using Blue/Green deployment strategy (so once i made new version of an app i created new environment and redirected traffic there). Now i would like to change this approach. I want to be able to specify users (more experienced or whatever) that would see new site after authentication while the others would still be redirected to old one. If something goes wrong with new version all users will see old version. Currently my loadbalancing is made in apache and authentication is done on application level. So is this even possible? I know i could hardcode it in application but what if there is a bug in new feature and new users are still being redirected there? I would then need to stop application for all users and rollback to old version and that's bad i guess. I was thinking about using external CAS however didnt find any information if it would be possible then. So i would like to ask is it possible and are there any tools (maybe some apache plugin) for that purpose?
Here's a working solution with nginx
create conf.d/balancer.conf
put the code into it (see below)
docker run -p8080:8080 -v ~/your_path/conf.d:/etc/nginx/conf.d openresty/openresty:alpine
use curl to play with it
balancer.conf:
map $cookie_is_special_user $upstream {
default http://example.com;
~^1$ http://scooterlabs.com/echo;
}
server {
listen 8080;
resolver 8.8.8.8;
location / {
proxy_pass $upstream;
}
}
testing
curl --cookie "is_special_user=1" http://localhost:8080
It would return the contents of scooterlabs.com dumping the request it receives
curl http://localhost:8080
Produces the contents of example.com
explanation
the idea is that you set a special cookie to the users you treat as special by the backend app after they get authorized as usual
of course it would only work if both app versions are served on the same domain so that the cookie is seen by both versions
after that you balance them to a desired server depending on the cookie value
you can easily disable such routing by tweaking your nginx config file
with this approach you can come up with even more complex scenarios like setting random cookie values in the range 1-10 and then gradually switching some of the special users in your config file i.e. start with those having value 1, after that 1-2 etc
How to I change the monitoring-agent.config to go out via proxy with authentication?
The change log states...
Monitoring Agent 2.3.1.89-1
Released 2014-07-08
Added support for HTTP proxy configuration in the agent configuration file.
But I can't see how to do this.
Following wdberkeley's link I can add this value to the monitoring-agent.config file.
httpProxy=http://"pxproxy01":3128
But this gives..
Failure getting conf. Op: Get Err: Proxy Authentication Required
Is there anyway to set the authentication user/password ?
Edit file:
C:\MMSData\Monitoring\monitoring-agent.config
Add line...
httpProxy=http://<insert_server_address>:<insert_port>
e.g.
httpProxy=http://PROXY01.server.com:3128
Then get the proxy control team, who ever they be, to exclude the following from requiring authentication.
https://mms.mongodb.com 80
https://mms.mongodb.com 443
This has worked for me. I now have the MMS Agent on Windows sending stat's to the MMS service.
Thanks to #wdberkeley for starting me off on this route.
wdberkeley, the page you linked to does not exist & the classic page PDF & HTTP versions state 'HTTP_PROXY' not 'httpproxy' (on OSx section & tar.gz section), section '6.6 Monitoring Agent Configuration' does state the correct property name 'httpproxy'.