I'm just learning OSE 3. I'd like to deploy two Node.js Web applications I have created. So I have created a Project with two Node.js deployments, which are now running in their own Pod.
My question is, how are they supposed to communicate ? say for example one application needs to redirect to the other, or include components from the other application.
Should I hardcode the route of each application in a configuration file or so ?
Thanks!
For internal communication between the two services, you can use the name of the service as the host name when making connections. This is possible because the name of the services are added to an internal DNS server so that a host name lookup on the name will yield the correct IP for the service at that time. When the service has multiple pods, an internal IP load balancer will automatically route the request to one of the pods.
For the question about redirects, that seems to suggest you have both services exposed publicly and want to have one service return a HTTP response that redirects the HTTP client to a URL which falls to the other service. What the redirect URL needs to be is going to depend on how you are exposing the services. That is, whether each service is exposed as a different hostname or you have used path based routing of OpenShift to overlay one at a sub URL of the other under the same host.
Either way, you probably want to use an environment variable passed in via the deployment configuration to indicate to the service triggering the redirect, to tell it what the URL prefix is that it needs to redirect to. You would manually set this up. This at least means you haven't hardwired it in your code.
If you mean something else by redirect, you will need to explain better what you mean.
Related
I have an application running in Openshift 4.6.
The pod is running, I can exec into it and check this, I can port-forward to it and access it.
when trying to access the application, I get the error message:
Application is not available The application is currently not serving
requests at this endpoint. It may not have been started or is still
starting.
Possible reasons you are seeing this page:
The host doesn't exist. Make sure the hostname was typed correctly and
that a route matching this hostname exists.
The host exists, but doesn't have a matching path. Check if the URL
path was typed correctly and that the route was created using the
desired path.
Route and path matches, but all pods are down. Make sure that the
resources exposed by this route (pods, services, deployment configs,
etc) have at least one pod running.
There could be multiple reasons for this. You don't really provide enough debugging details to get to the next steps. But I generally find it helps to work backwards through the request.
Can you access the pod via port-forward? You say you've already tested this, but I include it for completeness. But I also mention it to make sure that you are verifying that you are serving the protocol you expect. If you have HTTPS passthrough on the route, but you are serving HTTP from your pod, there will obviously be a problem.
Can you access the pod providing your service from outside the pod (but within the cluster)? e.g. create a debug pod and see if you can connect to your service with curl some other client. If this doesn't work, you may not be exposing the ports of your pod correctly. Check the pod definitions.
Can you access the service from outside the pod (but within the cluster)? e.g. from your debug pod, use the service directly. If this doesn't work, you may have the selector on your service wrong. Or some other problem with your service. Check the service definition.
Can you access the route from inside the cluster? e.g. from your debug pod, try to use the full route URL. If this doesn't work, you've narrowed it down to the route definition. Again, HTTPS vs HTTP can sometimes be a mistake here such as having HTTPS passthrough when your service doesn't support HTTPS. Check the route definition.
Finally, try accessing the route eternally. Which is sounds like you have already tried. But if you've narrowed it down such that your route works internally you've determined that the problem is something in the external network. It doesn't sound like this is your problem, but it's something to keep in mind.
I have a web app that does http and ws requests. I am trying to deploy it to Openshift v3. Hence, I need my requests to be mapped to ports 80 and 90 in the pod. However:
As mentioned in a related thread it is not possible for a route to expose multiple ports, so, I cannot just map requests to different services based on the port.
I tried setting one route mapping any port to a service with multiple ports, but I get a warning
Route has no target port, but service has multiple ports. The route
will round robin traffic across all exposed ports on the service
I cannot use different routes for http and ws, because the session cookie obtained for http would not be attached for web socket requests.
Solutions (?):
In the related thread Ingress Controller is suggested, but It seems that it can only be set up by a cluster administrator.
I could use two routes and set a separate cookie for each route, but this does not seem right -- why do I have to use 2 cookies for 2 domains, when essentially there is a single domain with a single authentication?
Switch to token authentication?
So, what am I missing? What would be the optimal way to handle this?
If any websocket endpoints are under a unique sub URL path, you could add a second route where which has a path definition for the sub URL path that the route applies to. You could then have requests under that sub URL path routed to the alternate port. You will need to have a definition for the alternate port on the service in addition to the primary port, or create a separate service for the alternate port. Would need to see your current service definition to be more specific. It is odd that you would be using ports 80 and 90 on the pod as that would imply you are running the container as root, which is not normal practice on OpenShift because of the security risks of running any container as root on a container hosting platform.
I am currently evaluating OpenShift for use in our company.
We have a web application in a container, which exposes both port 80 http and port 443 https. Is it possible to run this container in OpenShift, using both ports over the SAME hostname? The OpenShift GUI lets me select only one port per service, if I try to create a route, and either http or https, not both. My use-case is, that my application is reachable on http://my-app as well as on https://my-app (in my opinion a quite common use-case)
It is not possible to have multiple routes with the same hostname and path. Only first such route will be admitted to the router.
The routes with paths will work as mentioned by #Graham
You can put all 3 below in a single project without problem:
example.com
example.com/hello
example.com/world
They can have different protocols. Adding a duplicate route with different protocol will not work.
Additionally if you have Project B, you won't be able to use example.com host again. So, none of the below will be accepted to a router:
example.com
example.com/hello
example.com/world
example.com/path
Which makes sense, as you don't want someone else to use your domain.
What usually happens when you have https exposed is that all http traffic is redirected to https.
You can achieve it by creating edge terminated route (over UI) and selecting Insecure Traffic: Redirect. There is also an option to set it to Allow.
More documentation and yaml examples if you would like to create route from command line: OpenShift Origin: Secured routes
Our server setup is the following:
a proxy and load balancer directs all the requests to its machines behind. The problem is, that these machines behind do not know where they are. If the proxy gets the request for
www.bridge.de/m01
he redirects to machine01.
Machine01 only knows its local path
m01
For an application solution for a password reset functionality I considered several opportunities.
We decided to pass the value of URL from 'before proxy' to the database of machine01. So machine01 'knows' its external context for that specific requests.
My question is: Is there a better way to pass external URL context to machines behind a proxy? We are using JavaEE, JSP and MySql for our application. Virtual machines running with CentOS.
Thanks for any suggestions! :D
Your question is not fully clear.
I assume you have the issue, what your load balancer terminates the connection and forwards you the request.
Usually your balancer provides you the origin URL of the request, since you may need it from time to time.
In this case you can check your http headers. If it is not provided, you have to reconfigure your balancer to provide you the needed details.
check this: Strategies for dealing with URIs when building an application that sits behind a reverse proxy
How to configure SRX200 router?
I want to setup a LAN (trusted network) with my own series (ex: 10.x.x.x)
Router should forward the request based on port(Port based forwarding).
i.e If any machine sent a request on a port, router should forward the request to a specific machine based on that port number. Router should translate the destination address to one specific IP (specified by us).
We could configure the juniper router in two ways.
1. Through cli prompt
2. Web interface
To Configure router with web interface, find the complete information from the following link.
http://forums.juniper.net/jnet/attachments/jnet/Learning/47/
The above document provides complete information.
You can configure the port based redirection using Destination NAT and IP based redirection with Static NAT.