I would like to achieve the following. I have a C# server application which is run by a Windows Service. The service currently requires that the server application is located in a specific directory.
Is it possible to create a Windows Service that takes a directory at start and run the application in that directory? How do you do that?
Can such a "configurable" service be used to start multiple application (executables with same name but located in different directories). This would be used to run different versions of a server application in parallel. Or do you need one service per running instance?
Yes, simply set the context to reflect the desired environment.To do this use Environment.SetEnvironmentVariable.
A single service can start many applications, each with its environment. Use a configuration file or persistent data in the registry.
Related
I'm working in an application to obtain some data from a web service, create a text file in the local filesystem send a command to a command line application, obtain the result and then send the results back via the web service.
I need to be able to write to the local file system, read from it and then delete the temporary file. I was reading about bind mounts and volumes but this folder can be delete if a new version of the image is uploaded is just a staging area.
Any ideas how this can be done, thanks.
When using containers in App Service, I believe you will have to link a storage account and mount file shares accordingly. Depending on the OS (windows / linux), the steps vary a bit.
If you are not using containers, then you should be able to access the temporary file locations for file-based requirements. Do note that the storage available this way is limited and not shared across site instances.
We have a java application. It connects to the oracle database. It has three properties files and the customer changes value of those properties files when we deployed our application to the customer site. We have another python script that allows customer to modify those properties files and start the main app after configuration is done.
Now we want to containerized our java app and want to use swarm mode. the only problem is to find the easy way for customer to edit those properties files before I start the container.
Any ideas docker Gurus ?
Help is very much appreciated.
I have a DockerFile that starts 2 processes in a single docker container using a jar file and a config file as an argument
java -jar process1.jar process1.cfg &
java -jar process2.jar process2.cfg
process1.cfg and process2.cfg are residing in mounted directories. Now whenever there is a change in any of the cfg files, I would need to restart the corresponding process for the new change to take effect. All these to be done programmatically using Java in a REST microservice that updates the config file and restarts the process. Any idea on how to go about it ?
The problem can be generically solved by your Java app starting a config change monitoring service/thread, which manages the actual business service/thread(s) by starting it in the beginning and restarting on any change (if the change actually needs a restart). File change monitoring is standard Java functionality. The solution does not need any REST, it is not bound to microservice architecture (although it is more sensible within it) and it is not limited by or to docker containers.
If you do not want any file-based configs, do the same, but the monitoring bit can be e.g. a vert.x-based web server listening for external REST requests supplying configs, on start or for any update. The rest remains the same.
In my current workplace we actually have a module that functions in exactly this way, it is deployed to a docker and uses both file system monitoring and vert.x web server for config changes.
You can even go further and make the monitoring bit start multiple instances internally if multiple configs need to be supported.
I posted this question originally on the Docker forums, but didn't get any response there.
I'm wondering what the best way would be to model a set of services let's call them db, web, and batch. db is simply a running database server instance (think MySQL). web is a web application that needs to connect to the database. batch is a batch application that needs to connect to that same database (it can/will run in parallel with web). db needs to be running, for either web or batch to run. But web or batch can be run independently of each other (one or both can be running at the same time). If both are running at once, they need to be talking to the same database instance (so db is actually using volumes_from a separate data volume container). So if the use case was simpler (think just db and web, which always run together), then they would simply both be defined as services in the same compose file, with web having a link to db.
As far as I understand it, these can't all be defined in the same Docker compose configuration. Instead, I would need three different configurations. One for db, which is launched first, one for web (which uses external_links to find db), and a third for batch (which also uses external_links to find db). Is that correct, or is there some mechanism available that I'm not considering? Assuming a multi-configuration setup is needed, is there a way to "lazily" initialize the db composition if it's not running, when either the web or batch compositions are launched?
If web has a link defined to db in a docker-compose file, db will always start first.
As far as I know, Docker will never know when the database will be up. It will be your web container's responsibility to properly start and retry until the base is up (with a timeout).
For your batch service, assuming that you don't want to start it everytime you start your web and db containers (using a docker-compose up or run), you can try extending your service. See the docs for more informations on this.
Either you applications in the web and batch images known how to handle database down time and are able to wait for the db service to come up and auto-reconnect ; either you have to make a shell script that will be run when the docker container is started to wait for the db to be available before starting the app.
Depending on the docker images you are using for the web and batch services, you would have to override CMD, ENTRYPOINT or both.
This question has examples of shell script which waits for a MySQL service to be up.
And here are other technics for testing if a network port is opened.
I sucessfully managed to complete with my Grail's new website and now i want to run it on my machine to acess it everywhere. I would like to know what is the best approach to do that, i'm a bit noob in what concerns servers and connections. Any help would be aprecciated.
Jm
You need a Java servlet container. The quickest and easiest approach is probably to use Jetty on a Linux system -- most will allow you to install it directly. This allows you run a deployed system from a "war" file. Basically, you would do something like:
grails war
To build the war file, and then copy that (it'll be created in the target directory, with a name based on your application name and version) to the webapps directory for Jetty. On my (Ubuntu) system, that's /var/lib/jetty/webapps/. If you name it root.war, it will serve URLs from the root of the server configuration (typically on port 8080), so http://myhost.mydomain:8080/ will be passed to your Grails application. You'll need to restart Jetty to pick up the new root.war file, e.g., sudo /etc/init.d/jetty restart
Jetty is not the most flexible or powerful servlet container, but it is probably the quickest way to get something up and running, and you can explore more powerful alternatives (Tomcat being an obvious one) as you have time.
Unless you need persistent storage in your app (e.g. end users uploading pictures, etc), you can use Cloud Foundry. It's free for now and makes deployment very easy.
http://blog.springsource.com/2011/04/12/one-step-deployment-with-grails-and-cloud-foundry/
I've been using is via STS and it works really well. There's just one really annoying thing and that's the fact that STS ends up doing a build war with every change.
There's a cloud foundry plugin that gives you command line deployment.
http://www.grails.org/plugin/cloud-foundry
Or there's a Cloud Foundry UI plugin that "provides a simple monitoring UI for your applications deployed to Cloud Foundry. It uses the same API as the Cloud Foundry plugin but is more convenient since runs in a web browser."
http://www.grails.org/plugin/cloud-foundry-ui