Briefly question. As the title shows of, Im searching for a possibility to config openWRT so that only one client connection will be allowed over an access point. Further connection trials should be rejected if one client is connected already. Is this possible by configuration only within the openWRT config?
I think you need to set the maxassoc option in the wifi-iface section. Setting it to 1 should do it.
The option is described here: https://openwrt.org/docs/guide-user/network/wifi/basic#common_options1
Related
I'm currently developing a Wolkenkit application which is run on my local machine.
I want to upload a file from the Wolkenkit app to the blob server (as documented here).
When sending a POST request from the server to https://local.wolkenkit.io:3001/, Node.js gives me the error ECONNREFUSED.
I've tested the POST-Request with another program and it works there. Any idea why it doesn't work from the wolkenkit application itself?
Thanks!
The Storing files sample you linked to shows code that is to be run in the browser, not in the backend itself. Of course, both should work, but there are a few minor differences you need to watch out for.
Fixing the host name
First, I suppose that local.wolkenkit.io in your case maps to 127.0.0.1, which is the default for wolkenkit. That means that when you try to connect to this domain from within a Docker container, the container does not try to call out to the blog storage container, but it stays within itself. So, the first thing that needs to be fixed is the host name.
Basically, there are two options for this: You can either setup local.wolkenkit.io so that it resolves to the external IP address of your machine. This would work, but is pretty cumbersome. The other option is to directly address the appropriate container that is responsible for blob storage, by its internal name. The internal name is <name-of-your-app>-depot-file. So you need to replace https://local.wolkenkit.io:3001/ by https://<...>-depot-file.wolkenkit.io:3001/.
Fixing the port
Second, the port is wrong. This is because the blob storage service is internally running on port 3000, externally on 3001. So instead of https://<...>-depot-file.wolkenkit.io:3001/ you need to use https://<...>-depot-file.wolkenkit.io:3000/.
Once you have done this you should not get any more errors like ECONNREFUSED, since now the service can be found.
Fixing SSL issues
Third, since you are now connecting to the blob storage service using a different domain name, the SSL certificate doesn't match any more, since it was issued for local.wolkenkit.io. As a result, you will get SSL errors when trying to connect.
The simplest way to get around this is to disable any SSL checks (albeit this is also the most insecure way to handle this!). How to do this depends on the HTTP client module you are using. E.g., in request there is an option called strictSSL that you can set to false.
Of course, what you actually should do is to either use a custom certificate which includes this domain name as well, or to write a function that handles the certificate check and accepts the presented one, especially in this case.
If you do all of this, things should work :-)
PS: I am one of the authors of wolkenkit. Thanks a lot for bringing up this issue, and we will take care of this in the future, to make storing blobs easier.
Since 12h the website (Wordpress website) that is hosted on Google Cloud Platform has a time out issue. After 60 seconds of trying to load the website, the following message appears "The connection has timed out".
When trying to connect with SFTP, same issue.
What should I do to resolve this?
Since two different services stopped to work at the same time it
sounds like a networking issue. There is a timeout, therefore there is the server not answering at all to the requests.
What to do?
I would proceed with this general troubleshooting steps, if you want you can upload your question with the result of these commands/question to proceed with the troubleshooting.
First of all I would check if you are able to ping the
external/public IP of the instance.
I would check if the firewall rules allows TCP80/TCP443 and TCP22, Notice that on GCP you need to create the rule and assign the TAG to the machine from its detail page if the the rule does not apply to the whole network.
Are you able to ssh into the instance?
I would check if the processes are actually listening netstat -tuplen
If you are able when logged into the machine do you have access to the internet? Are you able to ping external IP? If not whats about internal IP?
I would go to the "activity" page of your Google Cloud Console to check which actions have been taken while the instance was still running.
I would check as well the history of the Linux machine to check if you run some commands acting on the network configuration of the machine.
Note that if you cannot SSH into the machine you can always access through serial console setting a password for your username through a startup script.
UPDATE
I had the possibility to take a look into the project, the machine was stopped due to issue with the billing account (it was closed) after the free trial period ended.
I would suggest you to go again trough the documentation regarding the upgrade of the billing account
If you have still some doubts or question after you perform this operations you can file a case at this link with the billing team and they will help you to solve the issue.
Hi i have googled all day long but i can't find an answer.
I have to write a web app which talks to asterisk.
It should be able to do ClicktoCall operations.
Can you guys recommend something ?
I came across a few projects but I'm still not sure.
I just want to connect to Asterisk and do calls from the web app.
thanks
If you're a Ruby programmer the best way for you to hook into Asterisk is adhearsion. It wraps up Asterisk's AGI and Manager (MAPI) APIs for you.
Also hAve a look at SIP, asterisk, adhearson and VoIP and in particular Adam Kalsey's answer. He works for Tropo which sponsor the adhearsion project.
First you need to know, that the protocol Asterisk uses is SIP, you can learn more at the Wikipedia.
Since you want to use an rails application, you may want to use ruby as well, so there's a ruby implementation named OverSip, you can check their API and see if it fits your requirements.
If you are aiming at web calls, you'll need an WebRTC, Flash or Java applet. For WebRTC you can check sipML5 for an opensource solution.
You can also opt for an interface, that will start a call from one number to another, using your phone. When the first call is picked up the server starts ringing in the destination.
Also you could make use of cloud communications providers like twilio, tropo, etc.
Try this Google search:
rails asterisk manager interface
I saw some interesting things right off. I am not trying to be one if those Use Google type people, just didn't want to paste all the links in that I found from this Google search.
Check it out, hope it helps.
There are several ways to do this but the three easiest ones are
1. Generate a call file on the Asterisk server
These files should be written to the dir
/var/spool/asterisk/outgoing
Asterisk will then pickup the file, process and delete it.
It's pretty aggressive when doing this so it's recommended to write the file into a temporary directory and then move it to the spool dir for processing.
An tutorial of the file format is here:
https://www.voip-info.org/asterisk-auto-dial-out/
(I personally feel this is a bit "hacky", and prefer doing it with an API call)
2. Generate the call by the AMI API interface.
Use the Originate function of the AMI API to generate the call. It's pretty easy to set this up just configure the manager.conf file whitch sets up a HTTP server on port 5038 from witch you can call the API.
https://www.voip-info.org/asterisk-config-managerconf/
3. Set up the call using the ARI API
First you need to setup ari.conf, this is enough for now:
[general]
enabled = yes
pretty=yes
allowed_origins=http://ari.asterisk.org
[my_username]
type = user
read_only = no
password = my_password
password_format = plain
This is a little bit more complicated to set up, but it really isn't that hard if you just get past the technical geek-speak. Just set up two channels, setup a mixing bridge and add both channels to the bridge.
To set up a click2call you dont even need to do that...
This is the call we use (ruby):
where
#{sip_id} is your registered SIP username
#{number} is the extension that is sent to the dialplan
#{USERNAME}
#{PASSWORD} is from ari.conf
HTTParty.post("http://sipserver.com/ari/channels?endpoint=SIP/#{sip_id}&extension=#{number}&context=outgoing&priority=1&timeout=30&api_key=#{USERNAME}:#{PASSWORD}")
(Note that you need to send the variabels for the variable parameter as a separate JSON for the originate command if you need to send them)
A really useful tool to understand how this works is the swagger at
http://ari.asterisk.org. We already allowed this origin in ari.conf so it should be ready to go. Remember to open your ports in firewalls etc.
Setup your Server IP and port and the API_KEY is in this format: my_username:my_password
I want to write an application in Delphi which filters requested URLs in the OS (not only web browsers) and if it matches - blocks it or changes the URL's content to blank. The problem is - I don't know where to start looking. Could you help me with some informations?
I think you're talking about a DNS service. usually, DNS services live outside, on your router, your ISP, or a 3rd-party like www.openDNS.org
But you could write your own, run it on your PC, and set your internet settings to use that as your DNS server.
I suspect that a lot of malware works like this....
Also, this sort of thing can be done with no programming at all - just edit your hosts file in C:\WINDOWS\system32\drivers\etc\hosts (it's a text file with no extension).
Anything in there should trump.
Also, before you start writing an application to do this, have a look at OpenDNS. If it's an app for personal use, you may find that you don't need it. If it's going to be a commercial offering, this is the bar for usability and usefulness that you need to meet or beat.
http://www.mail-archive.com/delphi-talk#elists.org/msg01558.html - text by Francois PIETTE quoted bellow(in case link will become unavailable):
"There are several way to achieve your goal. The two main I see are:
1) Write a LSP (Layered Service Provider)
2) Write a proxy server
The first is not possible with Delphi (At least I think so. If anyone know
how to write a LSP using Delphi, I would love to get the code).
The second - writing a proxy - is more or less easy with Delphi using ICS
components. See "usermade" link at ICS website (http://www.overbyte.be).
With this option, you have to configure IE to use the proxy: IE Menu / Tools
/ Internet options / Connections / Network parameters / Use a proxy and then
enter the IP address (127.0.0.1 if proxy run on the same computer) and port
number (pick anyone you like, for example 8080). Once IE is configured to
use a proxy, it will send all requests to the proxy. Then the proxy will
make the real request to the target server and return data back to IE. What
is important there is that you get all URL entered in IE or indirectly use
(clicking on links), and you can either really rely them to the target
server or forge and answer your self to say the page access is denied.
At ICS website, on the usermade page, you'll even find a HTTP proxy
component. If you need help with this component and/or the entire ICS,
please use ICS support mailing list (same server as this list). See
"support" link at ICS website for support details."
LE: it seems that this question is possible a duplicate
Using delphi to block websites
use GetExtendedTcpTable api locate if there are any connexions to the remote server you want to block on port 80 if there is a connection use SetTcpEntry to terminate that connexion is pretty simple
We use stateful DataSnap servers for some business logic tasks and also to provide clientdataset data.
If we have to update the server to modify a business rule, we copy the new version into a new empty folder and register it (depending on the Delphi version, just by launching or by running the TRegSvr utility).
We can do this even while the old server instance is running. However, after registering the new version, all new client connections will still use the currently running (old) server instance. All clients have to disconnect first, then the new server will be used for the next clients.
Is there a way to direct all new client connections to the new server, immediately after registering?
(I know that new or changed method signatures will also require a change and restart of the clients but this question is about internal modifications which do not affect the interface)
We are using Socket connections, and all clients share the same server application (only one application window is open). In the early days we have used a different configuration of the remote datamodule which resulted in one app window per client. Maybe this could be a solution? (because every new client will launch the currently registered executable)
Update: does Delphi XE offer some support for 'hot deployment' (of updated servers)? We use Delphi 2009 at the moment but would upgrade to XE if it offers easier implementation of 'hot deployment'.
you could separate your appserver into 2 new servers, one being a simple proxy object redirecting all methods (and optionally containing state info if any) to the second one actually implementing your business logic. you also need to implement "silent reconnect" feature within your proxy server in order not to disturb connected clients if you decide to replace business appserver any time you want. never did such design myself before but hope the idea is clear
Have you tried renaming the current server and placing the new in the same location with the correct name (versus changing the registry location). I have done this for COM libraries before with success. I am not sure if it would apply to remote launch rules through as it may look for an existing instance to attach to instead of a completely fresh server.
It may be a bit hackish but you would have the client call a method on the server indicating that a newer version is available. This would allow it to perform any necessary cleanup so it doesn't end up talking to both the existing server instance and new server instance at the same time.
There is probably not a simple answer to this question, and I suspect that you will have to modify the client. The simplest solution I can think of is to have a flag (a property or an out parameter on some commonly called method) on the server that the client checks periodically that tells the client to disconnect and reconnect (called something like ImBeingRetired).
It's also possible to write callbacks under certain circumstances for datasnap (although I've never done this). This would allow the server to inform the client that it should restart or reconnect.
The last option I can think of (that hasn't already been mentioned) would be to make the client/server stateless, so that every time the client wants something it connects, gets what it wants then disconnects.
Unfortunately none of these options are the answer you want to your question, but might give you some ideas.
(optional) set up vmware vSphere, ESX, or find a hosting service that already has one.
Store the session variables in db.
Prepare 2 web boxes with 2 distinct IP address and deploy your stuff.
Set up DNS, firewall, load balancer, or BSD vm so name "example.com" resolves to web box 1.
Deploy new version to web box 2.
Switch over to web box 2 using whatever routing method you chose.
Deploy new version to web box 1 if things look ok.
Using DNS is probably easiest, but it takes time for the mapping to propagate to the client (if the client is outside your LAN) and also two clients may see different results. Some firewalls have IP address mapping feature that you can map public IP address and internal IP address. The ideal way is to use load balancer and configure it to 50:50 and change it to 100:0 when you want to do upgrade, but it costs money. A cheaper alternative is to run software load balancer on BSD vm, but it probably requires some work.
Edit: What I meant to say is session variables, not session. You said the server is stateful. If it contains some business logic that uses session variable, it needs to get stored externally to be preserved across reconnection during switch over. Actual DataSnap session will be lost, so when you shutdown web box 1 during upgrade, the client will get "Session {some-uuid} is not found" error by web box 1, and it will reconnect to web box 2.
Also you could use 3 IP addresses (1 public and 2 private) so the client always sees 1 address , which is better method.
I have done something similar by having a specific table which held my "data version". Each time I would update the server or change a system wide global setting, I would increment this field. When a client starts it always checks this value, and will check again before any transactions/queries. If the value was ever different from when I first started, then I needed to go through my re-initialization logic, which could easily include a re-login to an updated server.
I was using IIS to publish my app servers, so the data that would change would be the path to the app server. I kept the old ones available, to respond to any existing transactions that were in play. Eventually these would be removed once I knew there were no more client connections to that version.
You could easily handle knowing what versions to keep around if you log what server the client last connected too (and therefore would know about).
For newer versions (Delphi 2010 and up), there is an interesting solution
for systems using the HTTP transport:
Implementing Failover and Load Balancing in DataSnap 2010 by Andreano Lanusse
and a related question for the TCP/IP transport:
How to direct DataSnap client connections to various DS Servers?