I am using an NSNetServiceBrowser to find services on my network. It can find them, but is unable to resolve any of them, neither mine nor the ones built in to my computer. When I check the domain of the unresolved service, I get "." for each one. The host is also always "(null)" when I NSLog it. In addition, it appears that the name of the service is actually the first part of the type (eg. I publish my service with type "_iListen._tcp." and the name shows up as "_iListen". The type also shows up as "_tcp.local."). My code for searching for services is:
[browser searchForServicesOfType:#"_services._dns-sd._udp." inDomain:#""];
Note: This is being done on an iPhone.
Browsing for "_services._dns-sd._udp." is a meta-query which lists all service types in the network. It makes no sense to resolve the responses. See Technical Q&A QA1337.
You have to browse for "_iListen._tcp." to find services of your type.
The "dns-sd" tool can be used on the OS X command line to test browsing/lookup/resolving.
Related
As I am new to coredns configurations in kubernetes and I'm trying to explore plugins provided by coredns in kubernetes. I see a plugin named local which will respond with a reply to local requests. But I could not understand a use-case where this plugin will be exactly useful for. Can someone explain with an example how it can be make use of? Also in unbound configuration man page, I see an option called local-zone: .
local-zone:
Configure a local zone. The type determines the answer to give if there is no match from local-data. The types are deny, refuse, static, transparent, redirect, nodefault, typetransparent, and are explained below. After that the default settings are listed. Use local-data: to enter data into the local zone. Answers for local zones are authoritative DNS answers. By default the zones are class IN.
nodefault:
Used to turn off default contents for AS112 zones. The other types also turn off default contents for the zone. The 'nodefault' option has no other effect than turning off default contents for the given zone.
Is this local plugin behaves similar to this unbound local-zone option? If not, Is there any plugin which act similar to local-zone in unbound ? I am expecting a coredns plugin to behave similar to local-data in unbound particularly for nodefault type in local-data. eg: local-zone: nodefault. It would be really helpful if someone helps me to clear out this. Thanks in advance!!!
As the author of the local plugin for CoreDNS explains, localhost.<searchpath> queries are hitting coredns, which is wrong. So, he wrote this plugin to intercept localhost.<'domain'> queries and return the correct response.
From the official CoreDNS github web page:
local will respond with a basic reply to a "local request". Local request are defined to be names in the following zones: localhost, 0.in-addr.arpa, 127.in-addr.arpa and 255.in-addr.arpa and any query asking for localhost.<domain>.
With local enabled any query falling under these zones will get a reply. This prevents the query from "escaping" to the internet and putting strain on external infrastructure.
You can check the code of the local plugin here. I don't see similar to the unbound local-zone nodefault functionality there.
See all in-tree plugins for CoreDNS here.
BitBake fails for me because it can't find https://www.example.com.
My computer is an x86-64 running native Xubuntu 18.04. Network connection is via DSL. I'm using the latest versions of the OpenEmbedded/Yocto toolchain.
This is the response I get when I run BitBake:
$ bitbake -k core-image-sato
WARNING: Host distribution "ubuntu-18.04" has not been validated with this version of the build system; you may possibly experience unexpected failures. It is recommended that you use a tested distribution.
ERROR: OE-core's config sanity checker detected a potential misconfiguration.
Either fix the cause of this error or at your own risk disable the checker (see sanity.conf).
Following is the list of potential problems / advisories:
Fetcher failure for URL: 'https://www.example.com/'. URL https://www.example.com/ doesn't work.
Please ensure your host's network is configured correctly,
or set BB_NO_NETWORK = "1" to disable network access if
all required sources are on local disk.
Summary: There was 1 WARNING message shown.
Summary: There was 1 ERROR message shown, returning a non-zero exit code.
The networking issue, the reason why I can't access www.example.com, is a question for the SuperUser forum. My question here is, why does BitBake rely on the existence of www.example.com? What is it about that website that is so vital to BitBake's operation? Why does BitBake post an Error if it cannot find https://www.example.com?
At this time, I don't wish to set BB_NO_NETWORK = "1". I would rather understand and resolve the root cause of the problem first.
Modifying poky.conf didn't work for me (and from what I read, modifying anything under Poky is a no-no for a long term solution).
Modifying /conf/local.conf was the only solution that worked for me. Simply add one of the two options:
#check connectivity using google
CONNECTIVITY_CHECK_URIS = "https://www.google.com/"
#skip connectivity checks
CONNECTIVITY_CHECK_URIS = ""
This solution was originally found here.
For me, this appears to be a problem with my ISP (CenturyLink) not correctly resolving www.example.com. If I try to navigate to https://www.example.com in the browser address bar I just get taken to the ISP's "this is not a valid address" page.
Technically speaking, this isn't supposed to happen, but for whatever reason it does. I was able to work around this temporarily by modifying the CONNECTIVITY_CHECK_URIS in poky/meta-poky/conf/distro/poky.conf to something that actually resolves:
# The CONNECTIVITY_CHECK_URI's are used to test whether we can succesfully
# fetch from the network (and warn you if not). To disable the test set
# the variable to be empty.
# Git example url: git://git.yoctoproject.org/yocto-firewall-test;protocol=git;rev=master
CONNECTIVITY_CHECK_URIS ?= "https://www.google.com/"
See this commit for more insight and discussion on the addition of the www.example.com check. Not sure what the best long-term fix is, but the change above allowed me to build successfully.
If you want to resolve this issue without modifying poky.conf or local.conf or any of the files for that matter, just do:
$touch conf/sanity.conf
It is clearly written in meta/conf/sanity.conf that:
Expert users can confirm their sanity with "touch conf/sanity.conf"
If you don't want to execute this command on every session or build, you can comment out the line INHERIT += "sanity" from meta/conf/sanity.conf, so the file looks something like this:
Had same issue with Bell ISP when accessing example.com gave DNS error.
Solved by switching ISP's DNS IP to Google's DNS (to avoid making changes to configs):
https://developers.google.com/speed/public-dns/docs/using
I'm working on a coreaudio user-space hal plugin based on the example
developer.apple.com/library/mac/samplecode/AudioDriverExamples/Introduction/Intro.html
In the plug-in implementation, I plan to obtain audio data from another process i.e. CFMessagePort
However, I got the following error in console trying to create port CFMessagePortCreateLocal...
sandboxd[251]: ([2597]) coreaudiod(2597) deny mach-register com.mycompnay.audio
I did some googlging and came to this article
Technical Q&A QA1811
https://developer.apple.com/library/mac/qa/qa1811/_index.html
about adding AudioServerPlugIn_MachServices in plist but still no success.
Is there anything else I need to do to make this work (like adding entitlements, code-sign) or this is not the correct approach.?
I am not sure if MesssagePort mechanism works anymore under sandbox. would XPC Services be viable?
Thank you very much for your time. Any help is greatly appreciated
update 1:
I should be creating a remote port instead of a local in the audio plug-in. Having that said, with the AudioServerPlugIn_MachServices attribute in the plist. now there is no sandboxd[559]: ([552]) coreaudiod(552) deny mach-lookup / register message in console.
However, in my audio hal plug-in (client side) I have
CFStringRef port_name = CFSTR("com.mycompany.audio.XPCService");
CFMessagePortRef port = CFMessagePortCreateRemote(kCFAllocatorDefault, port_name);
port has return the value of 0. I tried this in a different app and it works just fine.
This is my server side:
CFStringRef port_name = CFSTR("com.mycompany.audio.XPCService");
CFMessagePortRef port = CFMessagePortCreateLocal(kCFAllocatorDefault, port_name, &callback, NULL, NULL);
CFRunLoopSourceRef runLoopSource =
CFMessagePortCreateRunLoopSource(nil, port, 0);
CFRunLoopAddSource(CFRunLoopGetCurrent(),
runLoopSource,
kCFRunLoopCommonModes);
CFRunLoopRun();
I did get a console message regarding this.
com.apple.audio.DriverHelper[1314]: The plug-in named SimpleAudioPlugIn.driver requires extending the sandbox for the mach service named com.mycompnay.audio.XPCService
anyone know why??
update 2
I noticed that when I use the debug mode with coreaudiod it does successful get the object reference of the mach service. (same thing happened when I was trying the xpc_service approach)
project scheme setting
Anyone??
I'm pretty sure I was running into the same problems in my AudioServerPlugIn. I could look up and use every Mach service I tried, except for the ones I had created. And the ones I had created worked normally from a regular process.
Eventually I read the Daemonomicon and figured out that coreaudiod (which hosts the HAL plugins) was using the global bootstrap namespace, but my service was being registered in the per-user bootstrap namespace. And since "processes using the global namespace can only see services in the global namespace" my plugin couldn't see my service.
You can use launchctl to test this by having it run the program that registers your service, but with the same bootstrap namespace as coreaudiod. You'll probably need to have rootless disabled.
# launchctl bsexec $(pgrep coreaudiod) your_service_executable
With that running, try to connect from your plugin again.
From Table 2 in the Daemonomicon, you can see that only launchd daemons use the global bootstrap namespace. That explains why coreaudiod uses it. And I think it means that your Mach service needs to be created by a launchd daemon.
To make one, create a launchd.plist for your service in /Library/LaunchDaemons. Set its owner to root:wheel and make it only writable by the owner. In it, set the MachServices key and add the name of your service:
<key>MachServices</key>
<dict>
<key>com.mycompany.audio.XPCService</key>
<true/>
</dict>
Then register it:
# launchctl bootstrap system /Library/LaunchDaemons/com.mycompany.audio.XPCService.plist
This is what I ended up with: com.bearisdriving.BGM.XPCHelper.plist.template. Note that without the UserName/GroupName keys your daemon will run as root. (The code for my service and plugin is in that repo as well, in case that's helpful.)
I ended up having to use XPC, unfortunately, but I tried CFMessagePort first and it worked fine.
It also seems to all work fine whether the plugin is signed or not. Though, as you say, you do need the AudioServerPlugIn_MachServices key in your Info.plist.
Our team is completely new to the WSO2 tool. We got the basic training on how to add proxy services and were able to do so as well.
Now, we have to add a class in the In Sequence. We tried that using the Class mediator but it was not able to find the class. Then we realized that the jar file needs to be in the components/lib folder. So, its able to load the class now. It proceeds to the out sequence and fault sequence properly. But, in the end, it gives the following exception.
Unable to add proxy service :: Failed to add proxy service: Parse. Check whether the Proxy already exists-Failed to add proxy service: Parse. Check whether the Proxy already exists
So far, we're using the design view to configure it. I surveyed through most of the posts within this forum, and, all are using the source code to configure. Also, the proxy service is not present in the Source View section under Service Bus.
Are we missing any step in the configuration? Do we need to switch to coding method or it is possible this way.
Your explanation is strange. Above mentioned error log can appear at the time of deploying the proxy service. But you say your proxy is going to the out-sequence and fault-sequence. From that what I understand is the proxy is already deployed.
You can check whether a proxy with the same name is there by looking in the ESB_HOME/repository/deployment/server/synapse-config/default/proxy-service folder. If there is a file with name Parse.xml (I think the name of the proxy service is Parse) you can delete it from the file system and then go to the design view and add the proxy again.
It seems there is already a proxy with the name you provided. Go to WSO2 ESB "source view" and check whether there exist a proxy with that name. Source view is available on the left side of the management console.
This artical will take you step by step in writing custom class mediators.
This post may also be relevant for you.
I have followed the instructions at https://github.com/cloudfoundry/oss-docs/tree/master/vcap/adding_a_system_service and copied the echo service and created my new service. (That document is somewhat out-of-date in that "excluded components" no longer exists.
In any case, my service shows up as running with a gateway and a node when I look at 'vcap status' on the server. However, when I look at 'vmc services' from the client my service is not in the list. Where is this list maintained and why is my service not on the list?
Various services, including blob, filesystem, mongodb, etc, are shown on the 'vcm services' list even though they have never been included in my config. Where is this maintained and why are other services on this list?
The cloud_controller.log file shows a "Create service request:" for echo every minute. This service is not in my config file (it was once but it was removed and I repeated the deployment). What is prompting this request for a service that was not defined in the config?
The _gateway.log for my service shows the following:
INFO -- Sending info to cloud controller: ...api.vcap.me/services/v1/offerings
INFO -- Fetching handles from cloud controller .../offerings/.../handles
ERROR -- Failed registering with cloud controller, status=400
DEBUG -- [GaaS-Provisioner] Connected to node mbus..
ERROR -- Failed fetching handles, status=404
Why does my gateway fail to register with the cloud controller? I have found some reports that suggest that the problem is with domain name mapping. I have verified that the server can find itself:
$curl api.vcap.me
Welcome to VMware's Cloud Application Platform
What can I do to register my service?
You can also try asking your question on the vcap_dev google group.
https://groups.google.com/a/cloudfoundry.org/forum/?fromgroups#!forum/vcap-dev
They are focused in answering and discussing OSS subjects for Cloud Foundry!
If you follow the document correctly things should work just fine. I understand that the mechanism for maintaining the excluded list of components has changed and can be a point of confusion when following the steps mentioned in the article (just ignore that step totally).
ERROR -- Failed registering with cloud controller, status=400
Well this is a point of worry. I recently followed the article step by step and was able to add a new service.
Is the echo service showing up in vmc services?
Have you copied the the yml files for node and gateway at ./cloudfoundry/.deployments/devbox/config?
Are the tokens for your gateway unique? and matching in the two files? ./cloudfoundry/.deployments/devbox/config/cloud_controller.yml and ./cloudfoundry/.deployments/devbox/config/**_gateway.yml**
I would recommend that you first concentrate on getting the echo service to be listed in the vmc services output. Once done with this you should replicate the steps (with absolute care to modify things like the token) to get your custom service working.
Cheers,
Ankit
You should follow this guide
It work to me.
regards.