I want to export some data from MongoDB Atlas.
If I execute the command below, It tries connect localhost and export the data.
mongoexport --uri="mongodb+srv://<username>:<password>#name-of-project-x2lpw.mongodb.net/test" --collection users --out /tmp/testusers.json
Note: If you run this command from Windows CMD, it works fine
After researching the problem and with the help of a user, everything seems to point to a DNS problem and to the related resolv.conf file.
Below the original /etc/resolv.conf:
# This file is managed by man:systemd-resolved(8). Do not edit.
#
# This is a dynamic resolv.conf file for connecting local clients to the
# internal DNS stub resolver of systemd-resolved. This file lists all
# configured search domains.
#
# Run "systemd-resolve --status" to see details about the uplink DNS servers
# currently in use.
#
# Third party programs must not access this file directly, but only through the
# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,
# replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.
nameserver 127.0.0.53
options edns0
search name.com
At the beginning that resulted into a connection failure as shown below:
But if I would change that address into the following public available address according to what advised on this post to 1.1.1.1 the connection is successful, see below:
# This file is managed by man:systemd-resolved(8). Do not edit.
#
# This is a dynamic resolv.conf file for connecting local clients to the
# internal DNS stub resolver of systemd-resolved. This file lists all
# configured search domains.
#
# Run "systemd-resolve --status" to see details about the uplink DNS servers
# currently in use.
#
# Third party programs must not access this file directly, but only through the
# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,
# replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.
nameserver 1.1.1.1
options edns0
search name.com
Which resulted into a connection success as shown below:
HOWEVER the problem is that instead of explicitly connecting to the name of the MongoDB cluster, it will connect to the localhost, which is very strange as I successfully exported the files I was looking for from the real connection.
Which means that the machine was correctly connecting to the database but via localhost.
Everything seems to lead, also according to this source and also here to a DNS problem while connecting to MongoDB via terminal to export collections.
Now from this last post it not advisable to manually change this address for several reasons, therefore right after successfully exporting the data using DNS 1.1.1.1 I changed it back to its original DNS 127.0.0.53.
However I don't think this should be a proper behavior as every time I need to export data I will have to continuously and manually change this address.
What could be the reason for this strange behavior? And therefore what could be a long term solution without manually switching between DNS addresses?
Thanks for pointing to the right direction for solving this issue.
It seems you all ready have the answer in the links you mentioned. I will summarize this:
Install resolvconf (for Ubuntu apt install resolvconf), add the line nameserver 8.8.8.8 to /etc/resolvconf/resolv.conf.d/base, then run sudo resolvconf -u and to be sure service resolvconf restart.
To verify run systemd-resolve --status.
You should see on the first line your DNS server like here:
DNS Servers: 8.8.8.8
DNS Domain: sa-east-1.compute.internal
DNSSEC NTA: 10.in-addr.arpa
16.172.in-addr.arpa
This solution persists between reboots.
Related
I just got a new router and internet connection.
My phone and my second computer have no problem to connect to internet (wifi or cable). My first computer, where I am running Limux Mint 18.1 Serena, can connect with cable or wifi but I am unable to browser.
I can ping 8.8.8.8 but not google.com.
I do not understand much of DNS but I tried to follow some online tutorials.
I tried to modify the /etc/resolconf directory by adding a resolv.conf file with a new servername but didn't work (even after restarting network-manager). I tried as well to modify the /etc/resolv.conf.d/tail file (as read in other tutorials) by adding a new servername but still not working.
Any suggestion?
Your DNS resolving doesn't work.
Check your firewall for an open port UDP/53 to 8.8.8.8
# iptables -L -n -v
Check with your ISP for DNS server provided. They are probably blocking UDP/53 somewhere on the way out to force you to use internal DNS server.
If you are on DHCP, renew the lease.
Depends on distro (most probably networkmanager, ifdown/ifup combination may work as well). This happens quite often with resolvconfd and dnsmasq. You may need to restart the NetworkManager then
Again - command depends on distro, usually with systemd
# systemctl restart NetworkManager
If you are on static IP and have noone to ask or check their config, you may sniff (tcpdump -nnvv -i <interface> udp port 53).
The problem occurs due to trouble with DNS setting
If you are using linux follow:
Clear this file content (root permission required)
nano /etc/resolv.conf
Add the folling text:
nameserver 1.1.1.1
nameserver 8.8.8.8
Save and Reboot
If using Windows Follow:
Control Panel\Network and Internet\Network and Sharing Center
Select current active connection (wifi/broadband)
Properties > Networking > ipv4 > custom dns > 1.1.1.1 & 8.8.8.8
check Validate setting upon exit > save
I am trying to install metasploit on crentos 6.6 server
now when i tried to yum install or wget or even git any bundle i got errors
then after alot of search i found that it is a problem in the DNS so i tried to edit /etc/resolv.conf
and add 8.8.8.8 as name server it worked fine but after server reboot or even eth0 restart it keeps returning without the modifications i made
this is my /etc/resolv.conf content
# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
is there any solution for this problem
I remember I got similar errors with CentOS.
Problem was: No internet connection.
First check a network connection:
#ping google.com
If there is no connection. You have to debug this first.
You are getting your networking configuration from DHCP but your DHCP server is failing to give you any DNS server addresses.
Did you try doing what that file tells you to do? Because that will "fix" your problem for you (assuming you don't choose to get your DHCP server fixed to provide you with DNS servers correctly).
Check location /etc/yum.repos.d/mongodb-org-3.2.repo
Delete all the irrelevent repositories in that location but be careful at that. Ex:- delete datastax repo which may be present
Run yum clean all
Run yum update
I am currently deploying to Digital Ocean using Meteor Up. If I don't specify a MONGO_URL in the mup.json, can I get the value from the command line while the website is running, i.e. I don't want to shutdown the site?
If I go to the app directory and run meteor mongo --url, I get the following error:
mongo: Meteor isn't running a local MongoDB server.
This command only works while Meteor is running your application
locally. Start your application first. (This error will also occur if
you asked Meteor to use a different MongoDB server with $MONGO_URL when
you ran your application.)
If you're trying to connect to the database of an app you deployed
with 'meteor deploy', specify your site's name with this command.
Even if I run the app from the app directory, it will only give the localhost MONGO_URL. I need the MONGO_URL for the deployed app.
I have also taken a look at a similar question as suggested by some of the answers. I disagree that it is "impossible" to get the MONGO_URL without some other program running on the server. It's not as if we are defying the laws of physics here, folks. Fundamentally, there should be a way to access it. Just because no one has yet figured it out doesn't mean it is impossible.
meteor mongo --url should return the URL.
Try opening another shell in the app directory and running that command.
Meteor Up packages your app in production mode with meteor build so that it runs via node rather than the meteor command line interface. Among other things, this means meteor foo won't work on the remote server (at least not by default). So what you're really looking for is a way to access mongo itself remotely.
I recently set up mongo on an AWS EC2 instance and listed some lessons learned here: https://stackoverflow.com/a/28846703/2669596. Some details of how you do it are going to be different on Digital Ocean, but these are the main things you have to take care of once mongo itself is installed:
Public IP/DNS Address: This is probably fine already since you can deploy to the server.
Port Security Rules: You need to make sure port 27017 is open for TCP access, at least from your IP address. MongoDB also has an http interface you can set up; if you want to use that you'll need to open 28017 as well.
/etc/mongod.conf (file location may differ depending on Linux flavor):
Uncomment port=27017 to make sure you have the default port (I don't think this is actually necessary, but it made me feel better and it's good to know where to change the default port...).
Comment out bind_ip=127.0.0.1 in order to listen to external interfaces (e.g. remote connections).
Uncomment httpinterface=true if you want to use the http interface.
You may have to restart the mongod host via sudo service mongod restart. That's a problem if you can't have downtime, but I don't know of a way around that if you change the config file.
Create User: You need to create an admin and/or user to access the database remotely.
Once you've done all of that, you should be able to access the database from your local machine (assuming you have the mongo client installed locally) by running
mongo server.url.com:27017/mup-app-name -u username -p
where server.url.com is the URL or IP address of your remote server, mup-app-name is the appName parameter from your mup.json file, username is the user you created to access the database, and you'll be prompted for that user's password after you run the command (or you could put it after -p on the same line, depending on the password).
There may also be a way to do this by setting up nginx to reverse-proxy 127.0.0.1:27017 on your remote server, but I've never done it and that's just me speculating.
I have setup a basic infrastructure using chef. This includes a local chef server(ubuntu based), workstation and an ubuntu based server(to be used as the node). Please note that the entire infrastructure lies behind the firewall in my office network. And I have made necessary proxy settings for the servers to access the internet.
So here is the problem - When I try to bootstrap the node using -
knife bootstrap <node's ip> --sudo -x <username> -P <password> -N "<name>"
i get the following error
<node's ip> --2014-02-19 10:47:10-- https://www.opscode.com/chef/install.sh
<node's ip> Resolving www.opscode.com (www.opscode.com)... 184.106.28.91
<node's ip>1 Connecting to www.opscode.com (www.opscode.com)|184.106.28.91|:443... failed:Connection refused.
<node's ip> bash: line 83: chef-client: command not found
I was not able to find a solution to this. However I came across the knife[:bootstrap_proxy] = "http://username:password#proxyIP:port/" setting that can be added to knife.rb . I did this (by entering my office proxy details) and then the connection during bootstrap was successfull and the chef client was downloaded on the node. However this setting only defines the proxy that should be used by the node. So, this led to the http_proxy = "http://username:password#proxyIP:port/" being set in client.rb. But because I have already made all the proxy settings in my server, the chef client failed to launch. So I manually removed the http_proxy and https_proxy settings from client.rb and ran the command chef-client which was then successful.
I have two questions -
1) why did knife[:bootstrap_proxy] = "http://username:password#proxyIP:port/" work? because it only defines the proxy that should be used by the node.
2) Also, alll the proxy setting for the node has already been done. I do not want any proxy settings in client.rb. How do I achieve this?
Please help!
When it comes to your client.rb I'd suggest looking into https://github.com/opscode-cookbooks/chef-client
It's a wrapper script for client.rb(s).
Not sure about your knife[:bootstrap_proxy] though. Ideally that cookbook should take care of it. If you are still stumpped you can run chef-client -VV and knife -VV to see exactly what it's doing.
I am using lighttpd as my webserver.
Currently I am accessing it using the IP address as :
http://192.168.0.1
I want to access it as
http://myhostname.com
I would be using it in the local network only, and not the internet.
I don't know how to do this. I googled, but don't know the exact keywords to use.
Put the following line to the file /etc/hosts:
192.168.0.1 myhostname.com
For instance, using the following command:
$ sudo echo -e '192.168.0.1\tmyhostname.com' >> /etc/hosts
you can add a rule in your hosts file: C:\Windows\System32\drivers\etc\hosts
add a rule like
192.168.0.1 myhostname.com
In windows you can't do this with wildcards so for all subdomains you need to add a rule
Find your hosts file on your local machine, and then add the following line to it:
192.168.0.1 www.somedomain.com