For Docker 1.9 and up there&#39;s a native way:

List all orphaned volumes with

`$ docker volume ls -qf dangling=true`

Eliminate all of them with

`$ docker volume rm $(docker volume ls -qf dangling=true)`

From the Docker user guide:

&gt; If you remove containers that mount volumes, including the initial dbdata container, or the subsequent containers db1 and db2, the volumes will not be deleted. To delete the volume from disk, you must explicitly call docker rm -v against the last container with a reference to the volume. This allows you to upgrade, or effectively migrate data volumes between containers. - [source](https://docs.docker.com/userguide/dockervolumes/)

This is intentional behavior to avoid accidental data loss. You can use a tool like [docker-cleanup-volumes](https://github.com/chadoe/docker-cleanup-volumes) to clean out unused volumes.

For Docker 1.13+ and the ce/ee 17+ release numbers, use the [`volume prune` command][1]

    docker volume prune

Unlike the `dangling=true` query, this will not remove &quot;remote&quot; driver based volumes.  


  [1]: https://docs.docker.com/engine/reference/commandline/volume_prune/

using protobuf version 2.6.1 ( which i installed via homebrew)  

I am trying to run  

    $ protoc --go_out=../cloud/ *.proto

I keep receiving this error. 

    $ protoc-gen-go: program not found or is not executable
    $ --go_out: protoc-gen-go: Plugin failed with status code 1.

I have the protoc-gen-go installed in my go path. 
Anyone else have this issue?



Unable to build protobuf to go endpoint

I am trying to learn how to test with phpunit and laravel. When start the test using `phpunit` command, I am getting a warning :

    There was 1 failure:
    
    1) Warning
    No tests found in class &quot;PostsTest&quot;.
                                         
    FAILURES!                            
    Tests: 2, Assertions: 1, Failures: 

My test classname and filename matches. I have read other problems about unmatching names. my filename is `PostsTest.php` and my test file :


    class PostsTest extends ApiTester {
    
    	
    	public function it_fetches_posts()
    
    	{
    		$this-&gt;times(5)-&gt;makePost();
    
    		$this-&gt;getJson(&#39;api/v1/posts&#39;);
    
    		$this-&gt;assertResponseOk();
    
    	}
    
    	private function makePost($postFields=[])
    	{
    		$post = array_merge([
    			&#39;title&#39; =&gt; $this-&gt;fake-&gt;sentence,
    			&#39;content&#39; =&gt; $this-&gt;fake-&gt;paragragraph
    		], $postFields);
    
    		while($this-&gt;times --)Post::create($post);
    	}
    }
if necessary my ApiTester :

    use Faker\Factory as Faker;
    
    class ApiTester extends TestCase {
    	protected $fake;
    	protected $times = 1;
    	function __construct($faker)
    	{
    		$this-&gt;fake = Faker::create();
    	}
    }

I dont have any clue where the error is. Laravel or my local phpunit settings or anything else. Any helps is appreciated.

Thanks.

Phpunit tests gives warning no tests found in class

I just inspected my /var/lib/docker/volumes folder and discovered that is bursting with folders named as Docker UUIDs each of which contain a config.json file with contents along the lines of

    {&quot;ID&quot;:&quot;UUID&quot;,&quot;Path&quot;:&quot;/path/to/mounted/volume&quot;,&quot;IsBindMount&quot;:true,&quot;Writable&quot;:true}

where

    /path/to/mounted/volume

is the path to the folder on the host that was mounted on to a docker container with the -v switch at some point.  I have such folders dating back to the start of my experiments with Docker, i.e. about 3 weeks ago.

The containers in question were stopped and docker rm&#39;ed a long time ago so I cannot see that those entries are not past their sell-by date. This begs the question - is the left over I am seeing a bug or does one need to manually discard such entries from /var/lib/docker/volumes? 

Orphaned Docker mounted host volumes?

I just inspected my /var/lib/docker/volumes folder and discovered that is bursting with folders named as Docker UUIDs each of which contain a config.json file with contents along the lines of
<pre><code class="hljs language-json">{"ID":"UUID","Path":"/path/to/mounted/volume","IsBindMount":true,"Writable":true}
</code></pre>
where
<pre><code class="hljs language-bash">/path/to/mounted/volume
</code></pre>
is the path to the folder on the host that was mounted on to a docker container with the -v switch at some point. I have such folders dating back to the start of my experiments with Docker, i.e. about 3 weeks ago.
The containers in question were stopped and docker rm'ed a long time ago so I cannot see that those entries are not past their sell-by date. This begs the question - is the left over I am seeing a bug or does one need to manually discard such entries from /var/lib/docker/volumes?

I open an interactive shell into a docker container like so

    sudo docker exec -t -i {container_name} bash

So far so good but trying to run `nano` results in:

&gt;Error opening terminal: unknown.

Docker: Running nano in docker container

I have setup docker and I have used  completely different block device to store docker&#39;s system data:

    [root@blink1 /]# cat /etc/sysconfig/docker
    # /etc/sysconfig/docker
    
    other_args=&quot;-H tcp://0.0.0.0:9367 -H unix:///var/run/docker.sock -g /disk1/docker&quot;

Note that **`/disk/1`** is using a completely different hard drive **`/dev/xvdi`**

    Filesystem      Size  Used Avail Use% Mounted on
    /dev/xvda1      7.8G  5.1G  2.6G  67% /
    devtmpfs        1.9G  108K  1.9G   1% /dev
    tmpfs           1.9G     0  1.9G   0% /dev/shm
    /dev/xvdi        20G  5.3G   15G  27% /disk1
    /dev/dm-1       9.8G  1.7G  7.6G  18% /disk1/docker/devicemapper/mnt/bb6c540bae25aaf01aedf56ff61ffed8c6ae41aa9bd06122d440c6053e3486bf
    /dev/dm-2       9.8G  1.7G  7.7G  18% /disk1/docker/devicemapper/mnt/c85f756c59a5e1d260c3cdb473f3f4d9e55ac568967abe190eeaf9c4087afeac

The problem is that when I continue download docker images and run docker containers, it seems that the other hard drive **`/dev/xvda1`** is also used up.

I can verify this problem by remove some docker images. After I removed some docker images, **`/dev/xvda1`** has some more extra space now.

Am I missing something?

My docker version:

    [root@blink1 /]# docker info
    Containers: 2
    Images: 42
    Storage Driver: devicemapper
     Pool Name: docker-202:1-275421-pool
     Pool Blocksize: 64 Kb
     Data file: /disk1/docker/devicemapper/devicemapper/data
     Metadata file: /disk1/docker/devicemapper/devicemapper/metadata
     Data Space Used: 3054.4 Mb
     Data Space Total: 102400.0 Mb
     Metadata Space Used: 4.7 Mb
     Metadata Space Total: 2048.0 Mb
    Execution Driver: native-0.2
    Kernel Version: 3.14.20-20.44.amzn1.x86_64
    Operating System: Amazon Linux AMI 2014.09


Why is docker image eating up my disk space that is not used by docker

I&#39;m running Jenkins inside a Docker container. I wonder if it&#39;s ok for the Jenkins container to also be a Docker host? What I&#39;m thinking about is to start a new docker container for each integration test build from inside Jenkins (to start databases, message brokers etc). The containers should thus be shutdown after the integration tests are completed. Is there a reason to avoid running docker containers from inside another docker container in this way?

Is it ok to run docker from inside docker?

**Update II**

It&#39;s now July 16th, 2015 and things have changed again. I&#39;ve discovered this automagical container from Jason Wilder: https://github.com/jwilder/nginx-proxy and it solves this problem in about as long as it takes to docker run the container. This is now the solution I&#39;m using to solve this problem. 


**Update**

It&#39;s now July of 2015 and things have change drastically with regards to networking Docker containers. There are now many different offerings that solve this problem (in a variety of ways).

You should use this post to gain a basic understanding of the docker --link approach to service discovery, which is about as basic as it gets, works very well, and actually requires less fancy-dancing than most of the other solutions. It is limited in that it&#39;s quite difficult to network containers on separate hosts in any given cluster, and containers cannot be restarted once networked, but does offer a quick and relatively easy way to network containers on the same host. It&#39;s a good way to get an idea of what the software you&#39;ll likely be using to solve this problem is actually doing under the hood.

Additionally, you&#39;ll probably want to also check out Docker&#39;s nascent network, Hashicorp&#39;s consul, Weaveworks weave, Jeff Lindsay&#39;s progrium/consul &amp; gliderlabs/registrator, and Google&#39;s Kubernetes.

There&#39;s also the CoreOS offerings that utilize etcd, fleet, and flannel.

And if you really want to have a party you can spin up a cluster to run Mesosphere, or Deis, or Flynn.

If you&#39;re new to networking (like me) then you should get out your reading glasses, pop &quot;Paint The Sky With Stars — The Best of Enya&quot; on the Wi-Hi-Fi, and crack a beer — it&#39;s going to be a while before you really understand exactly what it is you&#39;re trying to do. Hint: You&#39;re trying to implement a Service Discovery Layer in your Cluster Control Plane. It&#39;s a very nice way to spend a Saturday night.

It&#39;s a lot of fun, but I wish I&#39;d taken the time to educate myself better about networking in general before diving right in. I eventually found a couple posts from the benevolent Digital Ocean Tutorial gods: Introduction to Networking Terminology and Understanding ... Networking. I suggest reading those a few times first before diving in.

Have fun!



**Original Post**

I can&#39;t seem to grasp port mapping for `Docker` containers. Specifically how to pass requests from Nginx to another container, listening on another port, on the same server.

I&#39;ve got a Dockerfile for an Nginx container like so:

    FROM ubuntu:14.04
    MAINTAINER Me &lt;me@myapp.com&gt;
    
    RUN apt-get update &amp;&amp; apt-get install -y htop git nginx
    
    ADD sites-enabled/api.myapp.com /etc/nginx/sites-enabled/api.myapp.com
    ADD sites-enabled/app.myapp.com /etc/nginx/sites-enabled/app.myapp.com
    ADD nginx.conf /etc/nginx/nginx.conf
    
    RUN echo &quot;daemon off;&quot; &gt;&gt; /etc/nginx/nginx.conf
    
    EXPOSE 80 443
    
    CMD [&quot;service&quot;, &quot;nginx&quot;, &quot;start&quot;]

&lt;br&gt;&lt;br&gt;
And then the `api.myapp.com` config file looks like so:

    upstream api_upstream{
    
    	server 0.0.0.0:3333;
    
    }
    
    
    server {
    
    	listen 80;
    	server_name api.myapp.com;
    	return 301 https://api.myapp.com/$request_uri;
    
    }
    
    
    server {
    
    	listen 443;
    	server_name api.mypp.com;
    	
    	location / {
    
        	proxy_http_version 1.1;
    		proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection &#39;upgrade&#39;;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
    		proxy_cache_bypass $http_upgrade;
    		proxy_pass http://api_upstream;
    	
    	}
    
    }

And then another for `app.myapp.com` as well.

And then I run:

    sudo docker run -p 80:80 -p 443:443 -d --name Nginx myusername/nginx

&lt;br&gt;
And it all stands up just fine, but the requests are not getting passed-through to the other containers/ports. And when I ssh into the Nginx container and inspect the logs I see no errors.

Any help?

How to configure Docker port mapping to use Nginx as an upstream proxy?

I&#39;m now trying to assign a static IP 172.17.0.1 when a Docker container be started up. 

I use port 2122 as the ssh port of this container so that I let this container listen port 2122.

    sudo docker run -i -t -p 2122:2122 ubuntu

This command will run a Docker container with a random IP like 172.17.0.5, but I need to assign a specific IP to the container.

 
The following shell script is what I reference Docker documentation in advanced network settings.


    pid=$(sudo docker inspect -f &#39;{{.State.Pid}}&#39; &lt;container_name&gt; 2&gt;/dev/null)
    sudo rm -rf /var/run/netns/*
    sudo ln -s /proc/$pid/ns/net /var/run/netns/$pid
    sudo ip link add A type veth peer name B
    sudo brctl addif docker0 A
    sudo ip link set A up
    sudo ip link set B netns $pid
    sudo ip netns exec $pid ip link set eth0 down
    sudo ip netns exec $pid ip link delete eth0
    sudo ip netns exec $pid ip link set dev B name eth0
    sudo ip netns exec $pid ip link set eth0 address 12:34:56:78:9a:bc
    sudo ip netns exec $pid ip link set eth0 down
    sudo ip netns exec $pid ip link set eth0 up
    sudo ip netns exec $pid ip addr add 172.17.0.1/16 dev eth0
    sudo ip netns exec $pid ip route add default via 172.17.42.1

This shell script will assign a static IP 172.17.0.1 and link to the world fine. But whenever I try to ssh to this container from my local, it didn&#39;t work. What&#39;s the problem possibly I met?

Content Type	Original Author	Original Content on Stackoverflow
Question	DroidOS	View Question on Stackoverflow
Solution 1 - Docker	Roman Usherenko	View Answer on Stackoverflow
Solution 2 - Docker	Kevan Ahlquist	View Answer on Stackoverflow
Solution 3 - Docker	Matt	View Answer on Stackoverflow

Orphaned Docker mounted host volumes?

Docker Problem Overview

Docker Solutions

Solution 1 - Docker

Solution 2 - Docker

Solution 3 - Docker

Phpunit tests gives warning no tests found in class

Unable to build protobuf to go endpoint

Attributions