github.com/wulonghui/docker@v1.8.0-rc2/docs/installation/ubuntulinux.md (about) 1 <!--[metadata]> 2 +++ 3 title = "Installation on Ubuntu " 4 description = "Instructions for installing Docker on Ubuntu. " 5 keywords = ["Docker, Docker documentation, requirements, virtualbox, installation, ubuntu"] 6 [menu.main] 7 parent = "smn_linux" 8 +++ 9 <![end-metadata]--> 10 11 # Ubuntu 12 13 Docker is supported on these Ubuntu operating systems: 14 15 - Ubuntu Vivid 15.04 16 - Ubuntu Trusty 14.04 (LTS) 17 - Ubuntu Precise 12.04 (LTS) 18 - Ubuntu Saucy 13.10 19 20 This page instructs you to install using Docker-managed release packages and 21 installation mechanisms. Using these packages ensures you get the latest release 22 of Docker. If you wish to install using Ubuntu-managed packages, consult your 23 Ubuntu documentation. 24 25 ## Prerequisites 26 27 Docker requires a 64-bit installation regardless of your Ubuntu version. 28 Additionally, your kernel must be 3.10 at minimum. The latest 3.10 minor version 29 or a newer maintained version are also acceptable. 30 31 Kernels older than 3.10 lack some of the features required to run Docker 32 containers. These older versions are known to have bugs which cause data loss 33 and frequently panic under certain conditions. 34 35 To check your current kernel version, open a terminal and use `uname -r` to display 36 your kernel version: 37 38 $ uname -r 39 3.11.0-15-generic 40 41 >**Caution** Some Ubuntu OS versions **require a version higher than 3.10** to 42 >run Docker, see the prerequisites on this page that apply to your Ubuntu 43 >version. 44 45 46 ### For Vivid 15.04 47 48 There are no prerequisites for this version. 49 50 ### For Trusty 14.04 51 52 There are no prerequisites for this version. 53 54 ### For Precise 12.04 (LTS) 55 56 For Ubuntu Precise, Docker requires the 3.13 kernel version. If your kernel 57 version is older than 3.13, you must upgrade it. Refer to this table to see 58 which packages are required for your environment: 59 60 <style type="text/css"> .tg {border-collapse:collapse;border-spacing:0;} .tg 61 td{font-size:14px;padding:10px 62 5px;border-style:solid;border-width:1px;overflow:hidden;word-break:normal;} 63 .tg-031{width:275px;font-family:monospace} </style> <table class="tg"> <tr> <td 64 class="tg-031">linux-image-generic-lts-trusty</td> <td class="tg-031e">Generic 65 Linux kernel image. This kernel has AUFS built in. This is required to run 66 Docker.</td> </tr> <tr> <td class="tg-031">linux-headers-generic-lts-trusty</td> 67 <td class="tg-031e">Allows packages such as ZFS and VirtualBox guest additions 68 which depend on them. If you didn't install the headers for your existing 69 kernel, then you can skip these headers for the"trusty" kernel. If you're 70 unsure, you should include this package for safety.</td> </tr> <tr> <td 71 class="tg-031">xserver-xorg-lts-trusty</td> <td class="tg-031e" 72 rowspan="2">Optional in non-graphical environments without Unity/Xorg. 73 <i>Required</i> when running Docker on machine with a graphical environment. 74 75 <p>To learn more about the reasons for these packages, read the installation 76 instructions for backported kernels, specifically the <a 77 href="https://wiki.ubuntu.com/Kernel/LTSEnablementStack" target="_blank">LTS 78 Enablement Stack</a> — refer to note 5 under each version.</p></td> </tr> 79 <tr> <td class="tg-031">libgl1-mesa-glx-lts-trusty</td> </tr> </table> 80 81 To upgrade your kernel and install the additional packages, do the following: 82 83 1. Open a terminal on your Ubuntu host. 84 85 2. Update your package manager. 86 87 $ sudo apt-get update 88 89 3. Install both the required and optional packages. 90 91 $ sudo apt-get install linux-image-generic-lts-trusty 92 93 Depending on your environment, you may install more as described in the preceding table. 94 95 4. Reboot your host. 96 97 $ sudo reboot 98 99 5. After your system reboots, go ahead and [install Docker](#installing-docker-on-ubuntu). 100 101 102 ### For Saucy 13.10 (64 bit) 103 104 Docker uses AUFS as the default storage backend. If you don't have this 105 prerequisite installed, Docker's installation process adds it. 106 107 ## Installation 108 109 Make sure you have installed the prerequisites for your Ubuntu version. Then, 110 install Docker using the following: 111 112 1. Log into your Ubuntu installation as a user with `sudo` privileges. 113 114 2. Verify that you have `wget` installed. 115 116 $ which wget 117 118 If `wget` isn't installed, install it after updating your manager: 119 120 $ sudo apt-get update 121 $ sudo apt-get install wget 122 123 3. Get the latest Docker package. 124 125 $ wget -qO- https://get.docker.com/ | sh 126 127 The system prompts you for your `sudo` password. Then, it downloads and 128 installs Docker and its dependencies. 129 130 >**Note**: If your company is behind a filtering proxy, you may find that the 131 >`apt-key` 132 >command fails for the Docker repo during installation. To work around this, 133 >add the key directly using the following: 134 > 135 > $ wget -qO- https://get.docker.com/gpg | sudo apt-key add - 136 137 4. Verify `docker` is installed correctly. 138 139 $ sudo docker run hello-world 140 141 This command downloads a test image and runs it in a container. 142 143 ## Optional configurations for Docker on Ubuntu 144 145 This section contains optional procedures for configuring your Ubuntu to work 146 better with Docker. 147 148 * [Create a docker group](#create-a-docker-group) 149 * [Adjust memory and swap accounting](#adjust-memory-and-swap-accounting) 150 * [Enable UFW forwarding](#enable-ufw-forwarding) 151 * [Configure a DNS server for use by Docker](#configure-a-dns-server-for-docker) 152 * [Configure Docker to start on boot](#configure-docker-to-start-on-boot) 153 154 ### Create a Docker group 155 156 The `docker` daemon binds to a Unix socket instead of a TCP port. By default 157 that Unix socket is owned by the user `root` and other users can access it with 158 `sudo`. For this reason, `docker` daemon always runs as the `root` user. 159 160 To avoid having to use `sudo` when you use the `docker` command, create a Unix 161 group called `docker` and add users to it. When the `docker` daemon starts, it 162 makes the ownership of the Unix socket read/writable by the `docker` group. 163 164 >**Warning**: The `docker` group is equivalent to the `root` user; For details 165 >on how this impacts security in your system, see [*Docker Daemon Attack 166 >Surface*](/articles/security/#docker-daemon-attack-surface) for details. 167 168 To create the `docker` group and add your user: 169 170 1. Log into Ubuntu as a user with `sudo` privileges. 171 172 This procedure assumes you log in as the `ubuntu` user. 173 174 3. Create the `docker` group and add your user. 175 176 $ sudo usermod -aG docker ubuntu 177 178 3. Log out and log back in. 179 180 This ensures your user is running with the correct permissions. 181 182 4. Verify your work by running `docker` without `sudo`. 183 184 $ docker run hello-world 185 186 If this fails with a message similar to this: 187 188 Cannot connect to the Docker daemon. Is 'docker daemon' running on this host? 189 190 Check that the `DOCKER_HOST` environment variable is not set for your shell. 191 If it is, unset it. 192 193 ### Adjust memory and swap accounting 194 195 When users run Docker, they may see these messages when working with an image: 196 197 WARNING: Your kernel does not support cgroup swap limit. WARNING: Your 198 kernel does not support swap limit capabilities. Limitation discarded. 199 200 To prevent these messages, enable memory and swap accounting on your system. To 201 enable these on system using GNU GRUB (GNU GRand Unified Bootloader), do the 202 following. 203 204 1. Log into Ubuntu as a user with `sudo` privileges. 205 206 2. Edit the `/etc/default/grub` file. 207 208 3. Set the `GRUB_CMDLINE_LINUX` value as follows: 209 210 GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1" 211 212 4. Save and close the file. 213 214 5. Update GRUB. 215 216 $ sudo update-grub 217 218 6. Reboot your system. 219 220 221 ### Enable UFW forwarding 222 223 If you use [UFW (Uncomplicated Firewall)](https://help.ubuntu.com/community/UFW) 224 on the same host as you run Docker, you'll need to do additional configuration. 225 Docker uses a bridge to manage container networking. By default, UFW drops all 226 forwarding traffic. As a result, for Docker to run when UFW is 227 enabled, you must set UFW's forwarding policy appropriately. 228 229 Also, UFW's default set of rules denies all incoming traffic. If you want to be able 230 to reach your containers from another host then you should also allow incoming 231 connections on the Docker port (default `2375`). 232 233 To configure UFW and allow incoming connections on the Docker port: 234 235 1. Log into Ubuntu as a user with `sudo` privileges. 236 237 2. Verify that UFW is installed and enabled. 238 239 $ sudo ufw status 240 241 3. Open the `/etc/default/ufw` file for editing. 242 243 $ sudo nano /etc/default/ufw 244 245 4. Set the `DEFAULT_FORWARD_POLICY` policy to: 246 247 DEFAULT_FORWARD_POLICY="ACCEPT" 248 249 5. Save and close the file. 250 251 6. Reload UFW to use the new setting. 252 253 $ sudo ufw reload 254 255 7. Allow incoming connections on the Docker port. 256 257 $ sudo ufw allow 2375/tcp 258 259 ### Configure a DNS server for use by Docker 260 261 Systems that run Ubuntu or an Ubuntu derivative on the desktop typically use 262 `127.0.0.1` as the default `nameserver` in `/etc/resolv.conf` file. The 263 NetworkManager also sets up `dnsmasq` to use the real DNS servers of the 264 connection and sets up `nameserver 127.0.0.1` in /`etc/resolv.conf`. 265 266 When starting containers on desktop machines with these configurations, Docker 267 users see this warning: 268 269 WARNING: Local (127.0.0.1) DNS resolver found in resolv.conf and containers 270 can't use it. Using default external servers : [8.8.8.8 8.8.4.4] 271 272 The warning occurs because Docker containers can't use the local DNS nameserver. 273 Instead, Docker defaults to using an external nameserver. 274 275 To avoid this warning, you can specify a DNS server for use by Docker 276 containers. Or, you can disable `dnsmasq` in NetworkManager. Though, disabling 277 `dnsmasq` might make DNS resolution slower on some networks. 278 279 To specify a DNS server for use by Docker: 280 281 1. Log into Ubuntu as a user with `sudo` privileges. 282 283 2. Open the `/etc/default/docker` file for editing. 284 285 $ sudo nano /etc/default/docker 286 287 3. Add a setting for Docker. 288 289 DOCKER_OPTS="--dns 8.8.8.8" 290 291 Replace `8.8.8.8` with a local DNS server such as `192.168.1.1`. You can also 292 specify multiple DNS servers. Separated them with spaces, for example: 293 294 --dns 8.8.8.8 --dns 192.168.1.1 295 296 >**Warning**: If you're doing this on a laptop which connects to various 297 >networks, make sure to choose a public DNS server. 298 299 4. Save and close the file. 300 301 5. Restart the Docker daemon. 302 303 $ sudo restart docker 304 305 306 307 308 309 **Or, as an alternative to the previous procedure,** disable `dnsmasq` in 310 NetworkManager (this might slow your network). 311 312 1. Open the `/etc/NetworkManager/NetworkManager.conf` file for editing. 313 314 $ sudo nano /etc/NetworkManager/NetworkManager.conf 315 316 2. Comment out the `dns=dsnmasq` line: 317 318 dns=dnsmasq 319 320 3. Save and close the file. 321 322 4. Restart both the NetworkManager and Docker. 323 324 $ sudo restart network-manager $ sudo restart docker 325 326 ### Configure Docker to start on boot 327 328 Ubuntu uses `systemd` as its boot and service manager `15.04` onwards and `upstart` 329 for versions `14.10` and below. 330 331 For `15.04` and up, to configure the `docker` daemon to start on boot, run 332 333 $ sudo systemctl enable docker 334 335 336 337 For `14.10` and below the above installation method automatically configures `upstart` 338 to start the docker daemon on boot 339 340 ## Upgrade Docker 341 342 To install the latest version of Docker with `wget`: 343 344 $ wget -qO- https://get.docker.com/ | sh 345 346 ## Uninstallation 347 348 To uninstall the Docker package: 349 350 $ sudo apt-get purge docker-engine 351 352 To uninstall the Docker package and dependencies that are no longer needed: 353 354 $ sudo apt-get autoremove --purge docker-engine 355 356 The above commands will not remove images, containers, volumes, or user created 357 configuration files on your host. If you wish to delete all images, containers, 358 and volumes run the following command: 359 360 $ rm -rf /var/lib/docker 361 362 You must delete the user created configuration files manually.