mirror of https://github.com/docker/cli.git
186 lines
9.3 KiB
Markdown
186 lines
9.3 KiB
Markdown
---
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keywords: "API, Usage, plugins, documentation, developer"
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title: Plugins and Services
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---
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<!-- This file is maintained within the docker/cli GitHub
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repository at https://github.com/docker/cli/. Make all
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pull requests against that repo. If you see this file in
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will be rejected.
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# Using Volume and Network plugins in Docker services
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In swarm mode, it is possible to create a service that allows for attaching
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to networks or mounting volumes that are backed by plugins. Swarm schedules
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services based on plugin availability on a node.
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### Volume plugins
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In this example, a volume plugin is installed on a swarm worker and a volume
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is created using the plugin. In the manager, a service is created with the
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relevant mount options. It can be observed that the service is scheduled to
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run on the worker node with the said volume plugin and volume. Note that,
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node1 is the manager and node2 is the worker.
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1. Prepare manager. In node 1:
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```bash
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$ docker swarm init
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Swarm initialized: current node (dxn1zf6l61qsb1josjja83ngz) is now a manager.
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```
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2. Join swarm, install plugin and create volume on worker. In node 2:
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```bash
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$ docker swarm join \
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--token SWMTKN-1-49nj1cmql0jkz5s954yi3oex3nedyz0fb0xx14ie39trti4wxv-8vxv8rssmk743ojnwacrr2e7c \
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192.168.99.100:2377
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```
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```bash
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$ docker plugin install tiborvass/sample-volume-plugin
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latest: Pulling from tiborvass/sample-volume-plugin
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eb9c16fbdc53: Download complete
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Digest: sha256:00b42de88f3a3e0342e7b35fa62394b0a9ceb54d37f4c50be5d3167899994639
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Status: Downloaded newer image for tiborvass/sample-volume-plugin:latest
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Installed plugin tiborvass/sample-volume-plugin
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```
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```bash
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$ docker volume create -d tiborvass/sample-volume-plugin --name pluginVol
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```
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3. Create a service using the plugin and volume. In node1:
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```bash
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$ docker service create --name my-service --mount type=volume,volume-driver=tiborvass/sample-volume-plugin,source=pluginVol,destination=/tmp busybox top
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$ docker service ls
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z1sj8bb8jnfn my-service replicated 1/1 busybox:latest
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```
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docker service ls shows service 1 instance of service running.
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4. Observe the task getting scheduled in node 2:
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```bash
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{% raw %}
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$ docker ps --format '{{.ID}}\t {{.Status}} {{.Names}} {{.Command}}'
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83fc1e842599 Up 2 days my-service.1.9jn59qzn7nbc3m0zt1hij12xs "top"
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{% endraw %}
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```
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### Network plugins
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In this example, a global scope network plugin is installed on both the
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swarm manager and worker. A service is created with replicated instances
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using the installed plugin. We will observe how the availability of the
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plugin determines network creation and container scheduling.
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Note that node1 is the manager and node2 is the worker.
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1. Install a global scoped network plugin on both manager and worker. On node1
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and node2:
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```bash
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$ docker plugin install bboreham/weave2
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Plugin "bboreham/weave2" is requesting the following privileges:
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- network: [host]
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- capabilities: [CAP_SYS_ADMIN CAP_NET_ADMIN]
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Do you grant the above permissions? [y/N] y
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latest: Pulling from bboreham/weave2
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7718f575adf7: Download complete
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Digest: sha256:2780330cc15644b60809637ee8bd68b4c85c893d973cb17f2981aabfadfb6d72
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Status: Downloaded newer image for bboreham/weave2:latest
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Installed plugin bboreham/weave2
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```
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2. Create a network using plugin on manager. On node1:
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```bash
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$ docker network create --driver=bboreham/weave2:latest globalnet
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$ docker network ls
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NETWORK ID NAME DRIVER SCOPE
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qlj7ueteg6ly globalnet bboreham/weave2:latest swarm
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```
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3. Create a service on the manager and have replicas set to 8. Observe that
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containers get scheduled on both manager and worker.
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On node 1:
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```bash
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$ docker service create --network globalnet --name myservice --replicas=8 mrjana/simpleweb simpleweb
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w90drnfzw85nygbie9kb89vpa
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```
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```bash
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$ docker ps
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CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
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87520965206a mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 5 seconds ago Up 4 seconds myservice.4.ytdzpktmwor82zjxkh118uf1v
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15e24de0f7aa mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 5 seconds ago Up 4 seconds myservice.2.kh7a9n3iauq759q9mtxyfs9hp
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c8c8f0144cdc mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 5 seconds ago Up 4 seconds myservice.6.sjhpj5gr3xt33e3u2jycoj195
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2e8e4b2c5c08 mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 5 seconds ago Up 4 seconds myservice.8.2z29zowsghx66u2velublwmrh
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```
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On node 2:
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```bash
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$ docker ps
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CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
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53c0ae7c1dae mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 2 seconds ago Up Less than a second myservice.7.x44tvvdm3iwkt9kif35f7ykz1
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9b56c627fee0 mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 2 seconds ago Up Less than a second myservice.1.x7n1rm6lltw5gja3ueikze57q
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d4f5927ba52c mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 2 seconds ago Up 1 second myservice.5.i97bfo9uc6oe42lymafs9rz6k
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478c0d395bd7 mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 2 seconds ago Up Less than a second myservice.3.yr7nkffa48lff1vrl2r1m1ucs
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```
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4. Scale down the number of instances. On node1:
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```bash
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$ docker service scale myservice=0
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myservice scaled to 0
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```
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5. Disable and uninstall the plugin on the worker. On node2:
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```bash
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$ docker plugin rm -f bboreham/weave2
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bboreham/weave2
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```
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6. Scale up the number of instances again. Observe that all containers are
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scheduled on the master and not on the worker, because the plugin is not available on the worker anymore.
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On node 1:
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```bash
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$ docker service scale myservice=8
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myservice scaled to 8
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```
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```bash
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$ docker ps
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CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
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cf4b0ec2415e mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 39 seconds ago Up 36 seconds myservice.3.r7p5o208jmlzpcbm2ytl3q6n1
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57c64a6a2b88 mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 39 seconds ago Up 36 seconds myservice.4.dwoezsbb02ccstkhlqjy2xe7h
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3ac68cc4e7b8 mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 39 seconds ago Up 35 seconds myservice.5.zx4ezdrm2nwxzkrwnxthv0284
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006c3cb318fc mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 39 seconds ago Up 36 seconds myservice.8.q0e3umt19y3h3gzo1ty336k5r
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dd2ffebde435 mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 39 seconds ago Up 36 seconds myservice.7.a77y3u22prjipnrjg7vzpv3ba
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a86c74d8b84b mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 39 seconds ago Up 36 seconds myservice.6.z9nbn14bagitwol1biveeygl7
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2846a7850ba0 mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 39 seconds ago Up 37 seconds myservice.2.ypufz2eh9fyhppgb89g8wtj76
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e2ec01efcd8a mrjana/simpleweb@sha256:317d7f221d68c86d503119b0ea12c29de42af0a22ca087d522646ad1069a47a4 "simpleweb" 39 seconds ago Up 38 seconds myservice.1.8w7c4ttzr6zcb9sjsqyhwp3yl
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```
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On node 2:
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```bash
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$ docker ps
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CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
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```
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