docs: service create: use markdown table for constraints

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit abeb7babdf)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
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Sebastiaan van Stijn 2020-02-10 11:13:26 +01:00
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1 changed files with 12 additions and 38 deletions

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@ -671,44 +671,18 @@ constraint expressions. Multiple constraints find nodes that satisfy every
expression (AND match). Constraints can match node or Docker Engine labels as
follows:
<table>
<tr>
<th>node attribute</th>
<th>matches</th>
<th>example</th>
</tr>
<tr>
<td><tt>node.id</tt></td>
<td>Node ID</td>
<td><tt>node.id==2ivku8v2gvtg4</tt></td>
</tr>
<tr>
<td><tt>node.hostname</tt></td>
<td>Node hostname</td>
<td><tt>node.hostname!=node-2</tt></td>
</tr>
<tr>
<td><tt>node.role</tt></td>
<td>Node role</td>
<td><tt>node.role==manager</tt></td>
</tr>
<tr>
<td><tt>node.labels</tt></td>
<td>user defined node labels</td>
<td><tt>node.labels.security==high</tt></td>
</tr>
<tr>
<td><tt>engine.labels</tt></td>
<td>Docker Engine's labels</td>
<td><tt>engine.labels.operatingsystem==ubuntu 14.04</tt></td>
</tr>
</table>
node attribute | matches | example
-------------------|--------------------------|-----------------------------------------------
`node.id` | Node ID | `node.id==2ivku8v2gvtg4`
`node.hostname` | Node hostname | `node.hostname!=node-2`
`node.role` | Node role | `node.role==manager`
`node.labels` | User-defined node labels | `node.labels.security==high`
`engine.labels` | Docker Engine's labels | `engine.labels.operatingsystem==ubuntu-14.04`
`engine.labels` apply to Docker Engine labels like operating system,
drivers, etc. Swarm administrators add `node.labels` for operational purposes by
using the [`docker node update`](node_update.md) command.
`engine.labels` apply to Docker Engine labels like operating system, drivers,
etc. Swarm administrators add `node.labels` for operational purposes by using
the [`docker node update`](node_update.md) command.
For example, the following limits tasks for the redis service to nodes where the
node type label equals queue:
@ -716,7 +690,7 @@ node type label equals queue:
```bash
$ docker service create \
--name redis_2 \
--constraint 'node.labels.type == queue' \
--constraint node.labels.type==queue \
redis:3.0.6
```
@ -730,7 +704,7 @@ of datacenters or availability zones. The example below illustrates this:
$ docker service create \
--replicas 9 \
--name redis_2 \
--placement-pref 'spread=node.labels.datacenter' \
--placement-pref spread=node.labels.datacenter \
redis:3.0.6
```