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README: Add more examples.
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Signed-off-by: Andrea Luzzardi <[email protected]>
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@aluzzardi
aluzzardi committed Jun 8, 2016
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140 changes: 115 additions & 25 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,7 @@ $ make all

## Usage Examples

### 3 Nodes Cluster
### Setting up a Swarm

These instructions assume that `swarmd` and `swarmctl` are in your PATH.

Expand Down Expand Up @@ -88,56 +88,146 @@ by2ihzjyg9m674j3cjdit3reo node-2 READY ACTIVE
```

**Create and manage a service**
### Creating Services

Start a *redis* service:

Start a 'redis' service:
```
$ swarmctl service create --name redis --image redis
$ swarmctl service create --name redis --image redis:3.0.5
89831rq7oplzp6oqcqoswquf2
```

List the running services:

```
$ swarmctl service ls
ID Name Image Instances
-- ---- ----- ---------
enf3gkwlnmasgurdyebp555ja redis redis 1
ID Name Image Instances
-- ---- ----- ---------
89831rq7oplzp6oqcqoswquf2 redis redis:3.0.5 1
```

Inspect the service:

```
$ swarmctl service inspect redis
ID : enf3gkwlnmasgurdyebp555ja
ID : 89831rq7oplzp6oqcqoswquf2
Name : redis
Instances : 1
Template
Container
Image : redis
Image : redis:3.0.5
Task ID Service Instance Image Desired State Last State Node
------- ------- -------- ----- ------------- ---------- ----
0dsiq9za9at3cqk4qx07n6v8j redis 1 redis:3.0.5 RUNNING RUNNING 2 seconds ago node-1
```

### Updating Services

You can update any attribute of a service.

For example, you can scale the service by changing the instance count:

```
$ swarmctl service update redis --instances 6
89831rq7oplzp6oqcqoswquf2
$ swarmctl service inspect redis
ID : 89831rq7oplzp6oqcqoswquf2
Name : redis
Instances : 6
Template
Container
Image : redis:3.0.5
Task ID Service Instance Image Desired State Last State Node
------- ------- -------- ----- ------------- ---------- ----
0dsiq9za9at3cqk4qx07n6v8j redis 1 redis:3.0.5 RUNNING RUNNING 1 minute ago node-1
9fvobwddp5ve3k0f4al1mhuhn redis 2 redis:3.0.5 RUNNING RUNNING 3 seconds ago node-2
e7pxax9mhjd4zamohobefqpy0 redis 3 redis:3.0.5 RUNNING RUNNING 3 seconds ago node-2
ceuwhcffcavur7k9q57vqw0zg redis 4 redis:3.0.5 RUNNING RUNNING 3 seconds ago node-1
8vqmbo95l6obbtb7fpmvz522f redis 5 redis:3.0.5 RUNNING RUNNING 3 seconds ago node-3
385utv15nalm2pyupao6jtu12 redis 6 redis:3.0.5 RUNNING RUNNING 3 seconds ago node-3
```

Changing *instances* from *1* to *6* forced *SwarmKit* to create *5* additional Tasks in order to
comply with the desired state.

Every other field can be changed as well, such as image, args, env, ...

Let's change the image from *redis:3.0.5* to *redis:3.0.6* (e.g. upgrade):

```
$ swarmctl service update redis --image redis:3.0.6
89831rq7oplzp6oqcqoswquf2
$ swarmctl service inspect redis
ID : 89831rq7oplzp6oqcqoswquf2
Name : redis
Instances : 6
Template
Container
Image : redis:3.0.6
Task ID Service Instance Image Desired State Last State Node
------- ------- -------- ----- ------------- ---------- ----
7947mlunwz2dmlet3c7h84ln3 redis 1 redis:3.0.6 RUNNING RUNNING 34 seconds ago node-3
56rcujrassh7tlljp3k76etyw redis 2 redis:3.0.6 RUNNING RUNNING 34 seconds ago node-1
8l7bwrduq80pkq9tu4bsd95p4 redis 3 redis:3.0.6 RUNNING RUNNING 36 seconds ago node-2
3xb1jxytdo07mqccadt06rgi0 redis 4 redis:3.0.6 RUNNING RUNNING 34 seconds ago node-1
16aate5akcimsye9cp5xis1ih redis 5 redis:3.0.6 RUNNING RUNNING 34 seconds ago node-2
dws408a3gz0zx0bygq3aj0ztk redis 6 redis:3.0.6 RUNNING RUNNING 34 seconds ago node-3
```

By default, all tasks are updated at the same time.

This behavior can be changed by defining update options.

For instance, in order to update tasks 2 at a time and wait at least 10 seconds between updates:

Task ID Service Instance Image Desired State Last State Node
------- ------- -------- ----- ------------- ---------- ----
8oobrcr5u9lofmcbg7goaluyw redis 1 redis RUNNING RUNNING 1 minute ago node-1
```
$ swarmctl service update redis --image redis:3.0.7 --update-parallelism 2 --update-delay 10s
$ watch -n1 "swarmctl service inspect redis" # watch the update
```

This will update 2 tasks, wait for them to become *RUNNING*, then wait an additional 10 seconds before moving to other tasks.

Update options can be set at service creation and updated later on. If an update command doesn't specify update options, the last set of options will be used.

### Node Management

*SwarmKit* monitors node health. In the case of node failures, it re-schedules tasks to other nodes.

Now change the instance count:
An operator can manually define the *Availability* of a node and can *Pause* and *Drain* nodes.

Let's put `node-1` into maintanance mode:

```
$ swarmctl service update redis --instances 4
enf3gkwlnmasgurdyebp555ja
$
$ swarmctl node drain node-1
$ swarmctl node ls
ID Name Membership Status Availability Manager status
-- ---- ---------- ------ ------------ --------------
2o8evbttw2sjj node-1 ACCEPTED READY DRAIN REACHABLE
2p7w0q83jargg node-2 ACCEPTED READY ACTIVE REACHABLE *
3ieflj99g4wh8 node-3 ACCEPTED READY ACTIVE REACHABLE
$ swarmctl service inspect redis
ID : enf3gkwlnmasgurdyebp555ja
ID : 89831rq7oplzp6oqcqoswquf2
Name : redis
Instances : 4
Instances : 6
Template
Container
Image : redis
Image : redis:3.0.7
Task ID Service Instance Image Desired State Last State Node
------- ------- -------- ----- ------------- ---------- ----
8oobrcr5u9lofmcbg7goaluyw redis 1 redis RUNNING RUNNING 2 minutes ago node-1
cdv2oca2zc5upft24494orn1v redis 2 redis RUNNING RUNNING 6 seconds ago node-2
0x7e6a1d74nrwgcbbk9c12cqo redis 3 redis RUNNING RUNNING 6 seconds ago node-2
1c8zxfj0eifhbdxrgforqz4dp redis 4 redis RUNNING RUNNING 6 seconds ago node-1
Task ID Service Instance Image Desired State Last State Node
------- ------- -------- ----- ------------- ---------- ----
2pbjiykmaltiujokm0r8hmpz4 redis 1 redis:3.0.7 RUNNING RUNNING 1 minute ago node-2
az8ias15auf6w11jndsk7bc2o redis 2 redis:3.0.7 RUNNING RUNNING 1 minute ago node-3
5gsogy426bnqxdfynheqcqdls redis 3 redis:3.0.7 RUNNING RUNNING 4 seconds ago node-2
6vfzoshzb4jhyvp59yuf4dtnj redis 4 redis:3.0.7 RUNNING RUNNING 5 seconds ago node-3
18p0ei3a43xermxsnvvv0v1vd redis 5 redis:3.0.7 RUNNING RUNNING 2 minutes ago node-2
70eln8ibd8aku6jvmu8xz3hbc redis 6 redis:3.0.7 RUNNING RUNNING 4 seconds ago node-3
```

As you can see, every Task running on `node-1` was rebalanced to either `node-2` or `node-3` by the reconcilation loop.
1 change: 0 additions & 1 deletion cmd/swarmctl/service/flagparser/port.go
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,6 @@ import (
"github.com/spf13/pflag"
)

// Merge merges a flagset into a service spec.
func parsePorts(flags *pflag.FlagSet, spec *api.ServiceSpec) error {
if !flags.Changed("ports") {
return nil
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