Go-Marathon
Go-marathon is a API library for working with Marathon. It currently supports
- Application and group deployment
- Helper filters for pulling the status, configuration and tasks
- Multiple Endpoint support for HA deployments
- Marathon Subscriptions and Event callbacks
Note: the library still under active development; requires >= Go 1.3
Code Examples
There is also a examples directory in the source, which show hints and snippets of code of how to use it - which is probably the best place to start.
Creating a client
import (
"flag"
marathon "github.com/gambol99/go-marathon"
"github.com/golang/glog"
"time"
)
marathon_url := http://10.241.1.71:8080
config := marathon.NewDefaultConfig()
config.URL = marathon_url
config.LogOutput = os.Stdout
if client, err := marathon.NewClient(config); err != nil {
glog.Fatalf("Failed to create a client for marathon, error: %s", err)
} else {
applications, err := client.Applications()
...
Note, you can also specify multiple endpoint for Marathon (i.e. you have setup Marathon in HA mode and having multiple running)
marathon := "http://10.241.1.71:8080,10.241.1.72:8080,10.241.1.73:8080"
The first one specified will be used, if that goes offline the member is marked as "unavailable" and a background process will continue to ping the member until it's back online.
Listing the applications
if applications, err := client.Applications(); err != nil
glog.Errorf("Failed to list applications")
} else {
glog.Infof("Found %d application running", len(applications.Apps))
for _, application := range applications.Apps {
glog.Infof("Application: %s", application)
details, err := client.Application(application.ID)
Assert(err)
if details.Tasks != nil && len(details.Tasks) > 0 {
for _, task := range details.Tasks {
glog.Infof("task: %s", task)
}
// check the health of the application
health, err := client.ApplicationOK(details.ID)
glog.Infof("Application: %s, healthy: %t", details.ID, health)
}
}
Creating a new application
glog.Infof("Deploying a new application")
application := marathon.NewDockerApplication()
application.Name("/product/name/frontend")
application.CPU(0.1).Memory(64).Storage(0.0).Count(2)
application.Arg("/usr/sbin/apache2ctl").Arg("-D").Arg("FOREGROUND")
application.AddEnv("NAME", "frontend_http")
application.AddEnv("SERVICE_80_NAME", "test_http")
// add the docker container
application.Container.Docker.Container("quay.io/gambol99/apache-php:latest").Expose(80).Expose(443)
application.CheckHTTP("/health", 10, 5)
if _, err := client.CreateApplication(application, true); err != nil {
glog.Errorf("Failed to create application: %s, error: %s", application, err)
} else {
glog.Infof("Created the application: %s", application)
}
Scale Application
Change the number of instance of the application to 4
glog.Infof("Scale to 4 instances")
if err := client.ScaleApplicationInstances(application.ID, 10); err != nil {
glog.Errorf("Failed to delete the application: %s, error: %s", application, err)
} else {
client.WaitOnApplication(application.ID, 0)
glog.Infof("Successfully scaled the application")
}
Subscription & Events
Request to listen to events related to applications - namely status updates, health checks changes and failures
/* step: lets register for events */
update := make(marathon.EventsChannel,5)
if err := client.AddEventsListener(update, marathon.EVENTS_APPLICATIONS); err != nil {
glog.Fatalf("Failed to register for subscriptions, %s", err)
} else {
for {
event := <-update
glog.Infof("EVENT: %s", event )
}
}
# A full list of the events
const (
EVENT_API_REQUEST = 1 << iota
EVENT_STATUS_UPDATE
EVENT_FRAMEWORK_MESSAGE
EVENT_SUBSCRIPTION
EVENT_UNSUBSCRIBED
EVENT_ADD_HEALTH_CHECK
EVENT_REMOVE_HEALTH_CHECK
EVENT_FAILED_HEALTH_CHECK
EVENT_CHANGED_HEALTH_CHECK
EVENT_GROUP_CHANGE_SUCCESS
EVENT_GROUP_CHANGE_FAILED
EVENT_DEPLOYMENT_SUCCESS
EVENT_DEPLOYMENT_FAILED
EVENT_DEPLOYMENT_INFO
EVENT_DEPLOYMENT_STEP_SUCCESS
EVENT_DEPLOYMENT_STEP_FAILED
)
const (
EVENTS_APPLICATIONS = EVENT_STATUS_UPDATE | EVENT_CHANGED_HEALTH_CHECK | EVENT_FAILED_HEALTH_CHECK
EVENTS_SUBSCRIPTIONS = EVENT_SUBSCRIPTION | EVENT_UNSUBSCRIBED
)
Contributing
- Fork it
- Create your feature branch (git checkout -b my-new-feature)
- Commit your changes (git commit -am 'Add some feature')
- Push to the branch (git push origin my-new-feature)
- Create new Pull Request
- If applicable, update the README.md