eremetic

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 Go to latest Published: Dec 7, 2020 License: Apache-2.0 Imports: 10 Imported by: 9

README

Eremetic

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Purpose

Eremetic is a Mesos Framework to run one-shot tasks. The vision is to provide a bridge between Applications that need to run tasks and Mesos. That way a developer creating an application that needs to schedule tasks (such as cron) wouldn't need to connect to Mesos directly.

Usage

Send a cURL to the eremetic framework with how much cpu and memory you need, what docker image to run and which command to run with that image.

curl -H "Content-Type: application/json" \
     -X POST \
     -d '{"mem":22.0, "cpu":1.0, "image": "busybox", "command": "echo $(date)"}' \
     http://eremetic_server:8080/api/v1/task

These basic fields are required but you can also specify volumes, container names to mounts volumes from, ports, environment variables, and URIs for the mesos fetcher to download. See examples.md for more examples on how to use eremetic.

JSON format:

{
  // Float64, fractions of a CPU to request
  "cpu":      1.0,
  // Float64, memory to use (MiB)
  "mem":       22.0,
  // String, full tag or hash of container to run
  "image":   "busybox",
  // Boolean, if set to true, docker image will be pulled before each task launch
  "force_pull_image": false,
  // Boolean, if set to true, docker will run the container in 'privileged' mode giving it all capabilities
  "privileged": false,
  // String, command to run in the docker container
  "command": "echo $(date)",
  // Array of Strings, arguements to pass to the docker container entrypoint
  "args": ["+%s"],
  // Array of Objects, volumes to mount in the container
  "volumes": [
    {
      "container_path": "/var/run/docker.sock",
      "host_path": "/var/run/docker.sock"
    }
  ],
  // Array of Strings, container names to get volumes from
  "volumes_from": ["+%s"],
  //String, name of the task. If empty, Eremetic assigns a random task name   
  "name" : "Task Name",
  //String, network mode to pass to the container.
  "network" : "BRIDGE",
  //String, DNS address to be used by the container.
   "dns" : "172.0.0.2",
  // Array of Objects, ports to forward to the container.
  // Assigned host ports are available as environment variables (e.g. PORT0, PORT1 and so on with PORT being an alias for PORT0).
  "ports": [
    {
      "container_port": 80,
      "protocol": "tcp"
    }
  ],
  // Object, Environment variables to pass to the container
  "env": {
    "KEY": "value"
  },
  // Object, Will be merged to `env` when passed to Mesos, but masked when doing a GET.
  // See Clarification of the Masked Env field below for more information
  "masked_env": {
    "KEY": "value"
  },
  // Object, labels to be passed to the Mesos task
  "labels": {
    "KEY": "value"
  },  
  // URIs and attributes of resource to download. You need to explicitly define
  // `"extract"` to unarchive files.
  "fetch": [
    {
      "uri" : "http://server.local/another_resource",
      "extract": false,
      "executable": false,
      "cache": false
    }
  ],
  // Constraints for which agent the task can run on (beyond cpu/memory).
  // Matching is strict and only attributes are currently supported. If
  // multiple constraints exist, they are evaluated using AND (ie: all or none).
  "agent_constraints": [
      {
          "attribute_name": "aws-region",
          "attribute_value": "us-west-2"
      }
  ],
  // String, URL to post a callback to. Callback message has format:
  // {"time":1451398320,"status":"TASK_FAILED","task_id":"eremetic-task.79feb50d-3d36-47cf-98ff-a52ef2bc0eb5"}
  "callback_uri": "http://callback.local"
}
Note

Most of this meta-data will not remain after a full restart of Eremetic.

Clarification of the Masked Env field

The purpose of the field is to provide a way to pass along environment variables that you don't want to have exposed in a subsequent GET call. It is not intended to provide full security, as someone with access to either the machine running Eremetic or the Mesos Agent that the task is being run on will still be able to view these values. These values are not encrypted, but simply masked when retrieved back via the API.

For security purposes, ensure TLS (https) is being used for the Eremetic communication and that access to any machines is properly restricted.

Configuration

create /etc/eremetic/eremetic.yml with:

address: 0.0.0.0
port: 8080
master: zk://<zookeeper_node1:port>,<zookeeper_node2:port>,(...)/mesos
messenger_address: <callback address for mesos>
messenger_port: <port for mesos to communicate on>
loglevel: DEBUG
logformat: json
queue_size: 100
url_prefix: <prefix to shim relative URLs behind a reverse proxy>

Database

Eremetic uses a database to store task information. The driver can be configured by setting the database_driver value.

Allowed values are: zk, boltdb

The location of the database can be configured by setting the database value.

BoltDB

The default database that will be used unless anything is configured.

The default value of the database field is db/eremetic.db

ZooKeeper

If you use zk as a database driver, the database field must be provided as a complete zk-uri (zk://zk1:1234,zk2:1234/my/database).

Authentication

To enable mesos framework authentication add the location of credential file to your configuration:

credential_file: /var/mesos_secret

The file should contain the Principal to authenticate and the secret separated by white space like so:

principal    secret_key

Building

Environment

Clone the repository into $GOPATH/src/github.com/eremetic-framework/eremetic. This is needed because of internal package dependencies

Install dependencies

First you need to install dependencies. Parts of the eremetic code is auto-generated (assets and templates for the HTML view are compiled). In order for go generate to work, go-bindata and go-bindata-assetfs needs to be manually installed.

curl https://bin.equinox.io/a/75VeNN6mcnk/github-com-kevinburke-go-bindata-go-bindata-linux-amd64.tar.gz | tar xvf - -C /usr/local/bin
go get github.com/elazarl/go-bindata-assetfs/...

All other dependencies are vendored, so it is recommended to run eremetic with Go >= 1.6 or with GO15VENDOREXPERIMENT=1

Creating the docker image

To build a docker image with eremetic, simply run

make docker
Compiling

Run make eremetic

Running on mesos

Eremetic can itself by run on mesos using e.g marathon. An example configuration for marathon is provided that is ready to be submitted through the api.

curl -X POST -H 'Content-Type: application/json' $MARATHON/v2/apps -d@misc/eremetic.json

Running tests

The default target of make builds and runs tests. Tests can also be run by running goconvey in the project root.

Running with minimesos

Using minimesos is a very simple way to test and play with eremetic.

docker run -e MASTER=$MINIMESOS_ZOOKEEPER -e HOST=0.0.0.0 -e DATABASE_DRIVER=zk -e DATABASE=$MINIMESOS_ZOOKEEPER/eremetic -e PORT=8000 -p 8000:8000 alde/eremetic:latest

hermit CLI

hermit is a command-line application to perform operations on a Eremetic server from the terminal.

Contributors

These are the fine folks who helped build eremetic

  • Rickard Dybeck
  • David Keijser
  • Aidan McGinley
  • William Strucke
  • Charles G.
  • Clément Laforet
  • Marcus Olsson
  • Rares Mirica

Acknowledgements

Thanks to Sebastian Norde for the awesome logo!

Licensing

Apache-2

Documentation

Index

Constants

View Source 
const (
	DefaultTaskFilterState = "active,queued"
	TerminatedState        = "terminated"
	ActiveState            = "active"
	QueuedState            = "queued"
)

Possible states for the TaskFilter. And the default state

View Source 
const Masking = "*******"

Masking is the string used for masking environment variables.

Variables

View Source 
var ErrQueueFull = errors.New("task queue is full")

ErrQueueFull is returned in the event of a full queue. This allows the caller to handle this as they see fit.

Functions

func ApplyMask 

func ApplyMask(task *Task)

ApplyMask replaces masked environment variables with a masking string.

func Encode 

func Encode(task *Task) ([]byte, error)

Encode encodes a task into a JSON byte array.

func IsActive added in v0.29.0 

func IsActive(state TaskState) bool

IsActive takes a string representation of a state and returns whether it is active or not.

func IsArchive added in v0.28.0 

func IsArchive(url string) bool

IsArchive is used to determine whether a url is an archive or not

func IsEnqueued added in v0.29.0 

func IsEnqueued(state TaskState) bool

IsEnqueued takes a string representation of a state and returns whether it is enqueued or not.

func IsTerminal 

func IsTerminal(state TaskState) bool

IsTerminal takes a string representation of a state and returns whether it is terminal or not.

func NotifyCallback 

func NotifyCallback(task *Task)

NotifyCallback handles posting a JSON back to the URI given with the task.

Types

type AgentConstraint added in v0.28.0 

type AgentConstraint struct {
	AttributeName  string `json:"attribute_name"`
	AttributeValue string `json:"attribute_value"`
}

AgentConstraint is a constraint that is validated for each agent when determining where to schedule a task.

type CallbackData 

type CallbackData struct {
	Time   int64  `json:"time"`
	Status string `json:"status"`
	TaskID string `json:"task_id"`
}

CallbackData holds information about the status update.

type DefaultTaskDB 

type DefaultTaskDB struct {
	// contains filtered or unexported fields
}

DefaultTaskDB is a in-memory implementation of TaskDB.

func NewDefaultTaskDB 

func NewDefaultTaskDB() *DefaultTaskDB

NewDefaultTaskDB returns a new instance of TaskDB.

func (*DefaultTaskDB) Clean 

func (db *DefaultTaskDB) Clean() error

Clean removes all tasks from the database.

func (*DefaultTaskDB) Close 

func (db *DefaultTaskDB) Close()

Close closes the connection to the database.

func (*DefaultTaskDB) DeleteTask added in v0.27.0 

func (db *DefaultTaskDB) DeleteTask(id string) error

DeleteTask removes the task with a given id, or an error if not found.

func (*DefaultTaskDB) ListTasks added in v0.29.0 

func (db *DefaultTaskDB) ListTasks(filter *TaskFilter) ([]*Task, error)

ListTasks returns all tasks based on the filter.

func (*DefaultTaskDB) PutTask 

func (db *DefaultTaskDB) PutTask(task *Task) error

PutTask adds a new task to the database.

func (*DefaultTaskDB) ReadTask 

func (db *DefaultTaskDB) ReadTask(id string) (Task, error)

ReadTask returns a task with a given id, or an error if not found.

func (*DefaultTaskDB) ReadUnmaskedTask 

func (db *DefaultTaskDB) ReadUnmaskedTask(id string) (Task, error)

ReadUnmaskedTask returns a task with all its environment variables unmasked.

type Port 

type Port struct {
	ContainerPort uint32 `json:"container_port"`
	HostPort      uint32 `json:"host_port"`
	Protocol      string `json:"protocol"`
}

Port defines a port mapping.

type Request 

type Request struct {
	TaskCPUs          float64
	TaskMem           float64
	DockerImage       string
	Command           string
	Args              []string
	Volumes           []Volume
	VolumesFrom       []string
	Ports             []Port
	Name              string
	Network           string
	DNS               string
	Environment       map[string]string
	MaskedEnvironment map[string]string
	Labels            map[string]string
	AgentConstraints  []AgentConstraint
	CallbackURI       string
	URIs              []string
	Fetch             []URI
	ForcePullImage    bool
	Privileged        bool
}

Request is the internal structure of a Request

type Scheduler 

type Scheduler interface {
	ScheduleTask(request Request) (string, error)
	Kill(taskID string) error
}

Scheduler defines an interface for scheduling tasks.

type Status 

type Status struct {
	Time   int64     `json:"time"`
	Status TaskState `json:"status"`
}

Status represents the task status at a given time.

type Task 

type Task struct {
	TaskCPUs          float64
	TaskMem           float64
	Command           string
	Args              []string
	User              string
	Environment       map[string]string
	MaskedEnvironment map[string]string
	Labels            map[string]string
	Image             string
	Volumes           []Volume
	VolumesFrom       []string
	Ports             []Port
	Status            []Status
	ID                string
	Name              string
	Network           string
	DNS               string
	FrameworkID       string
	AgentID           string
	AgentConstraints  []AgentConstraint
	Hostname          string
	Retry             int
	CallbackURI       string
	SandboxPath       string
	AgentIP           string
	AgentPort         int32
	ForcePullImage    bool
	Privileged        bool
	FetchURIs         []URI
}

Task represents the internal structure of a Task object

func NewTask 

func NewTask(request Request) (Task, error)

NewTask returns a new instance of a Task.

func (*Task) CurrentStatus added in v0.27.0 

func (task *Task) CurrentStatus() TaskState

CurrentStatus returns the current TaskState

func (*Task) IsActive added in v0.29.0 

func (task *Task) IsActive() bool

IsActive returns whether the task is still active.

func (*Task) IsEnqueued added in v0.29.0 

func (task *Task) IsEnqueued() bool

IsEnqueued returns whether the task is in queue.

func (*Task) IsRunning 

func (task *Task) IsRunning() bool

IsRunning returns whether the task is currently running.

func (*Task) IsTerminated 

func (task *Task) IsTerminated() bool

IsTerminated returns whether the task has been terminated.

func (*Task) IsTerminating added in v0.27.0 

func (task *Task) IsTerminating() bool

IsTerminating returns whether a task is in the process of terminating

func (*Task) LastUpdated 

func (task *Task) LastUpdated() time.Time

LastUpdated returns the time of the latest status update.

func (*Task) UpdateStatus 

func (task *Task) UpdateStatus(status Status)

UpdateStatus updates the current task status.

func (*Task) WasRunning 

func (task *Task) WasRunning() bool

WasRunning returns whether the task was running at some point.

type TaskDB 

type TaskDB interface {
	Clean() error
	Close()
	PutTask(task *Task) error
	ReadTask(id string) (Task, error)
	DeleteTask(id string) error
	ReadUnmaskedTask(id string) (Task, error)
	ListTasks(filter *TaskFilter) ([]*Task, error)
}

TaskDB defines the functions needed by the database abstraction layer

type TaskFilter added in v0.29.0 

type TaskFilter struct {
	Name  string `schema:"name"`
	State string `schema:"state"`
}

TaskFilter represents the query param state

func (TaskFilter) Match added in v0.29.0 

func (filter TaskFilter) Match(task *Task) bool

Match the conditions of TaskFilter with the current task

type TaskState 

type TaskState string

TaskState defines the valid task states. 

const (
	// Standard mesos states
	TaskStaging  TaskState = "TASK_STAGING"
	TaskStarting TaskState = "TASK_STARTING"
	TaskRunning  TaskState = "TASK_RUNNING"
	TaskFinished TaskState = "TASK_FINISHED"
	TaskFailed   TaskState = "TASK_FAILED"
	TaskKilled   TaskState = "TASK_KILLED"
	TaskLost     TaskState = "TASK_LOST"
	TaskError    TaskState = "TASK_ERROR"

	// Custom eremetic states
	TaskQueued      TaskState = "TASK_QUEUED"
	TaskTerminating TaskState = "TASK_TERMINATING"
)

Valid task states

func (TaskState) String 

func (s TaskState) String() string

type URI 

type URI struct {
	URI        string `json:"uri"`
	Executable bool   `json:"executable"`
	Extract    bool   `json:"extract"`
	Cache      bool   `json:"cache"`
}

URI holds meta-data for a sandbox resource.

type Volume 

type Volume struct {
	ContainerPath string `json:"container_path"`
	HostPath      string `json:"host_path"`
}

Volume is a mapping between ContainerPath and HostPath, to allow Docker to mount volumes.

Source Files

View all Source files

Directories

Path Synopsis
cmd
eremetic
hermit

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