package ecs import ( "net/http" "net/url" "time" "github.com/docker/docker/api/types" ) var ( ecsMetadataPath, _ = url.Parse("/v2/metadata") ecsMetaStatsPath, _ = url.Parse("/v2/stats") ) // Client is the ECS client contract type Client interface { Task() (*Task, error) ContainerStats() (map[string]types.StatsJSON, error) } type httpClient interface { Do(req *http.Request) (*http.Response, error) } // NewClient constructs an ECS client with the passed configuration params func NewClient(timeout time.Duration) (*EcsClient, error) { c := &http.Client{ Timeout: timeout, } return &EcsClient{ client: c, }, nil } // EcsClient contains ECS connection config type EcsClient struct { client httpClient BaseURL *url.URL taskURL string statsURL string } // Task calls the ECS metadata endpoint and returns a populated Task func (c *EcsClient) Task() (*Task, error) { if c.taskURL == "" { c.taskURL = c.BaseURL.ResolveReference(ecsMetadataPath).String() } req, _ := http.NewRequest("GET", c.taskURL, nil) resp, err := c.client.Do(req) if err != nil { return nil, err } task, err := unmarshalTask(resp.Body) if err != nil { return nil, err } return task, nil } // ContainerStats calls the ECS stats endpoint and returns a populated container stats map func (c *EcsClient) ContainerStats() (map[string]types.StatsJSON, error) { if c.statsURL == "" { c.statsURL = c.BaseURL.ResolveReference(ecsMetaStatsPath).String() } req, _ := http.NewRequest("GET", c.statsURL, nil) resp, err := c.client.Do(req) if err != nil { return map[string]types.StatsJSON{}, err } statsMap, err := unmarshalStats(resp.Body) if err != nil { return map[string]types.StatsJSON{}, err } return statsMap, nil } // PollSync executes Task and ContainerStats in parallel. If both succeed, both structs are returned. // If either errors, a single error is returned. func PollSync(c Client) (*Task, map[string]types.StatsJSON, error) { var task *Task var stats map[string]types.StatsJSON var err error if stats, err = c.ContainerStats(); err != nil { return nil, nil, err } if task, err = c.Task(); err != nil { return nil, nil, err } return task, stats, nil }