package dcos import ( "bytes" "context" "crypto/tls" "encoding/json" "fmt" "net/http" "net/url" "time" jwt "github.com/dgrijalva/jwt-go" ) const ( // How long to stayed logged in for loginDuration = 65 * time.Minute ) // Client is an interface for communicating with the DC/OS API. type Client interface { SetToken(token string) Login(ctx context.Context, sa *ServiceAccount) (*AuthToken, error) GetSummary(ctx context.Context) (*Summary, error) GetContainers(ctx context.Context, node string) ([]Container, error) GetNodeMetrics(ctx context.Context, node string) (*Metrics, error) GetContainerMetrics(ctx context.Context, node, container string) (*Metrics, error) GetAppMetrics(ctx context.Context, node, container string) (*Metrics, error) } type APIError struct { StatusCode int Title string Description string } // Login is request data for logging in. type Login struct { UID string `json:"uid"` Exp int64 `json:"exp"` Token string `json:"token"` } // LoginError is the response when login fails. type LoginError struct { Title string `json:"title"` Description string `json:"description"` } // LoginAuth is the response to a successful login. type LoginAuth struct { Token string `json:"token"` } // Slave is a node in the cluster. type Slave struct { ID string `json:"id"` } // Summary provides high level cluster wide information. type Summary struct { Cluster string Slaves []Slave } // Container is a container on a node. type Container struct { ID string } type DataPoint struct { Name string `json:"name"` Tags map[string]string `json:"tags"` Unit string `json:"unit"` Value float64 `json:"value"` } // Metrics are the DCOS metrics type Metrics struct { Datapoints []DataPoint `json:"datapoints"` Dimensions map[string]interface{} `json:"dimensions"` } // AuthToken is the authentication token. type AuthToken struct { Text string Expire time.Time } // ClusterClient is a Client that uses the cluster URL. type ClusterClient struct { clusterURL *url.URL httpClient *http.Client credentials *Credentials token string semaphore chan struct{} } type claims struct { UID string `json:"uid"` jwt.StandardClaims } func (e APIError) Error() string { if e.Description != "" { return fmt.Sprintf("%s: %s", e.Title, e.Description) } return e.Title } func NewClusterClient( clusterURL *url.URL, timeout time.Duration, maxConns int, tlsConfig *tls.Config, ) *ClusterClient { httpClient := &http.Client{ Transport: &http.Transport{ MaxIdleConns: maxConns, TLSClientConfig: tlsConfig, }, Timeout: timeout, } semaphore := make(chan struct{}, maxConns) c := &ClusterClient{ clusterURL: clusterURL, httpClient: httpClient, semaphore: semaphore, } return c } func (c *ClusterClient) SetToken(token string) { c.token = token } func (c *ClusterClient) Login(ctx context.Context, sa *ServiceAccount) (*AuthToken, error) { token, err := c.createLoginToken(sa) if err != nil { return nil, err } exp := time.Now().Add(loginDuration) body := &Login{ UID: sa.AccountID, Exp: exp.Unix(), Token: token, } octets, err := json.Marshal(body) if err != nil { return nil, err } req, err := http.NewRequest("POST", c.url("/acs/api/v1/auth/login"), bytes.NewBuffer(octets)) if err != nil { return nil, err } req.Header.Add("Content-Type", "application/json") req = req.WithContext(ctx) resp, err := c.httpClient.Do(req) if err != nil { return nil, err } defer resp.Body.Close() if resp.StatusCode == http.StatusOK { auth := &LoginAuth{} dec := json.NewDecoder(resp.Body) err = dec.Decode(auth) if err != nil { return nil, err } token := &AuthToken{ Text: auth.Token, Expire: exp, } return token, nil } loginError := &LoginError{} dec := json.NewDecoder(resp.Body) err = dec.Decode(loginError) if err != nil { err := &APIError{ StatusCode: resp.StatusCode, Title: resp.Status, } return nil, err } err = &APIError{ StatusCode: resp.StatusCode, Title: loginError.Title, Description: loginError.Description, } return nil, err } func (c *ClusterClient) GetSummary(ctx context.Context) (*Summary, error) { summary := &Summary{} err := c.doGet(ctx, c.url("/mesos/master/state-summary"), summary) if err != nil { return nil, err } return summary, nil } func (c *ClusterClient) GetContainers(ctx context.Context, node string) ([]Container, error) { list := []string{} path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/containers", node) err := c.doGet(ctx, c.url(path), &list) if err != nil { return nil, err } containers := make([]Container, 0, len(list)) for _, c := range list { containers = append(containers, Container{ID: c}) } return containers, nil } func (c *ClusterClient) getMetrics(ctx context.Context, url string) (*Metrics, error) { metrics := &Metrics{} err := c.doGet(ctx, url, metrics) if err != nil { return nil, err } return metrics, nil } func (c *ClusterClient) GetNodeMetrics(ctx context.Context, node string) (*Metrics, error) { path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/node", node) return c.getMetrics(ctx, c.url(path)) } func (c *ClusterClient) GetContainerMetrics(ctx context.Context, node, container string) (*Metrics, error) { path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/containers/%s", node, container) return c.getMetrics(ctx, c.url(path)) } func (c *ClusterClient) GetAppMetrics(ctx context.Context, node, container string) (*Metrics, error) { path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/containers/%s/app", node, container) return c.getMetrics(ctx, c.url(path)) } func createGetRequest(url string, token string) (*http.Request, error) { req, err := http.NewRequest("GET", url, nil) if err != nil { return nil, err } if token != "" { req.Header.Add("Authorization", "token="+token) } req.Header.Add("Accept", "application/json") return req, nil } func (c *ClusterClient) doGet(ctx context.Context, url string, v interface{}) error { req, err := createGetRequest(url, c.token) if err != nil { return err } select { case c.semaphore <- struct{}{}: break case <-ctx.Done(): return ctx.Err() } resp, err := c.httpClient.Do(req.WithContext(ctx)) if err != nil { <-c.semaphore return err } defer func() { resp.Body.Close() <-c.semaphore }() // Clear invalid token if unauthorized if resp.StatusCode == http.StatusUnauthorized { c.token = "" } if resp.StatusCode < 200 || resp.StatusCode >= 300 { return &APIError{ StatusCode: resp.StatusCode, Title: resp.Status, } } if resp.StatusCode == http.StatusNoContent { return nil } err = json.NewDecoder(resp.Body).Decode(v) return err } func (c *ClusterClient) url(path string) string { url := c.clusterURL url.Path = path return url.String() } func (c *ClusterClient) createLoginToken(sa *ServiceAccount) (string, error) { token := jwt.NewWithClaims(jwt.SigningMethodRS256, claims{ UID: sa.AccountID, StandardClaims: jwt.StandardClaims{ // How long we have to login with this token ExpiresAt: time.Now().Add(5 * time.Minute).Unix(), }, }) return token.SignedString(sa.PrivateKey) }