1 /* Simple Arvados Go SDK for communicating with API server. */
20 type StringMatcher func(string) bool
22 var UUIDMatch StringMatcher = regexp.MustCompile(`^[a-z0-9]{5}-[a-z0-9]{5}-[a-z0-9]{15}$`).MatchString
23 var PDHMatch StringMatcher = regexp.MustCompile(`^[0-9a-f]{32}\+\d+$`).MatchString
25 var MissingArvadosApiHost = errors.New("Missing required environment variable ARVADOS_API_HOST")
26 var MissingArvadosApiToken = errors.New("Missing required environment variable ARVADOS_API_TOKEN")
27 var ErrInvalidArgument = errors.New("Invalid argument")
29 // A common failure mode is to reuse a keepalive connection that has been
30 // terminated (in a way that we can't detect) for being idle too long.
31 // POST and DELETE are not safe to retry automatically, so we minimize
32 // such failures by always using a new or recently active socket.
33 var MaxIdleConnectionDuration = 30 * time.Second
35 var RetryDelay = 2 * time.Second
37 // Indicates an error that was returned by the API server.
38 type APIServerError struct {
39 // Address of server returning error, of the form "host:port".
42 // Components of server response.
44 HttpStatusMessage string
46 // Additional error details from response body.
50 func (e APIServerError) Error() string {
51 if len(e.ErrorDetails) > 0 {
52 return fmt.Sprintf("arvados API server error: %s (%d: %s) returned by %s",
53 strings.Join(e.ErrorDetails, "; "),
58 return fmt.Sprintf("arvados API server error: %d: %s returned by %s",
65 // Helper type so we don't have to write out 'map[string]interface{}' every time.
66 type Dict map[string]interface{}
68 // Information about how to contact the Arvados server
69 type ArvadosClient struct {
73 // Arvados API server, form "host:port"
76 // Arvados API token for authentication
79 // Whether to require a valid SSL certificate or not
82 // Client object shared by client requests. Supports HTTP KeepAlive.
85 // If true, sets the X-External-Client header to indicate
86 // the client is outside the cluster.
89 // Base URIs of Keep services, e.g., {"https://host1:8443",
90 // "https://host2:8443"}. If this is nil, Keep clients will
91 // use the arvados.v1.keep_services.accessible API to discover
92 // available services.
93 KeepServiceURIs []string
98 lastClosedIdlesAt time.Time
104 // MakeArvadosClient creates a new ArvadosClient using the standard
105 // environment variables ARVADOS_API_HOST, ARVADOS_API_TOKEN,
106 // ARVADOS_API_HOST_INSECURE, ARVADOS_EXTERNAL_CLIENT, and
107 // ARVADOS_KEEP_SERVICES.
108 func MakeArvadosClient() (ac ArvadosClient, err error) {
109 var matchTrue = regexp.MustCompile("^(?i:1|yes|true)$")
110 insecure := matchTrue.MatchString(os.Getenv("ARVADOS_API_HOST_INSECURE"))
111 external := matchTrue.MatchString(os.Getenv("ARVADOS_EXTERNAL_CLIENT"))
115 ApiServer: os.Getenv("ARVADOS_API_HOST"),
116 ApiToken: os.Getenv("ARVADOS_API_TOKEN"),
117 ApiInsecure: insecure,
118 Client: &http.Client{Transport: &http.Transport{
119 TLSClientConfig: &tls.Config{InsecureSkipVerify: insecure}}},
123 for _, s := range strings.Split(os.Getenv("ARVADOS_KEEP_SERVICES"), " ") {
127 if u, err := url.Parse(s); err != nil {
128 return ac, fmt.Errorf("ARVADOS_KEEP_SERVICES: %q: %s", s, err)
129 } else if !u.IsAbs() {
130 return ac, fmt.Errorf("ARVADOS_KEEP_SERVICES: %q: not an absolute URI", s)
132 ac.KeepServiceURIs = append(ac.KeepServiceURIs, s)
135 if ac.ApiServer == "" {
136 return ac, MissingArvadosApiHost
138 if ac.ApiToken == "" {
139 return ac, MissingArvadosApiToken
142 ac.lastClosedIdlesAt = time.Now()
147 // CallRaw is the same as Call() but returns a Reader that reads the
148 // response body, instead of taking an output object.
149 func (c ArvadosClient) CallRaw(method string, resourceType string, uuid string, action string, parameters Dict) (reader io.ReadCloser, err error) {
158 if resourceType != API_DISCOVERY_RESOURCE {
159 u.Path = "/arvados/v1"
162 if resourceType != "" {
163 u.Path = u.Path + "/" + resourceType
166 u.Path = u.Path + "/" + uuid
169 u.Path = u.Path + "/" + action
172 if parameters == nil {
173 parameters = make(Dict)
176 vals := make(url.Values)
177 for k, v := range parameters {
178 if s, ok := v.(string); ok {
180 } else if m, err := json.Marshal(v); err == nil {
181 vals.Set(k, string(m))
187 case "GET", "HEAD", "PUT", "OPTIONS", "DELETE":
191 // Non-retryable methods such as POST are not safe to retry automatically,
192 // so we minimize such failures by always using a new or recently active socket
194 if time.Since(c.lastClosedIdlesAt) > MaxIdleConnectionDuration {
195 c.lastClosedIdlesAt = time.Now()
196 c.Client.Transport.(*http.Transport).CloseIdleConnections()
201 var req *http.Request
202 var resp *http.Response
204 for attempt := 0; attempt <= c.Retries; attempt++ {
205 if method == "GET" || method == "HEAD" {
206 u.RawQuery = vals.Encode()
207 if req, err = http.NewRequest(method, u.String(), nil); err != nil {
211 if req, err = http.NewRequest(method, u.String(), bytes.NewBufferString(vals.Encode())); err != nil {
214 req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
217 // Add api token header
218 req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", c.ApiToken))
220 req.Header.Add("X-External-Client", "1")
223 resp, err = c.Client.Do(req)
226 time.Sleep(RetryDelay)
233 if resp.StatusCode == http.StatusOK {
234 return resp.Body, nil
237 defer resp.Body.Close()
239 switch resp.StatusCode {
240 case 408, 409, 422, 423, 500, 502, 503, 504:
241 time.Sleep(RetryDelay)
244 return nil, newAPIServerError(c.ApiServer, resp)
249 return nil, newAPIServerError(c.ApiServer, resp)
254 func newAPIServerError(ServerAddress string, resp *http.Response) APIServerError {
256 ase := APIServerError{
257 ServerAddress: ServerAddress,
258 HttpStatusCode: resp.StatusCode,
259 HttpStatusMessage: resp.Status}
261 // If the response body has {"errors":["reason1","reason2"]}
262 // then return those reasons.
264 if err := json.NewDecoder(resp.Body).Decode(&errInfo); err == nil {
265 if errorList, ok := errInfo["errors"]; ok {
266 if errArray, ok := errorList.([]interface{}); ok {
267 for _, errItem := range errArray {
268 // We expect an array of strings here.
269 // Non-strings will be passed along
271 if s, ok := errItem.(string); ok {
272 ase.ErrorDetails = append(ase.ErrorDetails, s)
273 } else if j, err := json.Marshal(errItem); err == nil {
274 ase.ErrorDetails = append(ase.ErrorDetails, string(j))
283 // Call an API endpoint and parse the JSON response into an object.
285 // method - HTTP method: GET, HEAD, PUT, POST, PATCH or DELETE.
286 // resourceType - the type of arvados resource to act on (e.g., "collections", "pipeline_instances").
287 // uuid - the uuid of the specific item to access. May be empty.
288 // action - API method name (e.g., "lock"). This is often empty if implied by method and uuid.
289 // parameters - method parameters.
290 // output - a map or annotated struct which is a legal target for encoding/json/Decoder.
292 // Returns a non-nil error if an error occurs making the API call, the
293 // API responds with a non-successful HTTP status, or an error occurs
294 // parsing the response body.
295 func (c ArvadosClient) Call(method, resourceType, uuid, action string, parameters Dict, output interface{}) error {
296 reader, err := c.CallRaw(method, resourceType, uuid, action, parameters)
305 dec := json.NewDecoder(reader)
306 if err = dec.Decode(output); err != nil {
313 // Create a new resource. See Call for argument descriptions.
314 func (c ArvadosClient) Create(resourceType string, parameters Dict, output interface{}) error {
315 return c.Call("POST", resourceType, "", "", parameters, output)
318 // Delete a resource. See Call for argument descriptions.
319 func (c ArvadosClient) Delete(resource string, uuid string, parameters Dict, output interface{}) (err error) {
320 return c.Call("DELETE", resource, uuid, "", parameters, output)
323 // Modify attributes of a resource. See Call for argument descriptions.
324 func (c ArvadosClient) Update(resourceType string, uuid string, parameters Dict, output interface{}) (err error) {
325 return c.Call("PUT", resourceType, uuid, "", parameters, output)
328 // Get a resource. See Call for argument descriptions.
329 func (c ArvadosClient) Get(resourceType string, uuid string, parameters Dict, output interface{}) (err error) {
330 if !UUIDMatch(uuid) && !(resourceType == "collections" && PDHMatch(uuid)) {
331 // No object has uuid == "": there is no need to make
332 // an API call. Furthermore, the HTTP request for such
333 // an API call would be "GET /arvados/v1/type/", which
334 // is liable to be misinterpreted as the List API.
335 return ErrInvalidArgument
337 return c.Call("GET", resourceType, uuid, "", parameters, output)
340 // List resources of a given type. See Call for argument descriptions.
341 func (c ArvadosClient) List(resource string, parameters Dict, output interface{}) (err error) {
342 return c.Call("GET", resource, "", "", parameters, output)
345 const API_DISCOVERY_RESOURCE = "discovery/v1/apis/arvados/v1/rest"
347 // Discovery returns the value of the given parameter in the discovery
348 // document. Returns a non-nil error if the discovery document cannot
349 // be retrieved/decoded. Returns ErrInvalidArgument if the requested
350 // parameter is not found in the discovery document.
351 func (c *ArvadosClient) Discovery(parameter string) (value interface{}, err error) {
352 if len(c.DiscoveryDoc) == 0 {
353 c.DiscoveryDoc = make(Dict)
354 err = c.Call("GET", API_DISCOVERY_RESOURCE, "", "", nil, &c.DiscoveryDoc)
361 value, found = c.DiscoveryDoc[parameter]
365 return value, ErrInvalidArgument