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.
92 lastClosedIdlesAt time.Time
98 // Create a new ArvadosClient, initialized with standard Arvados environment
99 // variables ARVADOS_API_HOST, ARVADOS_API_TOKEN, and (optionally)
100 // ARVADOS_API_HOST_INSECURE.
101 func MakeArvadosClient() (ac ArvadosClient, err error) {
102 var matchTrue = regexp.MustCompile("^(?i:1|yes|true)$")
103 insecure := matchTrue.MatchString(os.Getenv("ARVADOS_API_HOST_INSECURE"))
104 external := matchTrue.MatchString(os.Getenv("ARVADOS_EXTERNAL_CLIENT"))
108 ApiServer: os.Getenv("ARVADOS_API_HOST"),
109 ApiToken: os.Getenv("ARVADOS_API_TOKEN"),
110 ApiInsecure: insecure,
111 Client: &http.Client{Transport: &http.Transport{
112 TLSClientConfig: &tls.Config{InsecureSkipVerify: insecure}}},
116 if ac.ApiServer == "" {
117 return ac, MissingArvadosApiHost
119 if ac.ApiToken == "" {
120 return ac, MissingArvadosApiToken
123 ac.lastClosedIdlesAt = time.Now()
128 // CallRaw is the same as Call() but returns a Reader that reads the
129 // response body, instead of taking an output object.
130 func (c ArvadosClient) CallRaw(method string, resourceType string, uuid string, action string, parameters Dict) (reader io.ReadCloser, err error) {
139 if resourceType != API_DISCOVERY_RESOURCE {
140 u.Path = "/arvados/v1"
143 if resourceType != "" {
144 u.Path = u.Path + "/" + resourceType
147 u.Path = u.Path + "/" + uuid
150 u.Path = u.Path + "/" + action
153 if parameters == nil {
154 parameters = make(Dict)
157 vals := make(url.Values)
158 for k, v := range parameters {
159 if s, ok := v.(string); ok {
161 } else if m, err := json.Marshal(v); err == nil {
162 vals.Set(k, string(m))
168 case "GET", "HEAD", "PUT", "OPTIONS", "POST", "DELETE":
172 // POST and DELETE are not safe to retry automatically, so we minimize
173 // such failures by always using a new or recently active socket
174 if method == "POST" || method == "DELETE" {
175 if time.Since(c.lastClosedIdlesAt) > MaxIdleConnectionDuration {
176 c.lastClosedIdlesAt = time.Now()
177 c.Client.Transport.(*http.Transport).CloseIdleConnections()
182 var req *http.Request
183 var resp *http.Response
185 for attempt := 0; attempt <= c.Retries; attempt++ {
186 if method == "GET" || method == "HEAD" {
187 u.RawQuery = vals.Encode()
188 if req, err = http.NewRequest(method, u.String(), nil); err != nil {
192 if req, err = http.NewRequest(method, u.String(), bytes.NewBufferString(vals.Encode())); err != nil {
195 req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
198 // Add api token header
199 req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", c.ApiToken))
201 req.Header.Add("X-External-Client", "1")
204 resp, err = c.Client.Do(req)
207 time.Sleep(RetryDelay)
214 if resp.StatusCode == http.StatusOK {
215 return resp.Body, nil
218 defer resp.Body.Close()
220 switch resp.StatusCode {
221 case 408, 409, 422, 423, 500, 502, 503, 504:
222 time.Sleep(RetryDelay)
225 return nil, newAPIServerError(c.ApiServer, resp)
230 return nil, newAPIServerError(c.ApiServer, resp)
236 func newAPIServerError(ServerAddress string, resp *http.Response) APIServerError {
238 ase := APIServerError{
239 ServerAddress: ServerAddress,
240 HttpStatusCode: resp.StatusCode,
241 HttpStatusMessage: resp.Status}
243 // If the response body has {"errors":["reason1","reason2"]}
244 // then return those reasons.
246 if err := json.NewDecoder(resp.Body).Decode(&errInfo); err == nil {
247 if errorList, ok := errInfo["errors"]; ok {
248 if errArray, ok := errorList.([]interface{}); ok {
249 for _, errItem := range errArray {
250 // We expect an array of strings here.
251 // Non-strings will be passed along
253 if s, ok := errItem.(string); ok {
254 ase.ErrorDetails = append(ase.ErrorDetails, s)
255 } else if j, err := json.Marshal(errItem); err == nil {
256 ase.ErrorDetails = append(ase.ErrorDetails, string(j))
265 // Call an API endpoint and parse the JSON response into an object.
267 // method - HTTP method: GET, HEAD, PUT, POST, PATCH or DELETE.
268 // resourceType - the type of arvados resource to act on (e.g., "collections", "pipeline_instances").
269 // uuid - the uuid of the specific item to access. May be empty.
270 // action - API method name (e.g., "lock"). This is often empty if implied by method and uuid.
271 // parameters - method parameters.
272 // output - a map or annotated struct which is a legal target for encoding/json/Decoder.
274 // Returns a non-nil error if an error occurs making the API call, the
275 // API responds with a non-successful HTTP status, or an error occurs
276 // parsing the response body.
277 func (c ArvadosClient) Call(method string, resourceType string, uuid string, action string, parameters Dict, output interface{}) error {
278 reader, err := c.CallRaw(method, resourceType, uuid, action, parameters)
287 dec := json.NewDecoder(reader)
288 if err = dec.Decode(output); err != nil {
295 // Create a new resource. See Call for argument descriptions.
296 func (c ArvadosClient) Create(resourceType string, parameters Dict, output interface{}) error {
297 return c.Call("POST", resourceType, "", "", parameters, output)
300 // Delete a resource. See Call for argument descriptions.
301 func (c ArvadosClient) Delete(resource string, uuid string, parameters Dict, output interface{}) (err error) {
302 return c.Call("DELETE", resource, uuid, "", parameters, output)
305 // Modify attributes of a resource. See Call for argument descriptions.
306 func (c ArvadosClient) Update(resourceType string, uuid string, parameters Dict, output interface{}) (err error) {
307 return c.Call("PUT", resourceType, uuid, "", parameters, output)
310 // Get a resource. See Call for argument descriptions.
311 func (c ArvadosClient) Get(resourceType string, uuid string, parameters Dict, output interface{}) (err error) {
312 if !UUIDMatch(uuid) && !(resourceType == "collections" && PDHMatch(uuid)) {
313 // No object has uuid == "": there is no need to make
314 // an API call. Furthermore, the HTTP request for such
315 // an API call would be "GET /arvados/v1/type/", which
316 // is liable to be misinterpreted as the List API.
317 return ErrInvalidArgument
319 return c.Call("GET", resourceType, uuid, "", parameters, output)
322 // List resources of a given type. See Call for argument descriptions.
323 func (c ArvadosClient) List(resource string, parameters Dict, output interface{}) (err error) {
324 return c.Call("GET", resource, "", "", parameters, output)
327 const API_DISCOVERY_RESOURCE = "discovery/v1/apis/arvados/v1/rest"
329 // Discovery returns the value of the given parameter in the discovery
330 // document. Returns a non-nil error if the discovery document cannot
331 // be retrieved/decoded. Returns ErrInvalidArgument if the requested
332 // parameter is not found in the discovery document.
333 func (c *ArvadosClient) Discovery(parameter string) (value interface{}, err error) {
334 if len(c.DiscoveryDoc) == 0 {
335 c.DiscoveryDoc = make(Dict)
336 err = c.Call("GET", API_DISCOVERY_RESOURCE, "", "", nil, &c.DiscoveryDoc)
343 value, found = c.DiscoveryDoc[parameter]
347 return value, ErrInvalidArgument