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 // Use provided list of keep services, instead of using the
90 // API to discover available services.
91 KeepServiceURIs []string
96 lastClosedIdlesAt time.Time
102 // Create a new ArvadosClient, initialized with standard Arvados environment
103 // variables ARVADOS_API_HOST, ARVADOS_API_TOKEN, and (optionally)
104 // ARVADOS_API_HOST_INSECURE.
105 func MakeArvadosClient() (ac ArvadosClient, err error) {
106 var matchTrue = regexp.MustCompile("^(?i:1|yes|true)$")
107 insecure := matchTrue.MatchString(os.Getenv("ARVADOS_API_HOST_INSECURE"))
108 external := matchTrue.MatchString(os.Getenv("ARVADOS_EXTERNAL_CLIENT"))
112 ApiServer: os.Getenv("ARVADOS_API_HOST"),
113 ApiToken: os.Getenv("ARVADOS_API_TOKEN"),
114 ApiInsecure: insecure,
115 Client: &http.Client{Transport: &http.Transport{
116 TLSClientConfig: &tls.Config{InsecureSkipVerify: insecure}}},
120 if s := os.Getenv("ARVADOS_KEEP_SERVICES"); s != "" {
121 ac.KeepServiceURIs = strings.Split(s, " ")
124 if ac.ApiServer == "" {
125 return ac, MissingArvadosApiHost
127 if ac.ApiToken == "" {
128 return ac, MissingArvadosApiToken
131 ac.lastClosedIdlesAt = time.Now()
136 // CallRaw is the same as Call() but returns a Reader that reads the
137 // response body, instead of taking an output object.
138 func (c ArvadosClient) CallRaw(method string, resourceType string, uuid string, action string, parameters Dict) (reader io.ReadCloser, err error) {
147 if resourceType != API_DISCOVERY_RESOURCE {
148 u.Path = "/arvados/v1"
151 if resourceType != "" {
152 u.Path = u.Path + "/" + resourceType
155 u.Path = u.Path + "/" + uuid
158 u.Path = u.Path + "/" + action
161 if parameters == nil {
162 parameters = make(Dict)
165 vals := make(url.Values)
166 for k, v := range parameters {
167 if s, ok := v.(string); ok {
169 } else if m, err := json.Marshal(v); err == nil {
170 vals.Set(k, string(m))
176 case "GET", "HEAD", "PUT", "OPTIONS", "DELETE":
180 // Non-retryable methods such as POST are not safe to retry automatically,
181 // so we minimize such failures by always using a new or recently active socket
183 if time.Since(c.lastClosedIdlesAt) > MaxIdleConnectionDuration {
184 c.lastClosedIdlesAt = time.Now()
185 c.Client.Transport.(*http.Transport).CloseIdleConnections()
190 var req *http.Request
191 var resp *http.Response
193 for attempt := 0; attempt <= c.Retries; attempt++ {
194 if method == "GET" || method == "HEAD" {
195 u.RawQuery = vals.Encode()
196 if req, err = http.NewRequest(method, u.String(), nil); err != nil {
200 if req, err = http.NewRequest(method, u.String(), bytes.NewBufferString(vals.Encode())); err != nil {
203 req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
206 // Add api token header
207 req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", c.ApiToken))
209 req.Header.Add("X-External-Client", "1")
212 resp, err = c.Client.Do(req)
215 time.Sleep(RetryDelay)
222 if resp.StatusCode == http.StatusOK {
223 return resp.Body, nil
226 defer resp.Body.Close()
228 switch resp.StatusCode {
229 case 408, 409, 422, 423, 500, 502, 503, 504:
230 time.Sleep(RetryDelay)
233 return nil, newAPIServerError(c.ApiServer, resp)
238 return nil, newAPIServerError(c.ApiServer, resp)
243 func newAPIServerError(ServerAddress string, resp *http.Response) APIServerError {
245 ase := APIServerError{
246 ServerAddress: ServerAddress,
247 HttpStatusCode: resp.StatusCode,
248 HttpStatusMessage: resp.Status}
250 // If the response body has {"errors":["reason1","reason2"]}
251 // then return those reasons.
253 if err := json.NewDecoder(resp.Body).Decode(&errInfo); err == nil {
254 if errorList, ok := errInfo["errors"]; ok {
255 if errArray, ok := errorList.([]interface{}); ok {
256 for _, errItem := range errArray {
257 // We expect an array of strings here.
258 // Non-strings will be passed along
260 if s, ok := errItem.(string); ok {
261 ase.ErrorDetails = append(ase.ErrorDetails, s)
262 } else if j, err := json.Marshal(errItem); err == nil {
263 ase.ErrorDetails = append(ase.ErrorDetails, string(j))
272 // Call an API endpoint and parse the JSON response into an object.
274 // method - HTTP method: GET, HEAD, PUT, POST, PATCH or DELETE.
275 // resourceType - the type of arvados resource to act on (e.g., "collections", "pipeline_instances").
276 // uuid - the uuid of the specific item to access. May be empty.
277 // action - API method name (e.g., "lock"). This is often empty if implied by method and uuid.
278 // parameters - method parameters.
279 // output - a map or annotated struct which is a legal target for encoding/json/Decoder.
281 // Returns a non-nil error if an error occurs making the API call, the
282 // API responds with a non-successful HTTP status, or an error occurs
283 // parsing the response body.
284 func (c ArvadosClient) Call(method, resourceType, uuid, action string, parameters Dict, output interface{}) error {
285 reader, err := c.CallRaw(method, resourceType, uuid, action, parameters)
294 dec := json.NewDecoder(reader)
295 if err = dec.Decode(output); err != nil {
302 // Create a new resource. See Call for argument descriptions.
303 func (c ArvadosClient) Create(resourceType string, parameters Dict, output interface{}) error {
304 return c.Call("POST", resourceType, "", "", parameters, output)
307 // Delete a resource. See Call for argument descriptions.
308 func (c ArvadosClient) Delete(resource string, uuid string, parameters Dict, output interface{}) (err error) {
309 return c.Call("DELETE", resource, uuid, "", parameters, output)
312 // Modify attributes of a resource. See Call for argument descriptions.
313 func (c ArvadosClient) Update(resourceType string, uuid string, parameters Dict, output interface{}) (err error) {
314 return c.Call("PUT", resourceType, uuid, "", parameters, output)
317 // Get a resource. See Call for argument descriptions.
318 func (c ArvadosClient) Get(resourceType string, uuid string, parameters Dict, output interface{}) (err error) {
319 if !UUIDMatch(uuid) && !(resourceType == "collections" && PDHMatch(uuid)) {
320 // No object has uuid == "": there is no need to make
321 // an API call. Furthermore, the HTTP request for such
322 // an API call would be "GET /arvados/v1/type/", which
323 // is liable to be misinterpreted as the List API.
324 return ErrInvalidArgument
326 return c.Call("GET", resourceType, uuid, "", parameters, output)
329 // List resources of a given type. See Call for argument descriptions.
330 func (c ArvadosClient) List(resource string, parameters Dict, output interface{}) (err error) {
331 return c.Call("GET", resource, "", "", parameters, output)
334 const API_DISCOVERY_RESOURCE = "discovery/v1/apis/arvados/v1/rest"
336 // Discovery returns the value of the given parameter in the discovery
337 // document. Returns a non-nil error if the discovery document cannot
338 // be retrieved/decoded. Returns ErrInvalidArgument if the requested
339 // parameter is not found in the discovery document.
340 func (c *ArvadosClient) Discovery(parameter string) (value interface{}, err error) {
341 if len(c.DiscoveryDoc) == 0 {
342 c.DiscoveryDoc = make(Dict)
343 err = c.Call("GET", API_DISCOVERY_RESOURCE, "", "", nil, &c.DiscoveryDoc)
350 value, found = c.DiscoveryDoc[parameter]
354 return value, ErrInvalidArgument