X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/afef0760e7281eb7038778a12575dfc32b3162f3..0e57453d2b637a3d105d4e3d67031f3915f9d302:/sdk/go/arvadosclient/arvadosclient.go

diff --git a/sdk/go/arvadosclient/arvadosclient.go b/sdk/go/arvadosclient/arvadosclient.go
index 7c2442653c..99b08186a5 100644
--- a/sdk/go/arvadosclient/arvadosclient.go
+++ b/sdk/go/arvadosclient/arvadosclient.go
@@ -12,6 +12,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"regexp"
 	"strings"
 )
 
@@ -19,13 +20,33 @@ import (
 var MissingArvadosApiHost = errors.New("Missing required environment variable ARVADOS_API_HOST")
 var MissingArvadosApiToken = errors.New("Missing required environment variable ARVADOS_API_TOKEN")
 
-type ArvadosApiError struct {
-	error
-	HttpStatusCode int
-	HttpStatus string
+// Indicates an error that was returned by the API server.
+type APIServerError struct {
+	// Address of server returning error, of the form "host:port".
+	ServerAddress string
+
+	// Components of server response.
+	HttpStatusCode    int
+	HttpStatusMessage string
+
+	// Additional error details from response body.
+	ErrorDetails []string
 }
 
-func (e ArvadosApiError) Error() string { return e.error.Error() }
+func (e APIServerError) Error() string {
+	if len(e.ErrorDetails) > 0 {
+		return fmt.Sprintf("arvados API server error: %s (%d: %s) returned by %s",
+			strings.Join(e.ErrorDetails, "; "),
+			e.HttpStatusCode,
+			e.HttpStatusMessage,
+			e.ServerAddress)
+	} else {
+		return fmt.Sprintf("arvados API server error: %d: %s returned by %s",
+			e.HttpStatusCode,
+			e.HttpStatusMessage,
+			e.ServerAddress)
+	}
+}
 
 // Helper type so we don't have to write out 'map[string]interface{}' every time.
 type Dict map[string]interface{}
@@ -47,16 +68,20 @@ type ArvadosClient struct {
 	// If true, sets the X-External-Client header to indicate
 	// the client is outside the cluster.
 	External bool
+
+	// Discovery document
+	DiscoveryDoc Dict
 }
 
-// Create a new KeepClient, initialized with standard Arvados environment
+// Create a new ArvadosClient, initialized with standard Arvados environment
 // variables ARVADOS_API_HOST, ARVADOS_API_TOKEN, and (optionally)
 // ARVADOS_API_HOST_INSECURE.
-func MakeArvadosClient() (kc ArvadosClient, err error) {
-	insecure := (os.Getenv("ARVADOS_API_HOST_INSECURE") == "true")
-	external := (os.Getenv("ARVADOS_EXTERNAL_CLIENT") == "true")
+func MakeArvadosClient() (ac ArvadosClient, err error) {
+	var matchTrue = regexp.MustCompile("^(?i:1|yes|true)$")
+	insecure := matchTrue.MatchString(os.Getenv("ARVADOS_API_HOST_INSECURE"))
+	external := matchTrue.MatchString(os.Getenv("ARVADOS_EXTERNAL_CLIENT"))
 
-	kc = ArvadosClient{
+	ac = ArvadosClient{
 		ApiServer:   os.Getenv("ARVADOS_API_HOST"),
 		ApiToken:    os.Getenv("ARVADOS_API_TOKEN"),
 		ApiInsecure: insecure,
@@ -64,14 +89,14 @@ func MakeArvadosClient() (kc ArvadosClient, err error) {
 			TLSClientConfig: &tls.Config{InsecureSkipVerify: insecure}}},
 		External: external}
 
-	if kc.ApiServer == "" {
-		return kc, MissingArvadosApiHost
+	if ac.ApiServer == "" {
+		return ac, MissingArvadosApiHost
 	}
-	if kc.ApiToken == "" {
-		return kc, MissingArvadosApiToken
+	if ac.ApiToken == "" {
+		return ac, MissingArvadosApiToken
 	}
 
-	return kc, err
+	return ac, err
 }
 
 // Low-level access to a resource.
@@ -92,7 +117,9 @@ func (this ArvadosClient) CallRaw(method string, resource string, uuid string, a
 		Scheme: "https",
 		Host:   this.ApiServer}
 
-	u.Path = "/arvados/v1"
+	if resource != API_DISCOVERY_RESOURCE {
+		u.Path = "/arvados/v1"
+	}
 
 	if resource != "" {
 		u.Path = u.Path + "/" + resource
@@ -147,30 +174,36 @@ func (this ArvadosClient) CallRaw(method string, resource string, uuid string, a
 	}
 
 	defer resp.Body.Close()
-	errorText := fmt.Sprintf("API response: %s", resp.Status)
+	return nil, newAPIServerError(this.ApiServer, resp)
+}
+
+func newAPIServerError(ServerAddress string, resp *http.Response) APIServerError {
+
+	ase := APIServerError{
+		ServerAddress:     ServerAddress,
+		HttpStatusCode:    resp.StatusCode,
+		HttpStatusMessage: resp.Status}
 
 	// If the response body has {"errors":["reason1","reason2"]}
 	// then return those reasons.
 	var errInfo = Dict{}
 	if err := json.NewDecoder(resp.Body).Decode(&errInfo); err == nil {
 		if errorList, ok := errInfo["errors"]; ok {
-			var errorStrings []string
 			if errArray, ok := errorList.([]interface{}); ok {
 				for _, errItem := range errArray {
 					// We expect an array of strings here.
 					// Non-strings will be passed along
 					// JSON-encoded.
 					if s, ok := errItem.(string); ok {
-						errorStrings = append(errorStrings, s)
+						ase.ErrorDetails = append(ase.ErrorDetails, s)
 					} else if j, err := json.Marshal(errItem); err == nil {
-						errorStrings = append(errorStrings, string(j))
+						ase.ErrorDetails = append(ase.ErrorDetails, string(j))
 					}
 				}
-				errorText = strings.Join(errorStrings, "; ")
 			}
 		}
 	}
-	return nil, ArvadosApiError{errors.New(errorText), resp.StatusCode, resp.Status}
+	return ase
 }
 
 // Access to a resource.
@@ -247,3 +280,29 @@ func (this ArvadosClient) Update(resource string, uuid string, parameters Dict,
 func (this ArvadosClient) List(resource string, parameters Dict, output interface{}) (err error) {
 	return this.Call("GET", resource, "", "", parameters, output)
 }
+
+// API Discovery
+//
+//   parameter - name of parameter to be discovered
+// return
+//   value - value of the discovered parameter
+//   err - error accessing the resource, or nil if no error
+var API_DISCOVERY_RESOURCE string = "discovery/v1/apis/arvados/v1/rest"
+
+func (this *ArvadosClient) Discovery(parameter string) (value interface{}, err error) {
+	if len(this.DiscoveryDoc) == 0 {
+		this.DiscoveryDoc = make(Dict)
+		err = this.Call("GET", API_DISCOVERY_RESOURCE, "", "", nil, &this.DiscoveryDoc)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	var found bool
+	value, found = this.DiscoveryDoc[parameter]
+	if found {
+		return value, nil
+	} else {
+		return value, errors.New("Not found")
+	}
+}