README
¶
IBM Cloudant Go SDK Version 0.0.24
Go client library to interact with the various IBM Cloudant APIs.
Table of Contents
Overview
The IBM Cloudant Go SDK allows developers to programmatically interact
with Cloudant with the help of
cloudantv1 package.
Features
The purpose of this Go SDK is to wrap most of the HTTP request APIs provided by Cloudant and supply other functions to ease the usage of Cloudant. This SDK should make life easier for programmers to do what’s really important for them: develop.
Reasons why you should consider using Cloudant SDK for Go in your project:
- Supported by IBM Cloudant.
- Includes all the most popular and latest supported endpoints for applications.
- Handles the authentication.
- HTTP2 support for higher performance connections to IBM Cloudant.
- Familiar user experience of IBM Cloud SDKs.
- Perform requests synchronously
- Safe for concurrent use by multiple goroutines
Prerequisites
- An IBM Cloud account.
- An IAM API key to allow the SDK to access your account. Create one here.
- Go version 1.12 or above.
Installation
The current version of this SDK: 0.0.24
There are a few different ways to download and install the Cloudant Go SDK project for use by your Go application:
go get command
Use this command to download and install the SDK to allow your Go application to use it:
go get -u github.com/IBM/cloudant-go-sdk/cloudantv1
Go modules
If your application is using Go modules, you can add a suitable import to your Go application, like this:
import (
"github.com/IBM/cloudant-go-sdk/cloudantv1"
)
then run go mod tidy to download and install the new dependency and update your Go application's
go.mod file.
dep dependency manager
If your application is using the dep dependency management tool, you can add a dependency
to your Gopkg.toml file. Here is an example:
[[constraint]]
name = "github.com/IBM/cloudant-go-sdk"
version = "0.0.24"
then run dep ensure.
Getting started
Authentication
This library requires some of your Cloudant service credentials to authenticate with your account.
IAM,BASICorNOAUTHauthentication type.- IAM authentication is highly recommended when your back-end database server is Cloudant. This authentication type requires a server-generated
apikeyinstead of a user-given password. - Basic (or legacy) authentication is a fallback for both Cloudant and Apache CouchDB back-end database servers. This authentication type requires the good old
usernameandpasswordcredentials. - Noauth authentication does not need any credentials. Note that this authentication type will only work for queries against a database with read access for everyone.
- IAM authentication is highly recommended when your back-end database server is Cloudant. This authentication type requires a server-generated
- The service
url
You have to add these properties as your environment variables, because some examples that follow assume that these variables are set. To learn more about authentication configuration see the related documentation in the Cloudant API docs or in the general SDK usage information.
IAM authentication
For Cloudant IAM authentication set the following environmental variables by replacing <url> and <apikey> with your proper service credentials. There is no need to set CLOUDANT_AUTH_TYPE to IAM because it is the default.
CLOUDANT_URL=<url>
CLOUDANT_APIKEY=<apikey>
Basic authentication
For Basic authentication set the following environmental variables by replacing <url>, <username> and <password> with your proper service credentials.
CLOUDANT_AUTH_TYPE=BASIC
CLOUDANT_URL=<url>
CLOUDANT_USERNAME=<username>
CLOUDANT_PASSWORD=<password>
Note: We recommend using IAM for Cloudant and Basic for CouchDB authentication.
Code examples
1. Retrieve information from an existing database
This example code gathers some information about an existing database hosted on the https://examples.cloudant.com/ service url.
To do this, you need to extend your environment variables with the service url
and authentication type to use NOAUTH authentication while reaching the
animaldb database. This step is necessary for the SDK to distinguish the
EXAMPLES custom service name from the default service name which is
CLOUDANT.
EXAMPLES_URL=https://examples.cloudant.com
EXAMPLES_AUTH_TYPE=NOAUTH
Once the environment variables are set, you can try out the code examples.
package main
import (
"encoding/json"
"fmt"
"github.com/IBM/go-sdk-core/v4/core"
"github.com/IBM/cloudant-go-sdk/cloudantv1"
)
func main() {
// 1. Create a Cloudant client with "EXAMPLES" service name ============
examplesClient, err := cloudantv1.NewCloudantV1UsingExternalConfig(
&cloudantv1.CloudantV1Options{
ServiceName: "EXAMPLES",
},
)
if err != nil {
panic(err)
}
// 2. Get server information ===========================================
serverInformationResult, _, err := examplesClient.GetServerInformation(
&cloudantv1.GetServerInformationOptions{},
)
if err != nil {
panic(err)
}
fmt.Printf("Server Version: %s\n", *serverInformationResult.Version)
// 3. Get database information for "animaldb" ==========================
dbName := "animaldb"
databaseInformationResult, _, err := examplesClient.GetDatabaseInformation(
&cloudantv1.GetDatabaseInformationOptions{
Db: &dbName,
},
)
if err != nil {
panic(err)
}
// 4. Show document count in database ==================================
fmt.Printf("Document count in \"%s\" database is %d.\n",
*databaseInformationResult.DbName,
*databaseInformationResult.DocCount)
// 5. Get zebra document out of the database by document id ============
documentAboutZebraResult, _, err := examplesClient.GetDocument(
&cloudantv1.GetDocumentOptions{
Db: &dbName,
DocID: core.StringPtr("zebra"),
},
)
if err != nil {
panic(err)
}
// 6. Print out the Document content ===================================
aboutZebraBuffer, _ := json.MarshalIndent(documentAboutZebraResult, "", " ")
fmt.Println(string(aboutZebraBuffer))
}
The result of the code is similar to the following output.
Server Version: 2.1.1
Document count in "animaldb" database is 11.
{
"_id": "zebra",
"_rev": "3-750dac460a6cc41e6999f8943b8e603e",
"class": "mammal",
"diet": "herbivore",
"max_length": 2.5,
"max_weight": 387,
"min_length": 2,
"min_weight": 175,
"wiki_page": "http://en.wikipedia.org/wiki/Plains_zebra"
}
2. Create your own database and add a document
Now comes the exciting part of creating your own orders database and adding a document
about Bob Smith with your own IAM or Basic service credentials.
package main
import (
"encoding/json"
"fmt"
"github.com/IBM/cloudant-go-sdk/cloudantv1"
)
func main() {
// 1. Create a client with `CLOUDANT` default service name =============
client, err := cloudantv1.NewCloudantV1UsingExternalConfig(
&cloudantv1.CloudantV1Options{},
)
if err != nil {
panic(err)
}
// 2. Create a database ================================================
exampleDbName := "orders"
putDatabaseResult, putDatabaseResponse, err := client.PutDatabase(
client.NewPutDatabaseOptions(exampleDbName),
)
if err != nil {
if putDatabaseResponse.StatusCode == 412 {
fmt.Printf("Cannot create \"%s\" database, it already exists.\n",
exampleDbName)
} else {
panic(err)
}
}
if putDatabaseResult != nil && *putDatabaseResult.Ok {
fmt.Printf("\"%s\" database created.\n", exampleDbName)
}
// 3. Create a document ================================================
// 3.1. Create a document object with "example" id
exampleDocID := "example"
exampleDocument := cloudantv1.Document{
ID: &exampleDocID,
}
// 3.2. Add "name" and "joined" fields to the document
exampleDocument.SetProperty("name", "Bob Smith")
exampleDocument.SetProperty("joined", "2019-01-24T10:42:99.000Z")
// 3.3. Set the options to get the document out of the database if it exists
getDocumentOptions := client.NewGetDocumentOptions(
exampleDbName,
exampleDocID,
)
// 3.4. Check the document existence in the database
documentInfo, getDocumentResponse, err := client.GetDocument(
getDocumentOptions,
)
if err != nil {
if getDocumentResponse.StatusCode == 404 {
// Document does not exist in database
} else {
panic(err)
}
}
// 3.5. If it previously existed in the database, set revision of exampleDocument to the latest
if documentInfo != nil {
exampleDocument.Rev = documentInfo.Rev
fmt.Printf("The document revision for \"%s\" is set to \"%s\".\n",
exampleDocID,
*documentInfo.Rev)
}
// 3.6. Save the document in the database
postDocumentOption := client.NewPostDocumentOptions(
exampleDbName,
).SetDocument(&exampleDocument).SetContentType("application/json")
postDocumentResult, _, err := client.PostDocument(postDocumentOption)
if err != nil {
panic(err)
}
// 3.7. Keep track of the revision number from the `example` document object
exampleDocument.Rev = postDocumentResult.Rev
// 3.8. Print out the document content
exampleDocumentContent, _ := json.MarshalIndent(exampleDocument, "", " ")
fmt.Printf("You have created the document:\n%s\n", string(exampleDocumentContent))
}
The result of the code is similar to the following output.
"orders" database created.
You have created the document:
{
"_id": "example",
"_rev": "1-2c3b9502ed7c4a41d35c92bcf734869c",
"joined": "2019-01-24T10:42:99.000Z",
"name": "Bob Smith"
}
3. Update your previously created document
Note: this example code assumes that you have created both the orders
database and the example document by running this previous example
code successfully, otherwise
you get the Cannot update document because either "orders" database or "example" document was not found. message.
package main
import (
"encoding/json"
"fmt"
"github.com/IBM/cloudant-go-sdk/cloudantv1"
)
func main() {
// 1. Create a client with `IBM_CLOUDANT` default service name =========
client, err := cloudantv1.NewCloudantV1UsingExternalConfig(
&cloudantv1.CloudantV1Options{},
)
if err != nil {
panic(err)
}
// 2. Update the document ==============================================
exampleDbName := "orders"
exampleDocID := "example"
// 2.1. Get the document if it previously existed in the database
document, getDocumentResponse, err := client.GetDocument(
client.NewGetDocumentOptions(
exampleDbName,
exampleDocID,
),
)
if err != nil {
if getDocumentResponse.StatusCode == 404 {
fmt.Printf("Cannot update document because "+
"either \"%s\" database or \"%s\" document was not found.\n",
exampleDbName,
exampleDocID)
} else {
panic(err)
}
}
if document != nil {
// 2.2. Make some modifiction in the document content
// 2.2.1. Add Bob Smith's address to the document
document.SetProperty("address", "19 Front Street, Darlington, DL5 1TY")
// 2.2.2. Remove the joined property from document object
delete(document.GetProperties(), "joined")
// 2.3. Update the document in the database
postDocumentOption := client.NewPostDocumentOptions(
exampleDbName,
).SetDocument(document).SetContentType("application/json")
postDocumentResult, _, err := client.PostDocument(
postDocumentOption,
)
if err != nil {
panic(err)
}
// 2.4. Keep track the revision number of the document object
document.Rev = postDocumentResult.Rev
// 2.5. Print out the new document content
documentContent, _ := json.MarshalIndent(document, "", " ")
fmt.Printf("You have updated the document:\n%s\n", string(documentContent))
}
}
The result of the code is similar to the following output.
You have updated the document:
{
"_id": "example",
"_rev": "2-6cc06e9484d776322f7e697c03fb23f7",
"address": "19 Front Street, Darlington, DL5 1TY",
"name": "Bob Smith"
}
4. Delete your previously created document
Note: this example code assumes that you have created both the orders
database and the example document by running this previous example
code successfully, otherwise
you get the Cannot delete document because either "orders" database or "example" document was not found. message.
package main
import (
"fmt"
"github.com/IBM/cloudant-go-sdk/cloudantv1"
)
func main() {
// 1. Create a client with `IBM_CLOUDANT` default service name =========
client, err := cloudantv1.NewCloudantV1UsingExternalConfig(
&cloudantv1.CloudantV1Options{},
)
if err != nil {
panic(err)
}
// 2. Delete the document ==============================================
exampleDbName := "orders"
exampleDocID := "example"
// 2.1. Get the document if it previously existed in the database
document, getDocumentResponse, err := client.GetDocument(
&cloudantv1.GetDocumentOptions{
Db: &exampleDbName,
DocID: &exampleDocID,
},
)
if err != nil {
if getDocumentResponse.StatusCode == 404 {
fmt.Printf("Cannot delete document because "+
"either \"%s\" database or \"%s\" document was not found.\n",
exampleDbName,
exampleDocID)
} else {
panic(err)
}
}
// 2.2. Use its latest revision to delete
if document != nil {
deleteDocumentResult, _, err := client.DeleteDocument(
client.NewDeleteDocumentOptions(
exampleDbName,
*document.ID,
).SetRev(*document.Rev),
)
if err != nil {
panic(err)
}
if *deleteDocumentResult.Ok {
fmt.Println("You have deleted the document.")
}
}
}
The result of the code is the following output.
You have deleted the document.
Using the SDK
For general SDK usage information, please see this link
Questions
If you are having difficulties using this SDK or have a question about the IBM Cloud services, please ask a question at Stack Overflow.
Issues
If you encounter an issue with the project, you are welcome to submit a bug report. Before that, please search for similar issues. It's possible that someone has already reported the problem.
Further resources
- Cloudant API docs: API examples for Cloudant Go SDK.
- Cloudant docs: The official documentation page for Cloudant.
- Cloudant Learning Center: The official learning center with several useful videos which help you to use Cloudant successfully.
- Cloudant blog: Many useful articles how to optimize Cloudant for common problems.
Open source @ IBM
Find more open source projects on the IBM Github Page
Contributing
See CONTRIBUTING.
License
This SDK project is released under the Apache 2.0 license. The license's full text can be found in LICENSE.
Directories
¶
| Path | Synopsis |
|---|---|
|
Package cloudantv1 : Operations and models for the CloudantV1 service
|
Package cloudantv1 : Operations and models for the CloudantV1 service |
|
examples
|
|
|
src/create_db_and_doc
command
|
|
|
src/delete_doc
command
|
|
|
src/update_doc
command
|