Kivik

Common interface to CouchDB or CouchDB-like databases for Go and GopherJS

Description

Package kivik provides a common interface to CouchDB or CouchDB-like databases.

The kivik package must be used in conjunction with a database driver.

The kivik driver system is modeled after the standard library's sql and sql/driver packages, although the client API is completely different due to the different database models implemented by SQL and NoSQL databases such as CouchDB.

Programming language: Go

License: GNU General Public License v3.0 or later

Tags: Database     Database Drivers     NoSQL Databases     GopherJS    

Latest version: v3.2.3

README

Kivik

Package kivik provides a common interface to CouchDB or CouchDB-like databases.

The kivik package must be used in conjunction with a database driver.

The kivik driver system is modeled after the standard library's sql and sql/driver packages, although the client API is completely different due to the different database models implemented by SQL and NoSQL databases such as CouchDB.

Versions

You are browsing the development branch of Kivik. The latest stable version is available here. Please consult the documentation on that page for proper installation of the stable branch.

This branch which will eventually become the Kivik 4.0.0 release. The API is subject to rapid and unannounced changes at this stage of development. For production work, you are encouraged to use the latest 3.x release of Kivik, which is stable. Read a partial list of breaking changes.

Example configuration for common dependency managers follow.

Go Modules

Kivik 3.x and later supports Go modules, which is the recommended way to use it for Go version 1.11 or newer. Kivik 4.x only supports Go 1.13 and later. If your project is already using Go modules, simply fetch the desired version:

go get github.com/go-kivik/kivik/v3 # Stable release
go get github.com/go-kivik/kivik/v4 # Development release

Installation

Install Kivik as you normally would for any Go package:

go get -u github.com/go-kivik/kivik/v4
go get -u github.com/go-kivik/couchdb/v4

This will install the main Kivik package and the CouchDB database driver. See the list of Kivik database drivers for a complete list of available drivers.

Example Usage

Please consult the the package documentation for all available API methods, and a complete usage documentation. And for additional usage examples, consult the wiki.

package main

import (
    "context"
    "fmt"

    kivik "github.com/go-kivik/kivik/v4"
    _ "github.com/go-kivik/couchdb/v4" // The CouchDB driver
)

func main() {
    client, err := kivik.New("couch", "http://localhost:5984/")
    if err != nil {
        panic(err)
    }

    db := client.DB(context.TODO(), "animals")

    doc := map[string]interface{}{
        "_id":      "cow",
        "feet":     4,
        "greeting": "moo",
    }

    rev, err := db.Put(context.TODO(), "cow", doc)
    if err != nil {
        panic(err)
    }
    fmt.Printf("Cow inserted with revision %s\n", rev)
}

Frequently Asked Questions

Nobody has ever asked me any of these questions, so they're probably better called "Never Asked Questions" or possibly "Imagined Questions."

Why another CouchDB client API?

Read the design goals for the general design goals.

Specifically, I was motivated to write Kivik for a few reasons:

1. I was unhappy with any of the existing CouchDB drivers for Go. The best one had a number of shortcomings:

- It is no longer actively developed.
- It [doesn't have an open source license](https://github.com/fjl/go-couchdb/issues/15).
- It doesn't support iterating over result sets, forcing one to load all
  results of a query into memory at once.
- It [doesn't support CouchDB 2.0](https://github.com/fjl/go-couchdb/issues/14)
  sequence IDs or MongoDB-style queries.
- It doesn't natively support CookieAuth (it does allow a generic Auth method
  which could be used to do this, but I think it's appropriate to put directly
  in the library).

1. I wanted a single client API that worked with both CouchDB and PouchDB. I had previously written go-pouchdb, a GopherJS wrapper around the PouchDB library with a public API modeled after fjl/go-couchdb, but I still wanted a unified driver infrastructure.

2. I want an unambiguous, open source license. This software is released under the Apache 2.0 license. See the included LICENSE.md file for details.

3. I wanted the ability to mock CouchDB connections for testing. This is possible with the sql / sql/driver approach by implementing a mock driver, but was not possible with any existing CouchDB client libraries. This library makes that possible for CouchDB apps, too.

4. I wanted a simple, mock CouchDB server I could use for testing. It doesn't need to be efficient, or support all CouchDB servers, but it should be enough to test the basic functionality of a PouchDB app, for instance. Kivik aims to do this with the kivik serve command, in the near future.

5. I wanted a toolkit that would make it easy to build a proxy to sit in front of CouchDB to handle custom authentication or other logic that CouchDB cannot support natively. Kivik aims to accomplish this in the future.

What are Kivik's requirements?

Kivik's test suite is automatically run on Linux for every pull request, but should work on all supported Go architectures. If you find it not working for your OS/architecture, please submit a bug report.

Below are the compatibility targets for specific runtime and database versions. If you discover a bug affecting any of these supported environments, please let me know by submitting a bug report via GitHub.

• Go Kivik 4.x aims for full compatibility with all stable releases of Go from 1.13. For Go 1.7 or 1.8 you can use Kivik 1.x. For Go 1.9 through 1.12, you can use Kivik 3.x.
• CouchDB The Kivik 4.x CouchDB driver aims for compatibility with all stable releases of CouchDB from 1.6.1.
• GopherJS GopherJS always requires the latest stable version of Go, so building Kivik with GopherJS has this same requirement.
• PouchDB The Kivik 4.x PouchDB driver aims for compatibility with all stable releases of PouchDB from 6.0.0.

What is the development status?

Kivik 4.x is under active development, and subject to radical, and unannounced API changes. For production use, please use Kivik 3.x.

Why the name "Kivik"?

Kivik is a line of sofas (couches) from IKEA. And in the spirit of IKEA, and build-your-own furniture, Kivik aims to allow you to "build your own" CouchDB client, server, and proxy applications.

What license is Kivik released under?

Kivik is Copyright 2022 by the Kivik contributors, and is released under the terms of the Apache 2.0 license. See [LICENCE](LICENSE) for the full text of the license.

Changes from 3.x to 4.x

This is a partial list of breaking changes between 3.x and 4.x

• The return type for queries has been significantly changed.
  • In 3.x, queries returned a *Rows struct. Now they return the ResultSet interface.
  • The Offset(), TotalRows(), UpdateSeq(), Warning() and Bookmark() methods have been removed, and replaced with the ResultMetadata type which is accessed via the Finish() method. See #552
  • Calling most methods on Rows will now work after closing the iterator.
  • Calling ScanDoc, ScanKey, ScanValue, Key, or ID before calling Next will make the iterator operate in single-item mode, meaning that only the first item in the iterator will be processed, then the iterator will be closed immediately.
• Get() now returns a ResultSet, rather than a *Row. Semantics work roughly the same for standard use cases where Get() returns a single document: Just call ScanDoc() as before. However, this allows Get() to also return multiple docs, as it does when called with the open_revs flag. See the CouchDB docs.
• GetMeta() has been replaced with GetRev(), and no longer claims to return the document size. The document size was never really the document size, rather it is the Content-Length field of the HTTP response, which can vary depending on query parameters, making its use for determining document size dubious at best.

What projects currently use Kivik?

If your project uses Kivik, and you'd like to be added to this list, create an issue or submit a pull request.

• Cayley is an open-source graph database. It uses Kivik for the CouchDB and PouchDB storage backends.