/kivik

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

Primary LanguageGoOtherNOASSERTION

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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 current stable branch of Kivik, v4. If you are upgrading from the previous stable version, v3, read the 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 1.17 and later. If your project is already using Go modules, simply fetch the desired version:

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

Installation

Install Kivik as you normally would for any Go package:

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

This will install the main Kivik package and the CouchDB database driver. Three officially supported drivers are shipped with this Go module:

In addition, there are partial/experimental drivers available:

CLI

Consult the CLI README for full details on the kivik CLI tool.

Example Usage

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

package main

import (
    "context"
    "fmt"

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

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

    db := client.DB("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?

I had a number of specific design goals when creating this package:

  • Provide a generic database API for a variety of CouchDB-like databases. The previously existing drivers for CouchDB had patchy support for different versions of CouchDB, and different subsets of functionality.
  • Work equally well with CouchDB 1.6, 2.x, 3.x, and any future versions, as well as PouchDB.
  • Be as Go-idiomatic as possible.
  • Be unambiguously open-source. Kivik is released under the Apache license, same as CouchDB and PouchDB.
  • Separate out the basic implementation of a database driver (implementing the kivik/driver interfaces) vs the implementation of all the user-level types and convenience methods. It ought to be reasonably easy to create a new driver, for testing, mocking, implementing a new backend data storage system, or talking to other CouchDB-like databases.

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 2.x.
  • 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 8.0.0.

What is the development status?

Kivik 4.x is stable, and suitable for production use.

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 2017-2023 by the Kivik contributors, and is released under the terms of the Apache 2.0 license. See LICENCE 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

  • Options are no longer a simple map[string]interface{}, but are rather functional parameters. In most cases, you can just use kivik.Param(key, value), or kivik.Params(map[string]interface{}{key: value}) as a replacement. Some shortcuts for common params now exist, and driver-specific options may work differently. Consult the GoDoc.
  • The Authenticate method has been removed. Authentication is now handled via option parameters.
  • The CouchDB, PouchDB, and MockDB drivers, and the experimental FilesystemDB and MemoryDB drivers, have been merged with this repo, rather than being hosted in separate repos. For v3 you would have imported github.com/go-kivik/couchdb/v3, for example. With v4, you instead use github.com/go-kivik/kivik/v4/couchdb for CouchDB, or github.com/go-kivik/kivik/v4/x/fsdb for the experimental FilesystemDB driver.
  • The return type for queries has been significantly changed.
    • In 3.x, queries returned a *Rows struct. Now they return a *ResultSet.
    • The Offset(), TotalRows(), UpdateSeq(), Warning() and Bookmark() methods have been removed, and replaced with the ResultMetadata type which is accessed via the Metadata() method. See issue #552.
    • Calling most methods on ResultSet will now work after closing the iterator.
    • The new ResultSet type supports multi-query mode, which is triggered by calling NextResultSet before Next.
    • Key, ID, Rev, Attachments all now return row-specific errors, and ScanKey may successfully decode while also returning a row-specific error.
  • The Changes type has been changed to semantically match the ResultSet type. Specifically, the LastSeq() and Pending() methods have been replaced by the Metadata() method.
  • The DBUpdates() and Changes() methods now defer errors to the iterator, for easier chaining and consistency with other iterators.
  • DB.BulkDocs() no longer returns an iterator, but rather an array of all results.
  • Get now returns a simpler *Result type than before.
  • 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.
  • The StatusCode() int method on errors has been renamed to HTTPStatus() int, to be more descriptive. The related package function StatusCode(error) int has also been renamed to HTTPStatus(error) int to match.
  • Client.Close() and DB.Close() now block until any relevant calls have returned.
  • Client.Close() and DB.Close() no longer take a context.Context value. These operations cannot actually be canceled anyway, by the one driver that uses them (PouchDB); it only stops waiting. It makes more senes to make these functions blocking indefinitely, especially now that they wait for client requests to finish, and let the caller stop waiting if it wants to.

CouchDB specific changes

  • The SetTransport authentication method has been removed, as a duplicate of couchdb.OptionHTTPClient.
  • Options passed to Kivik functions are now functional options, rather than a map of string to empty interface. As such, many of the options have changed. Consult the relevant GoDoc.

New features and additions

  • Kivik now ships with the kivik command line tool (previously part of the github.com/go-kivik/xkivik repository).
  • The new Replicate function allows replication between arbitrary databases, such as between CouchDB and a directory structure using the FilesystemDB.

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.