FakeRiak

A small tool that fakes several key-value services on TCP ports, all backed by a single in-memory store. It speaks four wire protocols so you can point real clients at it:

Usage

The simplest way to start using fake_riak is to install it on your machine with the following command:

mix escript.install hex fake_riak

This will download from Hex and then install the fake_riak script globally. You can verify that the script is installed by executing mix escript. Open a terminal and start it, for example:

fake_riak --riak 10018 --verbose

This will listen for incoming Riak KV requests on the loopback interface at port 10018 (127.0.0.1:10018), and print information about the requests as they hit the service.

See fake_riak --help for more detailed information about how to use the tool.

Disclaimer

This software is not meant to run in production, handle high load, or be accessed by real clients (even though you can open it up to other hosts on the local network with --host 0.0.0.0). It's a tool for testing, debugging, and developing locally, letting you avoid installing heavy or hard-to-configure services like Riak.

Build

Build a single self-contained executable if you've downloaded the source code:

$ mix escript.build

This produces a fake_riak script in the root of the source tree that you can copy anywhere on your system.

Run

Enable one or more endpoints by passing its flag. Each takes an optional port; without one it uses its well-known default(s):

$ ./fake_riak --riak --redis            # Riak on 8098 and 8087, Redis on 6379
$ ./fake_riak --etcd 3000               # etcd on port 3000
$ ./fake_riak --riak=8100 --memcached   # equals form works too

A flag may also be repeated (--riak 8098 --riak 8099), or take several ports at once as a comma-separated list and/or a first..last range:

$ ./fake_riak --riak 10012,10013,10014  # three Riak listeners
$ ./fake_riak --etcd 6700..6705         # six etcd listeners, 6700-6705
$ ./fake_riak --riak 8098,9000..9002    # lists and ranges can be mixed

At least one endpoint must be enabled. By default it binds 127.0.0.1; pass --host 0.0.0.0 to listen on all interfaces. Press Ctrl-C to stop.

Options:

Every --riak port serves both the Riak HTTP API and the Riak Protocol Buffers (PBC) API, detected per connection, so there is no separate PBC flag — a single port is enough for either kind of client. A bare --riak (no port given) still opens both of Riak's conventional ports, 8098 (HTTP) and 8087 (PBC), so clients that assume the default port for their protocol find it there without any extra flags.

Every endpoint silently accepts both plain TCP and TLS on the same port — no extra flag needed to turn TLS on. Without --tls-cert/--tls-key it terminates TLS with an ephemeral self-signed certificate generated on startup, so clients need to skip certificate verification (this is a fake service, not a real CA-backed one).

Talk to it

# Riak (bucketed, HTTP)
$ curl -X PUT -d 'meow' http://127.0.0.1:8098/buckets/animals/keys/cat
$ curl http://127.0.0.1:8098/buckets/animals/keys/cat            # -> meow

# Riak (bucketed, PBC — an RpbPingReq on the same port)
$ printf '\x00\x00\x00\x01\x01' | nc -q1 127.0.0.1 8098 | xxd    # -> 00000001 02

# etcd (bucketless, v2 HTTP/JSON)
$ curl -X PUT http://127.0.0.1:2379/v2/keys/message -d value=hello
$ curl http://127.0.0.1:2379/v2/keys/message                     # -> {"action":"get",...}

# Redis (bucketless, RESP)
$ redis-cli -p 6379 set foo bar
$ redis-cli -p 6379 get foo                                      # -> "bar"

# memcached (bucketless, text)
$ printf 'set greeting 0 0 5\r\nhello\r\nget greeting\r\n' | nc 127.0.0.1 11211

Notes / limitations

These are deliberately faithful-enough fakes, not full servers:

• memcached accepts the flags/exptime on storage commands but does not persist them, so get always reports flags of 0 and keys never expire. add/replace/append/prepend behave properly, but the CAS value that gets reports is a hash of the value and the cas command itself is not implemented.
• Redis accepts the extra SET options (NX, XX, EX, ...) but ignores them — SET always stores and replies OK.
• etcd implements the v2 (HTTP/JSON) API, not the v3 (gRPC) API; indices are synthetic.
• Riak speaks both the HTTP API and the Protocol Buffers (PBC) API on every --riak port (PBC: ping, get, put, delete, server info, and the RpbStartTls in-band TLS upgrade). Vector clocks are a static opaque token, and siblings, 2i, bucket types/properties, and search are not implemented.

Trademarks

Riak, Redis, etcd, and memcached are trademarks of their respective owners. This project is an independent, unofficial testing tool. It is not affiliated with, sponsored by, or endorsed by any of those projects — it merely speaks their wire protocols so real clients can talk to it.