isaacm/mimic

An API mock service

MIMIC

Mimic is an API-compatible mock service for Openstack Compute and Rackspace's implementation of Identity and Cloud Load balancers. It is backed by in-memory data structure rather than a potentially expensive database.

Mimic helps with:

• fast set-up
• instant response
• cost efficient
• enables offline development
• enables ability to test unusual behaviors/errors of an api
• acts as a central repository for mocked responses from services

Come join us develop Mimic! Talk to us at ##mimic on irc.freenode.net

Build status:

Compute

Calls supported:

https://github.com/rackerlabs/mimic/blob/master/mimic/rest/nova_api.py

1. LIST servers - Lists servers on the tenant, in mimic
2. POST server - Creates a server in mimic (look at the 'Errors or unusual behaviors supported for compute' below)
3. GET server - Returns the server, if it exists in mimic else returns a 404
4. DELETE server - Deletes the server, if it exists in mimic else returns 404
5. LIST addresses - Lists the private and public Ips for the given server. 404 if not found.
6. GET image - If the image ID is anything but what is listed in the mimic presets, invalid_image_ref returns 200. Else returns a 400.
7. GET flavor - If the flavor ID is anything but what is listed in the mimic presets, invalid_flavor_ref returns 200. Else returns a 400.
8. GET limits - Returns only the absolute limits for compute

Errors or unusual behaviors supported for compute:

Based on the metadata (mimic_presets) provided when a server is being created, a server can be made to behave as follows:

• Fail with the given response message and response code
• Go into an error state on creation
• Remain in building state for the specified amount of time
• Fails to delete the server, with the specified response code for the number of times specified
• Returns 'image not found' or 'flavor not found' responses for specified IDs

Eg: Request for create server that remains in building for 120 seconds:

{ "server" : { "name" : "api-test-server-1", "imageRef" : "3afe97b2-26dc-49c5-a2cc-a2fc8d80c001", "flavorRef" : "2", "metadata": {"server_building": 120} } }

Rackspace Auth

Calls supported:

https://github.com/rackerlabs/mimic/blob/master/mimic/rest/auth_api.py

1. Authenticate - Given a tenant id, username and password, returns the service catalog with links to compute and load balancer links within mimic, and a test token.
2. Impersonate user (Admin call) - Given a token created by mimic in the header, returns a test token for the username.
3. GET endpoints - Given token created by mimic, returns the service catalog for that user.

Cloud Load Balancer

Calls supported:

https://github.com/rackerlabs/mimic/blob/master/mimic/rest/loadbalancer_api.py

1. LIST load balancers - Lists the load balancers created in mimic
2. POST load balancer - Creates a load balancer (look at the 'Errors or unusual behaviors supported for cloud load balancers' below)
3. GET load balancer - Returns the load balancer if it exists, else 404
4. DELETE load balancer - Deletes the load balancer if it exists, else returns 404
5. LIST nodes - Lists the nodes on the load balancer
6. POST node - Creates a node on the load balancer
7. GET node - Returns the node if it exists, else returns 404
8. DELETE node - Deletes the node if it exists, else returns 404

Errors or unusual behaviors supported for cloud load balancers:

Based on key and value of the metadata (mimic_presets) provided when a load balancer is being created, a load balancer can be made to behave as follows:

• Remain in 'BUILD' state for the specified amount of time
• Load balancer goes into 'PENDING-UPDATE' state on every add/delete node for the specified amout of time
• Load balancer goes into 'PENDING-DELETE' state on delete load balancer for the specified amout of time
• Load balancer goes into an error state on creation

Eg: Request for create load balancer that is expected to go into 'PENDING-UPDATE' state on every add/delete node, for 20 seconds:

{"loadBalancer": {"name": "a-new-loadbalancer2", "protocol": "HTTP", "virtualIps": [{"type": "PUBLIC"}], "metadata": [{"key": "lb_pending_update", "value": 20}], "nodes": []}}

Mimic Control APIs

When any of Mimic's included plugins schedule a timeout, you will need to cause Mimic's internal clock to advance for any of those timeouts to fire.

You can do this with the tick endpoint, like so:

curl -s -XPOST -d '{"amount": 1.0}' http://localhost:8900/mimic/v1.1/tick | python -m json.tool

which should result in output like this:

{
    "advanced": 1.0,
    "now": "1970-01-01T00:00:04.000000Z"
}

Note that Mimic begins its timekeeping when all time began, in 1970. If you would prefer to advance Mimic to something resembling the present day instead, a command like this right after Mimic starts up will do that:

curl -s -XPOST -d '{"amount": '"$(date +%s)"'}' http://localhost:8900/mimic/v1.1/tick | python -m json.tool

Mimic does not:

• support XML
• validate the auth token

Running Mimic on a cloud server

1. create a cloud server with an image that by default comes with python 2.7 (eg: ubuntu 12.04) and ssh into it
2. git clone https://github.com/rackerlabs/mimic.git
3. pip install -r requirements.txt from within the mimic folder (if there is a gcc error, apt-get install python-dev)
4. cd into mimic or add the mimic to the PYTHONPATH and run twistd -n mimic

Running Mimic on Docker

The repository root has a Dockerfile that does what you want. It exposes Mimic on port 8900 by default.

To play around with Mimic locally, try:

docker build -t mimic . && docker run --restart=no --rm=true -p 8900:8900 mimic

This will expose Mimic on port 8900, so you can access it directly from the host. The default port exposure is intended for communication between containers; see the Docker documentation for more information. If you're using boot2docker, run boot2docker ip to find the right IP.