IT on Swarm allows you to execute integration test in parallel across a Docker Swarm cluster
## Architecture
### Master service
- Works as a funker caller
- Calls a worker funker (`-worker-service`) with a chunk of `-check.f` filter strings (passed as a file via `-input` flag, typically `/mnt/input`)
### Worker service
- Works as a funker callee
- Executes an equivalent of `TESTFLAGS=-check.f TestFoo|TestBar|TestBaz ... make test-integration-cli` using the bind-mounted API socket (`docker.sock`)
### Client
- Controls master and workers via `docker stack`
- No need to have a local daemon
Typically, the master and workers are supposed to be running on a cloud environment,
while the client is supposed to be running on a laptop, e.g. Docker for Mac/Windows.
## Requirement
- Docker daemon 1.13 or later
- Private registry for distributed execution with multiple nodes
## Usage
### Step 1: Prepare images
$ make build-integration-cli-on-swarm
Following environment variables are known to work in this step:
Following environment variables are known to work in this step:
-`DOCKER_GRAPHDRIVER`
-`DOCKER_EXPERIMENTAL`
#### Flags
Basic flags:
-`-replicas N`: the number of worker service replicas. i.e. degree of parallelism.
-`-chunks N`: the number of chunks. By default, `chunks` == `replicas`.
-`-push-worker-image REGISTRY/IMAGE:TAG`: push the worker image to the registry. Note that if you have only single node and hence you do not need a private registry, you do not need to specify `-push-worker-image`.
Experimental flags for mitigating makespan nonuniformity:
-`-shuffle`: Shuffle the test filter strings
Flags for debugging IT on Swarm itself:
-`-rand-seed N`: the random seed. This flag is useful for deterministic replaying. By default(0), the timestamp is used.
-`-filters-file FILE`: the file contains `-check.f` strings. By default, the file is automatically generated.
