// constructTaskDefinitionCacheHash computes md5sum of the region, awsAccountId and the requested task definition data
// BUG(juanrhenals) The requested Task Definition data (taskDefinitionRequest) is not created in a deterministic fashion because there are maps within
// the request ecs.RegisterTaskDefinitionInput structure, and map iteration in Go is not deterministic. We need to fix this.
func (client *ecsClient) constructTaskDefinitionCacheHash(taskDefinition *ecs.TaskDefinition, request *ecs.RegisterTaskDefinitionInput) string {
// Get the region from the ecsClient configuration
region := aws.StringValue(client.params.Config.Region)
awsUserAccountId := utils.GetAwsAccountIdFromArn(aws.StringValue(taskDefinition.TaskDefinitionArn))
tdHashInput := fmt.Sprintf("%s-%s-%s", region, awsUserAccountId, request.GoString())
return fmt.Sprintf("%x", md5.Sum([]byte(tdHashInput)))
}
// RegisterTaskDefinitionIfNeeded checks if a task definition has already been
// registered via the provided cache, and if so returns it.
// Otherwise, it regsiters a new one.
//
// This exists to avoid an explosion of task definitions for automatically
// registered inputs
func (client *ecsClient) RegisterTaskDefinitionIfNeeded(
request *ecs.RegisterTaskDefinitionInput,
taskDefinitionCache cache.Cache) (*ecs.TaskDefinition, error) {
if request.Family == nil {
return nil, errors.New("invalid task definitions: family is required")
}
// md5sum of the 'GoString' formatted request
// Open questions: is the gostring output actually specified to be
// deterministic? Is it good enough that we don't care?
// TODO, describe the cache hit to make sure it's still ACTIVE
tdHash := fmt.Sprintf("%x", md5.Sum([]byte(request.GoString())))
td := &ecs.TaskDefinition{}
if err := taskDefinitionCache.Get(tdHash, td); err == nil {
log.WithFields(log.Fields{
"taskDefHash": tdHash,
"taskDef": td,
}).Debug("cache hit")
return td, nil
} else {
log.WithFields(log.Fields{
"taskDefHash": tdHash,
"taskDef": td,
}).Debug("cache miss")
}
resp, err := client.RegisterTaskDefinition(request)
if err != nil {
return nil, err
}
tdErr := taskDefinitionCache.Put(tdHash, resp)
if tdErr != nil {
log.WithFields(log.Fields{
"error": tdErr,
}).Warn("Could not cache task definition; redundant TDs might be created")
// We can keep going even if we can't cache and operate mostly fine
}
return resp, err
}
