// uninstallerManifold defines a simple start function which retrieves
// some dependencies, checks if the machine is dead and causes the
// agent to uninstall itself if it is. This doubles up on part of the
// machiner's functionality but the machiner doesn't run until
// upgrades are complete, and the upgrade related workers may not be
// able to make API requests if the machine is dead.
func uninstallerManifold(config uninstallerManifoldConfig) dependency.Manifold {
return dependency.Manifold{
Inputs: []string{
config.AgentName,
config.APICallerName,
},
Start: func(getResource dependency.GetResourceFunc) (worker.Worker, error) {
if config.WriteUninstallFile == nil {
return nil, errors.New("WriteUninstallFile not specified")
}
// Get the agent.
var agent agent.Agent
if err := getResource(config.AgentName, &agent); err != nil {
return nil, err
}
// Grab the tag and ensure that it's for a machine.
tag, ok := agent.CurrentConfig().Tag().(names.MachineTag)
if !ok {
return nil, errors.New("agent's tag is not a machine tag")
}
// Get API connection.
//
// TODO(mjs) - this should really be a base.APICaller to
// remove the possibility of the API connection being closed
// here.
var apiConn api.Connection
if err := getResource(config.APICallerName, &apiConn); err != nil {
return nil, err
}
// Check if the machine is dead and set the agent to
// uninstall if it is.
//
// TODO(mjs) - ideally this would be using its own facade.
machine, err := apiConn.Agent().Entity(tag)
if err != nil {
return nil, err
}
if machine.Life() == params.Dead {
if err := config.WriteUninstallFile(); err != nil {
return nil, errors.Annotate(err, "writing uninstall agent file")
}
return nil, worker.ErrTerminateAgent
}
// All is well - we're done (no actual worker is actually returned).
return nil, dependency.ErrUninstall
},
}
}
// Manifold returns a dependency manifold that runs an upgrader
// worker, using the resource names defined in the supplied config.
func Manifold(config ManifoldConfig) dependency.Manifold {
return dependency.Manifold{
Inputs: []string{
config.AgentName,
config.APICallerName,
config.UpgradeStepsGateName,
},
Start: func(getResource dependency.GetResourceFunc) (worker.Worker, error) {
// Sanity checks
if config.OpenStateForUpgrade == nil {
return nil, errors.New("missing OpenStateForUpgrade in config")
}
if config.PreUpgradeSteps == nil {
return nil, errors.New("missing PreUpgradeSteps in config")
}
// Get machine agent.
var agent agent.Agent
if err := getResource(config.AgentName, &agent); err != nil {
return nil, err
}
// Grab the tag and ensure that it's for a machine.
tag, ok := agent.CurrentConfig().Tag().(names.MachineTag)
if !ok {
return nil, errors.New("agent's tag is not a machine tag")
}
// Get API connection.
var apiConn api.Connection
if err := getResource(config.APICallerName, &apiConn); err != nil {
return nil, err
}
// Get the machine agent's jobs.
entity, err := apiConn.Agent().Entity(tag)
if err != nil {
return nil, err
}
jobs := entity.Jobs()
// Get machine instance for setting status on.
machine, err := apiConn.Machiner().Machine(tag)
if err != nil {
return nil, err
}
// Get upgradesteps completed lock.
var upgradeStepsLock gate.Lock
if err := getResource(config.UpgradeStepsGateName, &upgradeStepsLock); err != nil {
return nil, err
}
return NewWorker(
upgradeStepsLock,
agent,
apiConn,
jobs,
config.OpenStateForUpgrade,
config.PreUpgradeSteps,
machine,
)
},
}
}