The upgrades package provides infrastructure to upgrade previous Juju deployments to the current Juju version. The upgrade is performed on a per node basis, across all of the running Juju machines.

    Important exported APIs include:

    PerformUpgrade, which is invoked on each node by the machine agent with:
      fromVersion - the Juju version from which the upgrade is occurring
      target      - the type of Juju node being upgraded
      context     - provides API access to Juju state servers



    View Source
    const (
    	// AllMachines applies to any machine.
    	AllMachines = Target("allMachines")
    	// HostMachine is a machine on which units are deployed.
    	HostMachine = Target("hostMachine")
    	// StateServer is a machine participating in a Juju state server cluster.
    	StateServer = Target("stateServer")
    	// DatabaseMaster is a StateServer that has the master database, and as such
    	// is the only target that should run database schema upgrade steps.
    	DatabaseMaster = Target("databaseMaster")


    This section is empty.


    func AreUpgradesDefined

    func AreUpgradesDefined(from version.Number) bool

      AreUpgradesDefined returns true if there are upgrade operations defined between the version supplied and the running software version.

      func PerformUpgrade

      func PerformUpgrade(from version.Number, targets []Target, context Context) error

        PerformUpgrade runs the business logic needed to upgrade the current "from" version to this version of Juju on the "target" type of machine.


        type Context

        type Context interface {
        	// APIState returns an API connection to state.
        	APIState() api.Connection
        	// State returns a connection to state. This will be non-nil
        	// only in the context of a state server.
        	State() *state.State
        	// AgentConfig returns the agent config for the machine that is being
        	// upgraded.
        	AgentConfig() agent.ConfigSetter
        	// StateContext returns a new Context suitable for State-based
        	// upgrade steps.
        	StateContext() Context
        	// APIContext returns a new Context suitable for API-based upgrade
        	// steps.
        	APIContext() Context

          Context provides the dependencies used when executing upgrade steps.

          func NewContext

          func NewContext(agentConfig agent.ConfigSetter, api api.Connection, st *state.State) Context

            NewContext returns a new upgrade context.

            type Operation

            type Operation interface {
            	// The Juju version for which this operation is applicable.
            	// Upgrade operations designed for versions of Juju earlier
            	// than we are upgrading from are not run since such steps would
            	// already have been used to get to the version we are running now.
            	TargetVersion() version.Number
            	// Steps to perform during an upgrade.
            	Steps() []Step

              Operation defines what steps to perform to upgrade to a target version.

              type Step

              type Step interface {
              	// Description is a human readable description of what the upgrade step does.
              	Description() string
              	// Targets returns the target machine types for which the upgrade step is applicable.
              	Targets() []Target
              	// Run executes the upgrade business logic.
              	Run(Context) error

                Step defines an idempotent operation that is run to perform a specific upgrade step.

                type Target

                type Target string

                  Target defines the type of machine for which a particular upgrade step can be run.