github.com/graywolf-at-work-2/terraform-vendor@v1.4.5/internal/terraform/hook.go (about) 1 package terraform 2 3 import ( 4 "github.com/zclconf/go-cty/cty" 5 6 "github.com/hashicorp/terraform/internal/addrs" 7 "github.com/hashicorp/terraform/internal/plans" 8 "github.com/hashicorp/terraform/internal/providers" 9 "github.com/hashicorp/terraform/internal/states" 10 ) 11 12 // HookAction is an enum of actions that can be taken as a result of a hook 13 // callback. This allows you to modify the behavior of Terraform at runtime. 14 type HookAction byte 15 16 const ( 17 // HookActionContinue continues with processing as usual. 18 HookActionContinue HookAction = iota 19 20 // HookActionHalt halts immediately: no more hooks are processed 21 // and the action that Terraform was about to take is cancelled. 22 HookActionHalt 23 ) 24 25 // Hook is the interface that must be implemented to hook into various 26 // parts of Terraform, allowing you to inspect or change behavior at runtime. 27 // 28 // There are MANY hook points into Terraform. If you only want to implement 29 // some hook points, but not all (which is the likely case), then embed the 30 // NilHook into your struct, which implements all of the interface but does 31 // nothing. Then, override only the functions you want to implement. 32 type Hook interface { 33 // PreApply and PostApply are called before and after an action for a 34 // single instance is applied. The error argument in PostApply is the 35 // error, if any, that was returned from the provider Apply call itself. 36 PreApply(addr addrs.AbsResourceInstance, gen states.Generation, action plans.Action, priorState, plannedNewState cty.Value) (HookAction, error) 37 PostApply(addr addrs.AbsResourceInstance, gen states.Generation, newState cty.Value, err error) (HookAction, error) 38 39 // PreDiff and PostDiff are called before and after a provider is given 40 // the opportunity to customize the proposed new state to produce the 41 // planned new state. 42 PreDiff(addr addrs.AbsResourceInstance, gen states.Generation, priorState, proposedNewState cty.Value) (HookAction, error) 43 PostDiff(addr addrs.AbsResourceInstance, gen states.Generation, action plans.Action, priorState, plannedNewState cty.Value) (HookAction, error) 44 45 // The provisioning hooks signal both the overall start end end of 46 // provisioning for a particular instance and of each of the individual 47 // configured provisioners for each instance. The sequence of these 48 // for a given instance might look something like this: 49 // 50 // PreProvisionInstance(aws_instance.foo[1], ...) 51 // PreProvisionInstanceStep(aws_instance.foo[1], "file") 52 // PostProvisionInstanceStep(aws_instance.foo[1], "file", nil) 53 // PreProvisionInstanceStep(aws_instance.foo[1], "remote-exec") 54 // ProvisionOutput(aws_instance.foo[1], "remote-exec", "Installing foo...") 55 // ProvisionOutput(aws_instance.foo[1], "remote-exec", "Configuring bar...") 56 // PostProvisionInstanceStep(aws_instance.foo[1], "remote-exec", nil) 57 // PostProvisionInstance(aws_instance.foo[1], ...) 58 // 59 // ProvisionOutput is called with output sent back by the provisioners. 60 // This will be called multiple times as output comes in, with each call 61 // representing one line of output. It cannot control whether the 62 // provisioner continues running. 63 PreProvisionInstance(addr addrs.AbsResourceInstance, state cty.Value) (HookAction, error) 64 PostProvisionInstance(addr addrs.AbsResourceInstance, state cty.Value) (HookAction, error) 65 PreProvisionInstanceStep(addr addrs.AbsResourceInstance, typeName string) (HookAction, error) 66 PostProvisionInstanceStep(addr addrs.AbsResourceInstance, typeName string, err error) (HookAction, error) 67 ProvisionOutput(addr addrs.AbsResourceInstance, typeName string, line string) 68 69 // PreRefresh and PostRefresh are called before and after a single 70 // resource state is refreshed, respectively. 71 PreRefresh(addr addrs.AbsResourceInstance, gen states.Generation, priorState cty.Value) (HookAction, error) 72 PostRefresh(addr addrs.AbsResourceInstance, gen states.Generation, priorState cty.Value, newState cty.Value) (HookAction, error) 73 74 // PreImportState and PostImportState are called before and after 75 // (respectively) each state import operation for a given resource address. 76 PreImportState(addr addrs.AbsResourceInstance, importID string) (HookAction, error) 77 PostImportState(addr addrs.AbsResourceInstance, imported []providers.ImportedResource) (HookAction, error) 78 79 // PostStateUpdate is called each time the state is updated. It receives 80 // a deep copy of the state, which it may therefore access freely without 81 // any need for locks to protect from concurrent writes from the caller. 82 PostStateUpdate(new *states.State) (HookAction, error) 83 } 84 85 // NilHook is a Hook implementation that does nothing. It exists only to 86 // simplify implementing hooks. You can embed this into your Hook implementation 87 // and only implement the functions you are interested in. 88 type NilHook struct{} 89 90 var _ Hook = (*NilHook)(nil) 91 92 func (*NilHook) PreApply(addr addrs.AbsResourceInstance, gen states.Generation, action plans.Action, priorState, plannedNewState cty.Value) (HookAction, error) { 93 return HookActionContinue, nil 94 } 95 96 func (*NilHook) PostApply(addr addrs.AbsResourceInstance, gen states.Generation, newState cty.Value, err error) (HookAction, error) { 97 return HookActionContinue, nil 98 } 99 100 func (*NilHook) PreDiff(addr addrs.AbsResourceInstance, gen states.Generation, priorState, proposedNewState cty.Value) (HookAction, error) { 101 return HookActionContinue, nil 102 } 103 104 func (*NilHook) PostDiff(addr addrs.AbsResourceInstance, gen states.Generation, action plans.Action, priorState, plannedNewState cty.Value) (HookAction, error) { 105 return HookActionContinue, nil 106 } 107 108 func (*NilHook) PreProvisionInstance(addr addrs.AbsResourceInstance, state cty.Value) (HookAction, error) { 109 return HookActionContinue, nil 110 } 111 112 func (*NilHook) PostProvisionInstance(addr addrs.AbsResourceInstance, state cty.Value) (HookAction, error) { 113 return HookActionContinue, nil 114 } 115 116 func (*NilHook) PreProvisionInstanceStep(addr addrs.AbsResourceInstance, typeName string) (HookAction, error) { 117 return HookActionContinue, nil 118 } 119 120 func (*NilHook) PostProvisionInstanceStep(addr addrs.AbsResourceInstance, typeName string, err error) (HookAction, error) { 121 return HookActionContinue, nil 122 } 123 124 func (*NilHook) ProvisionOutput(addr addrs.AbsResourceInstance, typeName string, line string) { 125 } 126 127 func (*NilHook) PreRefresh(addr addrs.AbsResourceInstance, gen states.Generation, priorState cty.Value) (HookAction, error) { 128 return HookActionContinue, nil 129 } 130 131 func (*NilHook) PostRefresh(addr addrs.AbsResourceInstance, gen states.Generation, priorState cty.Value, newState cty.Value) (HookAction, error) { 132 return HookActionContinue, nil 133 } 134 135 func (*NilHook) PreImportState(addr addrs.AbsResourceInstance, importID string) (HookAction, error) { 136 return HookActionContinue, nil 137 } 138 139 func (*NilHook) PostImportState(addr addrs.AbsResourceInstance, imported []providers.ImportedResource) (HookAction, error) { 140 return HookActionContinue, nil 141 } 142 143 func (*NilHook) PostStateUpdate(new *states.State) (HookAction, error) { 144 return HookActionContinue, nil 145 }