terraform/internal/states/state_string.go
Martin Atkins b0b8d4aa6f states: Only track root module output values
For a very long time we've had an annoying discrepancy between the
in-memory state model and our state snapshot format where the in-memory
format stores output values for all modules whereas the snapshot format
only tracks the root module output values because those are all we
actually need to preserve between runs.

That design wart was a result of us using the state both as an internal
and an external artifact, due to having nowhere else to store the
transient values of non-root module output values while Terraform Core
does its work.

We now have namedvals.State to internally track all of the throwaway
results from named values that don't need to persist between runs, so now
we'll use that for our internal work instead and reserve the states.State
model only for the data that we will preserve between runs in state
snapshots.

The namedvals internal model isn't really designed to support enumerating
all of the output values for a particular module call, but our expression
evaluator currently depends on being able to do that and so we have a
temporary inefficient implementation of that which just scans the entire
table of values as a stopgap just to avoid this commit growing even larger
than it already is. In a future commit we'll rework the evaluator to
support the PartialEval mode and at the same time move the responsiblity
for enumerating all of the output values into the evaluator itself, since
it should be able to determine what it's expecting by analyzing the
configuration rather than just by trusting that earlier evaluation has
completed correctly.

Because our legacy state string serialization previously included output
values for all modules, some of our context tests were accidentally
depending on the implementation detail of how those got stored internally.
Those tests are updated here to test only the data that is a real part
of Terraform Core's result, by ensuring that the relevant data appears
somewhere either in a root output value or in a resource attribute.
2023-12-07 09:56:36 -08:00

285 lines
8.4 KiB
Go

package states
import (
"bufio"
"bytes"
"encoding/json"
"fmt"
"sort"
"strings"
ctyjson "github.com/zclconf/go-cty/cty/json"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/configs/hcl2shim"
)
// String returns a rather-odd string representation of the entire state.
//
// This is intended to match the behavior of the older terraform.State.String
// method that is used in lots of existing tests. It should not be used in
// new tests: instead, use "cmp" to directly compare the state data structures
// and print out a diff if they do not match.
//
// This method should never be used in non-test code, whether directly by call
// or indirectly via a %s or %q verb in package fmt.
func (s *State) String() string {
if s == nil {
return "<nil>"
}
// sort the modules by name for consistent output
modules := make([]string, 0, len(s.Modules))
for m := range s.Modules {
modules = append(modules, m)
}
sort.Strings(modules)
var buf bytes.Buffer
for _, name := range modules {
m := s.Modules[name]
mStr := m.testString(s)
// If we're the root module, we just write the output directly.
if m.Addr.IsRoot() {
buf.WriteString(mStr + "\n")
continue
}
// We need to build out a string that resembles the not-quite-standard
// format that terraform.State.String used to use, where there's a
// "module." prefix but then just a chain of all of the module names
// without any further "module." portions.
buf.WriteString("module")
for _, step := range m.Addr {
buf.WriteByte('.')
buf.WriteString(step.Name)
if step.InstanceKey != addrs.NoKey {
buf.WriteString(step.InstanceKey.String())
}
}
buf.WriteString(":\n")
s := bufio.NewScanner(strings.NewReader(mStr))
for s.Scan() {
text := s.Text()
if text != "" {
text = " " + text
}
buf.WriteString(fmt.Sprintf("%s\n", text))
}
}
return strings.TrimSpace(buf.String())
}
// testString is used to produce part of the output of State.String. It should
// never be used directly.
func (ms *Module) testString(state *State) string {
var buf bytes.Buffer
if len(ms.Resources) == 0 {
buf.WriteString("<no state>")
}
// We use AbsResourceInstance here, even though everything belongs to
// the same module, just because we have a sorting behavior defined
// for those but not for just ResourceInstance.
addrsOrder := make([]addrs.AbsResourceInstance, 0, len(ms.Resources))
for _, rs := range ms.Resources {
for ik := range rs.Instances {
addrsOrder = append(addrsOrder, rs.Addr.Instance(ik))
}
}
sort.Slice(addrsOrder, func(i, j int) bool {
return addrsOrder[i].Less(addrsOrder[j])
})
for _, fakeAbsAddr := range addrsOrder {
addr := fakeAbsAddr.Resource
rs := ms.Resource(addr.ContainingResource())
is := ms.ResourceInstance(addr)
// Here we need to fake up a legacy-style address as the old state
// types would've used, since that's what our tests against those
// old types expect. The significant difference is that instancekey
// is dot-separated rather than using index brackets.
k := addr.ContainingResource().String()
if addr.Key != addrs.NoKey {
switch tk := addr.Key.(type) {
case addrs.IntKey:
k = fmt.Sprintf("%s.%d", k, tk)
default:
// No other key types existed for the legacy types, so we
// can do whatever we want here. We'll just use our standard
// syntax for these.
k = k + tk.String()
}
}
id := LegacyInstanceObjectID(is.Current)
taintStr := ""
if is.Current != nil && is.Current.Status == ObjectTainted {
taintStr = " (tainted)"
}
deposedStr := ""
if len(is.Deposed) > 0 {
deposedStr = fmt.Sprintf(" (%d deposed)", len(is.Deposed))
}
buf.WriteString(fmt.Sprintf("%s:%s%s\n", k, taintStr, deposedStr))
buf.WriteString(fmt.Sprintf(" ID = %s\n", id))
buf.WriteString(fmt.Sprintf(" provider = %s\n", rs.ProviderConfig.String()))
// Attributes were a flatmap before, but are not anymore. To preserve
// our old output as closely as possible we need to do a conversion
// to flatmap. Normally we'd want to do this with schema for
// accuracy, but for our purposes here it only needs to be approximate.
// This should produce an identical result for most cases, though
// in particular will differ in a few cases:
// - The keys used for elements in a set will be different
// - Values for attributes of type cty.DynamicPseudoType will be
// misinterpreted (but these weren't possible in old world anyway)
var attributes map[string]string
if obj := is.Current; obj != nil {
switch {
case obj.AttrsFlat != nil:
// Easy (but increasingly unlikely) case: the state hasn't
// actually been upgraded to the new form yet.
attributes = obj.AttrsFlat
case obj.AttrsJSON != nil:
ty, err := ctyjson.ImpliedType(obj.AttrsJSON)
if err == nil {
val, err := ctyjson.Unmarshal(obj.AttrsJSON, ty)
if err == nil {
attributes = hcl2shim.FlatmapValueFromHCL2(val)
}
}
}
}
attrKeys := make([]string, 0, len(attributes))
for ak, val := range attributes {
if ak == "id" {
continue
}
// don't show empty containers in the output
if val == "0" && (strings.HasSuffix(ak, ".#") || strings.HasSuffix(ak, ".%")) {
continue
}
attrKeys = append(attrKeys, ak)
}
sort.Strings(attrKeys)
for _, ak := range attrKeys {
av := attributes[ak]
buf.WriteString(fmt.Sprintf(" %s = %s\n", ak, av))
}
// CAUTION: Since deposed keys are now random strings instead of
// incrementing integers, this result will not be deterministic
// if there is more than one deposed object.
i := 1
for _, t := range is.Deposed {
id := LegacyInstanceObjectID(t)
taintStr := ""
if t.Status == ObjectTainted {
taintStr = " (tainted)"
}
buf.WriteString(fmt.Sprintf(" Deposed ID %d = %s%s\n", i, id, taintStr))
i++
}
if obj := is.Current; obj != nil && len(obj.Dependencies) > 0 {
buf.WriteString("\n Dependencies:\n")
for _, dep := range obj.Dependencies {
buf.WriteString(fmt.Sprintf(" %s\n", dep.String()))
}
}
}
// This is a bit weird because we used to store output values for all
// modules in the state, but now we use it only for the root output
// values since they are the only ones that persist between runs.
//
// To keep this long-suffering legacy string representation compatible
// (since so many of our older tests depend on it) we have this structured
// in as close as possible to the same way it was when OutputValues was
// a field of ms, instead of RootOutputValues in State.
if ms.Addr.IsRoot() && len(state.RootOutputValues) != 0 {
buf.WriteString("\nOutputs:\n\n")
ks := make([]string, 0, len(state.RootOutputValues))
for k := range state.RootOutputValues {
ks = append(ks, k)
}
sort.Strings(ks)
for _, k := range ks {
v := state.RootOutputValues[k]
lv := hcl2shim.ConfigValueFromHCL2(v.Value)
switch vTyped := lv.(type) {
case string:
buf.WriteString(fmt.Sprintf("%s = %s\n", k, vTyped))
case []interface{}:
buf.WriteString(fmt.Sprintf("%s = %s\n", k, vTyped))
case map[string]interface{}:
var mapKeys []string
for key := range vTyped {
mapKeys = append(mapKeys, key)
}
sort.Strings(mapKeys)
var mapBuf bytes.Buffer
mapBuf.WriteString("{")
for _, key := range mapKeys {
mapBuf.WriteString(fmt.Sprintf("%s:%s ", key, vTyped[key]))
}
mapBuf.WriteString("}")
buf.WriteString(fmt.Sprintf("%s = %s\n", k, mapBuf.String()))
default:
buf.WriteString(fmt.Sprintf("%s = %#v\n", k, lv))
}
}
}
return buf.String()
}
// LegacyInstanceObjectID is a helper for extracting an object id value from
// an instance object in a way that approximates how we used to do this
// for the old state types. ID is no longer first-class, so this is preserved
// only for compatibility with old tests that include the id as part of their
// expected value.
func LegacyInstanceObjectID(obj *ResourceInstanceObjectSrc) string {
if obj == nil {
return "<not created>"
}
if obj.AttrsJSON != nil {
type WithID struct {
ID string `json:"id"`
}
var withID WithID
err := json.Unmarshal(obj.AttrsJSON, &withID)
if err == nil {
return withID.ID
}
} else if obj.AttrsFlat != nil {
if flatID, exists := obj.AttrsFlat["id"]; exists {
return flatID
}
}
// For resource types created after we removed id as special there may
// not actually be one at all. This is okay because older tests won't
// encounter this, and new tests shouldn't be using ids.
return "<none>"
}