add Rehash to terraform.BackendState

This method mirrors that of config.Backend, so we can compare the
configration of a backend read from a config vs that of a backend read
from a state. This will prevent init from reinitializing when using
`-backend-config` options that match the existing state.
This commit is contained in:
James Bardin 2017-03-29 12:50:20 -04:00
parent 80a1539bca
commit ff2d753062
5 changed files with 105 additions and 4 deletions

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@ -406,6 +406,64 @@ func TestInit_copyBackendDst(t *testing.T) {
} }
} }
func TestInit_backendReinitWithExtra(t *testing.T) {
td := tempDir(t)
copy.CopyDir(testFixturePath("init-backend-empty"), td)
defer os.RemoveAll(td)
defer testChdir(t, td)()
m := testMetaBackend(t, nil)
opts := &BackendOpts{
ConfigExtra: map[string]interface{}{"path": "hello"},
Init: true,
}
b, err := m.backendConfig(opts)
if err != nil {
t.Fatal(err)
}
ui := new(cli.MockUi)
c := &InitCommand{
Meta: Meta{
ContextOpts: testCtxConfig(testProvider()),
Ui: ui,
},
}
args := []string{"-backend-config", "path=hello"}
if code := c.Run(args); code != 0 {
t.Fatalf("bad: \n%s", ui.ErrorWriter.String())
}
// Read our saved backend config and verify we have our settings
state := testStateRead(t, filepath.Join(DefaultDataDir, DefaultStateFilename))
if v := state.Backend.Config["path"]; v != "hello" {
t.Fatalf("bad: %#v", v)
}
if state.Backend.Hash != b.Hash {
t.Fatal("mismatched state and config backend hashes")
}
if state.Backend.Rehash() != b.Rehash() {
t.Fatal("mismatched state and config re-hashes")
}
// init again and make sure nothing changes
if code := c.Run(args); code != 0 {
t.Fatalf("bad: \n%s", ui.ErrorWriter.String())
}
state = testStateRead(t, filepath.Join(DefaultDataDir, DefaultStateFilename))
if v := state.Backend.Config["path"]; v != "hello" {
t.Fatalf("bad: %#v", v)
}
if state.Backend.Hash != b.Hash {
t.Fatal("mismatched state and config backend hashes")
}
}
/* /*
func TestInit_remoteState(t *testing.T) { func TestInit_remoteState(t *testing.T) {
tmp, cwd := testCwd(t) tmp, cwd := testCwd(t)

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@ -415,8 +415,16 @@ func (m *Meta) backendFromConfig(opts *BackendOpts) (backend.Backend, error) {
case c != nil && s.Remote.Empty() && !s.Backend.Empty(): case c != nil && s.Remote.Empty() && !s.Backend.Empty():
// If our configuration is the same, then we're just initializing // If our configuration is the same, then we're just initializing
// a previously configured remote backend. // a previously configured remote backend.
if !s.Backend.Empty() && s.Backend.Hash == cHash { if !s.Backend.Empty() {
return m.backend_C_r_S_unchanged(c, sMgr) hash := s.Backend.Hash
// on init we need an updated hash containing any extra options
// that were added after merging.
if opts.Init {
hash = s.Backend.Rehash()
}
if hash == cHash {
return m.backend_C_r_S_unchanged(c, sMgr)
}
} }
if !opts.Init { if !opts.Init {
@ -451,7 +459,11 @@ func (m *Meta) backendFromConfig(opts *BackendOpts) (backend.Backend, error) {
case c != nil && !s.Remote.Empty() && !s.Backend.Empty(): case c != nil && !s.Remote.Empty() && !s.Backend.Empty():
// If the hashes are the same, we have a legacy remote state with // If the hashes are the same, we have a legacy remote state with
// an unchanged stored backend state. // an unchanged stored backend state.
if s.Backend.Hash == cHash { hash := s.Backend.Hash
if opts.Init {
hash = s.Backend.Rehash()
}
if hash == cHash {
if !opts.Init { if !opts.Init {
initReason := fmt.Sprintf( initReason := fmt.Sprintf(
"Legacy remote state found with configured backend %q", "Legacy remote state found with configured backend %q",

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@ -0,0 +1,4 @@
terraform {
backend "local" {
}
}

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@ -72,7 +72,7 @@ type Backend struct {
Hash uint64 Hash uint64
} }
// Hash returns a unique content hash for this backend's configuration // Rehash returns a unique content hash for this backend's configuration
// as a uint64 value. // as a uint64 value.
func (b *Backend) Rehash() uint64 { func (b *Backend) Rehash() uint64 {
// If we have no backend, the value is zero // If we have no backend, the value is zero

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@ -20,6 +20,7 @@ import (
"github.com/hashicorp/go-version" "github.com/hashicorp/go-version"
"github.com/hashicorp/terraform/config" "github.com/hashicorp/terraform/config"
"github.com/mitchellh/copystructure" "github.com/mitchellh/copystructure"
"github.com/mitchellh/hashstructure"
"github.com/satori/go.uuid" "github.com/satori/go.uuid"
) )
@ -801,6 +802,32 @@ func (s *BackendState) Empty() bool {
return s == nil || s.Type == "" return s == nil || s.Type == ""
} }
// Rehash returns a unique content hash for this backend's configuration
// as a uint64 value.
// The Hash stored in the backend state needs to match the config itself, but
// we need to compare the backend config after it has been combined with all
// options.
// This function must match the implementation used by config.Backend.
func (s *BackendState) Rehash() uint64 {
if s == nil {
return 0
}
// Use hashstructure to hash only our type with the config.
code, err := hashstructure.Hash(map[string]interface{}{
"type": s.Type,
"config": s.Config,
}, nil)
// This should never happen since we have just some basic primitives
// so panic if there is an error.
if err != nil {
panic(err)
}
return code
}
// RemoteState is used to track the information about a remote // RemoteState is used to track the information about a remote
// state store that we push/pull state to. // state store that we push/pull state to.
type RemoteState struct { type RemoteState struct {