Merge pull request #29860 from hashicorp/fix-init-after-error-take-two

command: Update backend hash value only after a successful migration
This commit is contained in:
Chris Arcand 2021-11-02 15:28:58 -05:00 committed by GitHub
commit f04ea2bd3d
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6 changed files with 132 additions and 23 deletions

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@ -616,6 +616,41 @@ func TestInit_backendMigrateWhileLocked(t *testing.T) {
}
}
func TestInit_backendConfigFileChangeWithExistingState(t *testing.T) {
// Create a temporary working directory that is empty
td := tempDir(t)
testCopyDir(t, testFixturePath("init-backend-config-file-change-migrate-existing"), td)
defer os.RemoveAll(td)
defer testChdir(t, td)()
ui := new(cli.MockUi)
c := &InitCommand{
Meta: Meta{
testingOverrides: metaOverridesForProvider(testProvider()),
Ui: ui,
},
}
oldState := testDataStateRead(t, filepath.Join(DefaultDataDir, DefaultStateFilename))
// we deliberately do not provide the answer for backend-migrate-copy-to-empty to trigger error
args := []string{"-migrate-state", "-backend-config", "input.config", "-input=true"}
if code := c.Run(args); code == 0 {
t.Fatal("expected error")
}
// Read our backend config and verify new settings are not saved
state := testDataStateRead(t, filepath.Join(DefaultDataDir, DefaultStateFilename))
if got, want := normalizeJSON(t, state.Backend.ConfigRaw), `{"path":"local-state.tfstate"}`; got != want {
t.Errorf("wrong config\ngot: %s\nwant: %s", got, want)
}
// without changing config, hash should not change
if oldState.Backend.Hash != state.Backend.Hash {
t.Errorf("backend hash should not have changed\ngot: %d\nwant: %d", state.Backend.Hash, oldState.Backend.Hash)
}
}
func TestInit_backendConfigKV(t *testing.T) {
// Create a temporary working directory that is empty
td := tempDir(t)

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@ -636,20 +636,37 @@ func (m *Meta) backendFromConfig(opts *BackendOpts) (backend.Backend, tfdiags.Di
// Potentially changing a backend configuration
case c != nil && !s.Backend.Empty():
// We are not going to migrate if were not initializing and the hashes
// match indicating that the stored config is valid. If we are
// initializing, then we also assume the the backend config is OK if
// the hashes match, as long as we're not providing any new overrides.
// We are not going to migrate if...
//
// We're not initializing
// AND the backend cache hash values match, indicating that the stored config is valid and completely unchanged.
// AND we're not providing any overrides. An override can mean a change overriding an unchanged backend block (indicated by the hash value).
if (uint64(cHash) == s.Backend.Hash) && (!opts.Init || opts.ConfigOverride == nil) {
log.Printf("[TRACE] Meta.Backend: using already-initialized, unchanged %q backend configuration", c.Type)
return m.backend_C_r_S_unchanged(c, cHash, sMgr)
return m.savedBackend(sMgr)
}
// If our configuration is the same, then we're just initializing
// a previously configured remote backend.
// If our configuration (the result of both the literal configuration and given
// -backend-config options) is the same, then we're just initializing a previously
// configured backend. The literal configuration may differ, however, so while we
// don't need to migrate, we update the backend cache hash value.
if !m.backendConfigNeedsMigration(c, s.Backend) {
log.Printf("[TRACE] Meta.Backend: using already-initialized %q backend configuration", c.Type)
return m.backend_C_r_S_unchanged(c, cHash, sMgr)
savedBackend, moreDiags := m.savedBackend(sMgr)
diags = diags.Append(moreDiags)
if moreDiags.HasErrors() {
return nil, diags
}
// It's possible for a backend to be unchanged, and the config itself to
// have changed by moving a parameter from the config to `-backend-config`
// In this case, we update the Hash.
moreDiags = m.updateSavedBackendHash(cHash, sMgr)
if moreDiags.HasErrors() {
return nil, diags
}
return savedBackend, diags
}
log.Printf("[TRACE] Meta.Backend: backend configuration has changed (from type %q to type %q)", s.Backend.Type, c.Type)
@ -810,7 +827,7 @@ func (m *Meta) backend_c_r_S(c *configs.Backend, cHash int, sMgr *clistate.Local
}
// Initialize the configured backend
b, moreDiags := m.backend_C_r_S_unchanged(c, cHash, sMgr)
b, moreDiags := m.savedBackend(sMgr)
diags = diags.Append(moreDiags)
if moreDiags.HasErrors() {
return nil, diags
@ -1008,7 +1025,7 @@ func (m *Meta) backend_C_r_S_changed(c *configs.Backend, cHash int, sMgr *clista
}
// Grab the existing backend
oldB, oldBDiags := m.backend_C_r_S_unchanged(c, cHash, sMgr)
oldB, oldBDiags := m.savedBackend(sMgr)
diags = diags.Append(oldBDiags)
if oldBDiags.HasErrors() {
return nil, diags
@ -1074,23 +1091,16 @@ func (m *Meta) backend_C_r_S_changed(c *configs.Backend, cHash int, sMgr *clista
return b, diags
}
// Initiailizing an unchanged saved backend
func (m *Meta) backend_C_r_S_unchanged(c *configs.Backend, cHash int, sMgr *clistate.LocalState) (backend.Backend, tfdiags.Diagnostics) {
// Initializing a saved backend from the cache file (legacy state file)
//
// TODO: This is extremely similar to Meta.backendFromState() but for legacy reasons this is the
// function used by the migration APIs within this file. The other handles 'init -backend=false',
// specifically.
func (m *Meta) savedBackend(sMgr *clistate.LocalState) (backend.Backend, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
s := sMgr.State()
// it's possible for a backend to be unchanged, and the config itself to
// have changed by moving a parameter from the config to `-backend-config`
// In this case we only need to update the Hash.
if c != nil && s.Backend.Hash != uint64(cHash) {
s.Backend.Hash = uint64(cHash)
if err := sMgr.WriteState(s); err != nil {
diags = diags.Append(err)
return nil, diags
}
}
// Get the backend
f := backendInit.Backend(s.Backend.Type)
if f == nil {
@ -1129,6 +1139,21 @@ func (m *Meta) backend_C_r_S_unchanged(c *configs.Backend, cHash int, sMgr *clis
return b, diags
}
func (m *Meta) updateSavedBackendHash(cHash int, sMgr *clistate.LocalState) tfdiags.Diagnostics {
var diags tfdiags.Diagnostics
s := sMgr.State()
if s.Backend.Hash != uint64(cHash) {
s.Backend.Hash = uint64(cHash)
if err := sMgr.WriteState(s); err != nil {
diags = diags.Append(err)
}
}
return diags
}
//-------------------------------------------------------------------
// Reusable helper functions for backend management
//-------------------------------------------------------------------

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@ -0,0 +1,22 @@
{
"version": 3,
"serial": 0,
"lineage": "666f9301-7e65-4b19-ae23-71184bb19b03",
"backend": {
"type": "local",
"config": {
"path": "local-state.tfstate"
},
"hash": 9073424445967744180
},
"modules": [
{
"path": [
"root"
],
"outputs": {},
"resources": {},
"depends_on": []
}
]
}

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@ -0,0 +1 @@
path = "hello"

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@ -0,0 +1,21 @@
{
"version": 3,
"terraform_version": "0.8.2",
"serial": 8,
"lineage": "local",
"modules": [
{
"path": [
"root"
],
"outputs": {
"foo": {
"type": "string",
"value": "bar"
}
},
"resources": {},
"depends_on": []
}
]
}

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@ -0,0 +1,5 @@
terraform {
backend "local" {
path = "local-state.tfstate"
}
}