Change Butane Configs conversion to compatible Ignition version

* Parse Ignition bytes to the compatible Ignition version (determined
by current Ignition module's `ParseCompatibleVersion`)
* Parse v1.3 Butane Configs to Ignition v3.3
* Parse v1.2 Butane Configs to Ignition v3.3
* Parse v1.1 Butane Configs to Ignition v3.3
* Parse v1.0 Butane Configs to Ignition v3.3
* Relies on Ignition v3.x spec's future compatibility, where lesser
Ignition can be converted forward to the current Ignition (e.g. any
new fields will be empty or equivalently zero effect)
* Add support for version skew among Butane Config snippets
  * Butane Config and snippets will always convert to the Ignition
  version set by this provider

Docs: https://github.com/poseidon/terraform-provider-ct#versions

Author: dghubble

CHANGES.md

@@ -4,6 +4,17 @@ Notable changes between releases.
 
 ## Latest
 
+## v0.10.0
+
+* Change how older (< 1.4) Butane Configs are parsed to Ignition ([#116](https://github.com/poseidon/terraform-provider-ct/pull/116))
+  * Parse Ignition bytes to the forward compatible Ignition version ([docs](https://github.com/poseidon/terraform-provider-ct#versions))
+  * Parse v1.3 Butane Configs to Ignition v3.3
+  * Parse v1.2 Butane Configs to Ignition v3.3
+  * Parse v1.1 Butane Configs to Ignition v3.3
+  * Parse v1.0 Butane Configs to Ignition v3.3
+* Add support for verison skew among Butane Config snippets
+  * Butane Config and snippets will always convert to the current Ignition version
+
 ## v0.9.2
 
 * Update butane, ignition, and Terraform SDK modules

README.md

@@ -13,7 +13,7 @@ terraform {
   required_providers {
     ct = {
       source  = "poseidon/ct"
-      version = "0.9.2"
+      version = "0.10.0"
     }
   }
 }
@@ -75,12 +75,15 @@ $ terraform init
 
 ## Versions
 
-Butane configs contain a `version` that is associated with an Ignition format version. For example, a Butane config with `version: 1.0.0` would produce an Ignition config with version `3.0.0`, across future releases.
+Butane configs are converted to the current (according to this provider) stable Ignition config and merged together. For example, a Butane Config with `version: 1.2.0` would produce an Ignition config with version `v3.3.0`. This relies on Ignition's [forward compatibility](https://github.com/coreos/ignition/blob/main/config/v3_3/config.go#L61).
 
 Container Linux Configs render a fixed Ignition version, depending on the `terraform-provider-ct` release, so updating alters the rendered Ignition version.
 
+Before `terraform-provider-ct` v0.10.0, Butane configs contained a `version` that was associated with an Ignition format version. For example, a Butane config with `version: 1.0.0` would produce an Ignition config with version `3.0.0`.
+
 | terraform-provider-ct | CLC to Ignition     | Butane to Ignition    |
 |-----------------------|---------------------|--------------------|
+| 0.10.x                | Renders 2.3.0       | Butane (1.0, 1.1, 1.2, 1.3, 1.4) -> Ignition 3.3 |
 | 0.9.x                 | Renders 2.3.0       | Butane (1.0, 1.1, 1.2, 1.3, 1.4) -> Ignition (3.0, 3.1, 3.2, 3.2, 3.3)
 | 0.8.x                 | Renders 2.3.0       | Butane (1.0, 1.1, 1.2, 1.3) -> Ignition (3.0, 3.1, 3.2, 3.2)
 | 0.7.x                 | Renders 2.3.0       | Butane (1.0, 1.1, 1.2) -> Ignition (3.0, 3.1, 3.2) |
@@ -90,10 +93,6 @@ Container Linux Configs render a fixed Ignition version, depending on the `terra
 | 0.3.x                 | Renders 2.2.0       | NA                 |
 | 0.2.x                 | Renders 2.0.0       | NA                 |
 
-Notes:
-
-* Butane config `snippets` must match the version set in the content. Version skew among snippets is **not** supported.
-
 ## Development
 
 ### Binary

ct/datasource_ct_config.go

@@ -16,14 +16,7 @@ import (
 
 	ignition "github.com/coreos/ignition/config/v2_3"
 	ignitionTypes "github.com/coreos/ignition/config/v2_3/types"
-	ignition30 "github.com/coreos/ignition/v2/config/v3_0"
-	ignition30Types "github.com/coreos/ignition/v2/config/v3_0/types"
-	ignition31 "github.com/coreos/ignition/v2/config/v3_1"
-	ignition31Types "github.com/coreos/ignition/v2/config/v3_1/types"
-	ignition32 "github.com/coreos/ignition/v2/config/v3_2"
-	ignition32Types "github.com/coreos/ignition/v2/config/v3_2/types"
 	ignition33 "github.com/coreos/ignition/v2/config/v3_3"
-	ignition33Types "github.com/coreos/ignition/v2/config/v3_3/types"
 )
 
 func dataSourceCTConfig() *schema.Resource {
@@ -97,8 +90,8 @@ func renderConfig(d *schema.ResourceData) (string, error) {
 		}
 	}
 
-	// Fedora CoreOS Config
-	ign, err := fccToIgnition([]byte(content), pretty, strict, snippets)
+	// Butane Config
+	ign, err := butaneToIgnition([]byte(content), pretty, strict, snippets)
 	if err == common.ErrNoVariant {
 		// consider as Container Linux Config
 		ign, err = renderCLC([]byte(content), platform, pretty, strict, snippets)
@@ -107,7 +100,7 @@ func renderConfig(d *schema.ResourceData) (string, error) {
 }
 
 // Translate Fedora CoreOS config to Ignition v3.X.Y
-func fccToIgnition(data []byte, pretty, strict bool, snippets []string) ([]byte, error) {
+func butaneToIgnition(data []byte, pretty, strict bool, snippets []string) ([]byte, error) {
 	ignBytes, report, err := butane.TranslateBytes(data, common.TranslateBytesOptions{
 		Pretty: pretty,
 	})
@@ -119,166 +112,40 @@ func fccToIgnition(data []byte, pretty, strict bool, snippets []string) ([]byte,
 		return nil, fmt.Errorf("strict parsing error: %v", report.String())
 	}
 
-	if len(snippets) == 0 {
-		return ignBytes, nil
-	}
-
 	// merge FCC snippets into main Ignition config
 	return mergeFCCSnippets(ignBytes, pretty, strict, snippets)
 }
 
-// Manually parse main Fedora CoreOS Config's Ignition using fallback Ignition
-// versions. Then translate and parse FCC snippets as the chosen Ignition
-// version to merge.
-// version
-// Upstream might later handle: https://github.com/coreos/butane/issues/118
-// Note: This means snippets version must match the main config version.
+// Parse Fedora CoreOS Ignition and Butane snippets into Ignition Config.
 func mergeFCCSnippets(ignBytes []byte, pretty, strict bool, snippets []string) ([]byte, error) {
-	ign33, _, err := ignition33.Parse(ignBytes)
-	if err == nil {
-		// FCC config v1.4.0
-		ign33, err = mergeFCC14(ign33, snippets, pretty, strict)
-		if err != nil {
-			return nil, fmt.Errorf("FCC v1.4.0 merge error: %v", err)
-		}
-		return marshalJSON(ign33, pretty)
-	}
-
-	ign32, _, err := ignition32.Parse(ignBytes)
-	if err == nil {
-		// FCC config v1.2.0
-		ign32, err = mergeFCC12(ign32, snippets, pretty, strict)
-		if err != nil {
-			return nil, fmt.Errorf("FCC v1.2.0 merge error: %v", err)
-		}
-		return marshalJSON(ign32, pretty)
-	}
-
-	ign31, _, err := ignition31.Parse(ignBytes)
-	if err == nil {
-		// FCC config v1.1.0
-		ign31, err = mergeFCC11(ign31, snippets, pretty, strict)
-		if err != nil {
-			return nil, fmt.Errorf("FCC v1.1.0 merge error: %v", err)
-		}
-		return marshalJSON(ign31, pretty)
-	}
-
-	var ign30 ignition30Types.Config
-	ign30, _, err = ignition30.Parse(ignBytes)
+	ign, _, err := ignition33.ParseCompatibleVersion(ignBytes)
 	if err != nil {
-		return nil, fmt.Errorf("FCC v1.0.0 parse error: %v", err)
+		return nil, fmt.Errorf("%v", err)
 	}
-	// FCC config v1.0.0
-	ign30, err = mergeFCCV10(ign30, snippets, pretty, strict)
-	if err != nil {
-		return nil, fmt.Errorf("FCC v1.0.0 merge error: %v", err)
-	}
-	return marshalJSON(ign30, pretty)
-}
 
-// merge FCC v1.4.0 snippets
-func mergeFCC14(ign ignition33Types.Config, snippets []string, pretty, strict bool) (ignition33Types.Config, error) {
 	for _, snippet := range snippets {
 		ignextBytes, report, err := butane.TranslateBytes([]byte(snippet), common.TranslateBytesOptions{
 			Pretty: pretty,
 		})
 		if err != nil {
 			// For FCC, require snippets be FCCs (don't fall-through to CLC)
 			if err == common.ErrNoVariant {
-				return ign, fmt.Errorf("Fedora CoreOS snippets require `variant`: %v", err)
+				return nil, fmt.Errorf("Butane snippets require `variant`: %v", err)
 			}
-			return ign, fmt.Errorf("snippet v1.4.0 translate error: %v", err)
+			return nil, fmt.Errorf("Butane translate error: %v", err)
 		}
 		if strict && len(report.Entries) > 0 {
-			return ign, fmt.Errorf("strict parsing error: %v", report.String())
+			return nil, fmt.Errorf("strict parsing error: %v", report.String())
 		}
 
-		ignext, _, err := ignition33.Parse(ignextBytes)
+		ignext, _, err := ignition33.ParseCompatibleVersion(ignextBytes)
 		if err != nil {
-			return ign, fmt.Errorf("snippet parse error: %v, expect v1.4.0", err)
+			return nil, fmt.Errorf("snippet parse error: %v, expect v1.4.0", err)
 		}
 		ign = ignition33.Merge(ign, ignext)
 	}
-	return ign, nil
-}
-
-// merge FCC v1.2.0 snippets
-func mergeFCC12(ign ignition32Types.Config, snippets []string, pretty, strict bool) (ignition32Types.Config, error) {
-	for _, snippet := range snippets {
-		ignextBytes, report, err := butane.TranslateBytes([]byte(snippet), common.TranslateBytesOptions{
-			Pretty: pretty,
-		})
-		if err != nil {
-			// For FCC, require snippets be FCCs (don't fall-through to CLC)
-			if err == common.ErrNoVariant {
-				return ign, fmt.Errorf("Fedora CoreOS snippets require `variant`: %v", err)
-			}
-			return ign, fmt.Errorf("snippet v1.2.0 translate error: %v", err)
-		}
-		if strict && len(report.Entries) > 0 {
-			return ign, fmt.Errorf("strict parsing error: %v", report.String())
-		}
-
-		ignext, _, err := ignition32.Parse(ignextBytes)
-		if err != nil {
-			return ign, fmt.Errorf("snippet parse error: %v, expect v1.2.0", err)
-		}
-		ign = ignition32.Merge(ign, ignext)
-	}
-	return ign, nil
-}
-
-// merge FCC v1.1.0 snippets
-func mergeFCC11(ign ignition31Types.Config, snippets []string, pretty, strict bool) (ignition31Types.Config, error) {
-	for _, snippet := range snippets {
-		ignextBytes, report, err := butane.TranslateBytes([]byte(snippet), common.TranslateBytesOptions{
-			Pretty: pretty,
-		})
-		if err != nil {
-			// For FCC, require snippets be FCCs (don't fall-through to CLC)
-			if err == common.ErrNoVariant {
-				return ign, fmt.Errorf("Fedora CoreOS snippets require `variant`: %v", err)
-			}
-			return ign, fmt.Errorf("snippet v1.1.0 translate error: %v", err)
-		}
-		if strict && len(report.Entries) > 0 {
-			return ign, fmt.Errorf("strict parsing error: %v", report.String())
-		}
-
-		ignext, _, err := ignition31.Parse(ignextBytes)
-		if err != nil {
-			return ign, fmt.Errorf("snippet parse error: %v, expect v1.1.0", err)
-		}
-		ign = ignition31.Merge(ign, ignext)
-	}
-	return ign, nil
-}
-
-// merge FCC v1.0.0 snippets
-func mergeFCCV10(ign ignition30Types.Config, snippets []string, pretty, strict bool) (ignition30Types.Config, error) {
-	for _, snippet := range snippets {
-		ignextBytes, report, err := butane.TranslateBytes([]byte(snippet), common.TranslateBytesOptions{
-			Pretty: pretty,
-		})
-		if err != nil {
-			// For FCC, require snippets be FCCs (don't fall-through to CLC)
-			if err == common.ErrNoVariant {
-				return ign, fmt.Errorf("Fedora CoreOS snippets require `variant`: %v", err)
-			}
-			return ign, fmt.Errorf("snippet v1.0.0 translate error: %v", err)
-		}
-		if strict && len(report.Entries) > 0 {
-			return ign, fmt.Errorf("strict parsing error: %v", report.String())
-		}
 
-		ignext, _, err := ignition30.Parse(ignextBytes)
-		if err != nil {
-			return ign, fmt.Errorf("snippet parse error: %v, expect v1.0.0", err)
-		}
-		ign = ignition30.Merge(ign, ignext)
-	}
-	return ign, nil
+	return marshalJSON(ign, pretty)
 }
 
 // Translate Container Linux Config as Ignition JSON.