Add support for Fedora CoreOS snippets

* Add support for Fedora CoreOS `snippets`
* Add a Fedora CoreOS example to the README
* Move example to examples for project consistency

Related: https://github.com/poseidon/terraform-provider-ct/pull/22

CHANGES.md

@@ -4,8 +4,9 @@ Notable changes between releases.
 
 ## Latest
 
+* Add support for Fedora CoreOS `snippets` ([#58](https://github.com/poseidon/terraform-provider-ct/pull/58))
 * Migrate to the Terraform Plugin SDK ([#56](https://github.com/poseidon/terraform-provider-ct/pull/56))
-* Upgrade fcct from v0.1.0 to v0.4.0
+* Upgrade fcct from v0.1.0 to v0.4.0 ([#57](https://github.com/poseidon/terraform-provider-ct/pull/57))
 
 ## v0.4.0
 

README.md

@@ -5,7 +5,20 @@
 Define a Container Linux Config (CLC) or Fedora CoreOS Config (FCC) in version control.
 
 ```yaml
-# worker.yaml Container Linux Config
+# Container Linux Config
+---
+passwd:
+  users:
+    - name: core
+      ssh_authorized_keys:
+        - ssh-key foo
+```
+
+```yaml
+# Fedora CoreOS Config
+---
+variant: fcos
+version: 1.0.0
 passwd:
   users:
     - name: core
@@ -16,22 +29,25 @@ passwd:
 Render the config with Terraform for machine consumption.
 
 ```hcl
+# Define a data source
 data "ct_config" "worker" {
   content      = file("worker.yaml")
   pretty_print = false
   strict       = true
+  snippets     = []
 }
 
+# Usage: Render the config as Ignition
 resource "aws_instance" "worker" {
   user_data = data.ct_config.worker.rendered
 }
 ```
 
-See the [Container Linux](example/container-linux.tf) or [Fedora CoreOS](example/fedora-coreos.tf) examples.
+See the [Container Linux](examples/container-linux.tf) or [Fedora CoreOS](examples/fedora-coreos.tf) examples.
 
 ## Requirements
 
-* Terraform v0.11+ [installed](https://www.terraform.io/downloads.html)
+* Terraform v0.12+ [installed](https://www.terraform.io/downloads.html)
 
 ### Ignition Outputs
 

ct/datasource_ct_config.go

@@ -11,8 +11,10 @@ import (
 	clct "github.com/coreos/container-linux-config-transpiler/config"
 	fcct "github.com/coreos/fcct/config"
 	"github.com/coreos/fcct/config/common"
+
 	ignition "github.com/coreos/ignition/config/v2_2"
-	ignitionTypesV2_2 "github.com/coreos/ignition/config/v2_2/types"
+	ignitionTypes "github.com/coreos/ignition/config/v2_2/types"
+	ignitionV2 "github.com/coreos/ignition/v2/config/v3_0"
 )
 
 func dataSourceCTConfig() *schema.Resource {
@@ -83,7 +85,7 @@ func renderConfig(d *schema.ResourceData) (string, error) {
 	}
 
 	// Fedora CoreOS Config
-	ign, err := fccToIgnition([]byte(content), pretty, strict)
+	ign, err := fccToIgnition([]byte(content), pretty, strict, snippets)
 	if err == fcct.ErrNoVariant {
 		// consider as Container Linux Config
 		ign, err = renderCLC([]byte(content), platform, pretty, strict, snippets)
@@ -92,12 +94,42 @@ func renderConfig(d *schema.ResourceData) (string, error) {
 }
 
 // Translate Fedora CoreOS config to Ignition v3.X.Y
-func fccToIgnition(data []byte, pretty, strict bool) ([]byte, error) {
-	ign, _, err := fcct.Translate(data, common.TranslateOptions{
+func fccToIgnition(data []byte, pretty, strict bool, snippets []string) ([]byte, error) {
+	ignBytes, _, err := fcct.Translate(data, common.TranslateOptions{
 		Pretty: pretty,
 		Strict: strict,
 	})
-	return ign, err
+	// ErrNoVariant indicates data is a CLC, not an FCC
+	if err != nil {
+		return nil, err
+	}
+
+	ign, _, err := ignitionV2.Parse(ignBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, snippet := range snippets {
+		ignextBytes, _, err := fcct.Translate([]byte(snippet), common.TranslateOptions{
+			Pretty: pretty,
+			Strict: strict,
+		})
+		if err != nil {
+			// For FCC, require snippets be FCCs (don't fall-through to CLC)
+			if err == fcct.ErrNoVariant {
+				return []byte{}, fmt.Errorf("Fedora CoreOS snippets require `variant`: %v", err)
+			}
+			return nil, err
+		}
+		ignext, _, err := ignitionV2.Parse(ignextBytes)
+
+		ign = ignitionV2.Merge(ign, ignext)
+	}
+
+	if pretty {
+		return json.MarshalIndent(ign, "", "  ")
+	}
+	return json.Marshal(ign)
 }
 
 // Translate Container Linux Config as Ignition JSON.
@@ -122,21 +154,21 @@ func renderCLC(data []byte, platform string, pretty, strict bool, snippets []str
 }
 
 // Parse Container Linux config and convert to Ignition v2.2.0 format.
-func clcToIgnition(data []byte, platform string, strict bool) (ignitionTypesV2_2.Config, error) {
+func clcToIgnition(data []byte, platform string, strict bool) (ignitionTypes.Config, error) {
 	// parse bytes into a Container Linux Config
 	clc, ast, report := clct.Parse([]byte(data))
 
 	if strict && len(report.Entries) > 0 {
-		return ignitionTypesV2_2.Config{}, fmt.Errorf("error strict parsing Container Linux Config: %v", report.String())
+		return ignitionTypes.Config{}, fmt.Errorf("error strict parsing Container Linux Config: %v", report.String())
 	}
 
 	if report.IsFatal() {
-		return ignitionTypesV2_2.Config{}, fmt.Errorf("error parsing Container Linux Config: %v", report.String())
+		return ignitionTypes.Config{}, fmt.Errorf("error parsing Container Linux Config: %v", report.String())
 	}
 	// convert Container Linux Config to an Ignition Config
 	ign, report := clct.Convert(clc, platform, ast)
 	if report.IsFatal() {
-		return ignitionTypesV2_2.Config{}, fmt.Errorf("error converting to Ignition: %v", report.String())
+		return ignitionTypes.Config{}, fmt.Errorf("error converting to Ignition: %v", report.String())
 	}
 	return ign, nil
 }

ct/datasource_ct_config_test.go

@@ -194,6 +194,7 @@ const snippetsExpected = `{
 const fedoraCoreOSResource = `
 data "ct_config" "fedora-coreos" {
   pretty_print = true
+  strict = true
   content = <<EOT
 ---
 variant: fcos
@@ -235,6 +236,69 @@ const fedoraCoreOSExpected = `{
   "systemd": {}
 }`
 
+const fedoraCoreOSWithSnippets = `
+data "ct_config" "fedora-coreos-snippets" {
+  pretty_print = true
+  strict = true
+  content = <<EOT
+---
+variant: fcos
+version: 1.0.0
+passwd:
+  users:
+    - name: core
+      ssh_authorized_keys:
+        - key
+EOT
+	snippets = [
+<<EOT
+---
+variant: fcos
+version: 1.0.0
+systemd:
+  units:
+    - name: docker.service
+      enabled: true
+EOT
+	]
+}
+`
+
+const fedoraCoreOSWithSnippetsExpected = `{
+  "ignition": {
+    "config": {
+      "replace": {
+        "source": null,
+        "verification": {}
+      }
+    },
+    "security": {
+      "tls": {}
+    },
+    "timeouts": {},
+    "version": "3.0.0"
+  },
+  "passwd": {
+    "users": [
+      {
+        "name": "core",
+        "sshAuthorizedKeys": [
+          "key"
+        ]
+      }
+    ]
+  },
+  "storage": {},
+  "systemd": {
+    "units": [
+      {
+        "enabled": true,
+        "name": "docker.service"
+      }
+    ]
+  }
+}`
+
 const invalidResource = `
 data "ct_config" "container-linux-strict" {
   content = "foo"
@@ -271,6 +335,12 @@ func TestRender(t *testing.T) {
 					r.TestCheckResourceAttr("data.ct_config.fedora-coreos", "rendered", fedoraCoreOSExpected),
 				),
 			},
+			r.TestStep{
+				Config: fedoraCoreOSWithSnippets,
+				Check: r.ComposeTestCheckFunc(
+					r.TestCheckResourceAttr("data.ct_config.fedora-coreos-snippets", "rendered", fedoraCoreOSWithSnippetsExpected),
+				),
+			},
 		},
 	})
 }

examples/content/fcc-snippet.yaml

@@ -0,0 +1,10 @@
+variant: fcos
+version: 1.0.0
+storage:
+  files:
+    - path: /etc/zincati/config.d/90-disable-feature.toml
+      contents:
+        inline: |
+          [updates]
+          enabled = false
+

examples/fedora-coreos.tf

@@ -8,6 +8,10 @@ resource "local_file" "fedora-coreos-ign" {
 data "ct_config" "fedora-coreos-config" {
   content      = data.template_file.fedora-coreos-worker.rendered
   pretty_print = true
+
+  snippets = [
+    file("${path.module}/content/fcc-snippet.yaml"),
+  ]
 }
 
 # Content (e.g. possibly templated)

examples/versions.tf

@@ -4,7 +4,7 @@ terraform {
   required_providers {
     local    = "~> 1.2"
     template = "~> 2.1"
-    ct = "~> 0.4.0"
+    ct = "~> 0.5.0"
   }
 }
 

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/coreos/container-linux-config-transpiler v0.9.0
 	github.com/coreos/fcct v0.4.0
 	github.com/coreos/ignition v0.28.0
+	github.com/coreos/ignition/v2 v2.1.1
 	github.com/hashicorp/terraform-plugin-sdk v1.8.0
 	go4.org v0.0.0-20200312051459-7028f7b4a332 // indirect
 )

go.sum

@@ -150,6 +150,7 @@ github.com/coreos/ignition v0.24.0 h1:RGCRIVtEcOIhrG+pxrrPriqeemAnUu6fSwKGKJoEJ6
 github.com/coreos/ignition v0.24.0/go.mod h1:WJQapxzEn9DE0ryxsGvm8QnBajm/XsS/PkrDqSpz+bA=
 github.com/coreos/ignition v0.28.0 h1:wfX5JdoYrzH7pTJZlebeuwcb/NjzsEO6wgqs2OtVUPE=
 github.com/coreos/ignition v0.28.0/go.mod h1:WJQapxzEn9DE0ryxsGvm8QnBajm/XsS/PkrDqSpz+bA=
+github.com/coreos/ignition v0.35.0 h1:UFodoYq1mOPrbEjtxIsZbThcDyQwAI1owczRDqWmKkQ=
 github.com/coreos/ignition/v2 v2.0.0 h1:2nIU6rQIh2bCSF0PNJKuNNa23L13G031CoxbI4GFojc=
 github.com/coreos/ignition/v2 v2.0.0/go.mod h1:EJP9Gk/u21BPwWa5nT6yYbm5mO0u8JQAAzFqaxgH7Fg=
 github.com/coreos/ignition/v2 v2.1.1 h1:siNZchKAWoLeV708X4QWG9chTYhssE93HBKkZx+JJO8=