From a707d09f92ee4d62d10229d640b18caed025e0c6 Mon Sep 17 00:00:00 2001
From: Krystian Panek <krystian.panek@wundermanthompson.com>
Date: Tue, 7 Nov 2023 10:00:37 +0100
Subject: [PATCH] System service PoC

---
 README.md                                     |  2 +-
 examples/ssh/aem.tf                           | 21 ++---
 go.mod                                        |  1 -
 .../provider/instance/config.yml              |  0
 internal/provider/instance/embed.go           |  9 +++
 internal/provider/instance/plan_modifiers.go  | 42 ----------
 .../provider/instance/systemd.conf.go.tpl     | 19 +++++
 internal/provider/instance_resource.go        | 77 ++++++++-----------
 internal/utils/template.go                    | 18 +++++
 9 files changed, 91 insertions(+), 98 deletions(-)
 rename examples/ssh/aem/default/etc/aem.yml => internal/provider/instance/config.yml (100%)
 create mode 100644 internal/provider/instance/embed.go
 delete mode 100644 internal/provider/instance/plan_modifiers.go
 create mode 100644 internal/provider/instance/systemd.conf.go.tpl
 create mode 100644 internal/utils/template.go

diff --git a/README.md b/README.md
index 115db73..39ee840 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ Built on top of [AEM Compose](https://github.com/wttech/aemc).
 
 ```hcl
 resource "aem_instance" "single" {
-  depends_on = [aws_instance.aem_single, aws_volume_attachment.aem_single_data]
+  depends_on = [aws_instance.aem_single, aws_volume_attachment.aem_single_data]§
 
   client {
     type     = "ssh"
diff --git a/examples/ssh/aem.tf b/examples/ssh/aem.tf
index ceb35bb..fcb7b3c 100644
--- a/examples/ssh/aem.tf
+++ b/examples/ssh/aem.tf
@@ -10,12 +10,14 @@ resource "aem_instance" "single" {
       private_key_file = local.ssh_private_key # cannot be put into state as this is OS-dependent
     }
   }
-  compose {
-    version  = "1.5.8"
-    data_dir = local.aem_single_compose_dir
+  /* TODO support this as well
+  files = {
+    "lib" = "${local.aem_single_compose_dir}/aem/home/lib"
   }
-  hook {
-    bootstrap  = <<EOF
+  */
+  system {
+    data_dir  = local.aem_single_compose_dir
+    bootstrap = <<EOF
       #!/bin/sh
       (
         echo "Mounting EBS volume into data directory"
@@ -34,11 +36,10 @@ resource "aem_instance" "single" {
         aws s3 cp --recursive --no-progress "s3://aemc/instance/classic/" "${local.aem_single_compose_dir}/aem/home/lib"
       )
     EOF
-    initialize = <<EOF
-      #!/bin/sh
-      # sh aemw instance backup restore
-    EOF
-    provision  = <<EOF
+  }
+  compose {
+    version    = "1.5.8"
+    launch = <<EOF
       #!/bin/sh
       sh aemw osgi bundle install --url "https://github.com/neva-dev/felix-search-webconsole-plugin/releases/download/2.0.0/search-webconsole-plugin-2.0.0.jar" && \
       sh aemw osgi config save --pid "org.apache.sling.jcr.davex.impl.servlets.SlingDavExServlet" --input-string "alias: /crx/server" && \
diff --git a/go.mod b/go.mod
index 566d0f7..2506cc6 100644
--- a/go.mod
+++ b/go.mod
@@ -63,6 +63,5 @@ require (
 	golang.org/x/sys v0.10.0 // indirect
 	golang.org/x/text v0.11.0 // indirect
 	google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 // indirect
-	google.golang.org/grpc v1.56.1 // indirect
 	google.golang.org/protobuf v1.31.0 // indirect
 )
diff --git a/examples/ssh/aem/default/etc/aem.yml b/internal/provider/instance/config.yml
similarity index 100%
rename from examples/ssh/aem/default/etc/aem.yml
rename to internal/provider/instance/config.yml
diff --git a/internal/provider/instance/embed.go b/internal/provider/instance/embed.go
new file mode 100644
index 0000000..4db5508
--- /dev/null
+++ b/internal/provider/instance/embed.go
@@ -0,0 +1,9 @@
+package instance
+
+import _ "embed"
+
+//go:embed config.yml
+var ConfigYML string
+
+//go:embed systemd.conf.go.tpl
+var ServiceTemplate string
diff --git a/internal/provider/instance/plan_modifiers.go b/internal/provider/instance/plan_modifiers.go
deleted file mode 100644
index e3a07e2..0000000
--- a/internal/provider/instance/plan_modifiers.go
+++ /dev/null
@@ -1,42 +0,0 @@
-package instance
-
-import (
-	"context"
-	"fmt"
-	"github.com/hashicorp/terraform-plugin-framework/path"
-	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
-	"github.com/hashicorp/terraform-plugin-framework/types"
-	"github.com/wttech/terraform-provider-aem/internal/utils"
-)
-
-func ConfigFileChecksumPlanModifier() planmodifier.String {
-	return &configFileChecksumPlanModifier{}
-}
-
-type configFileChecksumPlanModifier struct{}
-
-func (m *configFileChecksumPlanModifier) Description(ctx context.Context) string {
-	return "Updates AEM configuration file checksum when contents change."
-}
-
-func (m *configFileChecksumPlanModifier) MarkdownDescription(ctx context.Context) string {
-	return m.Description(ctx)
-}
-
-func (m *configFileChecksumPlanModifier) PlanModifyString(ctx context.Context, req planmodifier.StringRequest, resp *planmodifier.StringResponse) {
-	var configFile types.String
-	diags := req.Plan.GetAttribute(ctx, path.Root("compose").AtName("config_file"), &configFile)
-	resp.Diagnostics.Append(diags...)
-	if resp.Diagnostics.HasError() {
-		return
-	}
-	if !configFile.IsNull() {
-		configFilePath := configFile.ValueString()
-		checksum, err := utils.HashFileMD5(configFilePath)
-		if err != nil {
-			resp.Diagnostics.AddError("Unable to calculate checksum of AEM configuration file", fmt.Sprintf("path '%s', error: %s", configFilePath, err))
-			return
-		}
-		resp.PlanValue = types.StringValue(checksum)
-	}
-}
diff --git a/internal/provider/instance/systemd.conf.go.tpl b/internal/provider/instance/systemd.conf.go.tpl
new file mode 100644
index 0000000..fad660d
--- /dev/null
+++ b/internal/provider/instance/systemd.conf.go.tpl
@@ -0,0 +1,19 @@
+[Unit]
+Description=AEM Instances
+Requires=network.target
+After=cloud-final.service
+
+[Service]
+Type=forking
+
+ExecStart=su - "{{.USER}}" -c ". /etc/profile && cd {{.DATA_DIR}} && sh aemw instance start"
+ExecStop=su - "{{.USER}}" -c ". /etc/profile && cd {{.DATA_DIR}} && sh aemw instance stop"
+ExecReload=su - "{{.USER}}" -c ". /etc/profile && cd {{.DATA_DIR}} && sh aemw instance restart"
+KillMode=process
+RemainAfterExit=yes
+TimeoutStartSec=1810
+TimeoutStopSec=190
+LimitNOFILE=20000
+
+[Install]
+WantedBy=cloud-init.target
diff --git a/internal/provider/instance_resource.go b/internal/provider/instance_resource.go
index 1a1bf00..e44103c 100644
--- a/internal/provider/instance_resource.go
+++ b/internal/provider/instance_resource.go
@@ -37,19 +37,18 @@ type InstanceResourceModel struct {
 		Type     types.String `tfsdk:"type"`
 		Settings types.Map    `tfsdk:"settings"`
 	} `tfsdk:"client"`
+	Files  types.Map `tfsdk:"files"`
+	System struct {
+		DataDir   types.String `tfsdk:"data_dir"`
+		Service   types.String `tfsdk:"service"`
+		Bootstrap types.String `tfsdk:"bootstrap"`
+	} `tfsdk:"system"`
 	Compose struct {
-		DataDir            types.String `tfsdk:"data_dir"`
-		Version            types.String `tfsdk:"version"`
-		ConfigFile         types.String `tfsdk:"config_file"`
-		ConfigFileChecksum types.String `tfsdk:"config_file_checksum"`
-		LibDir             types.String `tfsdk:"lib_dir"`
-		InstanceId         types.String `tfsdk:"instance_id"`
+		Version types.String `tfsdk:"version"`
+		Config  types.String `tfsdk:"config"`
+		Init    types.String `tfsdk:"initialize"`
+		Launch  types.String `tfsdk:"provision"`
 	} `tfsdk:"compose"`
-	Hook struct {
-		Bootstrap  types.String `tfsdk:"bootstrap"`
-		Initialize types.String `tfsdk:"initialize"`
-		Provision  types.String `tfsdk:"provision"`
-	} `tfsdk:"hook"`
 	Instances types.List `tfsdk:"instances"`
 }
 
@@ -90,58 +89,48 @@ func (r *InstanceResource) Schema(ctx context.Context, req resource.SchemaReques
 					},
 				},
 			},
-			"compose": schema.SingleNestedBlock{
+			"system": schema.SingleNestedBlock{
 				Attributes: map[string]schema.Attribute{
+					"bootstrap": schema.StringAttribute{
+						MarkdownDescription: "Script executed once after connecting to the instance. Typically used for: providing AEM library files (quickstart.jar, license.properties, service packs), mounting data volume, etc. Forces instance recreation if changed.",
+						Optional:            true,
+						PlanModifiers:       []planmodifier.String{stringplanmodifier.RequiresReplace()},
+					},
 					"data_dir": schema.StringAttribute{
-						MarkdownDescription: "Remote path in which AEM Compose data will be stored",
+						MarkdownDescription: "Remote root path in which AEM Compose files and unpacked instances will be stored",
 						Computed:            true,
 						Optional:            true,
 						Default:             stringdefault.StaticString("/mnt/aemc"),
 						PlanModifiers:       []planmodifier.String{stringplanmodifier.RequiresReplace()},
 					},
+					"service": schema.StringAttribute{
+						MarkdownDescription: "Contents of the 'systemd' service configuration file",
+						Optional:            true,
+						Default:             stringdefault.StaticString(instance.ServiceTemplate),
+					},
+				},
+			},
+			"compose": schema.SingleNestedBlock{
+				Attributes: map[string]schema.Attribute{
 					"version": schema.StringAttribute{
 						MarkdownDescription: "Version of AEM Compose tool to use on remote AEM machine",
 						Computed:            true,
 						Optional:            true,
 						Default:             stringdefault.StaticString("1.4.1"),
 					},
-					"config_file": schema.StringAttribute{
-						MarkdownDescription: "Local path to the AEM configuration file",
-						Computed:            true,
-						Optional:            true,
-						Default:             stringdefault.StaticString("aem/default/etc/aem.yml"),
-					},
-					"config_file_checksum": schema.StringAttribute{
-						Computed:      true,
-						PlanModifiers: []planmodifier.String{instance.ConfigFileChecksumPlanModifier()},
-					},
-					"lib_dir": schema.StringAttribute{
-						MarkdownDescription: "Local path to directory from which AEM library files will be copied to the remote AEM machine",
+					"config": schema.StringAttribute{
+						MarkdownDescription: "Contents of the AEM Compose YML configuration file",
 						Computed:            true,
 						Optional:            true,
-						Default:             stringdefault.StaticString("aem/home/lib"),
-					},
-					"instance_id": schema.StringAttribute{
-						MarkdownDescription: "ID of the AEM instance to use (one of the instances defined in the configuration file)",
-						Optional:            true,
-					},
-				},
-			},
-			"hook": schema.SingleNestedBlock{
-				MarkdownDescription: "Scripts executed on the remote AEM machine at key stages of the AEM instance lifecycle",
-				Attributes: map[string]schema.Attribute{
-					"bootstrap": schema.StringAttribute{
-						MarkdownDescription: "Executed once after connecting to the instance. Forces instance recreation if changed. Typically used for: providing AEM library files (quickstart.jar, license.properties, service packs), mounting data volume, etc.",
-						Optional:            true,
-						PlanModifiers:       []planmodifier.String{stringplanmodifier.RequiresReplace()},
+						Default:             stringdefault.StaticString(instance.ConfigYML),
 					},
-					"initialize": schema.StringAttribute{
-						MarkdownDescription: "Executed once after initializing AEM Compose but before launching the instance. Forces instance recreation if changed. Can be used for restoring instances from backup.",
+					"init": schema.StringAttribute{
+						MarkdownDescription: "Script executed once after initializing AEM Compose but before launching the instance. Forces instance recreation if changed. Can be used for restoring instances from backup.",
 						Optional:            true,
 						PlanModifiers:       []planmodifier.String{stringplanmodifier.RequiresReplace()},
 					},
-					"provision": schema.StringAttribute{
-						MarkdownDescription: "Executed when the instance is launched. Must be idempotent as it is executed always when changed. Typically used for setting up replication agents, installing service packs, etc.",
+					"launch": schema.StringAttribute{
+						MarkdownDescription: "Script executed when the instance is launched. Must be idempotent as it is executed always when changed. Typically used for setting up replication agents, installing service packs, etc.",
 						Optional:            true,
 					},
 				},
diff --git a/internal/utils/template.go b/internal/utils/template.go
new file mode 100644
index 0000000..91dd44b
--- /dev/null
+++ b/internal/utils/template.go
@@ -0,0 +1,18 @@
+package utils
+
+import (
+	"bytes"
+	"text/template"
+)
+
+func TemplateString(tplContent string, data any) (string, error) {
+	tplParsed, err := template.New("string-template").Delims("[[", "]]").Parse(tplContent)
+	if err != nil {
+		return "", err
+	}
+	var tplOutput bytes.Buffer
+	if err := tplParsed.Execute(&tplOutput, data); err != nil {
+		return "", err
+	}
+	return tplOutput.String(), nil
+}