Allow client template config block to be parsed when using json config

- Adds tests
- Adds sample test data for parsing hcl and json
- Adds changelog

.changelog/24007.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+bug: Allow client template config block to be parsed when using json config
+```

client/config/config.go

@@ -401,14 +401,14 @@ type ClientTemplateConfig struct {
 	// time to wait for the Consul cluster to reach a consistent state before rendering a
 	// template. This is useful to enable in systems where Consul is experiencing
 	// a lot of flapping because it will reduce the number of times a template is rendered.
-	Wait *WaitConfig `hcl:"wait,optional" json:"-"`
+	Wait *WaitConfig `hcl:"wait,optional"`
 
 	// WaitBounds allows operators to define boundaries on individual template wait
 	// configuration overrides. If set, this ensures that if a job author specifies
 	// a wait configuration with values the cluster operator does not allow, the
 	// cluster operator's boundary will be applied rather than the job author's
 	// out of bounds configuration.
-	WaitBounds *WaitConfig `hcl:"wait_bounds,optional" json:"-"`
+	WaitBounds *WaitConfig `hcl:"wait_bounds,optional"`
 
 	// This controls the retry behavior when an error is returned from Consul.
 	// Consul Template is highly fault tolerant, meaning it does not exit in the
@@ -566,9 +566,9 @@ func (c *ClientTemplateConfig) Merge(o *ClientTemplateConfig) *ClientTemplateCon
 // to maintain parity with the external subsystem, not to establish a new standard.
 type WaitConfig struct {
 	Min    *time.Duration `hcl:"-"`
-	MinHCL string         `hcl:"min,optional" json:"-"`
+	MinHCL string         `hcl:"min,optional"`
 	Max    *time.Duration `hcl:"-"`
-	MaxHCL string         `hcl:"max,optional" json:"-"`
+	MaxHCL string         `hcl:"max,optional"`
 }
 
 // Copy returns a deep copy of the receiver.
@@ -696,11 +696,11 @@ type RetryConfig struct {
 	// Backoff is the base of the exponential backoff. This number will be
 	// multiplied by the next power of 2 on each iteration.
 	Backoff    *time.Duration `hcl:"-"`
-	BackoffHCL string         `hcl:"backoff,optional" json:"-"`
+	BackoffHCL string         `hcl:"backoff,optional"`
 	// MaxBackoff is an upper limit to the sleep time between retries
 	// A MaxBackoff of 0 means there is no limit to the exponential growth of the backoff.
 	MaxBackoff    *time.Duration `hcl:"-"`
-	MaxBackoffHCL string         `hcl:"max_backoff,optional" json:"-"`
+	MaxBackoffHCL string         `hcl:"max_backoff,optional"`
 }
 
 func (rc *RetryConfig) Copy() *RetryConfig {

command/agent/config_parse.go

@@ -295,7 +295,7 @@ func extraKeys(c *Config) error {
 		helper.RemoveEqualFold(&c.ExtraKeysHCL, "plugin")
 	}
 
-	for _, k := range []string{"options", "meta", "chroot_env", "servers", "server_join"} {
+	for _, k := range []string{"options", "meta", "chroot_env", "servers", "server_join", "template"} {
 		helper.RemoveEqualFold(&c.ExtraKeysHCL, k)
 		helper.RemoveEqualFold(&c.ExtraKeysHCL, "client")
 	}
@@ -315,6 +315,12 @@ func extraKeys(c *Config) error {
 		helper.RemoveEqualFold(&c.Client.ExtraKeysHCL, "host_network")
 	}
 
+	// Remove Template extra keys
+	for _, t := range []string{"function_denylist", "disable_file_sandbox", "max_stale", "wait", "wait_bounds", "block_query_wait", "consul_retry", "vault_retry", "nomad_retry"} {
+		helper.RemoveEqualFold(&c.Client.ExtraKeysHCL, t)
+		helper.RemoveEqualFold(&c.Client.ExtraKeysHCL, "template")
+	}
+
 	// Remove AuditConfig extra keys
 	for _, f := range c.Audit.Filters {
 		helper.RemoveEqualFold(&c.Audit.ExtraKeysHCL, f.Name)

command/agent/config_parse_test.go

@@ -1146,3 +1146,44 @@ func TestConfig_Telemetry(t *testing.T) {
 	must.Eq(t, mergedTelemetry2.inMemoryCollectionInterval, 1*time.Second)
 	must.Eq(t, mergedTelemetry2.inMemoryRetentionPeriod, 10*time.Second)
 }
+
+func TestConfig_Template(t *testing.T) {
+	ci.Parallel(t)
+
+	for _, suffix := range []string{"hcl", "json"} {
+		t.Run(suffix, func(t *testing.T) {
+			cfg := DefaultConfig()
+			fc, err := LoadConfig("testdata/template." + suffix)
+			must.NoError(t, err)
+			cfg = cfg.Merge(fc)
+
+			must.Eq(t, []string{"plugin"}, cfg.Client.TemplateConfig.FunctionDenylist)
+			must.True(t, cfg.Client.TemplateConfig.DisableSandbox)
+			must.Eq(t, pointer.Of(7600*time.Hour), cfg.Client.TemplateConfig.MaxStale)
+			must.Eq(t, pointer.Of(10*time.Minute), cfg.Client.TemplateConfig.BlockQueryWaitTime)
+
+			must.NotNil(t, cfg.Client.TemplateConfig.Wait)
+			must.Eq(t, pointer.Of(10*time.Second), cfg.Client.TemplateConfig.Wait.Min)
+			must.Eq(t, pointer.Of(10*time.Minute), cfg.Client.TemplateConfig.Wait.Max)
+
+			must.NotNil(t, cfg.Client.TemplateConfig.WaitBounds)
+			must.Eq(t, pointer.Of(1*time.Second), cfg.Client.TemplateConfig.WaitBounds.Min)
+			must.Eq(t, pointer.Of(10*time.Hour), cfg.Client.TemplateConfig.WaitBounds.Max)
+
+			must.NotNil(t, cfg.Client.TemplateConfig.ConsulRetry)
+			must.Eq(t, 6, *cfg.Client.TemplateConfig.ConsulRetry.Attempts)
+			must.Eq(t, pointer.Of(550*time.Millisecond), cfg.Client.TemplateConfig.ConsulRetry.Backoff)
+			must.Eq(t, pointer.Of(10*time.Minute), cfg.Client.TemplateConfig.ConsulRetry.MaxBackoff)
+
+			must.NotNil(t, cfg.Client.TemplateConfig.VaultRetry)
+			must.Eq(t, 6, *cfg.Client.TemplateConfig.VaultRetry.Attempts)
+			must.Eq(t, pointer.Of(550*time.Millisecond), cfg.Client.TemplateConfig.VaultRetry.Backoff)
+			must.Eq(t, pointer.Of(10*time.Minute), cfg.Client.TemplateConfig.VaultRetry.MaxBackoff)
+
+			must.NotNil(t, cfg.Client.TemplateConfig.NomadRetry)
+			must.Eq(t, 6, *cfg.Client.TemplateConfig.NomadRetry.Attempts)
+			must.Eq(t, pointer.Of(550*time.Millisecond), cfg.Client.TemplateConfig.NomadRetry.Backoff)
+			must.Eq(t, pointer.Of(10*time.Minute), cfg.Client.TemplateConfig.NomadRetry.MaxBackoff)
+		})
+	}
+}

command/agent/testdata/template.hcl

@@ -0,0 +1,37 @@
+client {
+  template {
+    function_denylist    = ["plugin"]
+    disable_file_sandbox = true
+    max_stale            = "7600h"
+
+    wait {
+      min = "10s"
+      max = "10m"
+    }
+
+    wait_bounds {
+      min = "1s"
+      max = "10h"
+    }
+
+    block_query_wait = "10m"
+
+    consul_retry {
+      attempts    = 6
+      backoff     = "550ms"
+      max_backoff = "10m"
+    }
+
+    vault_retry {
+      attempts    = 6
+      backoff     = "550ms"
+      max_backoff = "10m"
+    }
+
+    nomad_retry {
+      attempts    = 6
+      backoff     = "550ms"
+      max_backoff = "10m"
+    }
+  }
+}

command/agent/testdata/template.json

@@ -0,0 +1,33 @@
+{
+  "client": {
+    "template": {
+      "function_denylist": ["plugin"],
+      "disable_file_sandbox": true,
+      "max_stale": "7600h",
+      "wait": {
+        "min": "10s",
+        "max": "10m"
+      },
+      "wait_bounds": {
+        "min": "1s",
+        "max": "10h"
+      },
+      "block_query_wait": "10m",
+      "consul_retry": {
+        "attempts": 6,
+        "backoff": "550ms",
+        "max_backoff": "10m"
+      },
+      "vault_retry": {
+        "attempts": 6,
+        "backoff": "550ms",
+        "max_backoff": "10m"
+      },
+      "nomad_retry": {
+        "attempts": 6,
+        "backoff": "550ms",
+        "max_backoff": "10m"
+      }
+    }
+  }
+}