cluster: add tt cluster command

* `tt cluster show` to show a configuration.
* `tt cluster publish` to publish a configuration.

@TarantoolBot document
Title: new module - `cluster`

The patch introduces a new module `cluster`. The module has two
commands:

* show - to show a configuration for a cluster or an instance.
* publish - to publish a cluster or an instance configuration.

The target could be a cluster or an instance configuration. It could
be a fully-merged (from all sources) configuration for an application
or just a remote configuration part in case of etcd.

Usage:

* `tt cluster show (<APP_NAME> | <APP_NAME:INSTANCE_NAME> | <URI>) [--validate]`
  * The optional `--validate` flag enables validation for a showed
    configuration.
* `tt cluster publish (<APP_NAME> | <APP_NAME:INSTANCE_NAME> | <URI>) file [--force]`
  * The optional `--force` flag skips validation of uploaded
    configuration.

The `APP_NAME` is a name of an application.

The `INSTANCE_NAME` is a name of an instance in the application.

The `URI` specifies a etcd connection settings in the following format:

`http(s)://[username:password@]host:port[/prefix][?arguments]`

* `prefix` - a base path to Tarantool configuration in etcd.

Possible arguments:

* `name` - a name of an instance in the cluster configuration.
* `timeout` - a request timeout in seconds (default 3.0).
* `ssl_key_file` - a path to a private SSL key file.
* `ssl_cert_file` - a path to an SSL certificate file.
* `ssl_ca_file` - a path to a trusted certificate authorities (CA)
  file.
* `ssl_ca_path` - a path to a trusted certificate authorities (CA)
  directory.
* `verify_host` - set off (default true) verification of the
  certificate’s name against the host.
* `verify_peer` - set off (default true) verification of the peer’s
  SSL certificate.

Part of #506

Author: oleg-jukovec

.codespellrc

@@ -1,4 +1,4 @@
 [codespell]
-skip = */rocks/third_party,*/cartridge/third_party,tarantool-static-build.patch
+skip = */rocks/third_party,*/cartridge/third_party,tarantool-static-build.patch,./cli/cluster/paths.go
 count =
 quiet-level = 3

.github/actions/prepare-ce-test-env/action.yml

@@ -14,7 +14,7 @@ inputs:
     description: Whether to skip etcd installation
     type: boolean
     required: false
-    default: true
+    default: false
 
 runs:
   using: "composite"

.github/actions/prepare-ee-test-env/action.yml

@@ -12,7 +12,7 @@ inputs:
     description: Whether to skip etcd installation
     type: boolean
     required: false
-    default: true
+    default: false
 
 runs:
   using: "composite"

.github/workflows/full-ci.yml

@@ -38,7 +38,6 @@ jobs:
         uses: ./.github/actions/prepare-ce-test-env
         with:
           tarantool-version: '${{ matrix.tarantool-version }}'
-          skip-etcd-install: false
 
       - name: Static code check
         uses: ./.github/actions/static-code-check
@@ -93,7 +92,6 @@ jobs:
         with:
           sdk-version: '${{ matrix.sdk-version }}'
           sdk-download-token: '${{ secrets.SDK_DOWNLOAD_TOKEN }}'
-          skip-etcd-install: false
 
       - name: Static code check
         uses: ./.github/actions/static-code-check

.github/workflows/tests.yml

@@ -127,6 +127,9 @@ jobs:
           brew install --overwrite go mage
           pip3 install -r test/requirements.txt
 
+      - name: Install etcd
+        uses: ./.github/actions/setup-etcd
+
       - name: Build tt
         env:
           TT_CLI_BUILD_SSL: 'static'

CHANGELOG.md

@@ -18,6 +18,8 @@ prompt line when using 'app:instance' target format.
 The binary has the name tt/tarantool_ + seven-digit hash.
 - New `tt pack` flag `--tarantool-version` is added to specify tarantool
   version for pack in docker. It is supported only with `--use-docker` enabled.
+- Module ``tt cluster``, to show or publish a cluster or an instance
+  configuration.
 
 ### Fixed
 

cli/cluster/cluster.go

@@ -54,8 +54,8 @@ func (config *InstanceConfig) UnmarshalYAML(unmarshal func(any) error) error {
 	//
 	// The `parsed` type helps to break the recursion because the type does
 	// not have `UnmarshalYAML` call.
-	type parsed InstanceConfig
-	temp := parsed(*config)
+	type instanceConfig InstanceConfig
+	temp := instanceConfig(*config)
 	if err := unmarshal(&temp); err != nil {
 		return fmt.Errorf("failed to unmarshal InstanceConfig: %w", err)
 	}
@@ -87,8 +87,8 @@ func (config *ReplicasetConfig) UnmarshalYAML(unmarshal func(any) error) error {
 	//
 	// The `parsed` type helps to break the recursion because the type does
 	// not have `UnmarshalYAML` call.
-	type parsed ReplicasetConfig
-	temp := parsed(*config)
+	type replicasetConfig ReplicasetConfig
+	temp := replicasetConfig(*config)
 	if err := unmarshal(&temp); err != nil {
 		return fmt.Errorf("failed to unmarshal ReplicasetConfig: %w", err)
 	}
@@ -120,8 +120,8 @@ func (config *GroupConfig) UnmarshalYAML(unmarshal func(any) error) error {
 	//
 	// The `parsed` type helps to break the recursion because the type does
 	// not have `UnmarshalYAML` call.
-	type parsed GroupConfig
-	temp := parsed(*config)
+	type groupConfig GroupConfig
+	temp := groupConfig(*config)
 	if err := unmarshal(&temp); err != nil {
 		return fmt.Errorf("failed to unmarshal GroupConfig: %w", err)
 	}
@@ -191,7 +191,14 @@ func MakeClusterConfig(config *Config) (ClusterConfig, error) {
 	}
 
 	err := yaml.Unmarshal([]byte(config.String()), &cconfig)
-	return cconfig, err
+	if err != nil {
+		err = fmt.Errorf(
+			"failed to parse a configuration data as a cluster config: %w",
+			err)
+		return cconfig, err
+
+	}
+	return cconfig, nil
 }
 
 // mergeExclude merges a high priority configuration with a low priority
@@ -212,7 +219,9 @@ func findInstance(cluster ClusterConfig, name string) *Config {
 			for iname, instance := range replicaset.Instances {
 				if iname == name {
 					config := NewConfig()
-					config.Merge(instance.RawConfig)
+					if instance.RawConfig != nil {
+						config.Merge(instance.RawConfig)
+					}
 					mergeExclude(config, replicaset.RawConfig,
 						[]string{instancesLabel})
 					mergeExclude(config, group.RawConfig,
@@ -288,6 +297,8 @@ func collectEtcdConfig(clusterConfig ClusterConfig) (*Config, error) {
 			fmtErr := "unable to parse a etcd request timeout: %w"
 			return nil, fmt.Errorf(fmtErr, err)
 		}
+	} else {
+		opts.Timeout = DefaultEtcdTimeout
 	}
 
 	etcd, err := ConnectEtcd(opts)
@@ -372,3 +383,30 @@ func GetInstanceConfig(cluster ClusterConfig, instance string) (InstanceConfig,
 
 	return MakeInstanceConfig(iconfig)
 }
+
+// ReplaceInstanceConfig replaces an instance configuration.
+func ReplaceInstanceConfig(cconfig ClusterConfig,
+	instance string, iconfig *Config) (ClusterConfig, error) {
+	for gname, group := range cconfig.Groups {
+		for rname, replicaset := range group.Replicasets {
+			for iname, _ := range replicaset.Instances {
+				if instance == iname {
+					path := []string{groupsLabel, gname,
+						replicasetsLabel, rname,
+						instancesLabel, iname,
+					}
+					newConfig := NewConfig()
+					newConfig.Merge(cconfig.RawConfig)
+					if err := newConfig.Set(path, iconfig); err != nil {
+						err = fmt.Errorf("failed to set configuration: %w", err)
+						return cconfig, err
+					}
+					return MakeClusterConfig(newConfig)
+				}
+			}
+		}
+	}
+
+	return cconfig,
+		fmt.Errorf("cluster configuration has not an instance %q", instance)
+}

cli/cluster/cluster_test.go

@@ -472,3 +472,35 @@ func TestGetInstanceConfig_noinstance(t *testing.T) {
 
 	assert.EqualError(t, err, expected)
 }
+
+func TestReplaceInstanceConfig_not_found(t *testing.T) {
+	config := cluster.NewConfig()
+	cconfig, err := cluster.MakeClusterConfig(config)
+	require.NoError(t, err)
+
+	cconfig, err = cluster.ReplaceInstanceConfig(cconfig, "any", cluster.NewConfig())
+	assert.EqualError(t, err, "cluster configuration has not an instance \"any\"")
+}
+
+func TestReplaceInstanceConfig_replcase(t *testing.T) {
+	path := []string{"groups", "a", "replicasets", "b", "instances", "c", "foo"}
+	config := cluster.NewConfig()
+	err := config.Set(path, 1)
+	require.NoError(t, err)
+	old, err := cluster.MakeClusterConfig(config)
+	require.NoError(t, err)
+
+	replace := cluster.NewConfig()
+	err = replace.Set([]string{"foo"}, 2)
+	require.NoError(t, err)
+
+	newConfig, err := cluster.ReplaceInstanceConfig(old, "c", replace)
+	require.NoError(t, err)
+	oldValue, err := old.RawConfig.Get(path)
+	require.NoError(t, err)
+	newValue, err := newConfig.RawConfig.Get(path)
+	require.NoError(t, err)
+
+	assert.Equal(t, 1, oldValue)
+	assert.Equal(t, 2, newValue)
+}

cli/cluster/cmd/common.go

@@ -0,0 +1,131 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/tarantool/tt/cli/cluster"
+)
+
+// printRawClusterConfig prints a raw cluster configuration or an instance
+// configuration if the instance name is specified.
+func printRawClusterConfig(config *cluster.Config,
+	instance string, validate bool) error {
+	cconfig, err := cluster.MakeClusterConfig(config)
+	if err != nil {
+		return err
+	}
+
+	if instance == "" {
+		var err error
+		if validate {
+			err = validateClusterConfig(cconfig, false)
+		}
+		printConfig(cconfig.RawConfig)
+		return err
+	}
+
+	return printInstanceConfig(cconfig, instance, false, validate)
+}
+
+// printClusterConfig prints a full-merged cluster configuration or an instance
+// configuration if the instance name is specified.
+func printClusterConfig(cconfig cluster.ClusterConfig,
+	instance string, validate bool) error {
+	if instance == "" {
+		var err error
+		if validate {
+			err = validateClusterConfig(cconfig, true)
+		}
+		printConfig(cconfig.RawConfig)
+		return err
+	}
+
+	return printInstanceConfig(cconfig, instance, true, validate)
+}
+
+// printInstanceConfig prints an instance configuration in the cluster.
+func printInstanceConfig(config cluster.ClusterConfig,
+	instance string, full, validate bool) error {
+	if !cluster.HasInstance(config, instance) {
+		return fmt.Errorf("instance %q not found", instance)
+	}
+
+	var (
+		err     error
+		iconfig *cluster.Config
+	)
+	if full {
+		ic, _ := cluster.GetInstanceConfig(config, instance)
+		iconfig = ic.RawConfig
+	} else {
+		iconfig = cluster.Instantiate(config, instance)
+	}
+
+	if validate {
+		err = validateInstanceConfig(iconfig, instance)
+	}
+	printConfig(iconfig)
+	return err
+}
+
+// validateRawConfig validates a raw cluster or an instance configuration. The
+// configuration belongs to an instance if name != "".
+func validateRawConfig(config *cluster.Config, name string) error {
+	if name == "" {
+		return validateRawClusterConfig(config)
+	} else {
+		return validateInstanceConfig(config, name)
+	}
+}
+
+// validateRawClusterConfig validates a raw cluster configuration or an
+// instance configuration if the instance name is specified.
+func validateRawClusterConfig(config *cluster.Config) error {
+	cconfig, err := cluster.MakeClusterConfig(config)
+	if err != nil {
+		return err
+	}
+
+	return validateClusterConfig(cconfig, false)
+}
+
+// validateClusterConfig validates a cluster configuration.
+func validateClusterConfig(cconfig cluster.ClusterConfig, full bool) error {
+	var errs []error
+	if err := cluster.Validate(cconfig.RawConfig, cluster.TarantoolSchema); err != nil {
+		err = fmt.Errorf("an invalid cluster configuration: %s", err)
+		errs = append(errs, err)
+	}
+
+	for _, name := range cluster.Instances(cconfig) {
+		var iconfig *cluster.Config
+		if full {
+			ic, err := cluster.GetInstanceConfig(cconfig, name)
+			if err != nil {
+				return err
+			}
+			iconfig = ic.RawConfig
+		} else {
+			iconfig = cluster.Instantiate(cconfig, name)
+		}
+		if err := validateInstanceConfig(iconfig, name); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	return errors.Join(errs...)
+}
+
+// validateInstanceConfig validates an instance configuration.
+func validateInstanceConfig(config *cluster.Config, name string) error {
+	if err := cluster.Validate(config, cluster.TarantoolSchema); err != nil {
+		return fmt.Errorf("an invalid instance %q configuration: %w", name, err)
+	}
+	return nil
+}
+
+// printConfig just prints a configuration to stdout.
+func printConfig(config *cluster.Config) {
+	fmt.Print(config.String())
+}