[#56] Add use-context subcommand

Currently, airshipctl users switch their current context by modifying
the airshipctl config file or executing airshipctl config set-context
[NAME]. This change introduces the use-context subcommand, which
replaces the current behavior of using set-context without flags. After
this change, set-context will only be used to modify contexts.

Change-Id: If3980138a0abeeb6c59c07615b5373654073610a
Signed-off-by: Drew Walters <andrew.walters@att.com>

cmd/config/config.go

@@ -22,6 +22,7 @@ like "airshipctl config set-context my-context" `,
 	configRootCmd.AddCommand(NewCmdConfigInit(rootSettings))
 	configRootCmd.AddCommand(NewCmdConfigSetAuthInfo(rootSettings))
 	configRootCmd.AddCommand(NewCmdConfigGetAuthInfo(rootSettings))
+	configRootCmd.AddCommand(NewCmdConfigUseContext(rootSettings))
 
 	return configRootCmd
 }

cmd/config/testdata/TestConfigGoldenOutput/config-cmd-with-defaults.golden

@@ -13,6 +13,7 @@ Available Commands:
   set-cluster     Sets a cluster entry in the airshipctl config
   set-context     Switch to a new context or update context values in the airshipctl config
   set-credentials Sets a user entry in the airshipctl config
+  use-context     Switch to a different airshipctl context.
 
 Flags:
   -h, --help   help for config

cmd/config/testdata/TestConfigGoldenOutput/config-cmd-with-help.golden

@@ -13,6 +13,7 @@ Available Commands:
   set-cluster     Sets a cluster entry in the airshipctl config
   set-context     Switch to a new context or update context values in the airshipctl config
   set-credentials Sets a user entry in the airshipctl config
+  use-context     Switch to a different airshipctl context.
 
 Flags:
   -h, --help   help for config

cmd/config/testdata/TestConfigUseContextGoldenOutput/config-use-context-does-not-exist.golden

@@ -0,0 +1,12 @@
+Error: Missing configuration: Context with name 'foo'
+Usage:
+  use-context NAME [flags]
+
+Examples:
+
+# Switch to a context named "e2e"
+airshipctl config use-context e2e
+
+Flags:
+  -h, --help   help for use-context
+

cmd/config/testdata/TestConfigUseContextGoldenOutput/config-use-context-no-args.golden

@@ -0,0 +1,12 @@
+Error: accepts 1 arg(s), received 0
+Usage:
+  use-context NAME [flags]
+
+Examples:
+
+# Switch to a context named "e2e"
+airshipctl config use-context e2e
+
+Flags:
+  -h, --help   help for use-context
+

cmd/config/testdata/TestConfigUseContextGoldenOutput/config-use-context.golden

@@ -0,0 +1 @@
+Switched to context "dummy_context".

cmd/config/use_context.go

@@ -0,0 +1,59 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package config
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"opendev.org/airship/airshipctl/pkg/config"
+	"opendev.org/airship/airshipctl/pkg/environment"
+)
+
+var (
+	useContextLong = "Switch to a new context defined in the airshipctl config file."
+
+	useContextExample = `
+# Switch to a context named "e2e"
+airshipctl config use-context e2e`
+)
+
+// NewCmdConfigUseContext creates a command object for the "use-context" action, which
+// switches to a defined airshipctl context.
+func NewCmdConfigUseContext(rootSettings *environment.AirshipCTLSettings) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:     "use-context NAME",
+		Short:   "Switch to a different airshipctl context.",
+		Long:    useContextLong,
+		Example: useContextExample,
+		Args:    cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			contextName := args[0]
+			err := config.RunUseContext(contextName, rootSettings.Config())
+			if err != nil {
+				return err
+			}
+
+			fmt.Fprintf(cmd.OutOrStdout(), "Switched to context %q.\n", contextName)
+
+			return nil
+		},
+	}
+
+	return cmd
+}

cmd/config/use_context_test.go

@@ -0,0 +1,58 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package config_test
+
+import (
+	"errors"
+	"testing"
+
+	cmd "opendev.org/airship/airshipctl/cmd/config"
+	"opendev.org/airship/airshipctl/pkg/config"
+	"opendev.org/airship/airshipctl/pkg/environment"
+	"opendev.org/airship/airshipctl/testutil"
+)
+
+func TestConfigUseContext(t *testing.T) {
+	conf := config.DummyConfig()
+
+	settings := &environment.AirshipCTLSettings{}
+	settings.SetConfig(conf)
+
+	cmdTests := []*testutil.CmdTest{
+		{
+			Name:    "config-use-context",
+			CmdLine: "dummy_context",
+			Cmd:     cmd.NewCmdConfigUseContext(settings),
+		},
+		{
+			Name:    "config-use-context-no-args",
+			CmdLine: "",
+			Cmd:     cmd.NewCmdConfigUseContext(settings),
+			Error:   errors.New("accepts 1 arg(s), received 0"),
+		},
+		{
+			Name:    "config-use-context-does-not-exist",
+			CmdLine: "foo",
+			Cmd:     cmd.NewCmdConfigUseContext(settings),
+			Error:   errors.New("Missing configuration: Context with name 'foo'"),
+		},
+	}
+
+	for _, tt := range cmdTests {
+		testutil.RunTest(t, tt)
+	}
+}

pkg/config/cmds.go

@@ -237,3 +237,18 @@ func RunSetContext(o *ContextOptions, airconfig *Config, writeToStorage bool) (b
 
 	return modified, nil
 }
+
+func RunUseContext(desiredContext string, airconfig *Config) error {
+	if _, err := airconfig.GetContext(desiredContext); err != nil {
+		return err
+	}
+
+	if airconfig.CurrentContext != desiredContext {
+		airconfig.CurrentContext = desiredContext
+		if err := airconfig.PersistConfig(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

pkg/config/cmds_test.go

@@ -247,3 +247,17 @@ func TestRunSetContext(t *testing.T) {
 		assert.Equal(t, "new_namespace", conf.Contexts["dummy_context"].kContext.Namespace)
 	})
 }
+
+func TestRunUseContext(t *testing.T) {
+	t.Run("testUseContext", func(t *testing.T) {
+		conf := DummyConfig()
+		err := RunUseContext("dummy_context", conf)
+		assert.Nil(t, err)
+	})
+
+	t.Run("testUseContextDoesNotExist", func(t *testing.T) {
+		conf := NewConfig()
+		err := RunUseContext("foo", conf)
+		assert.Error(t, err)
+	})
+}