Merge pull request #89 from yangcao77/181-generate-initcontainers

add GenerateInitContainers function to generator

Author: yangcao77

README.md

@@ -1,5 +1,10 @@
 # Devfile Library
 
+<div id="header">
+
+[![Apache2.0 License](https://img.shields.io/badge/license-Apache2.0-brightgreen.svg)](LICENSE)
+</div>
+
 ## About
 
 The Devfile Parser library is a Golang module that:
@@ -11,7 +16,7 @@ The Devfile Parser library is a Golang module that:
 ## Usage
 
 The function documentation can be accessed via [pkg.go.dev](https://pkg.go.dev/github.com/devfile/library). 
-1. To parse a devfile, visit pkg/devfile/parse.go 
+1. To parse a devfile, visit [parse.go source file](pkg/devfile/parse.go)
    ```go
    // ParserArgs is the struct to pass into parser functions which contains required info for parsing devfile.
    parserArgs := parser.ParserArgs{
@@ -60,7 +65,7 @@ The function documentation can be accessed via [pkg.go.dev](https://pkg.go.dev/g
    })
    ```
 
-3. To get the Kubernetes objects from the devfile, visit pkg/devfile/generator/generators.go
+3. To get the Kubernetes objects from the devfile, visit [generators.go source file](pkg/devfile/generator/generators.go)
    ```go
     // To get a slice of Kubernetes containers of type corev1.Container from the devfile component containers
     containers, err := generator.GetContainers(devfile)
@@ -109,7 +114,7 @@ The function documentation can be accessed via [pkg.go.dev](https://pkg.go.dev/g
    err := devfile.Data.DeleteComponent(componentName)
    ```
 
-5. To write to a devfile, visit pkg/devfile/parser/writer.go
+5. To write to a devfile, visit [writer.go source file](pkg/devfile/parser/writer.go)
    ```go
    // If the devfile object has been created with devfile path already set, can simply call WriteYamlDevfile to writes the devfile
    err := devfile.WriteYamlDevfile()
@@ -159,7 +164,12 @@ The following projects are consuming this library as a Golang dependency
 * [odo](https://github.com/openshift/odo)
 * [OpenShift Console](https://github.com/openshift/console)
 
-In the future, [Workspace Operator](https://github.com/devfile/devworkspace-operator) will be the next consumer of devfile/library.
+## Tests
+
+To run unit tests and api tests. Visit [library tests](tests/README.md) to find out more information on tests
+```
+make test
+```
 
 ## Issues
 

pkg/devfile/generator/generators.go

@@ -1,6 +1,11 @@
 package generator
 
 import (
+	"fmt"
+	v1 "github.com/devfile/api/v2/pkg/apis/workspaces/v1alpha2"
+	"github.com/devfile/library/pkg/devfile/parser"
+	"github.com/devfile/library/pkg/devfile/parser/data/v2/common"
+	"github.com/devfile/library/pkg/util"
 	buildv1 "github.com/openshift/api/build/v1"
 	imagev1 "github.com/openshift/api/image/v1"
 	routev1 "github.com/openshift/api/route/v1"
@@ -9,10 +14,6 @@ import (
 	extensionsv1 "k8s.io/api/extensions/v1beta1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-
-	v1 "github.com/devfile/api/v2/pkg/apis/workspaces/v1alpha2"
-	"github.com/devfile/library/pkg/devfile/parser"
-	"github.com/devfile/library/pkg/devfile/parser/data/v2/common"
 )
 
 const (
@@ -27,6 +28,8 @@ const (
 
 	deploymentKind       = "Deployment"
 	deploymentAPIVersion = "apps/v1"
+
+	containerNameMaxLen = 55
 )
 
 // GetTypeMeta gets a type meta of the specified kind and version
@@ -91,6 +94,56 @@ func GetContainers(devfileObj parser.DevfileObj, options common.DevfileOptions)
 	return containers, nil
 }
 
+// GetInitContainers gets the init container for every preStart devfile event
+func GetInitContainers(devfileObj parser.DevfileObj) ([]corev1.Container, error) {
+	containers, err := GetContainers(devfileObj, common.DevfileOptions{})
+	if err != nil {
+		return nil, err
+	}
+	preStartEvents := devfileObj.Data.GetEvents().PreStart
+	var initContainers []corev1.Container
+	if len(preStartEvents) > 0 {
+		var eventCommands []string
+		commands, err := devfileObj.Data.GetCommands(common.DevfileOptions{})
+		if err != nil {
+			return nil, err
+		}
+
+		commandsMap := common.GetCommandsMap(commands)
+
+		for _, event := range preStartEvents {
+			eventSubCommands := common.GetCommandsFromEvent(commandsMap, event)
+			eventCommands = append(eventCommands, eventSubCommands...)
+		}
+
+		for i, commandName := range eventCommands {
+			if command, ok := commandsMap[commandName]; ok {
+				component := common.GetApplyComponent(command)
+
+				// Get the container info for the given component
+				for _, container := range containers {
+					if container.Name == component {
+						// Override the init container name since there cannot be two containers with the same
+						// name in a pod. This applies to pod containers and pod init containers. The convention
+						// for init container name here is, containername-eventname-<position of command in prestart events>
+						// If there are two events referencing the same devfile component, then we will have
+						// tools-event1-1 & tools-event2-3, for example. And if in the edge case, the same command is
+						// executed twice by preStart events, then we will have tools-event1-1 & tools-event1-2
+						initContainerName := fmt.Sprintf("%s-%s", container.Name, commandName)
+						initContainerName = util.TruncateString(initContainerName, containerNameMaxLen)
+						initContainerName = fmt.Sprintf("%s-%d", initContainerName, i+1)
+						container.Name = initContainerName
+
+						initContainers = append(initContainers, container)
+					}
+				}
+			}
+		}
+	}
+
+	return initContainers, nil
+}
+
 // DeploymentParams is a struct that contains the required data to create a deployment object
 type DeploymentParams struct {
 	TypeMeta          metav1.TypeMeta

pkg/devfile/generator/generators_test.go

@@ -1,7 +1,10 @@
 package generator
 
 import (
+	"github.com/devfile/library/pkg/devfile/parser/data"
+	"github.com/devfile/library/pkg/util"
 	"reflect"
+	"strings"
 	"testing"
 
 	v1 "github.com/devfile/api/v2/pkg/apis/workspaces/v1alpha2"
@@ -487,3 +490,186 @@ func TestGetVolumeMountPath(t *testing.T) {
 	}
 
 }
+
+func TestGetInitContainers(t *testing.T) {
+	shellExecutable := "/bin/sh"
+	containers := []v1.Component{
+		{
+			Name: "container1",
+			ComponentUnion: v1.ComponentUnion{
+				Container: &v1.ContainerComponent{
+					Container: v1.Container{
+						Image:   "container1",
+						Command: []string{shellExecutable, "-c", "cd execworkdir1 && execcommand1"},
+					},
+				},
+			},
+		},
+		{
+			Name: "container2",
+			ComponentUnion: v1.ComponentUnion{
+				Container: &v1.ContainerComponent{
+					Container: v1.Container{
+						Image:   "container2",
+						Command: []string{shellExecutable, "-c", "cd execworkdir3 && execcommand3"},
+					},
+				},
+			},
+		},
+	}
+
+	execCommands := []v1.Command{
+		{
+			Id: "apply1",
+			CommandUnion: v1.CommandUnion{
+				Apply: &v1.ApplyCommand{
+					Component: "container1",
+				},
+			},
+		},
+		{
+			Id: "apply2",
+			CommandUnion: v1.CommandUnion{
+				Apply: &v1.ApplyCommand{
+					Component: "container1",
+				},
+			},
+		},
+		{
+			Id: "apply3",
+			CommandUnion: v1.CommandUnion{
+				Apply: &v1.ApplyCommand{
+					Component: "container2",
+				},
+			},
+		},
+	}
+
+	compCommands := []v1.Command{
+		{
+			Id: "comp1",
+			CommandUnion: v1.CommandUnion{
+				Composite: &v1.CompositeCommand{
+					Commands: []string{
+						"apply1",
+						"apply3",
+					},
+				},
+			},
+		},
+	}
+
+	longContainerName := "thisisaverylongcontainerandkuberneteshasalimitforanamesize-exec2"
+	trimmedLongContainerName := util.TruncateString(longContainerName, containerNameMaxLen)
+
+	tests := []struct {
+		name              string
+		eventCommands     []string
+		wantInitContainer map[string]corev1.Container
+		longName          bool
+		wantErr           bool
+	}{
+		{
+			name: "Composite and Exec events",
+			eventCommands: []string{
+				"apply1",
+				"apply3",
+				"apply2",
+			},
+			wantInitContainer: map[string]corev1.Container{
+				"container1-apply1": {
+					Command: []string{shellExecutable, "-c", "cd execworkdir1 && execcommand1"},
+				},
+				"container1-apply2": {
+					Command: []string{shellExecutable, "-c", "cd execworkdir1 && execcommand1"},
+				},
+				"container2-apply3": {
+					Command: []string{shellExecutable, "-c", "cd execworkdir3 && execcommand3"},
+				},
+			},
+		},
+		{
+			name: "Long Container Name",
+			eventCommands: []string{
+				"apply2",
+			},
+			wantInitContainer: map[string]corev1.Container{
+				trimmedLongContainerName: {
+					Command: []string{shellExecutable, "-c", "cd execworkdir1 && execcommand1"},
+				},
+			},
+			longName: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+
+			if tt.longName {
+				containers[0].Name = longContainerName
+				execCommands[1].Apply.Component = longContainerName
+			}
+
+			devObj := parser.DevfileObj{
+				Data: func() data.DevfileData {
+					devfileData, err := data.NewDevfileData(string(data.APISchemaVersion210))
+					if err != nil {
+						t.Error(err)
+					}
+					err = devfileData.AddComponents(containers)
+					if err != nil {
+						t.Error(err)
+					}
+					err = devfileData.AddCommands(execCommands)
+					if err != nil {
+						t.Error(err)
+					}
+					err = devfileData.AddCommands(compCommands)
+					if err != nil {
+						t.Error(err)
+					}
+					err = devfileData.AddEvents(v1.Events{
+						DevWorkspaceEvents: v1.DevWorkspaceEvents{
+							PreStart: tt.eventCommands,
+						},
+					})
+					if err != nil {
+						t.Error(err)
+					}
+					return devfileData
+				}(),
+			}
+
+			initContainers, err := GetInitContainers(devObj)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("TestGetInitContainers() error = %v, wantErr %v", err, tt.wantErr)
+			}
+
+			if len(tt.wantInitContainer) != len(initContainers) {
+				t.Errorf("TestGetInitContainers() error: init container length mismatch, wanted %v got %v", len(tt.wantInitContainer), len(initContainers))
+			}
+
+			for _, initContainer := range initContainers {
+				nameMatched := false
+				commandMatched := false
+				for containerName, container := range tt.wantInitContainer {
+					if strings.Contains(initContainer.Name, containerName) {
+						nameMatched = true
+					}
+
+					if reflect.DeepEqual(initContainer.Command, container.Command) {
+						commandMatched = true
+					}
+				}
+
+				if !nameMatched {
+					t.Errorf("TestGetInitContainers() error: init container name mismatch, container name not present in %v", initContainer.Name)
+				}
+
+				if !commandMatched {
+					t.Errorf("TestGetInitContainers() error: init container command mismatch, command not found in %v", initContainer.Command)
+				}
+			}
+		})
+	}
+
+}

pkg/devfile/parser/data/v2/common/command_helper.go

@@ -50,6 +50,15 @@ func GetExecWorkingDir(dc v1.Command) string {
 	return ""
 }
 
+// GetApplyComponent returns the component of the apply command
+func GetApplyComponent(dc v1.Command) string {
+	if dc.Apply != nil {
+		return dc.Apply.Component
+	}
+
+	return ""
+}
+
 // GetCommandType returns the command type of a given command
 func GetCommandType(command v1.Command) (v1.CommandType, error) {
 	switch {
@@ -66,3 +75,31 @@ func GetCommandType(command v1.Command) (v1.CommandType, error) {
 		return "", fmt.Errorf("unknown command type")
 	}
 }
+
+// GetCommandsMap returns a map of the command Id to the command
+func GetCommandsMap(commands []v1.Command) map[string]v1.Command {
+	commandMap := make(map[string]v1.Command, len(commands))
+	for _, command := range commands {
+		commandMap[command.Id] = command
+	}
+	return commandMap
+}
+
+// GetCommandsFromEvent returns the list of commands from the event name.
+// If the event is a composite command, it returns the sub-commands from the tree
+func GetCommandsFromEvent(commandsMap map[string]v1.Command, eventName string) []string {
+	var commands []string
+
+	if command, ok := commandsMap[eventName]; ok {
+		if command.Composite != nil {
+			for _, compositeSubCmd := range command.Composite.Commands {
+				subCommands := GetCommandsFromEvent(commandsMap, compositeSubCmd)
+				commands = append(commands, subCommands...)
+			}
+		} else {
+			commands = append(commands, command.Id)
+		}
+	}
+
+	return commands
+}