[ORCA-554] Add support for limiting number of projects per PR. (#41)

cmd/server.go

@@ -24,6 +24,7 @@ import (
 	homedir "github.com/mitchellh/go-homedir"
 	"github.com/pkg/errors"
 	"github.com/runatlantis/atlantis/server"
+	"github.com/runatlantis/atlantis/server/events"
 	"github.com/runatlantis/atlantis/server/events/vcs/bitbucketcloud"
 	"github.com/runatlantis/atlantis/server/events/yaml/valid"
 	"github.com/runatlantis/atlantis/server/logging"
@@ -76,6 +77,7 @@ const (
 	HidePrevPlanComments       = "hide-prev-plan-comments"
 	LogLevelFlag               = "log-level"
 	ParallelPoolSize           = "parallel-pool-size"
+	MaxProjectsPerPR           = "max-projects-per-pr"
 	StatsNamespace             = "stats-namespace"
 	AllowDraftPRs              = "allow-draft-prs"
 	PortFlag                   = "port"
@@ -381,6 +383,10 @@ var intFlags = map[string]intFlag{
 		description:  "Max size of the wait group that runs parallel plans and applies (if enabled).",
 		defaultValue: DefaultParallelPoolSize,
 	},
+	MaxProjectsPerPR: {
+		description:  "Max number of projects to operate on in a given pull request.",
+		defaultValue: events.InfiniteProjectsPerPR,
+	},
 	PortFlag: {
 		description:  "Port to bind to.",
 		defaultValue: DefaultPort,
@@ -624,6 +630,9 @@ func (s *ServerCmd) setDefaults(c *server.UserConfig) {
 	if c.TFEHostname == "" {
 		c.TFEHostname = DefaultTFEHostname
 	}
+	if c.MaxProjectsPerPR == 0 {
+		c.MaxProjectsPerPR = events.InfiniteProjectsPerPR
+	}
 }
 
 func (s *ServerCmd) validate(userConfig server.UserConfig) error {

server/events/project_command_builder.go

@@ -29,6 +29,9 @@ const (
 	DefaultParallelPlanEnabled = false
 	// DefaultDeleteSourceBranchOnMerge being false is the default setting whether or not to remove a source branch on merge
 	DefaultDeleteSourceBranchOnMerge = false
+	// InfiniteProjectLimitPerPR is the default setting for number of projects per PR.
+	// this is set to -1 to signify no limit.
+	InfiniteProjectsPerPR = -1
 )
 
 func NewProjectCommandBuilder(
@@ -47,7 +50,43 @@ func NewProjectCommandBuilder(
 	scope stats.Scope,
 	logger logging.SimpleLogging,
 ) ProjectCommandBuilder {
-	projectCommandBuilder := &DefaultProjectCommandBuilder{
+	return NewProjectCommandBuilderWithLimit(
+		policyChecksSupported,
+		parserValidator,
+		projectFinder,
+		vcsClient,
+		workingDir,
+		workingDirLocker,
+		globalCfg,
+		pendingPlanFinder,
+		commentBuilder,
+		skipCloneNoChanges,
+		EnableRegExpCmd,
+		AutoplanFileList,
+		scope,
+		logger,
+		InfiniteProjectsPerPR,
+	)
+}
+
+func NewProjectCommandBuilderWithLimit(
+	policyChecksSupported bool,
+	parserValidator *yaml.ParserValidator,
+	projectFinder ProjectFinder,
+	vcsClient vcs.Client,
+	workingDir WorkingDir,
+	workingDirLocker WorkingDirLocker,
+	globalCfg valid.GlobalCfg,
+	pendingPlanFinder *DefaultPendingPlanFinder,
+	commentBuilder CommentBuilder,
+	skipCloneNoChanges bool,
+	EnableRegExpCmd bool,
+	AutoplanFileList string,
+	scope stats.Scope,
+	logger logging.SimpleLogging,
+	limit int,
+) ProjectCommandBuilder {
+	var projectCommandBuilder ProjectCommandBuilder = &DefaultProjectCommandBuilder{
 		ParserValidator:    parserValidator,
 		ProjectFinder:      projectFinder,
 		VCSClient:          vcsClient,
@@ -65,6 +104,11 @@ func NewProjectCommandBuilder(
 		),
 	}
 
+	projectCommandBuilder = &SizeLimitedProjectCommandBuilder{
+		Limit:                 limit,
+		ProjectCommandBuilder: projectCommandBuilder,
+	}
+
 	return &InstrumentedProjectCommandBuilder{
 		ProjectCommandBuilder: projectCommandBuilder,
 		Logger:                logger,

server/events/size_limited_project_command_builder.go

@@ -0,0 +1,48 @@
+package events
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+	"github.com/runatlantis/atlantis/server/events/models"
+)
+
+type SizeLimitedProjectCommandBuilder struct {
+	Limit int
+	ProjectCommandBuilder
+}
+
+func (b *SizeLimitedProjectCommandBuilder) BuildAutoplanCommands(ctx *CommandContext) ([]models.ProjectCommandContext, error) {
+	projects, err := b.ProjectCommandBuilder.BuildAutoplanCommands(ctx)
+
+	if err != nil {
+		return projects, err
+	}
+
+	return projects, b.CheckAgainstLimit(projects)
+}
+
+func (b *SizeLimitedProjectCommandBuilder) BuildPlanCommands(ctx *CommandContext, comment *CommentCommand) ([]models.ProjectCommandContext, error) {
+	projects, err := b.ProjectCommandBuilder.BuildPlanCommands(ctx, comment)
+
+	if err != nil {
+		return projects, err
+	}
+
+	return projects, b.CheckAgainstLimit(projects)
+}
+
+func (b *SizeLimitedProjectCommandBuilder) CheckAgainstLimit(projects []models.ProjectCommandContext) error {
+	if b.Limit != InfiniteProjectsPerPR && len(projects) > b.Limit {
+		return errors.New(
+			fmt.Sprintf(
+				"Number of projects cannot exceed %d.  This can either be caused by:\n"+
+					"1) GH failure in recognizing the diff\n"+
+					"2) Pull Request batch is too large for the given Atlantis instance\n\n"+
+					"Please break this pull request into smaller batches and try again.",
+				b.Limit,
+			),
+		)
+	}
+	return nil
+}

server/events/size_limited_project_command_builder_test.go

@@ -0,0 +1,143 @@
+package events_test
+
+import (
+	"testing"
+
+	. "github.com/petergtz/pegomock"
+	"github.com/runatlantis/atlantis/server/events"
+	"github.com/runatlantis/atlantis/server/events/mocks"
+	"github.com/runatlantis/atlantis/server/events/models"
+	. "github.com/runatlantis/atlantis/testing"
+)
+
+func TestSizeLimitedProjectCommandBuilder_autoplan(t *testing.T) {
+	RegisterMockTestingT(t)
+
+	delegate := mocks.NewMockProjectCommandBuilder()
+
+	ctx := &events.CommandContext{}
+
+	project1 := models.ProjectCommandContext{
+		ProjectName: "test1",
+	}
+
+	project2 := models.ProjectCommandContext{
+		ProjectName: "test2",
+	}
+
+	expectedResult := []models.ProjectCommandContext{project1, project2}
+
+	t.Run("Limit Defined and Breached", func(t *testing.T) {
+		subject := &events.SizeLimitedProjectCommandBuilder{
+			Limit:                 1,
+			ProjectCommandBuilder: delegate,
+		}
+
+		When(delegate.BuildAutoplanCommands(ctx)).ThenReturn(expectedResult, nil)
+
+		_, err := subject.BuildAutoplanCommands(ctx)
+
+		ErrEquals(t, `Number of projects cannot exceed 1.  This can either be caused by:
+1) GH failure in recognizing the diff
+2) Pull Request batch is too large for the given Atlantis instance
+
+Please break this pull request into smaller batches and try again.`, err)
+	})
+
+	t.Run("Limit defined and not breached", func(t *testing.T) {
+		subject := &events.SizeLimitedProjectCommandBuilder{
+			Limit:                 2,
+			ProjectCommandBuilder: delegate,
+		}
+
+		When(delegate.BuildAutoplanCommands(ctx)).ThenReturn(expectedResult, nil)
+
+		result, err := subject.BuildAutoplanCommands(ctx)
+
+		Ok(t, err)
+
+		Assert(t, len(result) == len(expectedResult), "size is expected")
+	})
+
+	t.Run("Limit not defined", func(t *testing.T) {
+		subject := &events.SizeLimitedProjectCommandBuilder{
+			Limit:                 events.InfiniteProjectsPerPR,
+			ProjectCommandBuilder: delegate,
+		}
+
+		When(delegate.BuildAutoplanCommands(ctx)).ThenReturn(expectedResult, nil)
+
+		result, err := subject.BuildAutoplanCommands(ctx)
+
+		Ok(t, err)
+
+		Assert(t, len(result) == len(expectedResult), "size is expected")
+	})
+}
+
+func TestSizeLimitedProjectCommandBuilder_planComment(t *testing.T) {
+	RegisterMockTestingT(t)
+
+	delegate := mocks.NewMockProjectCommandBuilder()
+
+	ctx := &events.CommandContext{}
+
+	comment := &events.CommentCommand{}
+
+	project1 := models.ProjectCommandContext{
+		ProjectName: "test1",
+	}
+
+	project2 := models.ProjectCommandContext{
+		ProjectName: "test2",
+	}
+
+	expectedResult := []models.ProjectCommandContext{project1, project2}
+
+	t.Run("Limit Defined and Breached", func(t *testing.T) {
+		subject := &events.SizeLimitedProjectCommandBuilder{
+			Limit:                 1,
+			ProjectCommandBuilder: delegate,
+		}
+
+		When(delegate.BuildPlanCommands(ctx, comment)).ThenReturn(expectedResult, nil)
+
+		_, err := subject.BuildPlanCommands(ctx, comment)
+
+		ErrEquals(t, `Number of projects cannot exceed 1.  This can either be caused by:
+1) GH failure in recognizing the diff
+2) Pull Request batch is too large for the given Atlantis instance
+
+Please break this pull request into smaller batches and try again.`, err)
+	})
+
+	t.Run("Limit defined and not breached", func(t *testing.T) {
+		subject := &events.SizeLimitedProjectCommandBuilder{
+			Limit:                 2,
+			ProjectCommandBuilder: delegate,
+		}
+
+		When(delegate.BuildPlanCommands(ctx, comment)).ThenReturn(expectedResult, nil)
+
+		result, err := subject.BuildPlanCommands(ctx, comment)
+
+		Ok(t, err)
+
+		Assert(t, len(result) == len(expectedResult), "size is expected")
+	})
+
+	t.Run("Limit not defined", func(t *testing.T) {
+		subject := &events.SizeLimitedProjectCommandBuilder{
+			Limit:                 events.InfiniteProjectsPerPR,
+			ProjectCommandBuilder: delegate,
+		}
+
+		When(delegate.BuildPlanCommands(ctx, comment)).ThenReturn(expectedResult, nil)
+
+		result, err := subject.BuildPlanCommands(ctx, comment)
+
+		Ok(t, err)
+
+		Assert(t, len(result) == len(expectedResult), "size is expected")
+	})
+}

server/server.go

@@ -426,7 +426,7 @@ func NewServer(userConfig UserConfig, config Config) (*Server, error) {
 		WorkingDir:            workingDir,
 		PreWorkflowHookRunner: runtime.DefaultPreWorkflowHookRunner{},
 	}
-	projectCommandBuilder := events.NewProjectCommandBuilder(
+	projectCommandBuilder := events.NewProjectCommandBuilderWithLimit(
 		policyChecksEnabled,
 		validator,
 		&events.DefaultProjectFinder{},
@@ -441,6 +441,7 @@ func NewServer(userConfig UserConfig, config Config) (*Server, error) {
 		userConfig.AutoplanFileList,
 		statsScope,
 		logger,
+		userConfig.MaxProjectsPerPR,
 	)
 
 	showStepRunner, err := runtime.NewShowStepRunner(terraformClient, defaultTfVersion)

server/user_config.go

@@ -45,6 +45,7 @@ type UserConfig struct {
 	HidePrevPlanComments       bool   `mapstructure:"hide-prev-plan-comments"`
 	LogLevel                   string `mapstructure:"log-level"`
 	ParallelPoolSize           int    `mapstructure:"parallel-pool-size"`
+	MaxProjectsPerPR           int    `mapstructure:"max-projects-per-pr"`
 	StatsNamespace             string `mapstructure:"stats-namespace"`
 	PlanDrafts                 bool   `mapstructure:"allow-draft-prs"`
 	Port                       int    `mapstructure:"port"`