Skip cloning PR repository in case of no projects configured in repo …

…config file were changed

cmd/server.go

@@ -73,6 +73,7 @@ const (
 	SilenceForkPRErrorsFlag    = "silence-fork-pr-errors"
 	SilenceVCSStatusNoPlans    = "silence-vcs-status-no-plans"
 	SilenceWhitelistErrorsFlag = "silence-whitelist-errors"
+	SkipCloneNoChanges         = "skip-clone-no-changes"
 	SlackTokenFlag             = "slack-token"
 	SSLCertFileFlag            = "ssl-cert-file"
 	SSLKeyFileFlag             = "ssl-key-file"
@@ -289,6 +290,10 @@ var boolFlags = map[string]boolFlag{
 			" This writes secrets to disk and should only be enabled in a secure environment.",
 		defaultValue: false,
 	},
+  SkipCloneNoChanges: {
+    description:  "Skips cloning the PR repo if there are no projects were changed in the PR.",
+    defaultValue: false,
+  },
 }
 var intFlags = map[string]intFlag{
 	PortFlag: {

cmd/server_test.go

@@ -82,6 +82,7 @@ var testFlags = map[string]interface{}{
 	SilenceForkPRErrorsFlag:    true,
 	SilenceWhitelistErrorsFlag: true,
 	SilenceVCSStatusNoPlans:    true,
+  SkipCloneNoChanges:         true,
 	SlackTokenFlag:             "slack-token",
 	SSLCertFileFlag:            "cert-file",
 	SSLKeyFileFlag:             "key-file",

server/events/project_command_builder.go

@@ -56,6 +56,7 @@ type DefaultProjectCommandBuilder struct {
 	GlobalCfg         valid.GlobalCfg
 	PendingPlanFinder *DefaultPendingPlanFinder
 	CommentBuilder    CommentBuilder
+  SkipCloneNoChanges bool
 }
 
 // See ProjectCommandBuilder.BuildAutoplanCommands.
@@ -96,39 +97,64 @@ func (p *DefaultProjectCommandBuilder) BuildApplyCommands(ctx *CommandContext, c
 // buildPlanAllCommands builds plan contexts for all projects we determine were
 // modified in this ctx.
 func (p *DefaultProjectCommandBuilder) buildPlanAllCommands(ctx *CommandContext, commentFlags []string, verbose bool) ([]models.ProjectCommandContext, error) {
-	// Need to lock the workspace we're about to clone to.
-	workspace := DefaultWorkspace
-	unlockFn, err := p.WorkingDirLocker.TryLock(ctx.BaseRepo.FullName, ctx.Pull.Num, workspace)
-	if err != nil {
-		ctx.Log.Warn("workspace was locked")
-		return nil, err
-	}
-	ctx.Log.Debug("got workspace lock")
-	defer unlockFn()
-
-	// We'll need the list of modified files.
-	modifiedFiles, err := p.VCSClient.GetModifiedFiles(ctx.BaseRepo, ctx.Pull)
-	if err != nil {
-		return nil, err
-	}
-	ctx.Log.Debug("%d files were modified in this pull request", len(modifiedFiles))
-
-	repoDir, _, err := p.WorkingDir.Clone(ctx.Log, ctx.BaseRepo, ctx.HeadRepo, ctx.Pull, workspace)
-	if err != nil {
-		return nil, err
-	}
-
-	// Parse config file if it exists.
-	hasRepoCfg, err := p.ParserValidator.HasRepoCfg(repoDir)
-	if err != nil {
-		return nil, errors.Wrapf(err, "looking for %s file in %q", yaml.AtlantisYAMLFilename, repoDir)
-	}
+  // We'll need the list of modified files.
+  modifiedFiles, err := p.VCSClient.GetModifiedFiles(ctx.BaseRepo, ctx.Pull)
+
+  if err != nil {
+    return nil, err
+  }
+  ctx.Log.Debug("%d files were modified in this pull request", len(modifiedFiles))
+
+  if p.SkipCloneNoChanges && p.VCSClient.IsSupportDownloadSingleFile(ctx.BaseRepo) {
+    hasRepoCfg, repoCfgData, err := p.VCSClient.DownloadRepoConfigFile(ctx.Pull)
+    if err != nil {
+      return nil, errors.Wrapf(err, "downloading %s", yaml.AtlantisYAMLFilename)
+    }
+
+    if hasRepoCfg {
+      repoCfg, err := p.ParserValidator.ParseRepoCfg(repoCfgData, "", p.GlobalCfg, ctx.BaseRepo.ID())
+      if err != nil {
+        return nil, errors.Wrapf(err, "parsing %s", yaml.AtlantisYAMLFilename)
+      }
+      ctx.Log.Info("successfully parsed remote %s file", yaml.AtlantisYAMLFilename)
+      matchingProjects, err := p.ProjectFinder.DetermineProjectsViaConfig(ctx.Log, modifiedFiles, repoCfg, "")
+      if err != nil {
+        return nil, err
+      }
+      ctx.Log.Info("%d projects are changed on MR %q based on their when_modified config", len(matchingProjects), ctx.Pull.Num)
+      if len(matchingProjects) == 0 {
+        ctx.Log.Info("skipping repo clone since no project was modified")
+        return []models.ProjectCommandContext{}, nil
+      }
+    }
+  }
+
+  // Need to lock the workspace we're about to clone to.
+  workspace := DefaultWorkspace
+
+  unlockFn, err := p.WorkingDirLocker.TryLock(ctx.BaseRepo.FullName, ctx.Pull.Num, workspace)
+  if err != nil {
+    ctx.Log.Warn("workspace was locked")
+    return nil, err
+  }
+  ctx.Log.Debug("got workspace lock")
+  defer unlockFn()
+
+  repoDir, _, err := p.WorkingDir.Clone(ctx.Log, ctx.BaseRepo, ctx.HeadRepo, ctx.Pull, workspace)
+  if err != nil {
+    return nil, err
+  }
+  // Parse config file if it exists.
+  hasRepoCfg, err := p.ParserValidator.HasRepoCfg(repoDir)
+  if err != nil {
+    return nil, errors.Wrapf(err, "looking for %s file in %q", yaml.AtlantisYAMLFilename, repoDir)
+  }
 
 	var projCtxs []models.ProjectCommandContext
 	if hasRepoCfg {
 		// If there's a repo cfg then we'll use it to figure out which projects
 		// should be planed.
-		repoCfg, err := p.ParserValidator.ParseRepoCfg(repoDir, p.GlobalCfg, ctx.BaseRepo.ID())
+		repoCfg, err := p.ParserValidator.ParseRepoCfg([]byte{}, repoDir, p.GlobalCfg, ctx.BaseRepo.ID())
 		if err != nil {
 			return nil, errors.Wrapf(err, "parsing %s", yaml.AtlantisYAMLFilename)
 		}
@@ -159,6 +185,7 @@ func (p *DefaultProjectCommandBuilder) buildPlanAllCommands(ctx *CommandContext,
 	return projCtxs, nil
 }
 
+
 // buildProjectPlanCommand builds a plan context for a single project.
 // cmd must be for only one project.
 func (p *DefaultProjectCommandBuilder) buildProjectPlanCommand(ctx *CommandContext, cmd *CommentCommand) (models.ProjectCommandContext, error) {
@@ -306,7 +333,7 @@ func (p *DefaultProjectCommandBuilder) getCfg(ctx *CommandContext, projectName s
 	}
 
 	var repoConfig valid.RepoCfg
-	repoConfig, err = p.ParserValidator.ParseRepoCfg(repoDir, p.GlobalCfg, ctx.BaseRepo.ID())
+	repoConfig, err = p.ParserValidator.ParseRepoCfg([]byte{}, repoDir, p.GlobalCfg, ctx.BaseRepo.ID())
 	if err != nil {
 		return
 	}

server/events/project_command_builder_internal_test.go

@@ -571,6 +571,7 @@ projects:
 				PendingPlanFinder: &DefaultPendingPlanFinder{},
 				CommentBuilder:    &CommentParser{},
 				GlobalCfg:         globalCfg,
+        SkipCloneNoChanges: false,
 			}
 
 			// We run a test for each type of command.

server/events/project_command_builder_test.go

@@ -143,6 +143,7 @@ projects:
 				PendingPlanFinder: &events.DefaultPendingPlanFinder{},
 				CommentBuilder:    &events.CommentParser{},
 				GlobalCfg:         valid.NewGlobalCfg(false, false, false),
+        SkipCloneNoChanges: false,
 			}
 
 			ctxs, err := builder.BuildAutoplanCommands(&events.CommandContext{
@@ -365,6 +366,7 @@ projects:
 					ProjectFinder:    &events.DefaultProjectFinder{},
 					CommentBuilder:   &events.CommentParser{},
 					GlobalCfg:        valid.NewGlobalCfg(true, false, false),
+          SkipCloneNoChanges: false,
 				}
 
 				var actCtxs []models.ProjectCommandContext
@@ -498,6 +500,7 @@ projects:
 				ProjectFinder:    &events.DefaultProjectFinder{},
 				CommentBuilder:   &events.CommentParser{},
 				GlobalCfg:        valid.NewGlobalCfg(true, false, false),
+        SkipCloneNoChanges: false,
 			}
 
 			ctxs, err := builder.BuildPlanCommands(
@@ -570,6 +573,7 @@ func TestDefaultProjectCommandBuilder_BuildMultiApply(t *testing.T) {
 		PendingPlanFinder: &events.DefaultPendingPlanFinder{},
 		CommentBuilder:    &events.CommentParser{},
 		GlobalCfg:         valid.NewGlobalCfg(false, false, false),
+    SkipCloneNoChanges: false,
 	}
 
 	ctxs, err := builder.BuildApplyCommands(
@@ -637,6 +641,7 @@ projects:
 		ProjectFinder:    &events.DefaultProjectFinder{},
 		CommentBuilder:   &events.CommentParser{},
 		GlobalCfg:        valid.NewGlobalCfg(true, false, false),
+    SkipCloneNoChanges: false,
 	}
 
 	ctx := &events.CommandContext{
@@ -699,6 +704,7 @@ func TestDefaultProjectCommandBuilder_EscapeArgs(t *testing.T) {
 				ProjectFinder:    &events.DefaultProjectFinder{},
 				CommentBuilder:   &events.CommentParser{},
 				GlobalCfg:        valid.NewGlobalCfg(true, false, false),
+        SkipCloneNoChanges: false,
 			}
 
 			var actCtxs []models.ProjectCommandContext
@@ -863,6 +869,7 @@ projects:
 				ProjectFinder:    &events.DefaultProjectFinder{},
 				CommentBuilder:   &events.CommentParser{},
 				GlobalCfg:        valid.NewGlobalCfg(true, false, false),
+        SkipCloneNoChanges: false,
 			}
 
 			actCtxs, err := builder.BuildPlanCommands(

server/events/vcs/azuredevops_client.go

@@ -364,3 +364,11 @@ func SplitAzureDevopsRepoFullName(repoFullName string) (owner string, project st
 	}
 	return repoFullName[:lastSlashIdx], "", repoFullName[lastSlashIdx+1:]
 }
+
+func (g *AzureDevopsClient) IsSupportDownloadSingleFile(repo models.Repo) bool {
+  return false
+}
+
+func (g *AzureDevopsClient) DownloadRepoConfigFile(pull models.PullRequest) (bool, []byte, error) {
+  return false, []byte{}, fmt.Errorf("Not Implemented")
+}

server/events/vcs/bitbucketcloud/client.go

@@ -243,3 +243,11 @@ func (b *Client) makeRequest(method string, path string, reqBody io.Reader) ([]b
 	}
 	return respBody, nil
 }
+
+func (b *Client) IsSupportDownloadSingleFile( models.Repo) bool {
+  return false
+}
+
+func (b *Client) DownloadRepoConfigFile(pull models.PullRequest) (bool, []byte, error) {
+  return false, []byte{}, fmt.Errorf("Not Implemented")
+}

server/events/vcs/bitbucketserver/client.go

@@ -311,3 +311,11 @@ func (b *Client) makeRequest(method string, path string, reqBody io.Reader) ([]b
 	}
 	return respBody, nil
 }
+
+func (b *Client) IsSupportDownloadSingleFile(repo models.Repo) bool {
+  return false
+}
+
+func (b *Client) DownloadRepoConfigFile(pull models.PullRequest) (bool, []byte, error) {
+  return false, []byte{}, fmt.Errorf("not implemented")
+}

server/events/vcs/client.go

@@ -38,4 +38,7 @@ type Client interface {
 	UpdateStatus(repo models.Repo, pull models.PullRequest, state models.CommitStatus, src string, description string, url string) error
 	MergePull(pull models.PullRequest) error
 	MarkdownPullLink(pull models.PullRequest) (string, error)
+
+  DownloadRepoConfigFile(pull models.PullRequest) (bool, []byte, error)
+	IsSupportDownloadSingleFile(repo models.Repo) bool
 }

server/events/vcs/github_client.go

@@ -16,8 +16,11 @@ package vcs
 import (
 	"context"
 	"fmt"
-	"net/url"
+  "github.com/runatlantis/atlantis/server/events/yaml"
+  "net/http"
+  "net/url"
 	"strings"
+	"encoding/base64"
 
 	"github.com/runatlantis/atlantis/server/events/models"
 	"github.com/runatlantis/atlantis/server/events/vcs/common"
@@ -324,3 +327,28 @@ func (g *GithubClient) MergePull(pull models.PullRequest) error {
 func (g *GithubClient) MarkdownPullLink(pull models.PullRequest) (string, error) {
 	return fmt.Sprintf("#%d", pull.Num), nil
 }
+
+
+func (g *GithubClient) DownloadRepoConfigFile(pull models.PullRequest) (bool, []byte, error) {
+  opt := github.RepositoryContentGetOptions{Ref: pull.BaseBranch}
+  fileContent, _, resp, err := g.client.Repositories.GetContents(g.ctx, pull.BaseRepo.Owner, pull.BaseRepo.Name, yaml.AtlantisYAMLFilename, &opt)
+
+  if resp.StatusCode == http.StatusNotFound {
+    return false, []byte{}, nil
+  }
+  if err != nil {
+    return true, []byte{}, err
+  }
+
+  decodedData, err := base64.StdEncoding.DecodeString(*fileContent.Content)
+  if err != nil {
+    return true, []byte{}, err
+  }
+
+  return true, decodedData, nil
+}
+
+func (g *GithubClient) IsSupportDownloadSingleFile(repo models.Repo) bool {
+  return true
+}
+

server/events/vcs/gitlab_client.go

@@ -14,19 +14,21 @@
 package vcs
 
 import (
-	"fmt"
-	"net"
-	"net/url"
-	"strings"
+  "fmt"
+  "github.com/runatlantis/atlantis/server/events/yaml"
+  "net"
+  "net/http"
+  "net/url"
+  "strings"
 
-	"github.com/runatlantis/atlantis/server/events/vcs/common"
+  "github.com/runatlantis/atlantis/server/events/vcs/common"
 
-	version "github.com/hashicorp/go-version"
-	"github.com/pkg/errors"
-	"github.com/runatlantis/atlantis/server/logging"
+  version "github.com/hashicorp/go-version"
+  "github.com/pkg/errors"
+  "github.com/runatlantis/atlantis/server/logging"
 
-	"github.com/runatlantis/atlantis/server/events/models"
-	gitlab "github.com/xanzy/go-gitlab"
+  "github.com/runatlantis/atlantis/server/events/models"
+  gitlab "github.com/xanzy/go-gitlab"
 )
 
 type GitlabClient struct {
@@ -263,3 +265,23 @@ func MustConstraint(constraint string) version.Constraints {
 	}
 	return c
 }
+
+
+func (g *GitlabClient) DownloadRepoConfigFile(pull models.PullRequest) (bool, []byte, error) {
+  opt := gitlab.GetRawFileOptions{Ref: gitlab.String(pull.BaseBranch)}
+
+  bytes, resp, err := g.Client.RepositoryFiles.GetRawFile(pull.BaseRepo.ID(), yaml.AtlantisYAMLFilename, &opt)
+  if resp.StatusCode == http.StatusNotFound {
+    return false, []byte{}, nil
+  }
+
+  if err != nil {
+    return true, []byte{}, err
+  }
+
+  return true, bytes, nil
+}
+
+func (g *GitlabClient) IsSupportDownloadSingleFile(repo models.Repo) bool {
+  return true
+}

server/events/vcs/not_configured_vcs_client.go

@@ -53,3 +53,11 @@ func (a *NotConfiguredVCSClient) MarkdownPullLink(pull models.PullRequest) (stri
 func (a *NotConfiguredVCSClient) err() error {
 	return fmt.Errorf("atlantis was not configured to support repos from %s", a.Host.String())
 }
+
+func (a *NotConfiguredVCSClient) IsSupportDownloadSingleFile(repo models.Repo) bool {
+  return false
+}
+
+func (a *NotConfiguredVCSClient) DownloadRepoConfigFile(pull models.PullRequest) (bool, []byte, error) {
+  return true, []byte{}, a.err()
+}

server/events/vcs/proxy.go

@@ -83,3 +83,11 @@ func (d *ClientProxy) MergePull(pull models.PullRequest) error {
 func (d *ClientProxy) MarkdownPullLink(pull models.PullRequest) (string, error) {
 	return d.clients[pull.BaseRepo.VCSHost.Type].MarkdownPullLink(pull)
 }
+
+func (d *ClientProxy) DownloadRepoConfigFile(pull models.PullRequest) (bool, []byte, error) {
+  return d.clients[pull.BaseRepo.VCSHost.Type].DownloadRepoConfigFile(pull)
+}
+
+func (d *ClientProxy) IsSupportDownloadSingleFile(repo models.Repo) bool {
+  return d.clients[repo.VCSHost.Type].IsSupportDownloadSingleFile(repo)
+}