Git resolver: validate repo URL

pkg/resolution/resolver/git/resolver.go

@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"regexp"
 	"strings"
 	"time"
 
@@ -142,6 +143,15 @@ func (r *Resolver) Resolve(ctx context.Context, origParams []pipelinev1.Param) (
 	return r.resolveAPIGit(ctx, params)
 }
 
+// validateRepoURL validates if the given URL is a valid git, http, https URL or
+// starting with a / (a local repository).
+func validateRepoURL(url string) bool {
+	// Explanation:
+	pattern := `^(/|[^@]+@[^:]+|(git|https?)://)`
+	re := regexp.MustCompile(pattern)
+	return re.MatchString(url)
+}
+
 func (r *Resolver) resolveAPIGit(ctx context.Context, params map[string]string) (framework.ResolvedResource, error) {
 	// If we got here, the "repo" param was specified, so use the API approach
 	scmType, serverURL, err := r.getSCMTypeAndServerURL(ctx, params)
@@ -502,7 +512,11 @@ func populateDefaultParams(ctx context.Context, params []pipelinev1.Param) (map[
 		return nil, fmt.Errorf("missing required git resolver params: %s", strings.Join(missingParams, ", "))
 	}
 
-	// TODO(sbwsg): validate repo url is well-formed, git:// or https://
+	// validate the url params if we are not using the SCM API
+	if paramsMap[repoParam] == "" && paramsMap[orgParam] == "" && !validateRepoURL(paramsMap[urlParam]) {
+		return nil, fmt.Errorf("invalid git repository url: %s", paramsMap[urlParam])
+	}
+
 	// TODO(sbwsg): validate pathInRepo is valid relative pathInRepo
 	return paramsMap, nil
 }

pkg/resolution/resolver/git/resolver_test.go

@@ -60,16 +60,84 @@ func TestGetSelector(t *testing.T) {
 }
 
 func TestValidateParams(t *testing.T) {
-	resolver := Resolver{}
-
-	paramsWithRevision := map[string]string{
-		urlParam:      "http://foo",
-		pathParam:     "bar",
-		revisionParam: "baz",
+	tests := []struct {
+		name    string
+		wantErr string
+		params  map[string]string
+	}{
+		{
+			name: "params with revision",
+			params: map[string]string{
+				urlParam:      "http://foo/bar/hello/moto",
+				pathParam:     "bar",
+				revisionParam: "baz",
+			},
+		},
+		{
+			name: "https url",
+			params: map[string]string{
+				urlParam:      "https://foo/bar/hello/moto",
+				pathParam:     "bar",
+				revisionParam: "baz",
+			},
+		},
+		{
+			name: "https url with username password",
+			params: map[string]string{
+				urlParam:      "https://user:pass@foo/bar/hello/moto",
+				pathParam:     "bar",
+				revisionParam: "baz",
+			},
+		},
+		{
+			name: "git server url",
+			params: map[string]string{
+				urlParam:      "git://repo/hello/moto",
+				pathParam:     "bar",
+				revisionParam: "baz",
+			},
+		},
+		{
+			name: "git url from a local repository",
+			params: map[string]string{
+				urlParam:      "/tmp/repo",
+				pathParam:     "bar",
+				revisionParam: "baz",
+			},
+		},
+		{
+			name: "git url from a git ssh repository",
+			params: map[string]string{
+				urlParam:      "git@host.com:foo/bar",
+				pathParam:     "bar",
+				revisionParam: "baz",
+			},
+		},
+		{
+			name: "bad url",
+			params: map[string]string{
+				urlParam:      "foo://bar",
+				pathParam:     "path",
+				revisionParam: "revision",
+			},
+			wantErr: "invalid git repository url: foo://bar",
+		},
 	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			resolver := Resolver{}
+			err := resolver.ValidateParams(context.Background(), toParams(tt.params))
+			if tt.wantErr == "" {
+				if err != nil {
+					t.Fatalf("unexpected error validating params: %v", err)
+				}
+				return
+			}
 
-	if err := resolver.ValidateParams(context.Background(), toParams(paramsWithRevision)); err != nil {
-		t.Fatalf("unexpected error validating params: %v", err)
+			if d := cmp.Diff(tt.wantErr, err.Error()); d != "" {
+				t.Errorf("unexpected error: %s", diff.PrintWantGot(d))
+			}
+		})
 	}
 }