fix(pkg/downloader): resolve repo alias before checking digests on build

`Update()` gets repo names before resolving a lock file by calling
`resolveRepoNames(req)`. But that method changes aliased repo URLs into
the actual URLs. That makes digests from `helm update` and `helm build`
be different for each other.

To make them in sync, setting actual (resolved) repo URLs into the
loaded chart during `helm build` is necessary. Thus, this commit adds an
extra step in the `Build()` implementation.

For comments, this commit also changes the name of `getRepoNames()` into
`resolveRepoNames()` to avoid misunderstanding since getters are
expected to not mutate their input data in general.

Signed-off-by: Hang Park <hangpark@kaist.ac.kr>

pkg/downloader/manager.go

@@ -79,7 +79,12 @@ func (m *Manager) Build() error {
 		return m.Update()
 	}
 
+	// Check that all of the repos we're dependent on actually exist.
 	req := c.Metadata.Dependencies
+	if _, err := m.resolveRepoNames(req); err != nil {
+		return err
+	}
+
 	if sum, err := resolver.HashReq(req, lock.Dependencies); err != nil || sum != lock.Digest {
 		return errors.New("Chart.lock is out of sync with Chart.yaml")
 	}
@@ -120,7 +125,7 @@ func (m *Manager) Update() error {
 
 	// Check that all of the repos we're dependent on actually exist and
 	// the repo index names.
-	repoNames, err := m.getRepoNames(req)
+	repoNames, err := m.resolveRepoNames(req)
 	if err != nil {
 		return err
 	}
@@ -372,8 +377,9 @@ Loop:
 	return nil
 }
 
-// getRepoNames returns the repo names of the referenced deps which can be used to fetch the cahced index file.
-func (m *Manager) getRepoNames(deps []*chart.Dependency) (map[string]string, error) {
+// resolveRepoNames returns the repo names of the referenced deps which can be used to fetch the cached index file
+// and replaces aliased repository URLs into resolved URLs in dependencies.
+func (m *Manager) resolveRepoNames(deps []*chart.Dependency) (map[string]string, error) {
 	rf, err := loadRepoConfig(m.RepositoryConfig)
 	if err != nil {
 		if os.IsNotExist(err) {

pkg/downloader/manager_test.go

@@ -161,7 +161,7 @@ func TestGetRepoNames(t *testing.T) {
 	}
 
 	for _, tt := range tests {
-		l, err := m.getRepoNames(tt.req)
+		l, err := m.resolveRepoNames(tt.req)
 		if err != nil {
 			if tt.err {
 				continue