What causes "could not retrieve list of apps from spinnaker url %s: %v" in Netflix/chaosmonkey?

Check network connectivity to the endpoint: curl --cert/--key from the chaosmonkey host

could not retrieve list of apps from spinnaker url %s: %v

Error message

could not retrieve list of apps from spinnaker url %s: %v

What it means

AppNames() lists all applications by calling the Spinnaker apps endpoint. This error wraps any failure of the underlying HTTP GET (s.client.Get(url)), typically a transport/TLS/connectivity problem, with the Spinnaker apps URL included for diagnosis.

Source

Thrown at spinnaker/spinnaker.go:350

				}

				data[account].Clusters[clusterName][region][asgName] = make([]D.InstanceID, len(asg.Instances))

				for i, instance := range asg.Instances {
					data[account].Clusters[clusterName][region][asgName][i] = D.InstanceID(instance.Name)
				}
			}
		}
	}
	return D.NewApp(appName, data), nil
}

// AppNames returns list of names of all apps
func (s Spinnaker) AppNames() (appnames []string, err error) {
	url := s.appsURL()
	resp, err := s.client.Get(url)
	if err != nil {
		return nil, fmt.Errorf("could not retrieve list of apps from spinnaker url %s: %v", url, err)
	}

	defer func() {
		if cerr := resp.Body.Close(); cerr != nil && err == nil {
			err = fmt.Errorf("failed to close response body from %s: %v", url, err)
		}
	}()

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read body when retrieving spinnaker app names from %s: %v", url, err)
	}
	var apps []spinnakerApp
	err = json.Unmarshal(body, &apps)
	if err != nil {
		return nil, fmt.Errorf("could not parse spinnaker apps list from %s: body: \"%s\": %v", url, string(body), err)
	}

View on GitHub (pinned to eaa28fb761)

Solutions

Check network connectivity to the endpoint: curl --cert/--key <appsURL> from the chaosmonkey host
Verify spinnaker.endpoint in the chaosmonkey config is correct and reachable
Confirm the TLS client certificate is valid and accepted (test handshake with openssl s_client)
Check for proxy/firewall/DNS issues on the host running chaosmonkey

Defensive patterns

Strategy: retry

Validate before calling

// Pre-flight connectivity check:
resp, err := http.Get(endpoint)
if err != nil {
	log.Fatalf("spinnaker endpoint %s unreachable: %v", endpoint, err)
}
resp.Body.Close()

Try / catch

names, err := spin.AppNames()
if err != nil {
	if strings.Contains(err.Error(), "could not retrieve list of apps") {
		// transient network problem: retry with backoff
		names, err = retryWithBackoff(3, spin.AppNames)
	}
	if err != nil { return err }
}

Prevention

Verify spinnaker.endpoint reachability from the chaosmonkey host
Test TLS client cert auth before production runs
Monitor Spinnaker gate availability
Set sane HTTP timeouts and allow retries for transient failures

When it happens

Trigger: Calling AppNames() when s.client.Get(appsURL()) returns a non-nil error: DNS failure, connection refused/timeout, TLS handshake failure with the client cert, or an invalid endpoint URL.

Common situations: Spinnaker endpoint unreachable or firewall blocking; wrong spinnaker.endpoint in config; TLS client cert (p12/x509) not accepted by the server; corporate proxy interference; Spinnaker gate down.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

AI-assisted analysis of Netflix/chaosmonkey@eaa28fb761 (2026-09-03). Data as JSON: /api/errors/6b929dfb54cac67a. Report an issue: GitHub.