graph TD
    req(Request Initiated)
    resp(Response closed)

    subgraph RedirectToHTTPS
        isRDHTTPs{Is redirect to HTTPs Enabled?}
        requestNeedsRedirect{Request is HTTP or X-Forwarded-Proto not HTTPS}
        redirectToHTTPS(Send redirect to HTTPs)
        rdHTTPSNext(Send to next server)
    end

    isGCPHealthCheck{Is GCP HealthCheck enabled?}

    subgraph GCPHealthCheck
        livenessCheck{Request path is /liveness_check}
        readinessCheck{Request path is /readiness_check}
        gcpUserAgent{Path is / and user agent is 'GoogleHC/1.0'}
        gcpOk(Send OK response)
        gcpNext(Send to next server)
    end

    req --> isRDHTTPs

    %% RedirectToHTTPS
    isRDHTTPs -- yes --> requestNeedsRedirect
    isRDHTTPs -- no --> rdHTTPSNext
    requestNeedsRedirect -- yes --> redirectToHTTPS
    requestNeedsRedirect -- no --> rdHTTPSNext
    redirectToHTTPS --> resp

    rdHTTPSNext --> isGCPHealthCheck

    %% GCPHealthCheck
    livenessCheck -- yes --> gcpOk
    livenessCheck -- no --> readinessCheck
    readinessCheck -- yes --> gcpOk
    readinessCheck -- no --> gcpUserAgent
    gcpUserAgent -- yes --> gcpOk
    gcpUserAgent -- no --> gcpNext
    gcpOk --> resp
    isGCPHealthCheck -- yes --> livenessCheck