osb-reverse-proxy

April 4, 2022 · View on GitHub

A reverse http proxy tailored for open service broker (OSB) api endpoints

Introduction

Some osb-clients such as Cloud Foundry do not support brokers that need to be reached through the http(s) proxy.

osb-reverse-proxy provides a generic reverse proxy to front service brokers.

The following ascii art diagram illustrates the network path when a developer requests a cf create-service command

developer -> Cloud Foundry cloud controller -> osb-reverse-proxy -> http proxy -> service broker

Configuration

The broker is configureable through usual spring-boot configuration style. The OsbReverseProxyProperties.java document the supported properties.

Osb-reverse-proxy is designed to support multiple hostnames. The property (whiteListedOsbDomain) controls which hostnames are whitelisted to accept OSB API calls. The host may be used to expose operation endpoints, including spring-boot actuator endpoints

Actuator endpoints

Osb-reverse-proxy embeds spring boot actuator endpoints ("beans,conditions,info,gateway,health,httptrace,loggers,metrics,threaddump") protected by a user configured by the spring.security.user.name and spring.security.user.password environment variables. See SecurityConfigTest.java and application.yml for full details.

This enables dynamic log level assignment through

curl -vvv -X POST -u redacted-user:redacted-password https://osb-reverse-proxy.mydomain.org/actuator/loggers/logging.level.org.springframework.cloud.gateway.debug -X POST -H 'Content-Type: application/json' -d '{"configuredLevel": "trace"}'

Sample relevant loggers are also available in the verbose osb-reverse-proxy spring profile. This may be set by setting the SPRING_PROFILES_ACTIVE env var to verbose.

Osb api logs

Osb-reverse proxy collects and serves logs of OSB API requests using an extension of springboot actuator httptrace support with request and response body added as http headers

$ curl -u redacted-user:redacted-password https://osb-reverse-proxy.redacted-domain.org/actuator/httptrace | jq .
[
    {
      "timestamp": "2020-10-27T11:22:53.529Z",
      "principal": null,
      "session": null,
      "request": {
        "method": "GET",
        "uri": "https://osb-reverse-proxy.internal-controlplane-cf.paas/v2/catalog",
        "headers": {
          "X-Cf-Instanceid": [
            "fa7644e2-7faf-4bb7-49a0-b3aa"
          ],
          "X-Broker-Api-Version": [
            "2.15"
          ],
          "Accept": [
            "application/json"
          ],
          "X-Forwarded-Proto": [
            "https"
          ],
          "X-Broker-Api-Request-Identity": [
            "e452c1f5-fdfe-4e47-b754-fbb31665f6ad"
          ],
          "User-Agent": [
            "HTTPClient/1.0 (2.8.3, ruby 2.5.5 (2019-03-15))"
          ],
          "X-Request-Start": [
            "1603797773450"
          ],
          "X-Broker-Api-Originating-Identity": [
            "cloudfoundry ewogICJ1c2VyX2lkIjogIjBkMDIxMTdiLWFhMjEtNDNlMi1iMzVlLThhZDZmODIyMzUxOSIKfQ=="
          ],
          "Host": [
            "osb-reverse-proxy.internal-controlplane-cf.paas"
          ],
          "X-Vcap-Request-Id": [
            "4ae90935-358e-45f4-6cde-83fca76bc6e7"
          ],
          "Date": [
            "Tue, 27 Oct 2020 11:22:53 GMT"
          ],
          "X-Cf-Instanceindex": [
            "0"
          ],
          "B3": [
            "d23918d4d277397c-d23918d4d277397c"
          ],
          "X-Api-Info-Location": [
            "api.redacted-cf-api-domain.org/v2/info"
          ],
          "X-B3-Spanid": [
            "d23918d4d277397c"
          ],
          "X-Cf-Applicationid": [
            "1c5cce4c-6f2c-439d-b647-8cb09d453c16"
          ],
          "X-Forwarded-For": [
            "192.168.35.66, 192.168.35.50"
          ],
          "X-B3-Traceid": [
            "d23918d4d277397c"
          ]
        },
        "remoteAddress": null
      },
      "response": {
        "status": 200,
        "headers": {
          "X-Content-Type-Options": [
            "nosniff"
          ],
          "response_body": [
            "{\"services\":[{\"name\":\"overview-service\",\"description\":\"Provides an ..."
          ],
          "Pragma": [
            "no-cache"
          ],
          "X-Vcap-Request-Id": [
            "ceef1981-6c91-4d51-701a-17f1f6b5a54c"
          ],
          "Date": [
            "Tue, 27 Oct 2020 11:22:53 GMT"
          ],
          "Referrer-Policy": [
            "no-referrer"
          ],
          "X-Frame-Options": [
            "DENY"
          ],
          "Strict-Transport-Security": [
            "max-age=31536000 ; includeSubDomains"
          ],
          "Cache-Control": [
            "no-cache, no-store, max-age=0, must-revalidate"
          ],
          "Etag": [
            "W/\"37ea-JtM0TfwLN4WsJxfxq42Qe2dtP7U\""
          ],
          "Expires": [
            "0"
          ],
          "X-XSS-Protection": [
            "1 ; mode=block"
          ],
          "Content-Length": [
            "14314"
          ],
          "X-Powered-By": [
            "Express"
          ],
          "Content-Type": [
            "application/json; charset=utf-8"
          ]
        }
      },
      "timeTaken": 0
    },
[...]
]

See sample jq query syntax below:

                    # filter PUT request                      # filter service binding uris 
jq -r '.traces[] | select (.request.method=="PUT") | select ( .request.uri|test(".binding"))'
                    # filter PUT request                      # filter status
jq -r '.traces[] | select (.request.method=="PUT" and .response.status!=200)'

Warning: the following two issues may require to query the httptrace endpoint multiple times:

Potential workaround by storing httptrace output in a local file and use jq to

merge files into a single array
remove duplicates (using unique)

Workaround:

#repeat in a loop
curl [...] > trace-`date +%Y-%m-%d.%H:%M:%S`.json
# remove duplicates and filter
jq -s . trace*.json | jq 'unique'

which results in paas-templates context to

# on bosh-cli
log-credhub
# repeat multiple times to reach both osb-reverse-proxy instances
curl -u serviceProvider:$(credhub-get /ops-depls/cf-apps-deployments/osb-reverse-proxy-4/service-provider-password) https://osb-reverse-proxy-4.internal-controlplane-cf.paas/actuator/httptrace | jq . > trace-`date +%Y-%m-%d.%H:%M:%S`.json

jq -s . trace*.json | jq -r 'unique' | jq -r '.[].traces[] | select (.request.method=="PUT")' | less
# clean up traces
rm trace*.json

Random Jq references:

https://stedolan.github.io/jq/manual/ jq manual
https://www.baeldung.com/linux/jq-command-json
https://gist.github.com/olih/f7437fb6962fb3ee9fe95bda8d2c8fa4 jq-cheetsheet.md

Deploying

This reverse proxy is a java springboot app which can be deployed onto cloufoundry using the java buildpack.

See the expected environment variables in the ApplicationTest

In this initial version, the jar distribution merely contains a packaged version of spring-cloud-gateway and is designed to be configured using additional springboot configuration matching the spring cloud gateway configuration

Multi-tenancy support with osb-specific configuration is planned. See TODO for details.

Releasing

manually edit the version in build.gradle (e.g version=0.2.0), commit & push
git tag v0.2.0 -a -m "0.2.0 release"
git push origin v0.2.0
let circle ci build and upload the binaries to github
edit the github release to complete release notes
manually edit the version in gradle.properties, commit & push e.g. version=0.2.0.BUILD-SNAPSHOT