path: root/guix-build-coordinator/client-communication.scm

;;; Guix Build Coordinator
;;;
;;; Copyright © 2020 Christopher Baines <mail@cbaines.net>
;;;
;;; This file is part of the guix-build-coordinator.
;;;
;;; The Guix Build Coordinator is free software; you can redistribute
;;; it and/or modify it under the terms of the GNU General Public
;;; License as published by the Free Software Foundation; either
;;; version 3 of the License, or (at your option) any later version.
;;;
;;; The Guix Build Coordinator is distributed in the hope that it will
;;; be useful, but WITHOUT ANY WARRANTY; without even the implied
;;; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
;;; See the GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with the guix-data-service.  If not, see
;;; <http://www.gnu.org/licenses/>.

(define-module (guix-build-coordinator client-communication)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-19)
  #:use-module (srfi srfi-43)
  #:use-module (srfi srfi-71)
  #:use-module (ice-9 format)
  #:use-module (ice-9 match)
  #:use-module (ice-9 streams)
  #:use-module (ice-9 exceptions)
  #:use-module (rnrs bytevectors)
  #:use-module (json)
  #:use-module (logging logger)
  #:use-module (gcrypt random)
  #:use-module (web uri)
  #:use-module (web client)
  #:use-module (web request)
  #:use-module (web response)
  #:use-module (system repl error-handling)
  #:use-module (guix store)
  #:use-module (guix derivations)
  #:use-module (guix-build-coordinator utils)
  #:use-module (guix-build-coordinator utils fibers)
  #:use-module (guix-build-coordinator datastore)
  #:use-module (guix-build-coordinator coordinator)
  #:export (start-client-request-server

            send-submit-build-request
            send-cancel-build-request
            send-update-build-priority-request
            fold-builds
            request-build-details
            request-output-details
            request-agent-details
            request-agent-build-allocation-plan
            request-agents-list
            request-failed-builds-with-blocking-count-list
            request-setup-failures
            send-create-agent-request
            send-agent-set-active-request
            send-create-agent-password-request
            send-create-dynamic-auth-token-request
            send-replace-agent-tags-request))

(define (start-client-request-server secret-key-base
                                     host
                                     port
                                     build-coordinator)
  (run-server/patched
   (lambda (request body)
     (log-msg (build-coordinator-logger build-coordinator)
              'INFO
              (format #f "~4a ~a\n"
                      (request-method request)
                      (uri-path (request-uri request))))
     (apply values
            (controller request
                        (cons (request-method request)
                              (split-and-decode-uri-path
                               (uri-path (request-uri request))))
                        body
                        secret-key-base
                        build-coordinator)))
   #:host host
   #:port port))

(define (controller request
                    method-and-path-components
                    raw-body
                    secret-key-base
                    build-coordinator)
  (define datastore
    (build-coordinator-datastore build-coordinator))

  (define body
    (if raw-body
        (json-string->scm (utf8->string raw-body))
        '()))

  (define (controller-thunk)
    (match method-and-path-components
      (('GET "build" uuid)
       (match (datastore-find-build datastore uuid)
         (#f
          (render-json '((error . "no build found"))
                       #:code 404))
         (build-details
          (let ((derivation-inputs
                 (map
                  (lambda (derivation-input-details)
                    (let ((builds (datastore-list-builds-for-output
                                   datastore
                                   (assq-ref derivation-input-details
                                             'output))))
                      `(,@derivation-input-details
                        (builds . ,(list->vector builds)))))
                  (datastore-find-derivation-inputs
                   datastore
                   (assq-ref build-details 'derivation-name))))
                (setup-failures
                 (map
                  (lambda (setup-failure)
                    `(,@setup-failure
                      ,@(if (string=? (assq-ref setup-failure 'failure-reason)
                                      "missing_inputs")
                            `((missing-inputs
                               . ,(list->vector
                                   (map
                                    (lambda (missing-input)
                                      (let ((builds-for-missing-input
                                             (datastore-list-builds-for-output
                                              datastore
                                              missing-input)))
                                        `((missing-input . ,missing-input)
                                          (builds . ,(list->vector
                                                      builds-for-missing-input)))))
                                    (datastore-list-setup-failure-missing-inputs
                                     datastore
                                     (assq-ref setup-failure 'id))))))
                            '())))
                  (datastore-list-setup-failures-for-build
                   datastore
                   (assq-ref build-details 'uuid))))
                (tags
                 (datastore-fetch-build-tags datastore uuid))
                (result
                 (datastore-find-build-result datastore uuid)))
            (render-json
             `(,@(alist-delete
                  'created-at
                  (alist-delete
                   'end-time
                   build-details))
               ,@(if (assq-ref build-details 'processed)
                     '()
                    (datastore-find-unprocessed-build-entry datastore uuid))
               (created-at        . ,(or (and=>
                                          (assq-ref build-details 'created-at)
                                          (lambda (time)
                                            (strftime "%F %T" time)))
                                         'null))
               (end-time          . ,(or (and=>
                                          (assq-ref build-details 'end-time)
                                          (lambda (time)
                                            (strftime "%F %T" time)))
                                         'null))
               (tags              . ,(vector-map
                                      (lambda (_ tag)
                                        (match tag
                                          ((key . value)
                                           `((key   . ,key)
                                             (value . ,value)))))
                                      tags))
               ,@(or (and=> result
                            (lambda (result)
                              `((result . ,result))))
                     '())
               (derivation-inputs . ,(list->vector derivation-inputs))
               (setup-failures    . ,(list->vector setup-failures))))))))
      (('POST "build" uuid "cancel")
       (let ((query-parameters (request-query-parameters request)))
         (render-json
          `((result
             .
             ,(cancel-build build-coordinator uuid
                            #:ignore-if-build-required-by-another?
                            (string=? (or (assq-ref
                                           query-parameters
                                           'ignore-if-build-required-by-another)
                                          "")
                                      "true")
                            #:skip-updating-derived-priorities?
                            (string=? (or
                                       (assq-ref query-parameters
                                                 'skip-updating-derived-priorities)
                                       "")
                                      "true")))))))
      (('POST "build" uuid "update-priority")
       (let ((query-parameters (request-query-parameters request)))
         (update-build-priority
          build-coordinator
          uuid
          (assoc-ref body "new_priority")
          #:skip-updating-derived-priorities?
          (string=? (or
                     (assq-ref query-parameters
                               'skip-updating-derived-priorities)
                     "")
                    "true")
          #:override-derived-priority
          (assoc-ref body "override_derived_priority"))

         (render-json
          `((result . "build-priority-updated")))))
      (('GET "builds" "blocking")
       (let ((query-parameters (request-query-parameters request)))
         (render-json
          `((builds
             . ,(list->vector
                 (datastore-list-failed-builds-with-blocking-count
                  datastore
                  (assq-ref query-parameters 'system)
                  #:include-cancelled?
                  (assq-ref query-parameters 'include_cancelled?))))))))
      (('GET "output" output-components ...)
       (let* ((output (string-append
                       "/" (string-join output-components "/")))
              (builds (datastore-list-builds-for-output datastore
                                                        output)))
         (render-json
          `((builds . ,(list->vector builds))))))
      (('GET "agents")
       (render-json
        `((agents
           . ,(list->vector
               (map (lambda (agent)
                      `(,@agent
                        (allocated_builds
                         . ,(list->vector
                             (datastore-list-agent-builds
                              datastore
                              (assq-ref agent 'uuid))))
                        (tags . ,(vector-map
                                  (match-lambda*
                                    ((index (key . value))
                                     `((key   . ,key)
                                       (value . ,value))))
                                  (datastore-fetch-agent-tags
                                   datastore
                                   (assq-ref agent 'uuid))))
                        (requested_systems
                         . ,(list->vector
                             (datastore-agent-requested-systems
                              datastore
                              (assq-ref agent 'uuid))))))
                    (datastore-list-agents datastore)))))))
      (('POST "agents")
       (let ((uuid (new-agent
                    datastore
                    #:requested-uuid (assoc-ref body "requested-uuid")
                    #:description (assoc-ref body "description"))))
         (render-json
          `((agent-id . ,uuid)))))
      (('POST "dynamic-auth-tokens")
       (let ((token (random-token)))
         (datastore-insert-dynamic-auth-token datastore token)
         (render-json
          `((token . ,token)))))
      (('GET "agent" agent-id)
       (let ((agent-details (datastore-find-agent datastore agent-id)))
         (render-json
          `((id . ,agent-id)
            ,@agent-details
            (tags                  . ,(vector-map
                                       (lambda (_ tag)
                                         (match tag
                                           ((key . value)
                                            `((key   . ,key)
                                              (value . ,value)))))
                                       (datastore-fetch-agent-tags
                                        datastore
                                        agent-id)))
            (allocated_builds      . ,(list->vector
                                       (datastore-list-agent-builds
                                        datastore
                                        agent-id)))))))
      (('GET "agent" agent-id (or "build-allocation-plan"
                                  ;; TODO Remove _ variant
                                  "build_allocation_plan"))
       (let ((agent-details (datastore-find-agent datastore agent-id)))
         (render-json
          `((build_allocation_plan
             . ,(list->vector
                 (datastore-list-allocation-plan-builds
                  datastore
                  agent-id)))))))
      (('POST "agent" agent-id "passwords")
       (let ((password (new-agent-password
                        datastore
                        #:agent agent-id)))
         (render-json
          `((new-password . ,password)))))
      (('POST "agent" agent-id "tags")
       (let ((agent-details (datastore-find-agent datastore agent-id)))
         (if agent-details
             (begin
               (datastore-replace-agent-tags
                datastore
                agent-id
                (vector-map
                 (lambda (_ tag)
                   `((key   . ,(assoc-ref tag "key"))
                     (value . ,(assoc-ref tag "value"))))
                 (assoc-ref body "tags")))
               (render-json
                `((result . success))))
             (render-json
              `((error . 404))
              #:code 404))))
      (('POST "agent" agent-id "active")
       (let ((agent-details (datastore-find-agent datastore agent-id)))
         (if agent-details
             (let ((active? (match (assoc "active" body)
                              (("active" . active?) active?))))
               (if (boolean? active?)
                   (begin
                     (set-agent-active build-coordinator
                                       agent-id
                                       active?)
                     (render-json
                      `((result . success))))
                   (render-json
                    `((error . "active must be a boolean"))
                    #:code 400)))
             (render-json
              `((error . 404))
              #:code 404))))
      (('GET "setup-failures")
       (let ((query-parameters (request-query-parameters request)))
         (render-json
          `((setup_failures
             . ,(hash-map->list
                 (lambda (k v)
                   (cons k (list->vector v)))
                 (datastore-fetch-setup-failures
                  datastore
                  #:agent-id (assq-ref query-parameters 'agent-id))))))))
      (('GET "builds")
       (let* ((query-parameters (request-query-parameters request))
              (fold-builds-args
               (list
                #:tags
                (filter-map (match-lambda
                              ((key . value)
                               (if (eq? key 'tag)
                                   (match (string-split value #\:)
                                     ((tag-key tag-value)
                                      (cons tag-key tag-value))
                                     ((tag-key) tag-key))
                                   #f)))
                            query-parameters)
                #:not-tags
                (filter-map (match-lambda
                              ((key . value)
                               (if (eq? key 'not_tag)
                                   (match (string-split value #\:)
                                     ((tag-key tag-value)
                                      (cons tag-key tag-value))
                                     ((tag_key) tag_key))
                                   #f)))
                            query-parameters)
                #:systems
                (filter-map (match-lambda
                              ((key . value)
                               (if (eq? key 'system)
                                   value
                                   #f)))
                            query-parameters)
                #:not-systems
                (filter-map (match-lambda
                              ((key . value)
                               (if (eq? key 'not-system)
                                   value
                                   #f)))
                            query-parameters)
                #:processed
                (match (assq 'processed query-parameters)
                  ((_ . val)
                   (string=? val "true"))
                  (#f 'unset))
                #:canceled
                (match (assq 'canceled query-parameters)
                  ((_ . val)
                   (string=? val "true"))
                  (#f 'unset))
                #:priority->
                (or (and=> (assq-ref query-parameters 'priority_gt)
                           string->number)
                    'unset)
                #:priority-<
                (or (and=> (assq-ref query-parameters 'priority_lt)
                           string->number)
                    'unset)
                #:relationship
                (or (and=> (assq-ref query-parameters 'relationship)
                           string->symbol)
                    'unset)
                #:after-id
                (assq-ref query-parameters 'after_id)
                #:limit
                (and=> (assq-ref query-parameters 'limit)
                       string->number))))

         (list
          (build-response
           #:code 200
           #:headers '((content-type . (application/json-seq))))
          (lambda (port)
            (apply datastore-fold-builds
                   datastore
                   (lambda (build-details _)
                     (scm->json-seq
                      `((,@(alist-delete
                            'created-at
                            (alist-delete
                             'end-time
                             build-details))
                         (created-at        . ,(or
                                                (and=>
                                                 (assq-ref build-details 'created-at)
                                                 (lambda (time)
                                                   (strftime "%F %T" time)))
                                                'null))
                         (end-time          . ,(or (and=>
                                                    (assq-ref build-details 'end-time)
                                                    (lambda (time)
                                                      (strftime "%F %T" time)))
                                                   'null))
                         (tags              . ,(vector-map
                                                (lambda (_ tag)
                                                  (match tag
                                                    ((key . value)
                                                     `((key   . ,key)
                                                       (value . ,value)))))
                                                (datastore-fetch-build-tags
                                                 datastore
                                                 (assq-ref build-details 'uuid))))))
                      port)
                     #t)
                   #t
                   fold-builds-args)))))
      (('POST "builds")
       (let ((derivation-file (assoc-ref body "derivation"))
             (substitute-urls
              (and=> (assoc-ref body "substitute-urls")
                     vector->list)))
         (unless (string? derivation-file)
           (raise-exception
            (make-exception-with-message
             (simple-format #f "derivation must be a string: ~A\n"
                            derivation))))

         (define (read-drv/substitute derivation-file)
           (with-store/non-blocking store
             (unless (valid-path? store derivation-file)
               (substitute-derivation store
                                      derivation-file
                                      #:substitute-urls substitute-urls)))
           (read-derivation-from-file* derivation-file))

         (let ((submit-build-result
                (call-with-delay-logging
                 submit-build
                 #:args
                 `(,build-coordinator
                   ,derivation-file
                   #:read-drv
                   ,(lambda (derivation-file)
                      (with-exception-handler
                          (lambda (exn)
                            (log-msg
                             (build-coordinator-logger build-coordinator)
                             'WARN
                             "exception substituting derivation " derivation-file
                             ": " exn)

                            (if (null? (or substitute-urls '()))
                                ;; Try again
                                (read-drv/substitute derivation-file)
                                (read-derivation-through-substitutes
                                 derivation-file
                                 substitute-urls)))
                        (lambda ()
                          (read-drv/substitute derivation-file))
                        #:unwind? #t))
                   ,@(let ((priority (assoc-ref body "priority")))
                       (if priority
                           `(#:priority ,priority)
                           '()))
                   ,@(if (assoc-ref body "ignore-if-build-for-derivation-exists")
                         '(#:ignore-if-build-for-derivation-exists? #t)
                         '())
                   ,@(if (assoc-ref body "ignore-if-build-for-outputs-exists")
                         '(#:ignore-if-build-for-outputs-exists? #t)
                         '())
                   ,@(if (assoc-ref
                          body "ensure-all-related-derivation-outputs-have-builds")
                         '(#:ensure-all-related-derivation-outputs-have-builds? #t)
                         '())
                   ,@(if (assoc-ref body "tags")
                         `(#:tags
                           ,(map
                             (lambda (tag)
                               (cons (assoc-ref tag "key")
                                     (assoc-ref tag "value")))
                             (vector->list (assoc-ref body "tags"))))
                         '())
                   ,@(or (and=> (assoc-ref body "defer-until")
                                (lambda (date)
                                  `(#:defer-until
                                    ,(string->date date "~Y-~m-~d ~H:~M:~S"))))
                         '()))
                 #:threshold 10)))
           (render-json submit-build-result))))
      (('GET "state")
       ;; Use a write transaction here to get a snapshot of the state plus the
       ;; state-id
       (render-json
        (datastore-call-with-transaction
         datastore
         (lambda (_)
           (let ((allocation-plan-counts
                  (datastore-count-build-allocation-plan-entries
                   datastore)))
             `((state_id . ,(build-coordinator-get-state-id build-coordinator))
               (agents   . ,(list->vector
                             (map
                              (lambda (agent-details)
                                (let ((agent-id
                                       (assq-ref agent-details 'uuid)))
                                  `(,@agent-details
                                    (last_status_update
                                     . ,(datastore-find-agent-status datastore
                                                                     agent-id))
                                    (requested_systems
                                     . ,(list->vector
                                         (datastore-agent-requested-systems
                                          datastore
                                          agent-id)))
                                    (allocation_plan
                                     . ((count . ,(or (assoc-ref allocation-plan-counts
                                                                 agent-id)
                                                      0))))
                                    (tags
                                     . ,(list->vector
                                         (map
                                          (match-lambda
                                            ((key . value)
                                             `((key   . ,key)
                                               (value . ,value))))
                                          (vector->list
                                           (datastore-fetch-agent-tags
                                            datastore
                                            agent-id)))))
                                    (builds
                                     . ,(list->vector
                                         (map
                                          (lambda (build)
                                            `(,@build
                                              (tags
                                               . ,(list->vector
                                                   (map
                                                    (match-lambda
                                                      ((key . value)
                                                       `((key   . ,key)
                                                         (value . ,value))))
                                                    (vector->list
                                                     (datastore-fetch-build-tags
                                                      datastore
                                                      (assq-ref build 'uuid))))))))
                                          (datastore-list-agent-builds
                                           datastore
                                           (assq-ref agent-details 'uuid))))))))
                              (datastore-list-agents datastore))))))))))
      (('GET "events")
       (let ((headers (request-headers request)))
         (list (build-response
                #:code 200
                #:headers '((content-type . (text/event-stream))))
               (lambda (port)
                 (build-coordinator-listen-for-events
                  build-coordinator
                  (lambda (state-id event-name data)
                    (display
                     (simple-format #f "id: ~A\nevent: ~A\ndata: ~A\n\n"
                                    state-id
                                    event-name
                                    (scm->json-string data))
                     port)
                    (force-output port)
                    ;; TODO because the chunked output port doesn't call
                    ;; force-output on the underlying port, do that here. We
                    ;; want this event to be sent now, rather than when some
                    ;; buffer fills up.
                    (force-output (request-port request)))
                  #:after-state-id
                  (with-exception-handler
                      (lambda (exn)
                        (simple-format
                         (current-error-port)
                         "error: when processing Last-Event-ID header value: ~A\n"
                         (assoc-ref headers 'last-event-id)))
                    (lambda ()
                      (and=> (assoc-ref headers 'last-event-id)
                             string->number))
                    #:unwind? #t))))))
      (_
       (render-json
        "not-found"
        #:code 404))))

  (with-exception-handler
      (lambda (exn)
        (cond
         ((client-error? exn)
          (render-json
           `((error . ,(client-error-details exn)))
           #:code 400))
         ((worker-thread-timeout-error? exn)
          (render-json
           `((error . ,(simple-format #f "~A" exn)))
           #:code 503))
         (else
          (render-json
           `((error . 500))
           #:code 500))))
    (lambda ()
      (with-throw-handler #t
        controller-thunk
        (lambda (key . args)
          (unless (and (eq? '%exception key)
                       (or
                        (worker-thread-timeout-error? (car args))
                        (client-error? (car args))))
            (match method-and-path-components
              ((method path-components ...)
               (simple-format
                (current-error-port)
                "error: when processing client request: /~A ~A\n  ~A ~A\n"
                method (string-join path-components "/")
                key args)))

            (let* ((stack (make-stack #t 4))
                   (backtrace
                    (call-with-output-string
                      (lambda (port)
                        (display "\nBacktrace:\n" port)
                        (display-backtrace stack port)
                        (newline port)
                        (newline port)))))
              (display
               backtrace
               (current-error-port)))))))
    #:unwind? #t))

(define* (render-json json #:key (extra-headers '())
                      (code 200))
  (list (build-response
         #:code code
         #:headers (append extra-headers
                           '((content-type . (application/json))
                             (vary . (accept)))))
        (scm->json-string json)))

(define* (send-request coordinator-uri
                       method
                       path
                       #:optional
                       request-body)
  (let* ((uri
          (string->uri
           (string-append coordinator-uri path)))
         (port
          socket
          (open-socket-for-uri* uri)))

    (let ((response
           body
           (http-request
            uri
            #:port port
            #:method method
            #:body (and=> request-body scm->json-string)
            #:decode-body? #f
            #:streaming? #t)))
      (if (>= (response-code response) 400)
          (begin
            (simple-format
             (current-error-port)
             "error: coordinator-http-request: ~A ~A: ~A\n"
             method path (response-code response))
            (let ((parsed-body
                   (catch #t
                     (lambda ()
                       (if (equal? '(application/json (charset . "utf-8"))
                                   (response-content-type response))
                           (json->scm body)
                           (utf8->string
                            (read-response-body response))))
                     (lambda (key . args)
                       (simple-format
                        (current-error-port)
                        "error decoding body ~A ~A\n"
                        key args)
                       #f))))
              (close-port body)
              (raise-exception
               (make-exception-with-message
                parsed-body))))

          (begin
            (set-port-encoding! body "UTF-8")

            (values
             (if (equal? '(application/json-seq)
                         (response-content-type response))
                 ;; TODO There's no mechanism to close the port after the
                 ;; stream/sequence has finished
                 (json-seq->scm
                  body
                  ;; TODO I would like to use 'throw, but it always raises an
                  ;; exception, so this needs fixing upstream first
                  #:handle-truncate 'replace)
                 (let ((parsed-body
                        (json->scm body)))
                   (close-port body)
                   parsed-body))
             response))))))

(define* (send-submit-build-request
          coordinator-uri
          derivation-file-name
          substitute-urls
          requested-uuid
          priority
          ignore-if-build-for-derivation-exists?
          ignore-if-build-for-outputs-exists?
          ensure-all-related-derivation-outputs-have-builds?
          tags
          #:key
          defer-until)
  (send-request coordinator-uri
                'POST
                "/builds"
                `((derivation      . ,derivation-file-name)
                  (priority        . ,priority)
                  ,@(if substitute-urls
                        `((substitute-urls . ,(list->vector substitute-urls)))
                        '())
                  ,@(if ignore-if-build-for-derivation-exists?
                        '((ignore-if-build-for-derivation-exists . #t))
                        '())
                  ,@(if ignore-if-build-for-outputs-exists?
                        '((ignore-if-build-for-outputs-exists . #t))
                        '())
                  ,@(if ensure-all-related-derivation-outputs-have-builds?
                        '((ensure-all-related-derivation-outputs-have-builds . #t))
                        '())
                  ,@(if (null? tags)
                        '()
                        `((tags . ,(list->vector tags))))
                  ,@(if defer-until
                        `((defer-until . ,(date->string defer-until "~1 ~3")))
                        '()))))

(define* (send-cancel-build-request
          coordinator-uri
          build-id
          #:key
          (ignore-if-build-required-by-another? #t)
          skip-updating-derived-priorities?)
  (send-request coordinator-uri
                'POST
                (string-append "/build/" build-id "/cancel"
                               "?ignore-if-build-required-by-another="
                               (if ignore-if-build-required-by-another?
                                   "true"
                                   "false")
                               (if skip-updating-derived-priorities?
                                   "&skip-updating-derived-priorities=true"
                                   ""))))

(define* (send-update-build-priority-request
          coordinator-uri
          build-id
          new-priority
          #:key skip-updating-derived-priorities?
          override-derived-priority)
  (send-request coordinator-uri
                'POST
                (string-append "/build/" build-id "/update-priority"
                               (if skip-updating-derived-priorities?
                                   "?skip-updating-derived-priorities=true"
                                   ""))
                `((new_priority . ,new-priority)
                  ,@(if override-derived-priority
                        `((override_derived_priority
                           . ,override-derived-priority))
                        '()))))

(define (request-build-details coordinator-uri
                               uuid)
  (send-request coordinator-uri
                'GET
                (string-append "/build/" uuid)))

(define* (fold-builds coordinator-uri
                      proc
                      init
                      #:key
                      (tags '())
                      (not-tags '())
                      (systems '())
                      (not-systems '())
                      (processed 'unset)
                      (canceled 'unset)
                      (priority-> 'unset)
                      (priority-< 'unset)
                      (relationship 'unset)
                      (after-id #f)
                      (limit #f))
  (let ((query-parameters
         `(,@(if (null? tags)
                 '()
                 (map (match-lambda
                        ((('key   . key)
                          ('value . value))
                         (simple-format #f "tag=~A:~A" key value))
                        (key
                         (simple-format #f "tag=~A" key)))
                      tags))
           ,@(if (null? not-tags)
                 '()
                 (map (match-lambda
                        ((('key   . key)
                          ('value . value))
                         (simple-format #f "not_tag=~A:~A" key value))
                        (key
                         (simple-format #f "not_tag=~A" key)))
                      not-tags))
           ,@(if (null? systems)
                 '()
                 (map (lambda (system)
                        (simple-format #f "system=~A" system))
                      systems))
           ,@(if (null? not-systems)
                 '()
                 (map (lambda (system)
                        (simple-format #f "not-system=~A" system))
                      not-systems))
           ,@(if (boolean? processed)
                 (if processed
                     '("processed=true")
                     '("processed=false"))
                 '())
           ,@(if (boolean? canceled)
                 (if canceled
                     '("canceled=true")
                     '("canceled=false"))
                 '())
           ,@(if (number? priority->)
                 (list (simple-format #f "priority_gt=~A" priority->))
                 '())
           ,@(if (number? priority-<)
                 (list (simple-format #f "priority_lt=~A" priority-<))
                 '())
           ,@(if (and relationship (not (eq? 'unset relationship)))
                 (list (simple-format #f "relationship=~A" relationship))
                 '())
           ,@(if after-id
                 (list (string-append "after_id=" after-id))
                 '())
           ,@(if limit
                 (list (simple-format #f "limit=~A" limit))
                 '()))))
        (let ((builds-stream
               response
               (send-request coordinator-uri
                             'GET
                             (string-append
                              "/builds"
                              (if (null? query-parameters)
                                  ""
                                  (string-append
                                   "?"
                                   (string-join query-parameters "&")))))))
          (with-exception-handler
              (lambda (exn)
                (close-port
                 (response-port response))
                (raise-exception exn))
            (lambda ()
              (call-with-values
                  (lambda ()
                    (stream-fold proc init builds-stream))
                (lambda vals
                  (close-port
                   (response-port response))
                  (apply values vals))))
            #:unwind? #t))))

(define (request-output-details coordinator-uri
                                output)
  (send-request coordinator-uri
                'GET
                (string-append "/output" output)))

(define (request-agent-details coordinator-uri agent-id)
  (send-request coordinator-uri
                'GET
                (string-append "/agent/" agent-id)))

(define (request-agent-build-allocation-plan coordinator-uri agent-id)
  (send-request coordinator-uri
                'GET
                (string-append "/agent/" agent-id "/build-allocation-plan")))

(define (request-agents-list coordinator-uri)
  (send-request coordinator-uri
                'GET
                (string-append "/agents")))


(define* (request-failed-builds-with-blocking-count-list
          coordinator-uri
          system
          #:key include-cancelled?)
  (send-request coordinator-uri
                'GET
                (string-append
                 "/builds/blocking"
                 (if system
                     (simple-format #f "?system=~A" system)
                     "")
                 (if include-cancelled?
                     (string-append
                      (if system "&" "?")
                      "include_cancelled="
                      (if include-cancelled?
                          "true"
                          "false"))
                     ""))))

(define* (request-setup-failures coordinator-uri #:key agent-id)
  (send-request coordinator-uri
                'GET
                (string-append
                 "/setup-failures"
                 (if agent-id
                     (simple-format #f "?agent-id=~A" agent-id)
                     ""))))

(define* (send-create-agent-request coordinator-uri
                                    #:key
                                    requested-uuid
                                    description)
  (send-request coordinator-uri
                'POST
                "/agents"
                `(,@(if requested-uuid
                        `((requested-uuid . ,requested-uuid))
                        '())
                  ,@(if description
                        `((description . ,description))
                        '()))))

(define* (send-agent-set-active-request coordinator-uri agent-uuid active?)
  (send-request coordinator-uri
                'POST
                (simple-format #f "/agent/~A/active" agent-uuid)
                `((active . ,active?))))

(define (send-create-agent-password-request coordinator-uri
                                            agent-id)
  (send-request coordinator-uri
                'POST
                (string-append "/agent/" agent-id "/passwords")))

(define (send-create-dynamic-auth-token-request coordinator-uri)
  (send-request coordinator-uri
                'POST
                "/dynamic-auth-tokens"))

(define (send-replace-agent-tags-request coordinator-uri
                                         agent-id
                                         tags)
  (send-request coordinator-uri
                'POST
                (string-append "/agent/" agent-id "/tags")
                `((tags . ,tags))))