[bug#52555] [RFC PATCH v2 3/5] Add (guix eris).

[pukkamustard]

* guix/ipfs.scm: New file.
* Makefile.am (MODULES): Add it.
---
 Makefile.am   |  1 +
 guix/eris.scm | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 guix/eris.scm

diff --git a/Makefile.am b/Makefile.am
index a10aeb817b..7219386361 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -131,6 +131,7 @@ MODULES =                                   \
   guix/cve.scm                                 \
   guix/workers.scm                             \
   guix/ipfs.scm                                        \
+  guix/eris.scm                                        \
   guix/build-system.scm                                \
   guix/build-system/android-ndk.scm            \
   guix/build-system/ant.scm                    \
diff --git a/guix/eris.scm b/guix/eris.scm
new file mode 100644
index 0000000000..163bbe05ac
--- /dev/null
+++ b/guix/eris.scm
@@ -0,0 +1,55 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022 pukkamustard <pukkamustard@posteo.net>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix 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.
+;;;
+;;; GNU Guix 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 GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix eris)
+  #:use-module (eris)
+  #:use-module (eris blocks ipfs)
+  #:use-module (web client)
+  #:use-module (web response)
+  #:use-module (srfi srfi-71)
+
+  #:export (guix-eris-block-reducer))
+
+(define (ipfs-daemon-alive?)
+  "Attempt to connect to the IPFS daemon. Returns #t if the daemon is alive
+and #f else."
+  (with-exception-handler
+      (const #f)
+    (lambda _
+      (let ((response _
+                      (http-post (string-append (%ipfs-base-url)
+                                                "/api/v0/version"))))
+        (equal? 200 (response-code response))))
+    #:unwind? #t))
+
+(define guix-eris-block-reducer
+  (case-lambda
+
+    ;; Check if IPFS Daemon is running.
+    (() (if (ipfs-daemon-alive?)
+            (eris-blocks-ipfs-reducer)
+            #f))
+
+    ;; Completion. Nothing to do.
+    ((_) #t)
+
+    ((ipfs ref-block)
+     ;; If IPFS has been initialized store block there
+     (if ipfs
+         (eris-blocks-ipfs-reducer ipfs ref-block)
+         ipfs))))
-- 
2.34.0