Added support for loading remote yaml configuration files over http/https (#254)

ChangeLog

@@ -11,6 +11,7 @@ SystemRescue ChangeLog
 * Remove Q-Logic Fibrechannel/Infiniband HBA firmware to save space (#256)
 * Implemented a script to determine the effective configuration from yaml files (#251)
 * Added boot option 'sysrescuecfg' to control how the configuration is loaded (#254)
+* Added support for loading remote yaml configuration files over http/https (#254)
 
 -------------------------------------------------------------------------------
 9.00 (2022-01-16):

airootfs/etc/systemd/system/sysrescue-configuration.service

@@ -1,6 +1,8 @@
 [Unit]
 Description=Determine SystemRescue effective configuration
-Before=sysrescue-initialize
+After=network.target network-online.target
+Before=sysrescue-initialize.service
+Wants=network-online.target
 
 [Service]
 Type=oneshot

airootfs/etc/systemd/system/sysrescue-initialize.service

@@ -1,6 +1,6 @@
 [Unit]
 Description=SystemRescue Initialization
-Before=sshd.service getty-pre.target iptables.service ip6tables.service
+Before=getty-pre.target
 Wants=getty-pre.target
 
 [Service]

airootfs/usr/bin/sysrescue-configuration.lua

@@ -15,7 +15,7 @@
 -- Shell scripts can read values from the JSON file using a command such as:
 -- jq --raw-output '.global.copytoram' /etc/sysrescue/sysrescue-effective-config.json
 -- This script requires the following lua packages to run on Arch Linux:
--- sudo pacman -Sy lua lua-yaml lua-dkjson
+-- sudo pacman -Sy lua lua-yaml lua-dkjson lua-http
 
 -- ==============================================================================
 -- Import modules
@@ -23,6 +23,7 @@
 local lfs = require('lfs')
 local yaml = require('yaml')
 local json = require("dkjson")
+local request = require("http.request")
 
 -- ==============================================================================
 -- Utility functions
@@ -120,6 +121,32 @@ function process_yaml_config(curconfig)
     return true
 end
 
+-- Download a file over http/https and return the contents of the file or nil if it fails
+function download_file(fileurl)
+    local req_timeout = 10
+    local req = request.new_from_uri(fileurl)
+    local headers, stream = req:go(req_timeout)
+
+    if headers == nil then
+        io.stderr:write(string.format("Failed to download %s: Could not connect\n", fileurl))
+        return nil
+    end
+
+    status = headers:get(":status")
+    if status ~= '200' then
+        io.stderr:write(string.format("Failed to download %s: Received HTTP code %s\n", fileurl, status))
+        return nil
+    end
+
+    local body, err = stream:get_body_as_string()
+    if not body and err then
+        io.stderr:write(string.format("Failed to download %s: Error %s\n", fileurl, tostring(err)))
+        return nil
+    end
+
+    return body
+end
+
 -- ==============================================================================
 -- Initialisation
 -- ==============================================================================
@@ -182,6 +209,18 @@ for _, curdir in ipairs(confdirs) do
     end
 end
 
+-- Process remote yaml configuration files
+print("Searching for remote yaml configuration files ...")
+for _, curfile in ipairs(conffiles) do
+    if string.match(curfile, "^https?://") then
+        print(string.format("Processing remote yaml configuration file: %s ...", curfile))
+        local contents = download_file(curfile)
+        if (contents == nil) or (process_yaml_config(yaml.load(contents)) == false) then
+            errcnt = errcnt + 1
+        end
+    end
+end
+
 -- ==============================================================================
 -- Override the configuration with values passed on the boot command line
 -- ==============================================================================

packages

@@ -114,6 +114,7 @@ lsof
 lsscsi
 lua
 lua-dkjson
+lua-http
 lua-yaml
 lvm2
 lz4