Add fetch-latest-releases.lua

fetch-latest-releases.lua

@@ -0,0 +1,155 @@
+#!/usr/bin/lua5.3
+
+-- script to fetch and parse latest-releases.yaml from master site
+-- and fetch the latest minirootfs images for all available branches
+
+local request = require("http.request")
+local cqueues = require("cqueues")
+local yaml = require("lyaml")
+local lfs = require("lfs")
+
+local m = {}
+m.mirror = os.getenv("MIRROR") or "https://cz.alpinelinux.org/alpine"
+
+
+function m.fatal(...)
+	m.errormsg(...)
+	os.exit(1)
+end
+
+function m.fetch(url)
+	local headers, stream = request.new_from_uri(url):go()
+	if not headers then
+		m.fatal("Error: %s: %s", url, stream)
+	end
+	local body = stream:get_body_as_string()
+	return headers:get(":status"), body
+end
+
+function m.errormsg(...)
+	local msg = string.format(...)
+	io.stderr:write(string.format("%s\n", msg))
+	return nil, msg
+end
+
+function m.fetch_file(url, outfile)
+	local headers, stream = request.new_from_uri(url):go()
+	if not headers then
+		m.fatal("Error: %s: %s", url, stream)
+	end
+	if headers:get(":status") ~= "200" then
+		m.fatal("Error: HTTP %s: %s", headers:get(":status"), url)
+	end
+
+	local partfile = string.format("%s.part", outfile)
+	local f, errmsg = io.open(partfile, "w")
+	if not f then
+		return errormsg("Error: %s: %s:", file, errmsg)
+	end
+	local ok, errmsg, errnum = stream:save_body_to_file(f)
+	f:close()
+	if not ok then
+		return errormsg("Error: %s: %s", errmsg, url)
+	end
+	return os.rename(partfile, outfile)
+end
+
+function m.mkdockerfile(dir, rootfsfile)
+	local filename = string.format("%s/Dockerfile", dir)
+	local f, err = io.open(filename, "w")
+	if not f then
+		m.fatal("Error: %s: %s", filename, err)
+	end
+	f:write(string.format("FROM scratch\nADD %s /\nCMD [\"/bin/sh\"]\n", rootfsfile))
+	f:close()
+end
+
+function m.minirootfs_image(images)
+	for _,img in pairs(images) do
+		if img.flavor == "alpine-minirootfs" then
+			return img
+		end
+	end
+	return nil
+end
+
+function m.get_minirootfs(images, destdir)
+	local img = m.minirootfs_image(images)
+	if destdir then
+		local url = string.format("%s/%s/releases/%s/%s",
+			m.mirror, img.branch, img.arch, img.file)
+		local archdir = string.format("%s/%s", destdir, img.arch)
+		local ok, errmsg = lfs.mkdir(archdir)
+		m.fetch_file(url, string.format("%s/%s", archdir, img.file))
+		m.mkdockerfile(archdir, img.file)
+		print(img.file)
+	end
+	return { version=img.version, file=img.file, sha512=img.sha512 }
+end
+
+-- get array of minirootsfs releases --
+function m.get_releases(branch, destdir)
+	local arches = { "aarch64", "armhf", "armv7", "ppc64le" , "riscv64", "s390x", "x86", "x86_64" }
+	local t = {}
+	local loop = cqueues.new()
+	for _, arch in pairs(arches) do
+		loop:wrap(function()
+			local url = string.format("%s/%s/releases/%s/latest-releases.yaml",
+				m.mirror, branch, arch)
+			local status, body = m.fetch(url)
+			if status == "200" then
+				t[arch] = m.get_minirootfs((yaml.load(body)), destdir)
+			end
+		end)
+	end
+	loop:loop()
+	return t
+end
+
+function m.equal_versions(releases)
+	local prev = nil
+	for arch, img in pairs(releases) do
+		if prev == nil then
+			prev = img.version
+		end
+		if prev ~= img.version then
+			return false, arch
+		end
+		prev = img.version
+	end
+	return true
+end
+
+-- return functions as module for unit testing
+if not string.match(arg[0], "fetch%-latest%-releases") then
+	return m
+end
+
+local branch = arg[1] or "edge"
+local destdir = arg[2] or "out"
+
+lfs.mkdir(destdir)
+
+local version
+local releases = m.get_releases(branch, destdir)
+
+if next(releases) == nil then
+	m.fatal("No releases found on %s/%s/releases", m.mirror, branch)
+end
+
+if not m.equal_versions(releases) then
+	m.fatal("not all versions are equal")
+end
+
+local f = io.open(string.format("%s/checksums.sha512", destdir), "w")
+for arch,rel in pairs(releases) do
+	local line = string.format("%s  %s/%s\n", rel.sha512, arch, rel.file)
+	f:write(line)
+	version=rel.version
+end
+f:close()
+
+-- write version
+f = io.open(string.format("%s/VERSION", destdir), "w")
+f:write(version)
+f:close()