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selfhostblocks/modules/haproxy-configcreator.nix
2023-07-10 18:36:25 -07:00

492 lines
14 KiB
Nix

{ lib
, pkgs
}:
with builtins;
with lib;
with lib.attrsets;
with lib.lists;
with lib.strings;
let
getAttrWithDefault = name: default: attrset:
if isAttrs attrset && hasAttr name attrset then
getAttr name attrset
else
default;
recursiveMerge = attrList:
let f = attrPath:
zipAttrsWith (n: values:
if all isList values then
concatLists values
else if all isAttrs values then
f (attrPath ++ [n]) values
else
last values
);
in f [] attrList;
augmentedContent = fieldName: rules: parent: set:
let
print = {rule = k: parent: v:
assert assertMsg (isString v || isInt v) "cannot print key '${fieldName}.${k}' of type '${typeOf v}', should be string or int instead";
"${k} ${toString v}";};
matchingRule = k: v: findFirst (rule: rule.match k parent v) print rules;
augment = parent: k: v:
let
match = matchingRule k v;
rule = if hasAttr "rule" match then match.rule else null;
rules = if hasAttr "rules" match then match.rules else null;
indent = map (x: if hasAttr "indent" match then match.indent + x else x);
headerFn = if hasAttr "header" match then match.header else null;
header = optional (headerFn != null) (headerFn k);
trailer = optional (headerFn != null) "";
content = header ++ indent (augmentedContent "${fieldName}.${k}" rules (parent ++ [k]) v) ++ trailer;
in
if rule != null
then rule k parent v
else
assert assertMsg (isAttrs v) "attempt to apply rules on key '${toString k}' which is a '${typeOf v}' but should be a set:\n${toString v}";
if hasAttr "order" match then
{
inherit (match) order;
inherit content;
}
else
content;
augmented = mapAttrsToList (augment parent) (
assert assertMsg (isAttrs set) "attempt to apply rules on field ${fieldName} having type '${typeOf set}':\n${toString set}";
set
);
sortAugmented = sort (a: b:
(isAttrs a && hasAttr "order" a)
&& (isAttrs b && hasAttr "order" b)
&& a.order < b.order
);
onlyContent = (x: if isAttrs x && hasAttr "content" x then x.content else x);
in
flatten (map onlyContent (sortAugmented augmented));
updateByPath = path: fn: set:
if hasAttrByPath path set then
recursiveUpdate set (setAttrByPath path (fn (getAttrFromPath path set)))
else
set;
schema =
let
mkRule =
{ redirect ? false
, scheme ? "https"
, code ? null
, condition ? null
}:
concatStringsRecursive " " [
(optional redirect "redirect")
"scheme" scheme
(optional (code != null) "code ${toString code}")
(optional (condition != null) "if ${condition}")
];
mkBind =
{ addr
, ssl ? false
, crt ? null
}:
concatStringsRecursive " " [
"bind"
addr
(optional ssl "ssl")
(optional (crt != null) "crt ${crt}")
];
mkServer =
{ name
, address
, balance ? null
, check ? null
, httpcheck ? null
, forwardfor ? true
, resolvers ? null
}:
[
"mode http"
(optional forwardfor "option forwardfor")
(optional (httpcheck != null) "option httpchk ${httpcheck}")
(optional (balance != null) "balance ${balance}")
(concatStringsRecursive " " [
"server"
name
address
(optionals (check != null) (if
isBool check
then (if check then ["check"] else [])
else mapAttrsToList (k: v: "${k} ${v}") check))
(optional (resolvers != null) "resolvers ${resolvers}")
])
];
# Lua's import system requires the import path to be something like:
#
# /nix/store/123-name/<package>/<file.lua>
#
# Then the lua-prepend-path can be:
#
# /nix/store/123-name/?/<file.lua>
#
# Then when lua code imports <package>, it will search in the
# prepend paths and replace the question mark with the <package>
# name to get a match.
#
# But the config.source is actually without the <package> name:
#
# /nix/store/123-name/<file.lua>
#
# This requires us to create a new directory structure and we're
# using a linkFarm for this.
createPluginLinks = configs:
let
mkLink = name: config: {
inherit name;
path = config.source;
};
in
pkgs.linkFarm "haproxyplugins" (mapAttrsToList mkLink configs);
mkPlugin = links: name:
{ luapaths ? []
, cpaths ? []
, load ? null
, ...
}:
{
lua-prepend-path =
let
f = ext: type: path:
{
inherit type;
path =
if path == "." then
"${links}/${name}/?.${ext}"
else
"${links}/${name}/${path}/?.${ext}";
};
in
map (f "lua" "path") (toList luapaths)
++ map (f "so" "cpath") (toList cpaths);
} // optionalAttrs (load != null) {
lua-load = ["${links}/${name}/${load}"];
};
# Takes plugins as an attrset of name to {init, load, source},
# transforms them to a [attrset] with fields lua-prepend-path
# and optionally lua-load then returns a list of lines with all
# lua-prepend-path first and all lua-load afterwards.
mkPlugins = v:
let
f = recursiveMerge (mapAttrsToList (mkPlugin (createPluginLinks v)) v);
lua-prepend-path = map ({path, type}: "lua-prepend-path ${path} ${type}") (getAttrWithDefault "lua-prepend-path" [] f);
lua-load = map (x: "lua-load ${x}") (getAttrWithDefault "lua-load" [] f);
in
lua-prepend-path ++ lua-load;
in [
{
match = k: parent: v: k == "defaults";
order = 2;
indent = " ";
header = k: k;
rules = [
{
match = k: parent: v: k == "timeout";
rule = k: parent: v: mapAttrsToList (k1: v1: "${k} ${k1} ${v1}") v;
}
];
}
{
match = k: parent: v: k == "global";
order = 1;
indent = " ";
header = k: k;
rules = [
{
match = k: parent: v: k == "plugins";
rule = k: parent: v: mkPlugins v;
}
{
match = k: parent: v: k == "setenv";
rule = k: parent: v: mapAttrsToList (k: v: "setenv ${k} ${v}" ) v;
}
];
}
{
match = k: parent: v: k == "resolvers";
order = 3;
rules = [
{
match = k: parent: v: true;
header = k: "resolvers " + k;
indent = " ";
rules = [
{
match = k: parent: v: k == "nameservers";
rule = k: parent: v: mapAttrsToList (k1: v1: "nameserver ${k1} ${v1}") v;
}
];
}
];
}
{
match = k: parent: v: k == "frontend";
order = 4;
rules = [
{
match = k: parent: v: true;
header = k: "frontend " + k;
indent = " ";
rules = [
{
match = k: parent: v: k == "rules";
rule = k: parent: v: map mkRule v;
}
{
match = k: parent: v: k == "bind" && isAttrs v;
rule = k: parent: v: mkBind v;
}
{
match = k: parent: v: k == "use_backend";
rule = k: parent: v:
let
use = name: value: "use_backend ${name} ${toString value}";
in
if isList v then
map (v: use v.name v.value) v
else
use v.name v.value;
}
{
match = k: parent: v: true ;
rule = k: parent: v:
let
l = prefix: v:
if isAttrs v then
mapAttrsToList (k: v: l "${prefix} ${k}" v) v
else if isList v then
map (l prefix) v
else if isBool v then
optional v prefix
else
assert assertMsg (isString v) "value for field ${k} should be a string, bool, attr or list, got: ${typeOf v}";
"${prefix} ${v}";
in
l k v;
}
];
}
];
}
{
match = k: parent: v: k == "backend";
order = 5;
rules = [
{
match = k: parent: v: true;
header = k: "backend " + k;
indent = " ";
rules = [
{
match = k: parent: v: k == "options";
rule = k: parent: v: v;
}
{
match = k: parent: v: k == "servers";
rule = k: parent: v: map mkServer v;
}
];
}
];
}
];
concatStringsRecursive = sep: strings:
concatStringsSep sep (flatten strings);
assertHasAttr = name: attrPath: v:
assertMsg
(hasAttrByPath attrPath v)
"no ${last attrPath} defined in config for site ${name}.${concatStringsSep "." (init attrPath)}, found attr names: ${toString (attrNames (getAttrFromPath (init attrPath) v))}";
# Takes a function producing a [nameValuePair], applies it to
# all name-value pair in the given set and merges the resulting
# [[nameValuePair]].
mapAttrsFlatten = f: set: listToAttrs (concatLists (mapAttrsToList f set));
mapIfIsAttrs = f: value:
if isAttrs value
then f value
else value;
flattenAttrs = sep: cond: set:
let
recurse = mapIfIsAttrs (mapAttrsFlatten (
n: v: let
result = recurse v;
in
if isAttrs result && cond n v
then mapAttrsToList (n2: v2: nameValuePair "${n}${sep}${n2}" v2) result
else [(nameValuePair n result)]
));
in recurse set;
in
{
inherit updateByPath recursiveMerge;
default =
{ user
, group
, certPath
, plugins ? {}
, globalEnvs ? {}
, stats ? null
, debug ? false
, sites ? {}
, globals ? {}
, defaults ? {}
, resolvers ? {}
}: {
global = {
# Silence a warning issued by haproxy. Using 2048
# instead of the default 1024 makes the connection stronger.
"tune.ssl.default-dh-param" = 2048;
maxconn = 20000;
inherit user group;
log = "/dev/log local0 info";
inherit plugins;
setenv = globalEnvs;
} // globals;
defaults = {
log = "global";
option = "httplog";
timeout = {
connect = "10s";
client = "15s";
server = "30s";
queue = "100s";
};
} // defaults;
frontend = {
http-to-https = {
mode = "http";
bind = "*:80";
rules = [
{
redirect = true;
scheme = "https";
code = 301;
condition = "!{ ssl_fc }";
}
];
backend = {};
};
https = (
let
r = (
[{
mode = "http";
bind = {
addr = "*:443";
ssl = true;
crt = certPath;
};
http-request = {
set-header = [
"X-Forwarded-Port %[dst_port]"
"X-Forwarded-For %[src]"
];
add-header = [
"X-Forwarded-Proto https"
];
};
http-response = {
set-header = [
''Strict-Transport-Security "max-age=15552000; includeSubDomains; preload;"''
];
};
}]
++ (mapAttrsToList (name: config:
assert assertHasAttr name ["frontend"] config;
(updateByPath ["frontend" "use_backend"] (x: [(nameValuePair name x)]) config).frontend
) sites)
++ (mapAttrsToList (name: config:
if (hasAttr "debugHeaders" config && (getAttr "debugHeaders" config) != null) then {
option = "httplog";
http-request = {
capture = "req.hdrs len 512 if ${config.debugHeaders}";
};
log-format = ''"%ci:%cp [%tr] %ft [[%hr]] %hs %{+Q}r"'';
} else {}
) sites)
);
in
recursiveMerge r
)
// optionalAttrs (debug) {
log-format = ''"%ci:%cp [%tr] %ft %b/%s %TR/%Tw/%Tc/%Tr/%Ta %ST %B %CC %CS %tsc %ac/%fc/%bc/%sc/%rc %sq/%bq %hr %hs %{+Q}r %sslv %sslc %[ssl_fc_cipherlist_str]"'';
};
} // optionalAttrs (stats != null)
(let
stats_ = {
enable = true;
port = 8404;
uri = "/stats";
refresh = "10s";
prometheusUri = null;
hide-version = false;
} // stats;
in
{
stats = {
bind = "localhost:${toString stats_.port}";
mode = "http";
stats = {
enable = stats_.enable;
hide-version = stats_.hide-version;
uri = stats_.uri;
refresh = stats_.refresh;
};
} // optionalAttrs (stats_.prometheusUri != null) {
http-request = [
"use-service prometheus-exporter if { path ${stats_.prometheusUri} }"
];
};
});
backend =
mapAttrs' (name: config:
assert assertMsg (hasAttr "backend" config) "no backend defined in config for site ${name}, found attr names: ${toString (attrNames config)}";
nameValuePair name config.backend)
sites;
inherit resolvers;
};
render = config:
concatStringsSep "\n" (augmentedContent "" schema [] config);
}