diff options
Diffstat (limited to 'krebs/3modules')
| -rw-r--r-- | krebs/3modules/cachecache.nix | 171 | ||||
| -rw-r--r-- | krebs/3modules/default.nix | 1 |
2 files changed, 172 insertions, 0 deletions
diff --git a/krebs/3modules/cachecache.nix b/krebs/3modules/cachecache.nix new file mode 100644 index 000000000..c02c7c80c --- /dev/null +++ b/krebs/3modules/cachecache.nix @@ -0,0 +1,171 @@ +{ config, lib, ... }: + + +# fork of https://gist.github.com/rycee/f495fc6cc4130f155e8b670609a1e57b +# related: https://github.com/nh2/nix-binary-cache-proxy + +with lib; + +let + + cfg = config.krebs.cachecache; + + nginxCfg = config.services.nginx; + + cacheFallbackConfig = { + proxyPass = "$upstream_endpoint"; + extraConfig = '' + # Default is HTTP/1, keepalive is only enabled in HTTP/1.1. + proxy_http_version 1.1; + + # Remove the Connection header if the client sends it, it could + # be "close" to close a keepalive connection + proxy_set_header Connection ""; + + # Needed for CloudFront. + proxy_ssl_server_name on; + + proxy_set_header Host $proxy_host; + proxy_cache nix_cache_cache; + proxy_cache_valid 200 302 60m; + proxy_cache_valid 404 1m; + + expires max; + add_header Cache-Control $nix_cache_cache_header always; + ''; + }; + +in + +{ + options = { + krebs.cachecache = { + enable = mkEnableOption "Nix binary cache cache"; + + virtualHost = mkOption { + type = types.str; + default = "nix-cache"; + description = '' + Name of the nginx virtualhost to use and setup. If null, do + not setup any virtualhost. + ''; + }; + enableSSL = mkOption { + type = types.bool; + default = true; + description = '' + enable SSL via letsencrypt. Requires working dns resolution and open + internet tls port. + ''; + }; + + # webRoot = mkOption { + # type = types.str; + # default = "/"; + # description = '' + # Directory on virtual host that serves the cache. Must end in + # <literal>/</literal>. + # ''; + # }; + + resolver = mkOption { + type = types.str; + description = "Address of DNS resolver."; + default = "8.8.8.8 ipv6=off"; + example = "127.0.0.1 ipv6=off"; + }; + + cacheDir = mkOption { + type = types.str; + default = "/var/cache/nix-cache-cache"; + description = '' + Where nginx should store cached data. + ''; + }; + + maxSize = mkOption { + type = types.str; + default = "50g"; + description = "Maximum cache size."; + }; + }; + }; + + config = { + networking.firewall.allowedTCPPorts = [ 80 443 ]; + + + systemd.services.nginx.preStart = '' + mkdir -p ${cfg.cacheDir} /srv/www/nix-cache-cache + chmod 700 ${cfg.cacheDir} /srv/www/nix-cache-cache + chown ${nginxCfg.user}:${nginxCfg.group} \ + ${cfg.cacheDir} /srv/www/nix-cache-cache + ''; + + services.nginx = { + enable = true; + + appendHttpConfig = '' + proxy_cache_path ${cfg.cacheDir} + levels=1:2 + keys_zone=nix_cache_cache:100m + max_size=${cfg.maxSize} + inactive=365d + use_temp_path=off; + + # Cache only success status codes; in particular we don't want + # to cache 404s. See https://serverfault.com/a/690258/128321. + map $status $nix_cache_cache_header { + 200 "public"; + 302 "public"; + default "no-cache"; + } + ''; + + virtualHosts.${cfg.virtualHost} = { + addSSL = cfg.enableSSL; + enableACME = cfg.enableSSL; + extraConfig = '' + # Using a variable for the upstream endpoint to ensure that it is + # resolved at runtime as opposed to once when the config file is loaded + # and then cached forever (we don't want that): + # see https://tenzer.dk/nginx-with-dynamic-upstreams/ + # This fixes errors like + # + # nginx: [emerg] host not found in upstream "upstream.example.com" + # + # when the upstream host is not reachable for a short time when + # nginx is started. + resolver ${cfg.resolver} valid=10s; + set $upstream_endpoint https://cache.nixos.org; + ''; + + locations."/" = + { + root = "/srv/www/nix-cache-cache"; + extraConfig = '' + expires max; + add_header Cache-Control $nix_cache_cache_header always; + + # Ask the upstream server if a file isn't available + # locally. + error_page 404 = @fallback; + + # Don't bother logging the above 404. + log_not_found off; + ''; + }; + + locations."@fallback" = cacheFallbackConfig; + + # We always want to copy cache.nixos.org's nix-cache-info + # file, and ignore our own, because `nix-push` by default + # generates one without `Priority` field, and thus that file + # by default has priority 50 (compared to cache.nixos.org's + # `Priority: 40`), which will make download clients prefer + # `cache.nixos.org` over our binary cache. + locations."= /nix-cache-info" = cacheFallbackConfig; + }; + }; + }; +} diff --git a/krebs/3modules/default.nix b/krebs/3modules/default.nix index ca67ce65c..24cbd9cc9 100644 --- a/krebs/3modules/default.nix +++ b/krebs/3modules/default.nix @@ -14,6 +14,7 @@ let ./buildbot/master.nix ./buildbot/slave.nix ./build.nix + ./cachecache.nix ./charybdis.nix ./ci.nix ./current.nix |