4 files changed, 162 insertions, 0 deletions
diff --git a/krebs/3modules/github/default.nix b/krebs/3modules/github/default.nix
new file mode 100644
index 000000000..2df4ba717
--- /dev/null
+++ b/krebs/3modules/github/default.nix
@@ -0,0 +1,6 @@
+{
+  imports = [
+    ./hosts-sync.nix
+    ./known-hosts.nix
+  ];
+}
diff --git a/krebs/3modules/github/hosts-sync.nix b/krebs/3modules/github/hosts-sync.nix
new file mode 100644
index 000000000..71eed6c69
--- /dev/null
+++ b/krebs/3modules/github/hosts-sync.nix
@@ -0,0 +1,86 @@
+{ config, lib, pkgs, ... }:
+
+with import <stockholm/lib>;
+let
+  cfg = config.krebs.github-hosts-sync;
+
+  out = {
+    options.krebs.github-hosts-sync = api;
+    config = lib.mkIf cfg.enable imp;
+  };
+
+  api = {
+    enable = mkEnableOption "krebs.github-hosts-sync";
+    dataDir = mkOption {
+      type = types.str; # TODO path (but not just into store)
+      default = "/var/lib/github-hosts-sync";
+    };
+    srcDir = mkOption {
+      type = types.str;
+      default = "${config.krebs.tinc.retiolum.confDir}/hosts";
+      defaultText = "\${config.krebs.tinc.retiolum.confDir}/hosts";
+    };
+    ssh-identity-file = mkOption {
+      type = types.suffixed-str [".ssh.id_ed25519" ".ssh.id_rsa"];
+      default = toString <secrets/github-hosts-sync.ssh.id_ed25519>;
+      defaultText = "‹secrets/github-hosts-sync.ssh.id_ed25519›";
+    };
+    url = mkOption {
+      type = types.str;
+      default = "git@github.com:krebs/hosts.git";
+    };
+    workTree = mkOption {
+      type = types.absolute-pathname;
+      default = "${cfg.dataDir}/cache";
+    };
+  };
+
+  imp = {
+    systemd.services.github-hosts-sync = {
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      environment = {
+        GITHUB_HOST_SYNC_USER_MAIL = user.mail;
+        GITHUB_HOST_SYNC_USER_NAME = user.name;
+        GITHUB_HOST_SYNC_SRCDIR = cfg.srcDir;
+        GITHUB_HOST_SYNC_WORKTREE = cfg.workTree;
+        GITHUB_HOST_SYNC_URL = cfg.url;
+      };
+      serviceConfig = {
+        PermissionsStartOnly = "true";
+        SyslogIdentifier = "github-hosts-sync";
+        User = user.name;
+        Type = "oneshot";
+        RemainAfterExit = true;
+        ExecStartPre = pkgs.writeDash "github-hosts-sync-init" ''
+          set -euf
+          install -m 0711 -o ${user.name} -d ${cfg.dataDir}
+          install -m 0700 -o ${user.name} -d ${cfg.dataDir}/.ssh
+          install -m 0400 -o ${user.name} \
+            ${cfg.ssh-identity-file} \
+            ${cfg.dataDir}/.ssh/${fileExtension cfg.ssh-identity-file}
+        '';
+        ExecStart = "${pkgs.github-hosts-sync}/bin/github-hosts-sync";
+      };
+    };
+
+    users.users.${user.name} = {
+      inherit (user) uid;
+      group = user.name;
+      home = cfg.dataDir;
+      isSystemUser = true;
+    };
+  };
+
+  users.groups.${user.name} = {};
+
+  user = rec {
+    mail = "${name}@${config.krebs.build.host.name}";
+    name = "github-hosts-sync";
+    uid = genid_uint31 name;
+  };
+
+  # TODO move to lib?
+  fileExtension = s: last (splitString "." s);
+
+in out
diff --git a/krebs/3modules/github/known-hosts.json b/krebs/3modules/github/known-hosts.json
new file mode 100644
index 000000000..694f9adba
--- /dev/null
+++ b/krebs/3modules/github/known-hosts.json
@@ -0,0 +1,58 @@
+[
+  "192.30.252.*",
+  "192.30.253.*",
+  "192.30.254.*",
+  "192.30.255.*",
+  "185.199.108.*",
+  "185.199.109.*",
+  "185.199.110.*",
+  "185.199.111.*",
+  "140.82.112.*",
+  "140.82.113.*",
+  "140.82.114.*",
+  "140.82.115.*",
+  "140.82.116.*",
+  "140.82.117.*",
+  "140.82.118.*",
+  "140.82.119.*",
+  "140.82.120.*",
+  "140.82.121.*",
+  "140.82.122.*",
+  "140.82.123.*",
+  "140.82.124.*",
+  "140.82.125.*",
+  "140.82.126.*",
+  "140.82.127.*",
+  "143.55.64.*",
+  "143.55.65.*",
+  "143.55.66.*",
+  "143.55.67.*",
+  "143.55.68.*",
+  "143.55.69.*",
+  "143.55.70.*",
+  "143.55.71.*",
+  "143.55.72.*",
+  "143.55.73.*",
+  "143.55.74.*",
+  "143.55.75.*",
+  "143.55.76.*",
+  "143.55.77.*",
+  "143.55.78.*",
+  "143.55.79.*",
+  "20.201.28.151",
+  "20.205.243.166",
+  "102.133.202.242",
+  "20.248.137.48",
+  "20.207.73.82",
+  "20.27.177.113",
+  "20.200.245.247",
+  "20.233.54.53",
+  "20.201.28.152",
+  "20.205.243.160",
+  "102.133.202.246",
+  "20.248.137.50",
+  "20.207.73.83",
+  "20.27.177.118",
+  "20.200.245.248",
+  "20.233.54.52"
+]
diff --git a/krebs/3modules/github/known-hosts.nix b/krebs/3modules/github/known-hosts.nix
new file mode 100644
index 000000000..f2705caa4
--- /dev/null
+++ b/krebs/3modules/github/known-hosts.nix
@@ -0,0 +1,12 @@
+{ lib, ... }: {
+  services.openssh.knownHosts.github = {
+    hostNames =
+      ["github.com"]
+      ++
+      # List generated with (IPv6 addresses are currently ignored):
+      # curl -sS https://api.github.com/meta | jq -r .git[] | grep -v : | nix-shell -p cidr2glob --run cidr2glob | jq -Rs 'split("\n")|map(select(.!=""))' > known-hosts.json
+      lib.importJSON ./known-hosts.json
+    ;
+    publicKey = "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==";
+  };
+}