Add new GitLab runner for gitlab.bsc.es

It uses docker based on alpine and the host nix store, so we can perform
builds but isolate them from the system.

m/hut/gitlab-runner.nix

@@ -1,8 +1,9 @@
 { pkgs, lib, config, ... }:
 
 {
-  age.secrets.gitlabRunnerShellToken.file = ../../secrets/gitlab-runner-shell-token.age;
-  age.secrets.gitlabRunnerDockerToken.file = ../../secrets/gitlab-runner-docker-token.age;
+  age.secrets.gitlab-pm-shell.file = ../../secrets/gitlab-runner-shell-token.age;
+  age.secrets.gitlab-pm-docker.file = ../../secrets/gitlab-runner-docker-token.age;
+  age.secrets.gitlab-bsc-docker.file = ../../secrets/gitlab-bsc-docker-token.age;
 
   services.gitlab-runner = {
     enable = true;
@@ -21,21 +22,89 @@
           "--docker-network-mode host"
         ];
         environmentVariables = {
-          https_proxy = "http://localhost:23080";
-          http_proxy = "http://localhost:23080";
+          https_proxy = "http://hut:23080";
+          http_proxy = "http://hut:23080";
         };
       };
     in {
       # For pm.bsc.es/gitlab
       gitlab-pm-shell = common-shell // {
-        authenticationTokenConfigFile = config.age.secrets.gitlabRunnerShellToken.path;
+        authenticationTokenConfigFile = config.age.secrets.gitlab-pm-shell.path;
       };
       gitlab-pm-docker = common-docker // {
-        authenticationTokenConfigFile = config.age.secrets.gitlabRunnerDockerToken.path;
+        authenticationTokenConfigFile = config.age.secrets.gitlab-pm-docker.path;
+      };
+
+      gitlab-bsc-docker = {
+        # gitlab.bsc.es still uses the old token mechanism
+        registrationConfigFile = config.age.secrets.gitlab-bsc-docker.path;
+        tagList = [ "docker" "hut" ];
+        environmentVariables = {
+          # We cannot access the hut local interface from docker, so we connect
+          # to hut directly via the ethernet one.
+          https_proxy = "http://hut:23080";
+          http_proxy = "http://hut:23080";
+        };
+        executor = "docker";
+        dockerImage = "alpine";
+        dockerVolumes = [
+          "/nix/store:/nix/store:ro"
+          "/nix/var/nix/db:/nix/var/nix/db:ro"
+          "/nix/var/nix/daemon-socket:/nix/var/nix/daemon-socket:ro"
+        ];
+        dockerExtraHosts = [
+          # Required to pass the proxy via hut
+          "hut:10.0.40.7"
+        ];
+        dockerDisableCache = true;
+        registrationFlags = [
+          # Increase build log length to 64 MiB
+          "--output-limit 65536"
+        ];
+        preBuildScript = pkgs.writeScript "setup-container" ''
+          mkdir -p -m 0755 /nix/var/log/nix/drvs
+          mkdir -p -m 0755 /nix/var/nix/gcroots
+          mkdir -p -m 0755 /nix/var/nix/profiles
+          mkdir -p -m 0755 /nix/var/nix/temproots
+          mkdir -p -m 0755 /nix/var/nix/userpool
+          mkdir -p -m 1777 /nix/var/nix/gcroots/per-user
+          mkdir -p -m 1777 /nix/var/nix/profiles/per-user
+          mkdir -p -m 0755 /nix/var/nix/profiles/per-user/root
+          mkdir -p -m 0700 "$HOME/.nix-defexpr"
+          mkdir -p -m 0700 "$HOME/.ssh"
+          cat > "$HOME/.ssh/config" << EOF
+          Host bscpm03.bsc.es gitlab-internal.bsc.es
+            User git
+            ProxyCommand nc -X connect -x hut:23080 %h %p
+          Host amdlogin1.bsc.es armlogin1.bsc.es hualogin1.bsc.es glogin1.bsc.es glogin2.bsc.es fpgalogin1.bsc.es
+            ProxyCommand nc -X connect -x hut:23080 %h %p
+          EOF
+          cat >> "$HOME/.ssh/known_hosts" << EOF
+          bscpm03.bsc.es ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIM2NuSUPsEhqz1j5b4Gqd+MWFnRqyqY57+xMvBUqHYUS
+          gitlab-internal.bsc.es ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIF9arsAOSRB06hdy71oTvJHG2Mg8zfebADxpvc37lZo3
+          EOF
+          . ${pkgs.nix}/etc/profile.d/nix-daemon.sh
+          # Required to load SSL certificate paths
+          . ${pkgs.cacert}/nix-support/setup-hook
+        '';
+        environmentVariables = {
+          ENV = "/etc/profile";
+          USER = "root";
+          NIX_REMOTE = "daemon";
+          PATH = "${config.system.path}/bin:/bin:/sbin:/usr/bin:/usr/sbin";
+        };
       };
     };
   };
 
+  # DOCKER* chains are useless, override at FORWARD
+  networking.firewall.extraCommands = ''
+    # Allow docker to use our proxy
+    iptables -I FORWARD 1 -p tcp -i docker0 -d hut --dport 23080 -j nixos-fw-accept
+    # Block anything else coming from docker
+    iptables -I FORWARD 2 -p all -i docker0 -j nixos-fw-log-refuse
+  '';
+
   #systemd.services.gitlab-runner.serviceConfig.Shell = "${pkgs.bash}/bin/bash";
   systemd.services.gitlab-runner.serviceConfig.DynamicUser = lib.mkForce false;
   systemd.services.gitlab-runner.serviceConfig.User = "gitlab-runner";