tv configs: add elm-package-proxy

tv/2configs/elm-packages-proxy.nix

@@ -0,0 +1,154 @@
+{ config, lib, pkgs, ... }: let
+
+  cfg.nameserver = "1.1.1.1";
+  cfg.packageDir = "/var/lib/elm-packages";
+  cfg.port = 7782;
+
+in {
+  services.nginx.virtualHosts."package.elm-lang.org" = {
+    addSSL = true;
+
+    # TODO secret files
+    sslCertificate = "/var/lib/certs/package.elm-lang.org/fullchain.pem";
+    sslCertificateKey = "/var/lib/certs/package.elm-lang.org/key.pem";
+
+    locations."/all-packages/since/".extraConfig = ''
+      proxy_pass http://127.0.0.1:${toString config.krebs.htgen.elm-packages-proxy.port};
+      proxy_pass_header Server;
+    '';
+
+    locations."~ ^/packages/(?<author>[A-Za-z0-9-]+)/(?<pname>[A-Za-z0-9-]+)/(?<version>(?<major>0|[1-9]\\d*)\\.(?<minor>0|[1-9]\\d*)\\.(?<patch>0|[1-9]\\d*)(?:-(?<prerelease>(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\\.(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\\+(?<buildmetadata>[0-9a-zA-Z-]+(?:\\.[0-9a-zA-Z-]+)*))?)/(?:zipball|elm.json|endpoint.json)\$".extraConfig = ''
+      set $zipball "${cfg.packageDir}/$author/$pname/$version/zipball";
+      proxy_set_header X-Author $author;
+      proxy_set_header X-Package $pname;
+      proxy_set_header X-Version $version;
+      proxy_set_header X-Zipball $zipball;
+      proxy_pass_header Server;
+      resolver ${cfg.nameserver};
+
+      if (-f $zipball) {
+        set $new_uri http://127.0.0.1:${toString config.krebs.htgen.elm-packages-proxy.port};
+      }
+      if (!-f $zipball) {
+        set $new_uri https://package.elm-lang.org$request_uri;
+      }
+
+      proxy_pass $new_uri;
+    '';
+  };
+
+  krebs.htgen.elm-packages-proxy = {
+    port = cfg.port;
+    script = /* sh */ ''(. ${pkgs.writeDash "elm-packages-proxy.sh" ''
+      PATH=${lib.makeBinPath [
+        pkgs.coreutils
+        pkgs.curl
+        pkgs.findutils
+        pkgs.gnugrep
+        pkgs.jq
+        pkgs.unzip
+      ]}
+      export PATH
+      file_response() {(
+        status_code=$1
+        status_reason=$2
+        file=$3
+        content_type=$4
+
+        content_length=$(wc -c "$file" | cut -d\  -f1)
+
+        printf "HTTP/1.1 $status_code $status_reason\r\n"
+        printf 'Connection: close\r\n'
+        printf 'Content-Length: %d\r\n' "$content_length"
+        printf 'Content-Type: %s\r\n' "$content_type"
+        printf 'Server: %s\r\n' "$Server"
+        printf '\r\n'
+        cat "$file"
+      )}
+      string_response() {(
+        status_code=$1
+        status_reason=$2
+        response_body=$3
+        content_type=$4
+
+        printf "HTTP/1.1 $status_code $status_reason\r\n"
+        printf 'Connection: close\r\n'
+        printf 'Content-Length: %d\r\n' ''${#response_body}
+        printf 'Content-Type: %s\r\n' "$content_type"
+        printf 'Server: %s\r\n' "$Server"
+        printf '\r\n'
+        printf '%s\n' "$response_body"
+      )}
+
+      case "$Method $Request_URI" in
+        'GET /packages/'*)
+
+          author=$req_x_author
+          pname=$req_x_package
+          version=$req_x_version
+
+          zipball=${cfg.packageDir}/$author/$pname/$version/zipball
+          elmjson=$HOME/cache/$author%2F$pname%2F$version%2Felm.json
+          endpointjson=$HOME/cache/$author%2F$pname%2F$version%2Fendpoint.json
+          mkdir -p "$HOME/cache"
+
+          case $(basename $Request_URI) in
+            zipball)
+              file_response 200 OK "$zipball" application/zip
+              exit
+            ;;
+            elm.json)
+              if ! test -f "$elmjson"; then
+                unzip -p "$zipball" \*/elm.json > "$elmjson"
+              fi
+              file_response 200 OK "$elmjson" 'application/json; charset=UTF-8'
+              exit
+            ;;
+            endpoint.json)
+              if ! test -f "$endpointjson"; then
+                hash=$(sha1sum "$zipball" | cut -d\  -f1)
+                url=https://package.elm-lang.org/packages/$author/$pname/$version/zipball
+                jq -n \
+                    --arg hash "$hash" \
+                    --arg url "$url" \
+                    '{ $hash, $url }' \
+                  > "$endpointjson"
+              fi
+              file_response 200 OK "$endpointjson" 'application/json; charset=UTF-8'
+              exit
+            ;;
+          esac
+        ;;
+        'POST /all-packages/since/'*)
+
+          # TODO only show newest?
+          my_packages=$(
+            cd ${cfg.packageDir}
+            find -mindepth 3 -maxdepth 3 |
+            jq -Rs '
+              split("\n") |
+              map(
+                select(.!="") |
+                sub("^\\./(?<author>[^/]+)/(?<pname>[^/]+)/(?<version>[^/]+)$";"\(.author)/\(.pname)@\(.version)")
+              )
+            '
+          )
+
+          new_upstream_packages=$(
+            curl -fsS https://package.elm-lang.org"$Request_URI"
+          )
+
+          response=$(
+            jq -n \
+                --argjson my_packages "$my_packages" \
+                --argjson new_upstream_packages "$new_upstream_packages" \
+                '$new_upstream_packages + $my_packages'
+          )
+
+          string_response 200 OK "$response" 'application/json; charset=UTF-8'
+          exit
+        ;;
+      esac
+    ''})'';
+  };
+}