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Diffstat (limited to 'web/bubblegum/default.nix')
| -rw-r--r-- | web/bubblegum/default.nix | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/web/bubblegum/default.nix b/web/bubblegum/default.nix new file mode 100644 index 000000000000..528d73032ba6 --- /dev/null +++ b/web/bubblegum/default.nix @@ -0,0 +1,267 @@ +{ depot, lib, pkgs, ... }: + +let + + inherit (depot.nix) + runExecline + getBins + utils + sparseTree + nint + ; + + minimalDepot = sparseTree depot.path.origSrc [ + # general depot things + "default.nix" + "nix/readTree" + # nixpkgs for lib and packages + "third_party/nixpkgs" + "third_party/overlays" + # bubblegum and its dependencies + "web/bubblegum" + "nix/runExecline" + "nix/utils" + "nix/sparseTree" + # tvix docs for svg demo + "tvix/docs" + # for blog.nix + "users/sterni/nix" + ]; + + statusCodes = { + # 1xx + "Continue" = 100; + "Switching Protocols" = 101; + "Processing" = 102; + "Early Hints" = 103; + # 2xx + "OK" = 200; + "Created" = 201; + "Accepted" = 202; + "Non-Authoritative Information" = 203; + "No Content" = 204; + "Reset Content" = 205; + "Partial Content" = 206; + "Multi Status" = 207; + "Already Reported" = 208; + "IM Used" = 226; + # 3xx + "Multiple Choices" = 300; + "Moved Permanently" = 301; + "Found" = 302; + "See Other" = 303; + "Not Modified" = 304; + "Use Proxy" = 305; + "Switch Proxy" = 306; + "Temporary Redirect" = 307; + "Permanent Redirect" = 308; + # 4xx + "Bad Request" = 400; + "Unauthorized" = 401; + "Payment Required" = 402; + "Forbidden" = 403; + "Not Found" = 404; + "Method Not Allowed" = 405; + "Not Acceptable" = 406; + "Proxy Authentication Required" = 407; + "Request Timeout" = 408; + "Conflict" = 409; + "Gone" = 410; + "Length Required" = 411; + "Precondition Failed" = 412; + "Payload Too Large" = 413; + "URI Too Long" = 414; + "Unsupported Media Type" = 415; + "Range Not Satisfiable" = 416; + "Expectation Failed" = 417; + "I'm a teapot" = 418; + "Misdirected Request" = 421; + "Unprocessable Entity" = 422; + "Locked" = 423; + "Failed Dependency" = 424; + "Too Early" = 425; + "Upgrade Required" = 426; + "Precondition Required" = 428; + "Too Many Requests" = 429; + "Request Header Fields Too Large" = 431; + "Unavailable For Legal Reasons" = 451; + # 5xx + "Internal Server Error" = 500; + "Not Implemented" = 501; + "Bad Gateway" = 502; + "Service Unavailable" = 503; + "Gateway Timeout" = 504; + "HTTP Version Not Supported" = 505; + "Variant Also Negotiates" = 506; + "Insufficient Storage" = 507; + "Loop Detected" = 508; + "Not Extended" = 510; + "Network Authentication Required" = 511; + }; + + /* Generate a CGI response. Takes three arguments: + + 1. Status of the response as a string which is + the descriptive name in the protocol, e. g. + `"OK"`, `"Not Found"` etc. + 2. Attribute set describing extra headers to + send, keys and values should both be strings. + 3. Response content as a string. + + See the [README](./README.md) for an example. + + Type: either int string -> attrs string -> string -> string + */ + respond = + # response status as an integer (status code) or its + # textual representation in the HTTP protocol. + # See `statusCodes` for a list of valid options. + statusArg: + # headers as an attribute set of strings + headers: + # response body as a string + bodyArg: + let + status = + if builtins.isInt statusArg + then { + code = statusArg; + line = lib.findFirst + (line: statusCodes."${line}" == statusArg) + null + (builtins.attrNames statusCodes); + } else if builtins.isString statusArg then { + code = statusCodes."${statusArg}" or null; + line = statusArg; + } else { + code = null; + line = null; + }; + renderedHeaders = lib.concatStrings + (lib.mapAttrsToList (n: v: "${n}: ${toString v}\r\n") headers); + internalError = msg: respond 500 + { + Content-type = "text/plain"; + } "bubblegum error: ${msg}"; + body = builtins.tryEval bodyArg; + in + if status.code == null || status.line == null + then internalError "Invalid status ${lib.generators.toPretty {} statusArg}." + else if !body.success + then internalError "Unknown evaluation error in user code" + else + lib.concatStrings [ + "Status: ${toString status.code} ${status.line}\r\n" + renderedHeaders + "\r\n" + body.value + ]; + + /* Returns the value of the `SCRIPT_NAME` environment + variable used by CGI. + */ + scriptName = builtins.getEnv "SCRIPT_NAME"; + + /* Returns the value of the `PATH_INFO` environment + variable used by CGI. All cases that could be + considered as the CGI script's root (i. e. + `PATH_INFO` is empty or `/`) is mapped to `"/"` + for convenience. + */ + pathInfo = + let + p = builtins.getEnv "PATH_INFO"; + in + if builtins.stringLength p == 0 + then "/" + else p; + + /* Helper function which converts a path from the + root of the CGI script (i. e. something which + could be the content of `PATH_INFO`) to an + absolute path from the web root by also + utilizing `scriptName`. + + Type: string -> string + */ + absolutePath = path: + if builtins.substring 0 1 path == "/" + then "${scriptName}${path}" + else "${scriptName}/${path}"; + + bins = getBins pkgs.coreutils [ "env" "tee" "cat" "printf" "chmod" ] + // getBins nint [ "nint" ]; + + /* Type: args -> either path derivation string -> derivation + */ + writeCGI = + { + # if given sets the `PATH` to search for `nix-instantiate` + # Useful when using for example thttpd which unsets `PATH` + # in the CGI environment. + binPath ? "" + # name of the resulting derivation. Defaults to `baseNameOf` + # the input path or name of the input derivation. + # Must be given if the input is a string. + , name ? null + , ... + }@args: + input: + let + drvName = + if builtins.isString input || args ? name + then args.name + else utils.storePathName input; + script = + if builtins.isPath input || lib.isDerivation input + then input + else if builtins.isString input + then pkgs.writeText "${drvName}-source" input + else builtins.throw "Unsupported input: ${lib.generators.toPretty {} input}"; + shebang = lib.concatStringsSep " " ([ + "#!${bins.env}" + # use the slightly cursed /usr/bin/env -S which allows us + # to pass any number of arguments to our interpreter + # instead of maximum one using plain shebang which considers + # everything after the first space as the second argument. + "-S" + ] ++ lib.optionals (builtins.stringLength binPath > 0) [ + "PATH=${binPath}" + ] ++ [ + "${bins.nint}" + # always pass depot so scripts can use this library + "--arg depot '(import ${minimalDepot} {})'" + ]); + in + runExecline.local drvName { } [ + "importas" + "out" + "out" + "pipeline" + [ + "foreground" + [ + "if" + [ bins.printf "%s\n" shebang ] + ] + "if" + [ bins.cat script ] + ] + "if" + [ bins.tee "$out" ] + "if" + [ bins.chmod "+x" "$out" ] + "exit" + "0" + ]; + +in +{ + inherit + respond + pathInfo + scriptName + absolutePath + writeCGI + ; +} |