Package cloud is the root of the packages used to access Google Cloud Services. See https://godoc.org/cloud.google.com/go for a full list of sub-packages. All clients in sub-packages are configurable via client options. These options are described here: https://godoc.org/google.golang.org/api/option. All the clients in sub-packages support authentication via Google Application Default Credentials (see https://cloud.google.com/docs/authentication/production), or by providing a JSON key file for a Service Account. See the authentication examples in this package for details. By default, all requests in sub-packages will run indefinitely, retrying on transient errors when correctness allows. To set timeouts or arrange for cancellation, use contexts. See the examples for details. Do not attempt to control the initial connection (dialing) of a service by setting a timeout on the context passed to NewClient. Dialing is non-blocking, so timeouts would be ineffective and would only interfere with credential refreshing, which uses the same context. Connection pooling differs in clients based on their transport. Cloud clients either rely on HTTP or gRPC transports to communicate with Google Cloud. Cloud clients that use HTTP (bigquery, compute, storage, and translate) rely on the underlying HTTP transport to cache connections for later re-use. These are cached to the default http.MaxIdleConns and http.MaxIdleConnsPerHost settings in http.DefaultTransport. For gRPC clients (all others in this repo), connection pooling is configurable. Users of cloud client libraries may specify option.WithGRPCConnectionPool(n) as a client option to NewClient calls. This configures the underlying gRPC connections to be pooled and addressed in a round robin fashion. Minimal docker images like Alpine lack CA certificates. This causes RPCs to appear to hang, because gRPC retries indefinitely. See https://github.com/GoogleCloudPlatform/google-cloud-go/issues/928 for more information. To see gRPC logs, set the environment variable GRPC_GO_LOG_SEVERITY_LEVEL. See https://godoc.org/google.golang.org/grpc/grpclog for more information. For HTTP logging, set the GODEBUG environment variable to "http2debug=1" or "http2debug=2". Google Application Default Credentials is the recommended way to authorize and authenticate clients. For information on how to create and obtain Application Default Credentials, see https://developers.google.com/identity/protocols/application-default-credentials. To arrange for an RPC to be canceled, use context.WithCancel. You can use a file with credentials to authenticate and authorize, such as a JSON key file associated with a Google service account. Service Account keys can be created and downloaded from https://console.developers.google.com/permissions/serviceaccounts. This example uses the Datastore client, but the same steps apply to the other client libraries underneath this package. In some cases (for instance, you don't want to store secrets on disk), you can create credentials from in-memory JSON and use the WithCredentials option. The google package in this example is at golang.org/x/oauth2/google. This example uses the PubSub client, but the same steps apply to the other client libraries underneath this package. To set a timeout for an RPC, use context.WithTimeout.
Package libc provides run time support for programs generated by the ccgo C to Go transpiler, version 4 or later. Many C libc functions are not thread safe. Such functions are not safe for concurrent use by multiple goroutines in the Go translation as well. C threads are modeled as Go goroutines. Every such C thread, ie. a Go goroutine, must use its own Thread Local Storage instance implemented by the TLS type. Signal handling in translated C code is not coordinated with the Go runtime. This is probably the same as when running C code via CGo. This package synchronizes its environ with the current Go environ lazily and only once. From Linux man-pages Copyleft
Package data is a reverse proxy. It translates gRPC into RESTful JSON APIs.
Package flipt is a reverse proxy. It translates gRPC into RESTful JSON APIs.
Package tabwriter implements a write filter (tabwriter.Writer) that translates tabbed columns in input into properly aligned text. It is a drop-in replacement for the golang text/tabwriter package (https://golang.org/pkg/text/tabwriter), based on that package at https://github.com/golang/go/tree/cf2c2ea89d09d486bb018b1817c5874388038c3a with support for additional features. The package is using the Elastic Tabstops algorithm described at http://nickgravgaard.com/elastictabstops/index.html.
Package gorilla/schema fills a struct with form values. The basic usage is really simple. Given this struct: ...we can fill it passing a map to the Decode() function: This is just a simple example and it doesn't make a lot of sense to create the map manually. Typically it will come from a http.Request object and will be of type url.Values, http.Request.Form, or http.Request.MultipartForm: Note: it is a good idea to set a Decoder instance as a package global, because it caches meta-data about structs, and an instance can be shared safely: To define custom names for fields, use a struct tag "schema". To not populate certain fields, use a dash for the name and it will be ignored: The supported field types in the destination struct are: Non-supported types are simply ignored, however custom types can be registered to be converted. To fill nested structs, keys must use a dotted notation as the "path" for the field. So for example, to fill the struct Person below: ...the source map must have the keys "Name", "Phone.Label" and "Phone.Number". This means that an HTML form to fill a Person struct must look like this: Single values are filled using the first value for a key from the source map. Slices are filled using all values for a key from the source map. So to fill a Person with multiple Phone values, like: ...an HTML form that accepts three Phone values would look like this: Notice that only for slices of structs the slice index is required. This is needed for disambiguation: if the nested struct also had a slice field, we could not translate multiple values to it if we did not use an index for the parent struct. There's also the possibility to create a custom type that implements the TextUnmarshaler interface, and in this case there's no need to register a converter, like: ...an HTML form that accepts three Email values would look like this:
Package feegrant provides functionality for authorizing the payment of transaction fees from one account (key) to another account (key). Effectively, this allows for a user to pay fees using the balance of an account different from their own. Example use cases would be allowing a key on a device to pay for fees using a master wallet, or a third party service allowing users to pay for transactions without ever really holding their own coins. This package provides ways for specifying fee allowances such that authorizing fee payment to another account can be done with clear and safe restrictions. A user would authorize granting fee payment to another user using MsgGrantAllowance and revoke that delegation using MsgRevokeAllowance. In both cases, Granter is the one who is authorizing fee payment and Grantee is the one who is receiving the fee payment authorization. So grantee would correspond to the one who is signing a transaction and the granter would be the address that pays the fees. The fee allowance that a grantee receives is specified by an implementation of the FeeAllowance interface. Two FeeAllowance implementations are provided in this package: BasicAllowance and PeriodicAllowance. Package feegrant is a reverse proxy. It translates gRPC into RESTful JSON APIs.
Package pcre is a library that provides pcre2 regular expressions in pure Go, allowing for features such as cross-compiling. The lib directory contains source code automatically translated from pcre2's C source code for each supported architecture and/or OS. This package wraps the automatically-translated source to provide a safe interface as close to Go's regexp library as possible.
Package ice implements RFC 8445 Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal
Package fuse enables writing FUSE file systems on Linux, OS X, and FreeBSD. On OS X, it requires OSXFUSE (http://osxfuse.github.com/). There are two approaches to writing a FUSE file system. The first is to speak the low-level message protocol, reading from a Conn using ReadRequest and writing using the various Respond methods. This approach is closest to the actual interaction with the kernel and can be the simplest one in contexts such as protocol translators. Servers of synthesized file systems tend to share common bookkeeping abstracted away by the second approach, which is to call fs.Serve to serve the FUSE protocol using an implementation of the service methods in the interfaces FS* (file system), Node* (file or directory), and Handle* (opened file or directory). There are a daunting number of such methods that can be written, but few are required. The specific methods are described in the documentation for those interfaces. The hellofs subdirectory contains a simple illustration of the fs.Serve approach. The required and optional methods for the FS, Node, and Handle interfaces have the general form where Op is the name of a FUSE operation. Op reads request parameters from req and writes results to resp. An operation whose only result is the error result omits the resp parameter. Multiple goroutines may call service methods simultaneously; the methods being called are responsible for appropriate synchronization. The operation must not hold on to the request or response, including any []byte fields such as WriteRequest.Data or SetxattrRequest.Xattr. Operations can return errors. The FUSE interface can only communicate POSIX errno error numbers to file system clients, the message is not visible to file system clients. The returned error can implement ErrorNumber to control the errno returned. Without ErrorNumber, a generic errno (EIO) is returned. Error messages will be visible in the debug log as part of the response. In some file systems, some operations may take an undetermined amount of time. For example, a Read waiting for a network message or a matching Write might wait indefinitely. If the request is cancelled and no longer needed, the context will be cancelled. Blocking operations should select on a receive from ctx.Done() and attempt to abort the operation early if the receive succeeds (meaning the channel is closed). To indicate that the operation failed because it was aborted, return fuse.EINTR. If an operation does not block for an indefinite amount of time, supporting cancellation is not necessary. All requests types embed a Header, meaning that the method can inspect req.Pid, req.Uid, and req.Gid as necessary to implement permission checking. The kernel FUSE layer normally prevents other users from accessing the FUSE file system (to change this, see AllowOther, AllowRoot), but does not enforce access modes (to change this, see DefaultPermissions). Behavior and metadata of the mounted file system can be changed by passing MountOption values to Mount.