mirror of https://github.com/ceph/go-ceph
85 lines
2.1 KiB
Markdown
85 lines
2.1 KiB
Markdown
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# API Hints & Quick How-Tos
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Below you'll find some brief sections that show how some of the API calls
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in go-ceph work together. This is not meant to cover every possible use
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case but are recorded here as a quick way to get familiar with these
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calls.
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## rados Package
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### Connecting to a cluster
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Connect to a Ceph cluster using a configuration file located in the default
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search paths.
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```go
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conn, _ := rados.NewConn()
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conn.ReadDefaultConfigFile()
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conn.Connect()
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```
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A connection can be shutdown by calling the `Shutdown` method on the
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connection object (e.g. `conn.Shutdown()`). There are also other methods for
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configuring the connection. Specific configuration options can be set:
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```go
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conn.SetConfigOption("log_file", "/dev/null")
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```
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and command line options can also be used using the `ParseCmdLineArgs` method.
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```go
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args := []string{ "--mon-host", "1.1.1.1" }
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err := conn.ParseCmdLineArgs(args)
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```
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For other configuration options see the full documentation.
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### Object I/O
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Object in RADOS can be written to and read from with through an interface very
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similar to a standard file I/O interface:
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```go
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// open a pool handle
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ioctx, err := conn.OpenIOContext("mypool")
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// write some data
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bytesIn := []byte("input data")
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err = ioctx.Write("obj", bytesIn, 0)
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// read the data back out
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bytesOut := make([]byte, len(bytesIn))
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_, err := ioctx.Read("obj", bytesOut, 0)
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if !bytes.Equal(bytesIn, bytesOut) {
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fmt.Println("Output is not input!")
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}
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```
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### Pool maintenance
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The list of pools in a cluster can be retreived using the `ListPools` method
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on the connection object. On a new cluster the following code snippet:
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```go
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pools, _ := conn.ListPools()
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fmt.Println(pools)
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```
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will produce the output `[data metadata rbd]`, along with any other pools that
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might exist in your cluster. Pools can also be created and destroyed. The
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following creates a new, empty pool with default settings.
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```go
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conn.MakePool("new_pool")
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```
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Deleting a pool is also easy. Call `DeletePool(name string)` on a connection object to
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delete a pool with the given name. The following will delete the pool named
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`new_pool` and remove all of the pool's data.
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```go
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conn.DeletePool("new_pool")
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```
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