54 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Markdown
		
	
	
	
		
			Vendored
		
	
	
	
			
		
		
	
	
			54 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Markdown
		
	
	
	
		
			Vendored
		
	
	
	
| # procfs
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| 
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| This procfs package provides functions to retrieve system, kernel and process
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| metrics from the pseudo-filesystems /proc and /sys.
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| 
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| *WARNING*: This package is a work in progress. Its API may still break in
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| backwards-incompatible ways without warnings. Use it at your own risk.
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| 
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| [](https://godoc.org/github.com/prometheus/procfs)
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| [](https://travis-ci.org/prometheus/procfs)
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| [](https://goreportcard.com/report/github.com/prometheus/procfs)
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| 
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| ## Usage
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| 
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| The procfs library is organized by packages based on whether the gathered data is coming from
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| /proc, /sys, or both.  Each package contains an `FS` type which represents the path to either /proc, /sys, or both.  For example, current cpu statistics are gathered from
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| `/proc/stat` and are available via the root procfs package.  First, the proc filesystem mount
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| point is initialized, and then the stat information is read.
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| 
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| ```go
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| fs, err := procfs.NewFS("/proc")
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| stats, err := fs.Stat()
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| ```
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| 
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| Some sub-packages such as `blockdevice`, require access to both the proc and sys filesystems.
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| 
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| ```go
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|     fs, err := blockdevice.NewFS("/proc", "/sys")
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|     stats, err := fs.ProcDiskstats()
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| ```
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| 
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| ## Building and Testing
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| 
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| The procfs library is normally built as part of another application.  However, when making
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| changes to the library, the `make test` command can be used to run the API test suite.
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| 
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| ### Updating Test Fixtures
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| 
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| The procfs library includes a set of test fixtures which include many example files from
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| the `/proc` and `/sys` filesystems.  These fixtures are included as a [ttar](https://github.com/ideaship/ttar) file
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| which is extracted automatically during testing.  To add/update the test fixtures, first
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| ensure the `fixtures` directory is up to date by removing the existing directory and then
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| extracting the ttar file using `make fixtures/.unpacked` or just `make test`.
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| 
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| ```bash
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| rm -rf fixtures
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| make test
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| ```
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| 
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| Next, make the required changes to the extracted files in the `fixtures` directory.  When
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| the changes are complete, run `make update_fixtures` to create a new `fixtures.ttar` file
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| based on the updated `fixtures` directory.  And finally, verify the changes using
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| `git diff fixtures.ttar`.
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