1. govendor簡介

golang工程的依賴包經常使用go get命令來獲取，例如：go get github.com/kardianos/govendor ，會將依賴包下載到GOPATH的路徑下。

常用的依賴包管理工具有godep，govendor等，在Golang1.5之後，Go提供了 GO15VENDOREXPERIMENT 環境變數(Go 1.6版本預設開啟該環境變數)，用於將go build時的應用路徑搜尋調整成為 當前專案目錄/vendor 目錄方式。通過這種形式，我們可以實現類似於 godep 方式的專案依賴管理。

2. 安裝與使用

2.1. 安裝

go get -u -v github.
 
com/kardianos/govendor

2.2. 使用

#進入到專案目錄
cd /home/gopath/src/mytool

#初始化vendor目錄
govendor init

#檢視vendor目錄
[[email protected] mytool]# ls
commands  main.go  vendor  mytool_test.sh

#將GOPATH中本工程使用到的依賴包自動移動到vendor目錄中
#說明：如果本地GOPATH沒有依賴包，先go get相應的依賴包
govendor add +external
或使用縮寫： govendor add +e 

#Go 1.6以上版本預設開啟 GO15VENDOREXPERIMENT 環境變數，可忽略該步驟。
 

#通過設定環境變數 GO15VENDOREXPERIMENT=1 使用vendor資料夾構建檔案。
#可以選擇 export GO15VENDOREXPERIMENT=1 或 GO15VENDOREXPERIMENT=1 go build 執行編譯
export GO15VENDOREXPERIMENT=1

2.3. 說明

govendor只是用來管理專案的依賴包，如果GOPATH中本身沒有專案的依賴包，則需要通過go get先下載到GOPATH中，再通過govendor add +external拷貝到vendor目錄中。Go 1.6以上版本預設開啟GO15VENDOREXPERIMENT環境變數

3. govendor使用命令

[[email protected] mytool]# govendor
govendor (v1.0.8): record dependencies and copy into vendor folder
    -govendor-licenses    Show govendor's licenses.
    -version              Show govendor version
    -cpuprofile 'file'    Writes a CPU profile to 'file' for debugging.
    -memprofile 'file'    Writes a heap profile to 'file' for debugging.
Sub-Commands
    init     Create the "vendor" folder and the "vendor.json" file.
    list     List and filter existing dependencies and packages.
    add      Add packages from $GOPATH.
    update   Update packages from $GOPATH.
    remove   Remove packages from the vendor folder.
    status   Lists any packages missing, out-of-date, or modified locally.
    fetch    Add new or update vendor folder packages from remote repository.
    sync     Pull packages into vendor folder from remote repository with revisions
                 from vendor.json file.
    migrate  Move packages from a legacy tool to the vendor folder with metadata.
    get      Like "go get" but copies dependencies into a "vendor" folder.
    license  List discovered licenses for the given status or import paths.
    shell    Run a "shell" to make multiple sub-commands more efficient for large
                 projects.
    go tool commands that are wrapped:
      "+status" package selection may be used with them
    fmt, build, install, clean, test, vet, generate, tool
Status Types
    +local    (l) packages in your project
    +external (e) referenced packages in GOPATH but not in current project
    +vendor   (v) packages in the vendor folder
    +std      (s) packages in the standard library
    +excluded (x) external packages explicitly excluded from vendoring
    +unused   (u) packages in the vendor folder, but unused
    +missing  (m) referenced packages but not found
    +program  (p) package is a main package
    +outside  +external +missing
    +all      +all packages
    Status can be referenced by their initial letters.
Package specifier
    <path>[::<origin>][{/...|/^}][@[<version-spec>]]
Ignoring files with build tags, or excluding packages from being vendored:
    The "vendor.json" file contains a string field named "ignore".
    It may contain a space separated list of build tags to ignore when
    listing and copying files.
    This list may also contain package prefixes (containing a "/", possibly
    as last character) to exclude when copying files in the vendor folder.
    If "foo/" appears in this field, then package "foo" and all its sub-packages
    ("foo/bar", …) will be excluded (but package "bar/foo" will not).
    By default the init command adds the "test" tag to the ignore list.
If using go1.5, ensure GO15VENDOREXPERIMENT=1 is set.

4. vendor.json

govendor配置檔案，記錄依賴包列表。

{
    "comment": "",
    "ignore": "test",
    "package": [
        {
            "checksumSHA1": "uGalSICR4r7354vvKuNnh7Y/R/4=",
            "path": "github.com/urfave/cli",
            "revision": "b99aa811b4c1dd84cc6bccb8499c82c72098085a",
            "revisionTime": "2017-08-04T09:34:15Z"
        }
    ],
    "rootPath": "mytool"
}