如您所指出的，没有用于golang的官方keycloak适配器。但是实现它非常简单。这是一个小步。

Keycloak服务器

对于此示例，我将使用官方的keycloak docker映像来启动服务器。使用的版本是4.1.0.Final。我认为这也适用于较旧的KeyCloak版本。

docker run -d -p 8080:8080 -e KEYCLOAK_USER=keycloak -e KEYCLOAK_PASSWORD=k --name keycloak jboss/keycloak:4.1.0.Final

服务器启动并运行后，可以localhost:8080/auth在浏览器中打开，导航到管理控制台，并使用用户名keycloak和k相应的密码登录。

我不会完成创建领域/客户/用户的完整过程。您可以在https://www.keycloak.org/docs/latest/server_admin/index.html#admin-
console下查找此内容

这只是我为重现此示例所做的概述：

1. 创建一个名为 demo
2. 关闭此领域的SSL要求（realmsettings->登录-> require ssl）
3. 创建一个名为的客户端demo-client（将“访问类型”更改为机密）
4. 使用密码演示创建一个名为demo的用户（用户->添加用户）。确保激活并模拟该用户。
5. 将演示客户端配置为机密并http://localhost:8181/demo/callback用作有效的重定向URI。

生成的keycloak.json（从安装选项卡获得）如下所示：

{
    "realm": "demo",
    "auth-server-url": "http://localhost:8080/auth",
    "ssl-required": "none",
    "resource": "demo-client",
    "credentials": {
        "secret": "cbfd6e04-a51c-4982-a25b-7aaba4f30c81"
    },
    "confidential-port": 0
}

请注意，您的秘密将有所不同。

Go服务器

让我们转到go服务器。我将github.com/coreos/go-oidc包装用于繁重的工作：

package main

import (
    "context"
    "encoding/json"
    "log"
    "net/http"
    "strings"

    oidc "github.com/coreos/go-oidc"
    "golang.org/x/oauth2"
)

func main() {
    configURL := "http://localhost:8080/auth/realms/demo"
    ctx := context.Background()
    provider, err := oidc.NewProvider(ctx, configURL)
    if err != nil {
        panic(err)
    }

    clientID := "demo-client"
    clientSecret := "cbfd6e04-a51c-4982-a25b-7aaba4f30c81"

    redirectURL := "http://localhost:8181/demo/callback"
    // Configure an OpenID Connect aware OAuth2 client.
    oauth2Config := oauth2.Config{
        ClientID:     clientID,
        ClientSecret: clientSecret,
        RedirectURL:  redirectURL,
        // Discovery returns the OAuth2 endpoints.
        Endpoint: provider.Endpoint(),
        // "openid" is a required scope for OpenID Connect flows.
        Scopes: []string{oidc.ScopeOpenID, "profile", "email"},
    }
    state := "somestate"

    oidcConfig := &oidc.Config{
        ClientID: clientID,
    }
    verifier := provider.Verifier(oidcConfig)

    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        rawAccessToken := r.Header.Get("Authorization")
        if rawAccessToken == "" {
            http.Redirect(w, r, oauth2Config.AuthCodeURL(state), http.StatusFound)
            return
        }

        parts := strings.Split(rawAccessToken, " ")
        if len(parts) != 2 {
            w.WriteHeader(400)
            return
        }
        _, err := verifier.Verify(ctx, parts[1])

        if err != nil {
            http.Redirect(w, r, oauth2Config.AuthCodeURL(state), http.StatusFound)
            return
        }

        w.Write([]byte("hello world"))
    })

    http.HandleFunc("/demo/callback", func(w http.ResponseWriter, r *http.Request) {
        if r.URL.Query().Get("state") != state {
            http.Error(w, "state did not match", http.StatusBadRequest)
            return
        }

        oauth2Token, err := oauth2Config.Exchange(ctx, r.URL.Query().Get("code"))
        if err != nil {
            http.Error(w, "Failed to exchange token: "+err.Error(), http.StatusInternalServerError)
            return
        }
        rawIDToken, ok := oauth2Token.Extra("id_token").(string)
        if !ok {
            http.Error(w, "No id_token field in oauth2 token.", http.StatusInternalServerError)
            return
        }
        idToken, err := verifier.Verify(ctx, rawIDToken)
        if err != nil {
            http.Error(w, "Failed to verify ID Token: "+err.Error(), http.StatusInternalServerError)
            return
        }

        resp := struct {
            OAuth2Token   *oauth2.Token
            IDTokenClaims *json.RawMessage // ID Token payload is just JSON.
        }{oauth2Token, new(json.RawMessage)}

        if err := idToken.Claims(&resp.IDTokenClaims); err != nil {
            http.Error(w, err.Error(), http.StatusInternalServerError)
            return
        }
        data, err := json.MarshalIndent(resp, "", "    ")
        if err != nil {
            http.Error(w, err.Error(), http.StatusInternalServerError)
            return
        }
        w.Write(data)
    })

    log.Fatal(http.ListenAndServe("localhost:8181", nil))
}

该程序启动具有两个端点的常规http服务器。第一个（“ /”）是处理应用程序逻辑的常规端点。在这种情况下，它只会向您的客户返回“ hello world”。

第二个端点（“ / demo /
callback”）用作keycloak的回调。该终结点需要在您的keycloak服务器上注册。成功进行用户身份验证后，Keycloak将发出重定向到该回调URL的链接。重定向包含一些其他查询参数。这些参数包含可用于获取访问/
ID令牌的代码。

验证您的设置

为了测试此设置，您可以打开Web浏览器并将其导航到http://localhost:8181。该请求应到达您的go服务器，该服务器尝试对您进行身份验证。由于您未发送令牌，因此go服务器会将您重定向到keycloak进行身份验证。您应该会看到keycloak的登录屏幕。使用您为此领域创建的演示用户（演示/演示）登录。如果您正确配置了密钥斗篷，它将对您进行身份验证并将您重定向到go服务器回调。

最终结果应该是这样的json

{
    "OAuth2Token": {
        "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJsc1hHR2VxSmx3UUZweWVYR0x6b2plZXBYSEhXUngtTHVJTVVLdDBmNmlnIn0.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.KERz8rBddxM9Qho3kgigX-fClWqbKY-3JcWT3JOQDoLa-prkorfa40BWlyf9ULVgjzT2d8FLJpqQIQYvucKU7Q7vFBVIjTGucUZaE7b6JGMea5H34A1i-MNm7L2CzDJ2GnBONhNwLKoftTSl0prbzwkzcVrps-JAZ6L2gssSa5hBBGJYBKAUfm1OIb57Jq0vzro3vLghZ4Ay7iNunwfcHUrxiFJfUjaU6PQwzrA5pnItOPuavJFUgso7-3JLtn3X9GQuyyZKrkDo6-gzU0JZmkQQzAXXgt43NxooryImuacwSB5xbIKY6qFkedldoOPehld1-oLv0Yy_FIwEad3uLw",
        "token_type": "bearer",
        "refresh_token": "eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJsc1hHR2VxSmx3UUZweWVYR0x6b2plZXBYSEhXUngtTHVJTVVLdDBmNmlnIn0.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.FvvDW6ZSH8mlRR2zgaN1zesX14SmkCs9RrIVU4Jn1-SHVdKEA6YKur0-RUAFTObQDMLVhFFJ05AjGVGWpBrgVDcAwW2pI9saM-OHlyTJ3VfFoylgfzakVOIpbIDnHO12UaJrkOI9NWPAJdbBOzBHfsDhKbxhjg4ZX8SwlKr42rV4WWuSRcNu4_YDVO19SiXSCKXVldZ1_2S-qPvViq7VZfaoRLHuYyDvma_ByMsmib9JUkevJ8dxsYxVQ5FWaAfFanh1a1f8HxNRI-Cl180oPn1_Tqq_SYwxzBCw7Q_ENkMirwRS1a4cX9yMVEDW2uvKz2D-OiNAUK8d_ONuPEkTGQ",
        "expiry": "2018-07-21T13:47:28.986686385+02:00"
    },
    "IDTokenClaims": {
        "jti": "f4d56526-37d9-4d32-b99d-81090e92d3a7",
        "exp": 1532173652,
        "nbf": 0,
        "iat": 1532173352,
        "iss": "http://localhost:8080/auth/realms/demo",
        "aud": "demo-client",
        "sub": "38338c8b-ad7f-469f-8398-17989581ba12",
        "typ": "ID",
        "azp": "demo-client",
        "auth_time": 1532173352,
        "session_state": "ce865add-67b8-4905-8f03-9c1603c1ba0d",
        "acr": "1",
        "email_verified": true,
        "preferred_username": "demo",
        "email": "demo@demo.com"
    }
}

您可以复制访问令牌并使用curl来验证服务器是否能够接受您的令牌：

# use your complete access token here
export TOKEN="eyJhbG..."
curl -H "Authorization: Bearer $TOKEN" localhost:8181
# output hello world

您可以在令牌过期后重试-或对令牌进行调整。如果这样做，您应该再次重定向到您的keycloak服务器。