Python 如何获取在Google云上运行的计算引擎实例数

在Google Cloud文档中，获取在Google Cloud中的项目上运行的实例的列表和数量的命令行如下所示：

gcloud compute instances list

或

---

如何使用Google Cloud获得Python中的等效函数？

这里有相关文档：

简言之：

import googleapiclient.discovery

project="your project"
zone="your zone"

compute = googleapiclient.discovery.build('compute', 'v1')
instances = compute.instances().list(project=project, zone=zone).execute()

for instance in instances:
    print(' - ' + instance['name'])

---

这里有关于这方面的文件：

简言之：

import googleapiclient.discovery

project="your project"
zone="your zone"

compute = googleapiclient.discovery.build('compute', 'v1')
instances = compute.instances().list(project=project, zone=zone).execute()

for instance in instances:
    print(' - ' + instance['name'])

---

下面是我编写的一个示例，它使用RESTAPI而不使用Google Cloud SDK

本例将向您介绍服务帐户、授权、访问令牌和计算引擎RESTAPI的底层细节

'''
This program lists lists the Google Compute Engine Instances in one zone
'''

import time
import json
import jwt
import requests
import httplib2

# Project ID for this request.
project = 'development-123456'

# The name of the zone for this request.
zone = 'us-west1-a'

# Service Account Credentials, Json format
json_filename = 'service-account.json'

# Permissions to request for Access Token
scopes = "https://www.googleapis.com/auth/cloud-platform"

# Set how long this token will be valid in seconds
expires_in = 3600   # Expires in 1 hour

def load_json_credentials(filename):
    ''' Load the Google Service Account Credentials from Json file '''

    with open(filename, 'r') as f:
        data = f.read()

    return json.loads(data)

def load_private_key(json_cred):
    ''' Return the private key from the json credentials '''

    return json_cred['private_key']

def create_signed_jwt(pkey, pkey_id, email, scope):
    '''
    Create a Signed JWT from a service account Json credentials file
    This Signed JWT will later be exchanged for an Access Token
    '''

    # Google Endpoint for creating OAuth 2.0 Access Tokens from Signed-JWT
    auth_url = "https://www.googleapis.com/oauth2/v4/token"

    issued = int(time.time())
    expires = issued + expires_in   # expires_in is in seconds

    # Note: this token expires and cannot be refreshed. The token must be recreated

    # JWT Headers
    additional_headers = {
            'kid': pkey_id,
            "alg": "RS256",
            "typ": "JWT"    # Google uses SHA256withRSA
    }

    # JWT Payload
    payload = {
        "iss": email,       # Issuer claim
        "sub": email,       # Issuer claim
        "aud": auth_url,    # Audience claim
        "iat": issued,      # Issued At claim
        "exp": expires,     # Expire time
        "scope": scope      # Permissions
    }

    # Encode the headers and payload and sign creating a Signed JWT (JWS)
    sig = jwt.encode(payload, pkey, algorithm="RS256", headers=additional_headers)

    return sig

def exchangeJwtForAccessToken(signed_jwt):
    '''
    This function takes a Signed JWT and exchanges it for a Google OAuth Access Token
    '''

    auth_url = "https://www.googleapis.com/oauth2/v4/token"

    params = {
        "grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
        "assertion": signed_jwt
    }

    r = requests.post(auth_url, data=params)

    if r.ok:
        return(r.json()['access_token'], '')

    return None, r.text

def gce_list_instances(accessToken):
    '''
    This functions lists the Google Compute Engine Instances in one zone
    '''

    # Endpoint that we will call
    url = "https://www.googleapis.com/compute/v1/projects/" + project + "/zones/" + zone + "/instances"

    # One of the headers is "Authorization: Bearer $TOKEN"
    headers = {
        "Host": "www.googleapis.com",
        "Authorization": "Bearer " + accessToken,
        "Content-Type": "application/json"
    }

    h = httplib2.Http()

    resp, content = h.request(uri=url, method="GET", headers=headers)

    status = int(resp.status)

    if status < 200 or status >= 300:
        print('Error: HTTP Request failed')
        return

    j = json.loads(content.decode('utf-8').replace('\n', ''))

    print('Compute instances in zone', zone)
    print('------------------------------------------------------------')
    for item in j['items']:
        print(item['name'])

if __name__ == '__main__':
    cred = load_json_credentials(json_filename)

    private_key = load_private_key(cred)

    s_jwt = create_signed_jwt(
            private_key,
            cred['private_key_id'],
            cred['client_email'],
            scopes)

    token, err = exchangeJwtForAccessToken(s_jwt)

    if token is None:
        print('Error:', err)
        exit(1)

    gce_list_instances(token)

“”
此程序在一个区域中列出Google计算引擎实例
'''
导入时间
导入json
进口jwt
导入请求
导入httplib2
#此请求的项目ID。
项目='development-123456'
#此请求的区域的名称。
区域='us-west1-a'
#服务帐户凭据，Json格式
json_filename='service account.json'
#请求访问令牌的权限
作用域=”https://www.googleapis.com/auth/cloud-platform"
#设置此令牌的有效时间（秒）
expires_in=3600#1小时后过期
def load_json_凭据（文件名）：
''从Json文件''加载Google服务帐户凭据'
将open（filename，'r'）作为f：
data=f.read（）
返回json.loads（数据）
def load_private_key（json_cred）：
''从json凭据返回私钥''
返回json_cred['private_key']
def create_signed_jwt（pkey、pkey_id、电子邮件、范围）：
'''
从服务帐户Json凭据文件创建签名JWT
该签名JWT稍后将被交换为访问令牌
'''
#用于从签名JWT创建OAuth 2.0访问令牌的Google端点
验证url=”https://www.googleapis.com/oauth2/v4/token"
已发布=int（time.time（））
expires=已发布+过期（以秒为单位）
#注意：此令牌过期，无法刷新。必须重新创建令牌
#JWT头
其他_头={
“孩子”：pkey_id，
“alg”：“RS256”，
“类型”：“JWT”#谷歌将SHA256与RSA一起使用
}
#JWT有效载荷
有效载荷={
“iss”：电子邮件，#发行人索赔
“sub”：电子邮件，#发行人索赔
“aud”：授权url，#观众声明
“iat”：签发，#在索赔时签发
“exp”：过期，#过期时间
“范围”：范围#权限
}
#对报头和有效负载进行编码并签名创建签名JWT（JWS）
sig=jwt.encode（有效载荷，pkey，algorithm=“RS256”，头文件=附加的头文件）
返回信号
def exchangeJwtForAccessToken（已签名）：
'''
此函数获取签名JWT并将其交换为Google OAuth访问令牌
'''
验证url=”https://www.googleapis.com/oauth2/v4/token"
参数={
“授权类型”：“urn:ietf:params:oauth:grant-type:jwt-bearer”，
“断言”：签名的jwt
}
r=requests.post（auth_url，data=params）
如果r.ok：
返回（r.json（）['access_token']，''）
返回None，r.text
def gce_列表_实例（accessToken）：
'''
此函数在一个区域中列出Google计算引擎实例
'''
#我们将调用的端点
url=”https://www.googleapis.com/compute/v1/projects/“+project+”/zones/“+zone+”/instances”
#其中一个标题是“Authorization:Bearer$TOKEN”
标题={
“主持人”：“www.googleapis.com”，
“授权”：“持票人”+accessToken，
“内容类型”：“应用程序/json”
}
h=httplib2.Http（）
resp，content=h.request（uri=url，method=“GET”，headers=headers）
状态=整数（对应状态）
如果状态<200或状态>=300：
打印（'错误：HTTP请求失败'）
返回
j=json.load（content.decode（'utf-8'）。replace（'\n'，''）
打印（'区域中的计算实例'，区域）
打印（'---------------------------------------------------------------'）
对于j['items']中的项目：
打印（项目['name']）
如果uuuu name uuuuuu='\uuuuuuu main\uuuuuuu'：
cred=load_json_凭证（json_文件名）
私钥=加载私钥（cred）
s_jwt=创建_签名的_jwt(
私钥，
cred['private_key_id']，
cred[“客户电子邮件”]，
范围）
令牌，err=exchangeJwtForAccessToken（s_jwt）
如果令牌为无：
打印（'错误：'，错误）
出口（1）
gce_列表_实例（令牌）

下面是我编写的一个示例，它使用RESTAPI而不使用Google Cloud SDK

本例将向您介绍服务帐户、授权、访问令牌和计算引擎RESTAPI的底层细节

'''
This program lists lists the Google Compute Engine Instances in one zone
'''

import time
import json
import jwt
import requests
import httplib2

# Project ID for this request.
project = 'development-123456'

# The name of the zone for this request.
zone = 'us-west1-a'

# Service Account Credentials, Json format
json_filename = 'service-account.json'

# Permissions to request for Access Token
scopes = "https://www.googleapis.com/auth/cloud-platform"

# Set how long this token will be valid in seconds
expires_in = 3600   # Expires in 1 hour

def load_json_credentials(filename):
    ''' Load the Google Service Account Credentials from Json file '''

    with open(filename, 'r') as f:
        data = f.read()

    return json.loads(data)

def load_private_key(json_cred):
    ''' Return the private key from the json credentials '''

    return json_cred['private_key']

def create_signed_jwt(pkey, pkey_id, email, scope):
    '''
    Create a Signed JWT from a service account Json credentials file
    This Signed JWT will later be exchanged for an Access Token
    '''

    # Google Endpoint for creating OAuth 2.0 Access Tokens from Signed-JWT
    auth_url = "https://www.googleapis.com/oauth2/v4/token"

    issued = int(time.time())
    expires = issued + expires_in   # expires_in is in seconds

    # Note: this token expires and cannot be refreshed. The token must be recreated

    # JWT Headers
    additional_headers = {
            'kid': pkey_id,
            "alg": "RS256",
            "typ": "JWT"    # Google uses SHA256withRSA
    }

    # JWT Payload
    payload = {
        "iss": email,       # Issuer claim
        "sub": email,       # Issuer claim
        "aud": auth_url,    # Audience claim
        "iat": issued,      # Issued At claim
        "exp": expires,     # Expire time
        "scope": scope      # Permissions
    }

    # Encode the headers and payload and sign creating a Signed JWT (JWS)
    sig = jwt.encode(payload, pkey, algorithm="RS256", headers=additional_headers)

    return sig

def exchangeJwtForAccessToken(signed_jwt):
    '''
    This function takes a Signed JWT and exchanges it for a Google OAuth Access Token
    '''

    auth_url = "https://www.googleapis.com/oauth2/v4/token"

    params = {
        "grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
        "assertion": signed_jwt
    }

    r = requests.post(auth_url, data=params)

    if r.ok:
        return(r.json()['access_token'], '')

    return None, r.text

def gce_list_instances(accessToken):
    '''
    This functions lists the Google Compute Engine Instances in one zone
    '''

    # Endpoint that we will call
    url = "https://www.googleapis.com/compute/v1/projects/" + project + "/zones/" + zone + "/instances"

    # One of the headers is "Authorization: Bearer $TOKEN"
    headers = {
        "Host": "www.googleapis.com",
        "Authorization": "Bearer " + accessToken,
        "Content-Type": "application/json"
    }

    h = httplib2.Http()

    resp, content = h.request(uri=url, method="GET", headers=headers)

    status = int(resp.status)

    if status < 200 or status >= 300:
        print('Error: HTTP Request failed')
        return

    j = json.loads(content.decode('utf-8').replace('\n', ''))

    print('Compute instances in zone', zone)
    print('------------------------------------------------------------')
    for item in j['items']:
        print(item['name'])

if __name__ == '__main__':
    cred = load_json_credentials(json_filename)

    private_key = load_private_key(cred)

    s_jwt = create_signed_jwt(
            private_key,
            cred['private_key_id'],
            cred['client_email'],
            scopes)

    token, err = exchangeJwtForAccessToken(s_jwt)

    if token is None:
        print('Error:', err)
        exit(1)

    gce_list_instances(token)

“”
此程序在一个区域中列出Google计算引擎实例
'''
导入时间
导入json
进口jwt
导入请求
导入httplib2
#此请求的项目ID。
项目='development-123456'
#此请求的区域的名称。
区域='us-west1-a'
#服务帐户凭据，Json格式
json_filename='service account.json'
#请求访问令牌的权限
作用域=”https://www.googleapis.com/auth/cloud-platform"
#设置此令牌的有效时间（秒）
expires_in=3600#1小时后过期
def load_json_凭据（文件名）：
''从Json文件''加载Google服务帐户凭据'
将open（filename，'r'）作为f：
data=f.read（）
返回json.loads（数据）
def load_private_key（json_cred）：
''从json凭据返回私钥''
返回json_cred['private_key']
def create_signed_jwt（pkey、pkey_id、电子邮件、范围）：
'''
从服务帐户Json凭据文件创建签名JWT
该签名JWT稍后将被交换为访问令牌
'''
#用于从签名JWT创建OAuth 2.0访问令牌的Google端点
验证url=”https://www.googleapis.com/oauth2/v4/token"
已发布=int（time.time）