View and query VM metadata

Linux

1. Connect to your Linux VM.

2. From your Linux VM, use the curl tool to make a query. To query for a VM instance or project metadata entry, run the following command:

   curl "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY" -H "Metadata-Flavor: Google"
   

   Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

   • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
   • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
   • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.

   For example, to query the boot image for the VM, run the following query:

   user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/image" -H "Metadata-Flavor: Google"
   

   The output is similar to the following:

   projects/rhel-cloud/global/images/rhel-8-v20210122

Windows

1. Connect to your Windows VM.

2. From your Windows VM, use the Invoke-RestMethod command to make a query. To query for a VM instance or project metadata entry, run the following command:

   $value = (Invoke-RestMethod `
             -Headers @{'Metadata-Flavor' = 'Google'} `
             -Uri "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY")
   $value
   

   Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

   • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
   • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
   • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.

   For example, to query the boot image for the VM, run the following query:

   PS C:\> 
   $value = (Invoke-RestMethod `
             -Headers @{'Metadata-Flavor' = 'Google'} `
             -Uri "http://metadata.google.internal/computeMetadata/v1/instance/image")
   $value
   

   The output is similar to the following:

   projects/windows-cloud/global/images/windows-server-2019-dc-v20210112

Linux

1. Connect to your Linux VM.

2. To query for a VM instance or project metadata directory, from your Linux VM, run the following command:

     curl "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_DIRECTORY/" -H "Metadata-Flavor: Google"
     

   Replace the PATH_TO_METADATA_DIRECTORY with the path to the VM instance or project metadata directory for which you want to recursively query the listings. For example:

   • To view the attributes project metadata directory entry, the path to specify is project/attributes/.
   • To view the disks VM instance metadata directory entry, the path to specify is instance/disks/.

   For example, consider the disks/ entry, which is a directory of disks that is attached to the VM. To query the disks/ entry, complete the following steps:

   1. Run the curl tool command on the disks directory.

      user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/disks/" -H "Metadata-Flavor: Google"
      

      The output is similar to the following:

      0/
      1/
      2/
      

   2. If you want more information about disk 0/ directory, you can then query the specific URL for that directory:

      user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/disks/0/" -H "Metadata-Flavor: Google"
      

      The output is similar to the following:

      device-name
      index
      mode
      type
      

   3. Then to query the disk type (type) for disks 0/, you can run the following:

      user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/disks/0/type" -H "Metadata-Flavor: Google"
      

      The output is similar to the following:

      PERSISTENT
      

Windows

The disks/ entry is a directory of disks that is attached to the VM. To query the disks entry, complete the following steps:

1. Connect to your Windows VM.

2. To query for a VM instance or project metadata directory, from your Windows VM, run the following command:

   $value = (Invoke-RestMethod `
             -Headers @{'Metadata-Flavor' = 'Google'} `
             -Uri "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_DIRECTORY/")
   $value
   

   Replace the PATH_TO_METADATA_DIRECTORY with the path to the VM instance or project metadata directory for which you want to recursively query the listings. For example:

   • To view the attributes project metadata directory entry, the path to specify is project/attributes/.
   • To view the disks VM instance metadata directory entry, the path to specify is instance/disks/.

   For example, consider the disks/ entry, which is a directory of disks that is attached to the VM. To query the disks/ entry, complete the following steps:

   1. Use the Invoke-RestMethod command on the disks directory.

      PS C:\> 
      $value = (Invoke-RestMethod `
                -Headers @{'Metadata-Flavor' = 'Google'} `
                -Uri "http://metadata.google.internal/computeMetadata/v1/instance/disks/")
      $value
      

      The output is similar to the following:

      0/
      1/
      2/
      

   2. If you want more information about disk 0/ directory, you can query the specific URL for that directory:

      PS C:\> 
      $value = (Invoke-RestMethod `
                -Headers @{'Metadata-Flavor' = 'Google'} `
                -Uri "http://metadata.google.internal/computeMetadata/v1/instance/disks/0/")
      $value
      

      The output is similar to the following:

      device-name
      index
      mode
      type
      

   3. Then to query the disk type (type) for disks 0/, you can run the following:

      PS C:\> 
      $value = (Invoke-RestMethod `
                -Headers @{'Metadata-Flavor' = 'Google'} `
                -Uri "http://metadata.google.internal/computeMetadata/v1/instance/disks/0/type")
      $value
      

      The output is similar to the following:

      PERSISTENT
      

Linux

1. Connect to your Linux VM.

2. From your Linux VM, use the curl tool to make a query. To recursively query the listings for a VM instance or project metadata directory, run the following command:

   curl "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_DIRECTORY/?recursive=true" -H "Metadata-Flavor: Google"
   

   Replace the PATH_TO_METADATA_DIRECTORY with the path to the VM instance or project metadata directory for which you want to recursively query the listings. For example:

   • To view the attributes project metadata directory entry, the path to specify is project/attributes/.
   • To view the disks VM instance metadata directory entry, the path to specify is instance/disks/.

   For example, the following command recursively queries the instance metadata listings for the disks/ directory.

     user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/disks/?recursive=true" -H "Metadata-Flavor: Google"
     

   The output is similar to the following:

     [{"deviceName":"boot","index":0,"mode":"READ_WRITE","type":"PERSISTENT"},
     {"deviceName":"persistent-disk-1","index":1,"mode":"READ_WRITE","type":"PERSISTENT"},
     {"deviceName":"persistent-disk-2","index":2,"mode":"READ_ONLY","type":"PERSISTENT"}]
     

   By default, recursive contents are returned in JSON format. If you want to return these contents in text format, append the alt=text query parameter:

     user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/disks/?recursive=true&alt=text" -H "Metadata-Flavor: Google"
     

   The output is similar to the following:

     0/device-name boot
     0/index 0
     0/mode READ_WRITE
     0/type PERSISTENT
     1/device-name persistent-disk-1
     1/index 1
     1/mode READ_WRITE
     1/type PERSISTENT
     2/device-name persistent-disk-1
     2/index 2
     2/mode READ_ONLY
     2/type PERSISTENT
     

Windows

1. Connect to your Windows VM.

2. From your Windows VM, use the Invoke-RestMethod command to make a query. To recursively query the listings for a VM instance or project metadata directory, run the following command:

     $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
               -Uri "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_DIRECTORY/?recursive=true")
     $value
     

   Replace the PATH_TO_METADATA_DIRECTORY with the path to the VM instance or project metadata directory for which you want to recursively query the listings. For example:

   • To view the attributes project metadata directory entry, the path to specify is project/attributes/.
   • To view the disks VM instance metadata directory entry, the path to specify is instance/disks/.

   For example, the following command recursively queries the instance metadata listings for the disks/ directory.

   PS C:\> 
   $value = (Invoke-RestMethod `
             -Headers @{'Metadata-Flavor' = 'Google'} `
             -Uri "http://metadata.google.internal/computeMetadata/v1/instance/disks/?recursive=true")
   $value
   

   The output is similar to the following:

   [{"deviceName":"boot","index":0,"mode":"READ_WRITE","type":"PERSISTENT"},
   {"deviceName":"persistent-disk-1","index":1,"mode":"READ_WRITE","type":"PERSISTENT"},
   {"deviceName":"persistent-disk-2","index":2,"mode":"READ_ONLY","type":"PERSISTENT"}]
   

   By default, recursive contents are returned in JSON format. If you want to return these contents in text format, append the alt=text query parameter:

   PS C:\> 
   $value = (Invoke-RestMethod `
             -Headers @{'Metadata-Flavor' = 'Google'} `
             -Uri "http://metadata.google.internal/computeMetadata/v1/instance/disks/?recursive=true&alt=text")
   $value
   

   The output is similar to the following:

   0/device-name boot
   0/index 0
   0/mode READ_WRITE
   0/type PERSISTENT
   1/device-name persistent-disk-1
   1/index 1
   1/mode READ_WRITE
   1/type PERSISTENT
   2/device-name persistent-disk-1
   2/index 2
   2/mode READ_ONLY
   2/type PERSISTENT
   

Linux

1. Connect to your Linux VM.

2. From your Linux VM, use the curl tool to make a query. To change the query response data format for a VM instance or project metadata entry, run the following command:

   curl "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY?alt=DATA_FORMAT" -H "Metadata-Flavor: Google"
   

   Replace the following:

   • Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

     • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
     • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
     • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.
   • DATA_FORMAT: the format in which you want the query response data—for example, text or json.

Example

For example, the tags key automatically returns data in JSON format. You can return data in text format instead, by specifying the alt=text query parameter.

Default query

  user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/tags" -H "Metadata-Flavor: Google"
  

The output is similar to the following:

  ["http-server", "db-client", "app-server", "mysql-server"]
  

Query with formatting

  user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/tags?alt=text" -H "Metadata-Flavor: Google"
  

The output is similar to the following:

  http-server
  db-client
  app-server
  mysql-server

Windows

1. Connect to your Windows VM.

2. From your Windows VM, use the Invoke-RestMethod command to make a query. To change the query response data format for a VM instance or project metadata entry, run the following command:

     $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
               -Uri "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY?alt=DATA_FORMAT")
     $value
     

   Replace the following:

   • Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

     • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
     • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
     • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.
   • DATA_FORMAT: the format in which you want the query response data—for example, text or json.

Example

For example, the tags key automatically returns data in JSON format. You can return data in text format instead, by specifying the alt=text query parameter.

Default query

  PS C:> 
  $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
            -Uri "http://metadata.google.internal/computeMetadata/v1/instance/tags")
  $value
  

The output is similar to the following:

  ["http-server", "db-client", "app-server", "mysql-server"]
  

Query with formatting

  PS C:> 
  $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
            -Uri "http://metadata.google.internal/computeMetadata/v1/instance/tags?alt=text")
  $value
  

The output is similar to the following:

  http-server
  db-client
  app-server
  mysql-server

Linux

1. Connect to your Linux VM.

2. From your Linux VM, use the curl tool to make a query. To perform a wait-for-change request for a VM instance or project metadata entry, run the following command:

   curl "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY?wait_for_change=true" -H "Metadata-Flavor: Google"
   

   Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

   • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
   • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
   • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.

   After there is a change to the specified metadata key, the query returns with the new value.

Examples

In this example, if a request is made to the setInstanceTags method, the request returns with the new values:

  user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/tags?wait_for_change=true" -H "Metadata-Flavor: Google"
  

The output is similar to the following:

  http-server
  db-client
  

You can also perform a wait-for-change request recursively on the contents of a directory:

  user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/attributes/?recursive=true&wait_for_change=true" -H "Metadata-Flavor: Google"
  

The metadata server returns the new contents if there is any change:

  {"foo":"bar","baz":"bat"}
  

Windows

1. Connect to your Windows VM.

2. From your Windows VM, use the Invoke-RestMethod command to make a query. To perform a wait-for-change request for a VM instance or project metadata entry, run the following command:

   $value = (Invoke-RestMethod `
             -Headers @{'Metadata-Flavor' = 'Google'} `
             -Uri "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY?wait_for_change=true")
   $value
   

   Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

   • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
   • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
   • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.

   After there is a change to the specified metadata key, the query returns with the new value.

Examples

After there is a change to the specified metadata key, the query returns with the new value. In this example, if a request is made to the setInstanceTags method, the request returns with the new values:

  PS C:> 
  $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
            -Uri "http://metadata.google.internal/computeMetadata/v1/instance/tags?wait_for_change=true")
  $value
  

The output is similar to the following:

  http-server
  db-client
  

You can also perform a wait-for-change request recursively on the contents of a directory:

  PS C:> 
  $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
            -Uri "http://metadata.google.internal/computeMetadata/v1/instance/attributes?recursive=true&wait_for_change=true")
  $value
  

The metadata server returns the new contents if there is any change:

  {"foo":"bar","baz":"bat"}
  

Linux VMs

To get the current ETag value for a metadata key, complete the following steps:

1. Connect to your Linux VM.

2. Make a request to that key and print the headers. To do this, use the curl tool with the -v flag. To get the current ETag for a VM instance or project metadata entry, run the following command:

   curl -v "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY" -H "Metadata-Flavor: Google"
   

   Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

   • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
   • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
   • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.

   For example, the following command gets the current ETag value for the tags instance metadata key.

     user@myinst:~$ curl -v "http://metadata.google.internal/computeMetadata/v1/instance/tags" -H "Metadata-Flavor: Google"
     

   The output is similar to the following:

   * About to connect() to metadata port 80 (#0)
   * Trying 169.254.169.254... connected
   * Connected to metadata (169.254.169.254) port 80 (#0)
   > GET /computeMetadata/v1/instance/tags HTTP/1.1
   > User-Agent: curl/7.19.7 (x86_64-pc-linux-gnu) libcurl/7.19.7 OpenSSL/0.9.8k zlib/1.2.3.3 libidn/1.15
   > Host: metadata
   > Accept: */*
   >
   < HTTP/1.1 200 OK
   < Content-Type: application/text
   < ETag: 411261ca6c9e654e
   < Date: Wed, 13 Feb 2013 22:43:45 GMT
   < Server: Metadata Server for VM
   < Content-Length: 26
   < X-XSS-Protection: 1; mode=block
   < X-Frame-Options: SAMEORIGIN
   <
   http-server
   db-client

3. You can then use that ETag value with the curl tool command in your wait-for-change request. To use the ETag value for the wait-for-change request of instance or project metadata, run the following command:

     curl "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY?wait_for_change=true&last_etag=ETAG" -H "Metadata-Flavor: Google"
     

   Replace the following:

   • Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

     • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
     • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
     • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.
   • ETAG: the ETag value for the metadata key.

   In this example, the following command uses the ETag value for the tags key and queries for the instance metadata entry.

     user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/tags?wait_for_change=true&last_etag=411261ca6c9e654e" -H "Metadata-Flavor: Google"
     

   The metadata server matches your specified ETag value, and if that value changes, the request returns with the new contents of your metadata key.

Windows VMs

To get the current ETag value for a metadata key, complete the following steps:

1. Connect to your Windows VM.

2. Make a request to that key and print the headers. On Windows, use the Invoke-WebRequest command. To get the current ETag for a VM instance or project metadata entry, run the following command:

     $value = (Invoke-WebRequest -Headers @{'Metadata-Flavor' = 'Google'} `
     -Uri http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY)
   
   
   $value.Headers.ETag
     

   Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

   • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
   • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
   • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.

   For example, the following command gets the current ETag value for the tags instance metadata key.

     PS C:> 
     $value = (Invoke-WebRequest -Headers @{'Metadata-Flavor' = 'Google'} `
     -Uri http://metadata.google.internal/computeMetadata/v1/instance/tags)
   
   
   $value.Headers.ETag
     

   The output is similar to the following:

     * About to connect() to metadata port 80 (#0)
     * Trying 169.254.169.254... connected
     * Connected to metadata (169.254.169.254) port 80 (#0)
     > GET /computeMetadata/v1/instance/tags HTTP/1.1
     > User-Agent: curl/7.19.7 (x86_64-pc-linux-gnu) libcurl/7.19.7 OpenSSL/0.9.8k zlib/1.2.3.3 libidn/1.15
     > Host: metadata
     > Accept: /
     >
     < HTTP/1.1 200 OK
     < Content-Type: application/text
     < ETag: 411261ca6c9e654e
     < Date: Wed, 13 Feb 2013 22:43:45 GMT
     < Server: Metadata Server for VM
     < Content-Length: 26
     < X-XSS-Protection: 1; mode=block
     < X-Frame-Options: SAMEORIGIN
     <
     http-server
     db-client

3. You can then use that ETag value in your wait-for-change request. To use the ETag value for the wait-for-change request of instance or project metadata, run the following command:

     $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
             -Uri "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY?wait_for_change=true&last_etag=ETAG")
     $value
     

   Replace the following:

   • Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

     • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
     • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
     • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.
   • ETAG: the ETag value for the metadata key.

   In this example, the following command uses the ETag value for the tags key and queries for the instance metadata entry.

     PS C:> 
     $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
               -Uri "http://metadata.google.internal/computeMetadata/v1/instance/tags?wait_for_change=true&last_etag=411261ca6c9e654e")
     $value
     

   The metadata server matches your specified ETag value, and if that value changes, the request returns with the new contents of your metadata key.

Python

The following Python sample shows how to programmatically watch the metadata server for changes.

This sample sets the initial ETag to 0. The metadata server doesn't return a response with 0 as the ETag value. When 0 is specified as the last ETag in a request, the metadata server responds with the current value and ETag. This saves a bit of the code needed to get the initial value and ETag.

last_etag = "0"

while True:
    r = requests.get(
        url,
        params={"last_etag": last_etag, "wait_for_change": True},
        headers=METADATA_HEADERS,
    )

    # During maintenance the service can return a 503, so these should
    # be retried.
    if r.status_code == 503:
        time.sleep(1)
        continue
    r.raise_for_status()

    last_etag = r.headers["etag"]

Linux

1. Connect to your Linux VM.

2. From your Linux VM, use the curl tool to make a query. To perform a wait-for-change request with a time out value for a VM instance or project metadata entry, run the following command:

     curl "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY?wait_for_change=true&timeout_sec=TIMEOUT" -H "Metadata-Flavor: Google"
     

   Replace the following:

   • Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

     • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
     • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
     • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.
   • TIMEOUT: the time out value.

For example, the following command performs a wait-for-change request that is set to time out after 360 seconds:

  user@myinst:~$ curl "http://metadata.google.internal/computeMetadata/v1/instance/tags?wait_for_change=true&timeout_sec=360" -H "Metadata-Flavor: Google"
  

Windows

1. Connect to your Windows VM.

2. From your Windows VM, use the Invoke-RestMethod command to make a query. To perform a wait-for-change request with a time out value for a VM instance or project metadata entry, run the following command:

     $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
             -Uri "http://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY?wait_for_change=true&timeout_sec=TIMEOUT")
     $value
     

   Replace the following:

   • Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

     • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
     • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
     • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.
   • TIMEOUT: the time out value.

For example, the following command performs a wait-for-change request that is set to time out after 360 seconds:

  PS C:> 
  $value = (Invoke-RestMethod -Headers @{'Metadata-Flavor' = 'Google'}
            -Uri "http://metadata.google.internal/computeMetadata/v1/instance/tags?wait_for_change=true&timeout_sec=360")
  $value
  

Linux

1. Connect to your Linux VM.

2. From your Linux VM, use the curl tool to make a query and specify the client identity certificate. Optionally, you can also specify the root certificate.

   curl "https://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY" \
     -E CLIENT_CERTIFICATE \
     [--cacert ROOT_CERTIFICATE] \
     -H "Metadata-Flavor: Google"
   

   Replace the following:

   • Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

     • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
     • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
     • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.
   • CLIENT_CERTIFICATE: the path to the client identity certificate: /run/google-mds-mtls/client.key.
   • Optional: ROOT_CERTIFICATE: the path to the root certificate: /run/google-mds-mtls/root.crt.

   For example, to query the boot image for a VM, run the following query:

   user@myinst:~$ 
   curl "https://metadata.google.internal/computeMetadata/v1/instance/image" \
     -E /run/google-mds-mtls/client.key \
     -H "Metadata-Flavor: Google"
   

   The output is similar to the following:

   projects/rhel-cloud/global/images/rhel-8-v20210122

   If you see an error message, review the troubleshooting documentation.

Windows

1. Connect to your Windows VM.

2. Get the client identity certificate by using one of the following commands:

   • $cert = Get-PfxCertificate -FilePath "C:\ProgramData\Google\Compute Engine\mds-mtls-client.key.pfx"
     

   • $cert = Get-ChildItem Cert:\LocalMachine\My | Where-Object { $_.Issuer -like "google.internal" }
     

3. From your Windows VM, use the Invoke-RestMethod command and specify the client identity certificate to make a query.

   PS C:\> 
   $value = (Invoke-RestMethod `
             -Headers @{'Metadata-Flavor' = 'Google'} -Certificate CLIENT_CERTIFICATE `
             -Uri "https://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY")
   $value
   

   Replace the following:

   • CLIENT_CERTIFICATE: the path to the client identity certificate on the VM. This is the $cert variable that is set in the previous step.

   • Replace the PATH_TO_METADATA_ENTRY with the path to the VM instance or project metadata key for which you want to query the value. If the key is in a sub-directory of the instance or project directory, ensure to also include the sub-directory. For example:

     • To view the project-id metadata key, which is stored in project metadata, specify project/project-id.
     • To view the image metadata key, which is stored in VM instance metadata, specify instance/image.
     • To view the enable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify either project/attributes/enable-oslogin or instance/attributes/enable-oslogin depending on your use case.

   For example, to query the boot image for a Windows server 2019 VM, run the following query:

   PS C:\> 
   $value = (Invoke-RestMethod `
             -Headers @{'Metadata-Flavor' = 'Google'} -Certificate $cert `
             -Uri "https://metadata.google.internal/computeMetadata/v1/instance/image")
   $value
   

   The output is similar to the following:

   projects/windows-cloud/global/images/windows-server-2019-dc-v20210112

Console

1. In the Google Cloud console, go to the Metadata page.

   Go to the Metadata page

   On the Metadata page,you see a list of all custom project metadata entries for your project.

gcloud

Use the gcloud compute project-info describe command to query project metadata:

gcloud compute project-info describe --flatten="commonInstanceMetadata[]"

The output is similar to the following:

---
fingerprint: HcSFdS_1_1I=
items:
- key: ssh-keys
  value: USERNAME:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDWZ...
kind: compute#metadata

REST

To query project metadata, create a GET request to the project.get method.

Replace PROJECT_ID with your project ID.

GET https://compute.googleapis.com/compute/v1/projects/PROJECT_ID

The output is similar to the following:

"kind": "compute#project",
"id": "XXXXXXX",
"creationTimestamp": "2018-12-10T08:34:33.616-08:00",
"name": "YOUR_PROJECT",
"commonInstanceMetadata": {
  "kind": "compute#metadata",
  "fingerprint": "XXXXXCdg=",
  "items": [
    {
      "key": "enable-guest-attributes",
      "value": "TRUE"
    },
    {
      "key": "enable-os-inventory",
      "value": "true"
    },
    {
      "key": "enable-osconfig",
      "value": "TRUE"
    },
    {
      "key": "enable-oslogin",
      "value": "TRUE"
    },
    {
      "key": "sshKeys",
      "value": "XXXXX"
    }
  ]
}, ...

gcloud

To query the custom zonal metadata, use the gcloud compute project-zonal-metadata describe command.

gcloud compute project-zonal-metadata describe \
    --zone=ZONE \
    --project=PROJECT_ID

Replace the following:

• PROJECT_ID: your project ID
• ZONE: the zone for which you want to view the zonal metadata.

The output is similar to the following:

{
  "fingerprint": "VlRIl8dx9vk=",
  "metadata": {
    items: {
      "key-1": "value-1",
      "key-2": "value-2"
    }
  }
}

REST

To query the custom zonal metadata, make a GET request to the instanceSettings().get method

GET https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/zones/ZONE/instanceSettings

Replace the following:

• PROJECT_ID: your project ID
• ZONE: the zone for which you want to view the zonal metadata.

The output is similar to the following:

{
  "fingerprint": "VlRIl8dx9vk=",
  "metadata": {
    items: {
      "key-1": "value-1",
      "key-2": "value-2"
    }
  }
}

Console

1. In the Google Cloud console, go to the VM instances page.

   Go to VM instances

2. Click the name of the VM for which you want to view metadata.

   • SSH keys for this VM. In the Security and access section, view the SSH keys field.

     • A value of None indicates there are no SSH keys stored in instance metadata.

     • Any other value indicates that there are SSH keys stored in instance metadata.

   • SSH keys for a project. In the Security and access section, view the Block project-wide SSH keys field.

     • A value of On indicates that the value of the metadata key block-project-ssh-keys is TRUE in instance metadata.

     • A value of Off indicates that the value of the metadata key block-project-ssh-keys is FALSE, or that the key isn't set.

   • All other custom metadata. View the Custom metadata section. You see all custom metadata keys and values, other than SSH key metadata.

gcloud

Use the gcloud compute instances describe command to query instance metadata:

gcloud compute instances describe VM_NAME --flatten="metadata[]"

Replace VM_NAME with the name of the VM you want to find metadata for.

The output is similar to the following:

---
fingerprint: MTgTJ5m-Cjs=
items:
- key: enable-oslogin
  value: 'true'
kind: compute#metadata

REST

To query metadata for a specific VM, send a GET request to the instances.get method.

GET https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/zones/ZONE/instances/VM_NAME

The output is similar to the following:

......
"metadata": {
"kind": "compute#metadata",
"fingerprint": "XXXXXXVo=",
"items": [
  {
    "key": "enable-oslogin",
    "value": "true"
  }
]
},....

Replace the following:

• PROJECT_ID: your project ID
• ZONE: the zone where the VM is located
• VM_NAME: the name of the VM