Linux

1. Connect to your Linux VM.

2. From your Linux VM, use thecurl tool to make a query. Toquery for a VM instance or project metadata entry, run the followingcommand:

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

   Replace thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
   • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
   • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/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 theInvoke-RestMethod command to make a query.To query for a VM instance or project metadata entry, run the followingcommand:

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

   Replace thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
   • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
   • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/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 thePATH_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 theattributes project metadata directory entry, the path to specify isproject/attributes/.
   • To view thedisks VM instance metadata directory entry, the path to specify isinstance/disks/.

   For example, consider thedisks/ entry, which is a directory of disksthat is attached to the VM. To query thedisks/ entry, complete thefollowing steps:

   1. Run thecurl 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 disk0/ directory, you can thenquery 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-nameindexmodetype

   3. Then to query the disk type (type) for disks0/, 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

Thedisks/ 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 thePATH_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 theattributes project metadata directory entry, the path to specify isproject/attributes/.
   • To view thedisks VM instance metadata directory entry, the path to specify isinstance/disks/.

   For example, consider thedisks/ entry, which is a directory of disksthat is attached to the VM. To query thedisks/ entry, complete thefollowing steps:

   1. Use theInvoke-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 disk0/ directory, you can query thespecific 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-nameindexmodetype

   3. Then to query the disk type (type) for disks0/, 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 thecurl tool to make a query. To recursively query the listings for a VM instance orproject metadata directory, run the following command:

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

   Replace thePATH_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 theattributes project metadata directory entry, the path to specify isproject/attributes/.
   • To view thedisks VM instance metadata directory entry, the path to specify isinstance/disks/.

   For example, the following command recursively queries the instancemetadata listings for thedisks/ 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 toreturn these contents in text format, append thealt=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 theInvoke-RestMethod command to make aquery. To recursively query the listings for a VM instance or projectmetadata 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 thePATH_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 theattributes project metadata directory entry, the path to specify isproject/attributes/.
   • To view thedisks VM instance metadata directory entry, the path to specify isinstance/disks/.

   For example, the following command recursively queries the instancemetadata listings for thedisks/ 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 toreturn these contents in text format, append thealt=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 boot0/index 00/mode READ_WRITE0/type PERSISTENT1/device-name persistent-disk-11/index 11/mode READ_WRITE1/type PERSISTENT2/device-name persistent-disk-12/index 22/mode READ_ONLY2/type PERSISTENT

Linux

1. Connect to your Linux VM.

2. From your Linux VM, use thecurl tool to make a query. To change the query response data format for a VMinstance 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 thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
     • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
     • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.
   • DATA_FORMAT: the format in which you wantthe query response data—for example,text orjson.

Example

For example, thetags keyautomatically returns data in JSON format. You can return data in textformat instead, by specifying thealt=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 theInvoke-RestMethod command to make aquery. To change the query response data format for a VM instance orproject 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 thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
     • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
     • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.
   • DATA_FORMAT: the format in which you wantthe query response data—for example,text orjson.

Example

For example, thetags keyautomatically returns data in JSON format. You can return data in textformat instead, by specifying thealt=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 thecurl tool to make a query. To perform await-for-change request for a VM instanceor 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 thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
   • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
   • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.

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

Examples

In this example, if a request is made to thesetInstanceTags method, therequest 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 await-for-change request recursively on thecontents 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 theInvoke-RestMethod command to make aquery. To perform await-for-change request for a VM instance or projectmetadata 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 thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
   • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
   • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.

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

Examples

After there is a change to the specified metadata key, the query returnswith the new value. In this example, if a request is made to thesetInstanceTags 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 await-for-change request recursively on the contents of adirectory:

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 followingsteps:

1. Connect to your Linux VM.

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

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

   Replace thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
   • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
   • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.

   For example, the following command gets the current ETag value for thetags 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-serverdb-client

3. You can then use that ETag value with thecurl tool command in yourwait-for-change request. To use the ETag value for thewait-for-change request of instance or project metadata, run thefollowing 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 thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
     • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
     • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/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 thetags 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 valuechanges, 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 followingsteps:

1. Connect to your Windows VM.

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

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

   Replace thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
   • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
   • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.

   For example, the following command gets the current ETag value for thetags 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 yourwait-for-change request. Touse the ETag value for thewait-for-change request of instance orproject 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 thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
     • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
     • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/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 thetags 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 valuechanges, the request returns with the new contents of your metadata key.

Python

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

This sample sets the initial ETag to0. The metadata server doesn'treturn a response with0 as the ETag value. When0 is specified as thelast ETag in a request, the metadata server responds with the current valueand ETag. This saves a bit of the code needed to get the initial value andETag.

last_etag="0"whileTrue: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.ifr.status_code==503:time.sleep(1)continuer.raise_for_status()last_etag=r.headers["etag"]

Linux

1. Connect to your Linux VM.

2. From your Linux VM, use thecurl tool to make a query. To perform await-for-change request with a time outvalue for a VM instance or project metadata entry, run the followingcommand:

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

For example, the following command performs await-for-change request thatis 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 theInvoke-RestMethod command to make a query.To perform await-for-change request with a time out value for a VMinstance 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 thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
     • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
     • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.
   • TIMEOUT: the time out value.

For example, the following command performs await-for-change request thatis 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 thecurl tool to make a query andspecify the client identity certificate. Optionally, you can also specifythe root certificate.

   curl "https://metadata.google.internal/computeMetadata/v1/PATH_TO_METADATA_ENTRY" \  -ECLIENT_CERTIFICATE \  [--cacertROOT_CERTIFICATE] \  -H "Metadata-Flavor: Google"

   Replace the following:

   • Replace thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
     • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
     • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.
   • CLIENT_CERTIFICATE: the path to theclient identity certificate:/run/google-mds-mtls/client.key.
   • Optional:ROOT_CERTIFICATE: the path to theroot certificate:/run/google-mds-mtls/root.crt. You must specify thisvalue if the root certificate isn't added to the OS trust store.

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

   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 thetroubleshooting documentation.

Windows

1. Connect to your Windows VM.

2. Get theclient identity certificateby 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 theInvoke-RestMethod command and specify the client identitycertificate to make a query.

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

   Replace the following:

   • CLIENT_CERTIFICATE: the path to theclient identity certificateon the VM. This is the$cert variable that is set in the previous step.

   • Replace thePATH_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 theproject-id metadata key, which is stored in project metadata, specifyproject/project-id.
     • To view theimage metadata key, which is stored in VM instance metadata, specifyinstance/image.
     • To view theenable-oslogin which can be stored in the attributes sub-directory of either project or VM instance metadata, specify eitherproject/attributes/enable-oslogin orinstance/attributes/enable-oslogin depending on your use case.

   For example, to query the boot image for a Windows server 2019 VM, runthe 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 theMetadata page.

   Go to the Metadata page

   On theMetadata page, you see a list of all custom project metadataentries for your project.

gcloud

Use thegcloud compute project-info describe commandto 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 aGET request to theproject.get method.

ReplacePROJECT_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 thegcloud 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 thezonal 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 aGET request to theinstanceSettings().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 thezonal 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 theVM 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 theSecurity and access section,view theSSH keys field.

     • A value ofNone indicates there are no SSH keys stored in instancemetadata.

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

   • SSH keys for a project. In theSecurity and access section,view theBlock project-wide SSH keys field.

     • A value ofOn indicates that the value of the metadata keyblock-project-ssh-keys isTRUE in instance metadata.

     • A value ofOff indicates that the value of the metadata keyblock-project-ssh-keys isFALSE, or that the key isn't set.

   • All other custom metadata. View theCustom metadata section.You see all custom metadata keys and values, other than SSH keymetadata.

gcloud

Use thegcloud compute instances describe commandto query instance metadata:

gcloud compute instances describeVM_NAME --flatten="metadata[]"

ReplaceVM_NAME with the name of the VM you want tofind 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 aGET request to theinstances.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