サマリ
個人的によく使うjqコマンドの備忘録。
適宜で追加予定（多分）
詳細
jq使いたくなる時の状況として大体がクソデカjsonのparse用なので、サンプルも大きなものを用意。
生成方法としては適当にAWS EC2インスタンスを立てて、そのconfigをjson形式で出力した。
sample.json
{
"Reservations": [
{
"Groups": [],
"Instances": [
{
"AmiLaunchIndex": 0,
"ImageId": "ami-0595d6e81396a9efb",
"InstanceId": "i-0af291a70792eedcc",
"InstanceType": "t2.micro",
"KeyName": "MyKeyPair",
"LaunchTime": "2024-05-04T14:12:50+00:00",
"Monitoring": {
"State": "disabled"
},
"Placement": {
"AvailabilityZone": "ap-northeast-1c",
"GroupName": "",
"Tenancy": "default"
},
"PrivateDnsName": "ip-172-31-9-174.ap-northeast-1.compute.internal",
"PrivateIpAddress": "172.31.9.174",
"ProductCodes": [],
"PublicDnsName": "ec2-18-181-216-211.ap-northeast-1.compute.amazonaws.com",
"PublicIpAddress": "18.181.216.211",
"State": {
"Code": 16,
"Name": "running"
},
"StateTransitionReason": "",
"SubnetId": "subnet-0e107b67fa58f9d8e",
"VpcId": "vpc-08502774e7262a266",
"Architecture": "x86_64",
"BlockDeviceMappings": [
{
"DeviceName": "/dev/sda1",
"Ebs": {
"AttachTime": "2024-05-04T14:12:51+00:00",
"DeleteOnTermination": true,
"Status": "attached",
"VolumeId": "vol-0284e71624766a1a4"
}
}
],
"ClientToken": "daf82584-2b91-4c32-b310-4a38cbfab382",
"EbsOptimized": false,
"EnaSupport": true,
"Hypervisor": "xen",
"NetworkInterfaces": [
{
"Association": {
"IpOwnerId": "amazon",
"PublicDnsName": "ec2-18-181-216-211.ap-northeast-1.compute.amazonaws.com",
"PublicIp": "18.181.216.211"
},
"Attachment": {
"AttachTime": "2024-05-04T14:12:50+00:00",
"AttachmentId": "eni-attach-08c3c7f2a0b6102cd",
"DeleteOnTermination": true,
"DeviceIndex": 0,
"Status": "attached",
"NetworkCardIndex": 0
},
"Description": "",
"Groups": [
{
"GroupName": "default",
"GroupId": "sg-0190b89b3d4a36149"
}
],
"Ipv6Addresses": [],
"MacAddress": "0a:cf:9e:fc:4a:11",
"NetworkInterfaceId": "eni-0e13d5d8e11546e9d",
"OwnerId": "471112995230",
"PrivateDnsName": "ip-172-31-9-174.ap-northeast-1.compute.internal",
"PrivateIpAddress": "172.31.9.174",
"PrivateIpAddresses": [
{
"Association": {
"IpOwnerId": "amazon",
"PublicDnsName": "ec2-18-181-216-211.ap-northeast-1.compute.amazonaws.com",
"PublicIp": "18.181.216.211"
},
"Primary": true,
"PrivateDnsName": "ip-172-31-9-174.ap-northeast-1.compute.internal",
"PrivateIpAddress": "172.31.9.174"
}
],
"SourceDestCheck": true,
"Status": "in-use",
"SubnetId": "subnet-0e107b67fa58f9d8e",
"VpcId": "vpc-08502774e7262a266",
"InterfaceType": "interface"
}
],
"RootDeviceName": "/dev/sda1",
"RootDeviceType": "ebs",
"SecurityGroups": [
{
"GroupName": "default",
"GroupId": "sg-0190b89b3d4a36149"
}
],
"SourceDestCheck": true,
"VirtualizationType": "hvm",
"CpuOptions": {
"CoreCount": 1,
"ThreadsPerCore": 1
},
"CapacityReservationSpecification": {
"CapacityReservationPreference": "open"
},
"HibernationOptions": {
"Configured": false
},
"MetadataOptions": {
"State": "applied",
"HttpTokens": "optional",
"HttpPutResponseHopLimit": 1,
"HttpEndpoint": "enabled",
"HttpProtocolIpv6": "disabled",
"InstanceMetadataTags": "disabled"
},
"EnclaveOptions": {
"Enabled": false
},
"BootMode": "uefi-preferred",
"PlatformDetails": "Linux/UNIX",
"UsageOperation": "RunInstances",
"UsageOperationUpdateTime": "2024-05-04T14:12:50+00:00",
"PrivateDnsNameOptions": {
"HostnameType": "ip-name",
"EnableResourceNameDnsARecord": false,
"EnableResourceNameDnsAAAARecord": false
},
"MaintenanceOptions": {
"AutoRecovery": "default"
},
"CurrentInstanceBootMode": "legacy-bios"
}
],
"OwnerId": "471112995230",
"ReservationId": "r-05fea8fdf1007909f"
}
]
}
要素確認
# トップレベルのjson propertyを確認
$ cat sample.json | jq 'keys'
[
"Reservations"
]
直接参照する
# 配列参照
$ cat sample.json | jq 'keys[0]'
"Reservations"
# -rオプションでダブルクォーテーションが外せる
$ cat sample.json | jq -r 'keys[0]'
Reservations
ネストされた要素の確認
$ cat sample.json | jq '.Reservations | keys'
[
0,
1
]
# 配列参照
$ cat sample.json | jq '.Reservations[0] | keys'
[
"Groups",
"Instances",
"OwnerId",
"ReservationId"
]
更にネストされた要素の確認
# 同様の記述で参照が出来る
$ cat sample.json | jq '.Reservations[0].Instances | keys'
[
0
]
# 配列参照
$ cat sample.json | jq '.Reservations[0].Instances[0] | keys'
[
"AmiLaunchIndex",
"Architecture",
"BlockDeviceMappings",
"BootMode",
"CapacityReservationSpecification",
"ClientToken",
"CpuOptions",
"CurrentInstanceBootMode",
"EbsOptimized",
"EnaSupport",
"EnclaveOptions",
"HibernationOptions",
"Hypervisor",
"ImageId",
"InstanceId",
"InstanceType",
"KeyName",
"LaunchTime",
"MaintenanceOptions",
"MetadataOptions",
"Monitoring",
"NetworkInterfaces",
"Placement",
"PlatformDetails",
"PrivateDnsName",
"PrivateDnsNameOptions",
"PrivateIpAddress",
"ProductCodes",
"PublicDnsName",
"PublicIpAddress",
"RootDeviceName",
"RootDeviceType",
"SecurityGroups",
"SourceDestCheck",
"State",
"StateTransitionReason",
"SubnetId",
"UsageOperation",
"UsageOperationUpdateTime",
"VirtualizationType",
"VpcId"
]
特定要素の値を取得する
Reservations.Instancesのプロパティ参照する
単一取得
# 直接プロパティ名を指定する。"."を接頭するのを忘れないように
$ cat sample.json | jq '.Reservations[0].Instances[0] | .VpcId'
"vpc-08502774e7262a266"
複数取得
# 複数出力の場合、出力形式をkey-value型にしないとerrorになる
$ cat sample.json | jq '.Reservations[0].Instances[0] | {VpcId: .VpcId, VirtualizationType: .VirtualizationType}'
{
"VpcId": "vpc-08502774e7262a266",
"VirtualizationType": "hvm"
}