nomad job inject environment variables to containers

[dyrnq]

eg. HOST_IP

[dyrnq]

xref hashicorp/nomad#2429

[dyrnq]

NOMAD_REGION=global
CHARSET=UTF-8
NOMAD_CPU_LIMIT=100
HOSTNAME=netshoot
NOMAD_HOST_PORT_http=24803
NOMAD_JOB_ID=netshoot-2
NOMAD_TASK_NAME=netshoot-task-2
PWD=/root
NOMAD_SECRETS_DIR=/secrets
NOMAD_HOST_ADDR_http=10.0.2.15:24803
DB_USER=web
HOME=/root
LANG=C.UTF-8
NOMAD_NAMESPACE=default
NOMAD_IP_http=10.0.2.15
NOMAD_ALLOC_INDEX=0
NOMAD_ALLOC_DIR=/alloc
NOMAD_PORT_http=8080
NOMAD_JOB_NAME=netshoot-2
NOMAD_ALLOC_PORT_http=8080
DB_HOST=db01.example.com
NOMAD_SHORT_ALLOC_ID=a17c1d0a
NOMAD_ADDR_http=10.0.2.15:24803
NOMAD_DC=dc1
NOMAD_ALLOC_NAME=netshoot-2.netshoot-group[0]
SHLVL=1
NOMAD_GROUP_NAME=netshoot-group
NOMAD_PARENT_CGROUP=/nomad
NOMAD_TASK_DIR=/local
NOMAD_MEMORY_LIMIT=300
LC_COLLATE=C
NOMAD_HOST_IP_http=10.0.2.15
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
NOMAD_ALLOC_ID=a17c1d0a-be3b-0782-b00e-75201680ee86
DB_PASS=loremipsum
HOST_IP=10.0.2.15
_=/usr/bin/env

[dyrnq]

            env {
                DB_HOST = "db01.example.com"
                DB_USER = "web"
                DB_PASS = "loremipsum"
                HOST_IP = "${attr.unique.network.ip-address}"
            }

${attr.unique.network.ip-address} seem can not found the main working iface which enp0s8

ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 02:58:89:fc:8c:39 brd ff:ff:ff:ff:ff:ff
    inet 10.0.2.15/24 brd 10.0.2.255 scope global dynamic enp0s3
       valid_lft 80970sec preferred_lft 80970sec
3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 08:00:27:96:86:62 brd ff:ff:ff:ff:ff:ff
    inet 192.168.33.4/24 brd 192.168.33.255 scope global enp0s8
       valid_lft forever preferred_lft forever
4: flannel.1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN group default 
    link/ether f2:31:38:02:2a:57 brd ff:ff:ff:ff:ff:ff
    inet 10.5.27.0/32 scope global flannel.1
       valid_lft forever preferred_lft forever
5: nerdctl0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 82:d7:91:ec:96:67 brd ff:ff:ff:ff:ff:ff
    inet 10.4.0.1/24 brd 10.4.0.255 scope global nerdctl0
       valid_lft forever preferred_lft forever
6: vethb649c486@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master nerdctl0 state UP group default 
    link/ether c2:3e:a0:79:6e:45 brd ff:ff:ff:ff:ff:ff link-netnsid 0
7: veth77292d7f@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master nerdctl0 state UP group default 
    link/ether ba:ef:5a:79:a9:c6 brd ff:ff:ff:ff:ff:ff link-netnsid 1
8: cni0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UP group default qlen 1000
    link/ether 0a:ec:e7:db:27:92 brd ff:ff:ff:ff:ff:ff
    inet 10.5.27.1/24 brd 10.5.27.255 scope global cni0
       valid_lft forever preferred_lft forever
25: veth329fc5de@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue master cni0 state UP group default 
    link/ether d2:c2:84:3a:45:e8 brd ff:ff:ff:ff:ff:ff link-netns 7a342afc-3360-e0bf-cf25-e525fdb74a02
26: vethe068f0d9@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue master cni0 state UP group default 
    link/ether aa:4d:91:3f:09:1a brd ff:ff:ff:ff:ff:ff link-netns 75d23223-3f87-5a53-498b-41d53045c480
27: veth8caf3b6d@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue master cni0 state UP group default 
    link/ether 96:35:bf:8a:09:bf brd ff:ff:ff:ff:ff:ff link-netns 0c348ef7-8a6d-3eac-6ed1-fc88324c7cfb
28: veth6c88fa73@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue master cni0 state UP group default 
    link/ether 3a:84:48:74:cd:98 brd ff:ff:ff:ff:ff:ff link-netns 7b02531e-c8af-bf53-cec9-2b802f122523