fix: allow to stats not-running container

[zhuangqh]

Ⅰ. Describe what this PR did

Signed-off-by: zhuangqh zhuangqhc@gmail.com

Both docker api or CRI allows to get stats from not-running container.
For docker api, just return empty statistics result expect the systemCPUUsage.
For CRI, return empty statistics result expect the container meta data.

Ⅱ. Does this pull request fix one issue?

Ⅲ. Why don't you add test cases (unit test/integration test)? (你真的觉得不需要加测试吗？)

TO BE DESIGN

Ⅳ. Describe how to verify it

crictl stats would show the statistics from containers which just running by default. -a options would list those who are not in running state.

[root@pouch ~]# pouch ps -a
Name                                                            ID       Status       Created       Image                                                                 Runtime
k8s_ubuntu_nnginx-sandbox_default_hdishd83djaidwnduwk28bcsb_0   09bece   created      9 hours ago   registry.hub.docker.com/library/busybox:latest                        runc
k8s_POD_nnginx-sandbox_default_hdishd83djaidwnduwk28bcsb_1      8505cc   Up 9 hours   9 hours ago   registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0   runc
k8s_ubuntu_nginx-sandbox_default_hdishd83djaidwnduwk28bcsb_0    9d6a9c   Up 9 hours   9 hours ago   registry.hub.docker.com/library/busybox:latest                        runc
k8s_POD_nginx-sandbox_default_hdishd83djaidwnduwk28bcsb_1       ca9ce8   Up 9 hours   9 hours ago   registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0   runc
0556fc                                                          0556fc   Up 9 hours   9 hours ago   
[root@pouch ~]# crictl stats -a
CONTAINER           CPU %               MEM                 DISK                INODES
09becec027cbe       0.00                0B                  0B                  0
9d6a9c6b107fa       0.00                57.34kB             0B                  0
[root@pouch ~]# crictl stats
CONTAINER           CPU %               MEM                 DISK                INODES
9d6a9c6b107fa       0.00                57.34kB             0B                  0

Get stats from a not-running container through docker style api is allowed

[root@pouch ~]# pouch ps -a
Name                                                            ID       Status                 Created         Image                                                                 Runtime
3bec99    3bec99   Exited (0) 3 seconds   3 seconds ago   registry.hub.docker.com/library/busybox:latest                        runc

[root@pouch ~]# pouch stats --no-stream 3bec99
CONTAINER ID   NAME     CPU %   MEM %   MEM USAGE / LIMIT   NET I/O   BLOCK I/O   PIDS
3bec99c4a993   3bec99   0.00%   0.00%   0B / 0B             0B / 0B   0B / 0B     0

Ⅴ. Special notes for reviews

[codecov]

Codecov Report

Merging #2802 into master will decrease coverage by <.01%.
The diff coverage is 37.93%.

@@            Coverage Diff            @@
##           master   #2802      +/-   ##
=========================================
- Coverage    69.4%   69.4%   -0.01%     
=========================================
  Files         278     278              
  Lines       17373   17373              
=========================================
- Hits        12058   12057       -1     
+ Misses       3971    3970       -1     
- Partials     1344    1346       +2

Flag	Coverage Δ
#criv1alpha2_test	39.15% <13.79%> (-0.14%)	⬇️
#integration_test_0	36.48% <0%> (-0.08%)	⬇️
#integration_test_1	35.34% <0%> (+0.03%)	⬆️
#integration_test_2	36.5% <20.68%> (+0.04%)	⬆️
#integration_test_3	35.37% <20.68%> (+0.03%)	⬆️
#node_e2e_test	34.98% <17.24%> (-0.08%)	⬇️
#unittest	28.72% <0%> (ø)	⬆️

Impacted Files	Coverage Δ
cri/v1alpha2/cri_utils.go	88.84% <100%> (+0.2%)	⬆️
daemon/mgr/container_stats.go	67.79% <28%> (-2.73%)	⬇️
ctrd/watch.go	71.83% <0%> (-5.64%)	⬇️
daemon/mgr/container.go	59.82% <0%> (-0.64%)	⬇️
ctrd/container.go	53.91% <0%> (-0.39%)	⬇️
cri/v1alpha2/cri.go	71.48% <0%> (+0.51%)	⬆️
daemon/mgr/container_utils.go	82.38% <0%> (+0.56%)	⬆️
cri/stream/runtime.go	70.23% <0%> (+2.38%)	⬆️
cri/stream/portforward/httpstream.go	77.77% <0%> (+6.83%)	⬆️

[zhuangqh]

PTAL thanks 😀 @ZYecho

[ZYecho]

LGTM.

[fuweid]

LGTM