feature: make env support inputting empty value when creation

[allencloud]

Signed-off-by: Allen Sun [email protected]

Ⅰ. Describe what this PR did

env management of container may have some incompatibilities there. Here is the case:

For create env:

1. --env a=b: add env a with value b in container
2. --env a=: add env a with empty value in container
3. --env a: remove env a in container's envs which are inherited from image;
4. --env a="b c": add env a with value "b c" in container, which has a whitespace there.

What I did:

1. modify the cli instruction;
2. modify the swagger.yml to be more clear;
3. add test case

Ⅱ. Does this pull request fix one issue?

none

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

added

Ⅳ. Describe how to verify it

none

Ⅴ. Special notes for reviews

@wangforthinker @zjumoon01 @rudyfly

[codecov]

Codecov Report

Merging #2745 into master will increase coverage by 0.19%.
The diff coverage is 91.11%.

@@            Coverage Diff             @@
##           master    #2745      +/-   ##
==========================================
+ Coverage   69.32%   69.52%   +0.19%     
==========================================
  Files         278      278              
  Lines       17448    17740     +292     
==========================================
+ Hits        12096    12333     +237     
- Misses       4025     4068      +43     
- Partials     1327     1339      +12

Flag	Coverage Δ
#criv1alpha2_test	39.37% <68.88%> (-0.1%)	⬇️
#integration_test_0	36.67% <82.22%> (+0.08%)	⬆️
#integration_test_1	35.52% <68.88%> (-0.01%)	⬇️
#integration_test_2	36.55% <68.88%> (-0.01%)	⬇️
#integration_test_3	35.4% <77.77%> (-0.01%)	⬇️
#node_e2e_test	35.43% <68.88%> (+0.13%)	⬆️
#unittest	28.4% <55.55%> (-0.03%)	⬇️

Impacted Files	Coverage Δ
daemon/mgr/container_utils.go	82.38% <88.23%> (ø)	⬆️
apis/opts/env.go	87.09% <92.85%> (+7.09%)	⬆️
pkg/streams/utils.go	82.14% <0%> (-9.53%)	⬇️
ctrd/image_commit.go	61.34% <0%> (-6.68%)	⬇️
daemon/mgr/image_load.go	45.45% <0%> (-4.55%)	⬇️
ctrd/utils.go	78.43% <0%> (-3.93%)	⬇️
daemon/mgr/image_utils.go	84.7% <0%> (-0.75%)	⬇️
cri/v1alpha2/cri.go	72.14% <0%> (+0.89%)	⬆️
ctrd/image.go	71.03% <0%> (+1.77%)	⬆️
daemon/containerio/cio.go	70.83% <0%> (+2.15%)	⬆️
... and 4 more

[allencloud]

I think this PR is going to fail, I am just testing to see whether the current implementation meets the demand.

[wangforthinker]

LGTM

[zjumoon01]

Caution function updateContainerEnv() which writes env to /etc/profile.d/pouchenv.sh in container.
It splits env by "=", and use "parts[1]" without checking split result's length. I'm not sure whether that can cause panic if len(parts)=1 .

[allencloud]

@zjumoon01

[zjumoon01]

@zjumoon01

all right

[allencloud]

Thanks for your review. @wangforthinker @zjumoon01
Merging...