"null" inserted in config file when value is None

[Zane Bitter]

When rendering a config file, if a value supplied is None then the literal string "null" (JSON rendering of None) gets inserted into the config file. This is pretty much never what you want.

This was the cause of a regression when the heat-config agent started configuring a region_name in os-collect-config.conf: https://storyboard.openstack.org/#!/story/2005797

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/662082

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/662082
Committed: https://git.openstack.org/cgit/openstack/os-apply-config/commit/?id=75d527ab8fd13185f8db05ad69c43b3c89e06dc3
Submitter: Zuul
Branch: master

commit 75d527ab8fd13185f8db05ad69c43b3c89e06dc3
Author: Zane Bitter <email address hidden>
Date: Wed May 29 15:57:42 2019 -0400

    Don't render None as "null"

    In a config file you never want the string "null" in place of a null
    value. Just render an empty string instead.

    Change-Id: Ibe145c4929d4944cd8d51c07a64aee6fd5f831f2
    Closes-Bug: #1830967
    Story: 2005797

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/stein
Review: https://review.opendev.org/664747

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/rocky
Review: https://review.opendev.org/664748

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/queens
Review: https://review.opendev.org/664749

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/664747
Committed: https://git.openstack.org/cgit/openstack/os-apply-config/commit/?id=e817b6d0ca8f3d767cf4978968056b53db621521
Submitter: Zuul
Branch: stable/stein

commit e817b6d0ca8f3d767cf4978968056b53db621521
Author: Zane Bitter <email address hidden>
Date: Wed May 29 15:57:42 2019 -0400

    Don't render None as "null"

    In a config file you never want the string "null" in place of a null
    value. Just render an empty string instead.

    Change-Id: Ibe145c4929d4944cd8d51c07a64aee6fd5f831f2
    Closes-Bug: #1830967
    Story: 2005797
    (cherry picked from commit 75d527ab8fd13185f8db05ad69c43b3c89e06dc3)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/664748
Committed: https://git.openstack.org/cgit/openstack/os-apply-config/commit/?id=07165a907a01408485526950739183a6154f6515
Submitter: Zuul
Branch: stable/rocky

commit 07165a907a01408485526950739183a6154f6515
Author: Zane Bitter <email address hidden>
Date: Wed May 29 15:57:42 2019 -0400

    Don't render None as "null"

    In a config file you never want the string "null" in place of a null
    value. Just render an empty string instead.

    Change-Id: Ibe145c4929d4944cd8d51c07a64aee6fd5f831f2
    Closes-Bug: #1830967
    Story: 2005797

    (cherry picked from commit 75d527ab8fd13185f8db05ad69c43b3c89e06dc3)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/664749
Committed: https://git.openstack.org/cgit/openstack/os-apply-config/commit/?id=ad29f1d44923d12c8c91e6389fda6535653dac2c
Submitter: Zuul
Branch: stable/queens

commit ad29f1d44923d12c8c91e6389fda6535653dac2c
Author: Zane Bitter <email address hidden>
Date: Wed May 29 15:57:42 2019 -0400

    Don't render None as "null"

    In a config file you never want the string "null" in place of a null
    value. Just render an empty string instead.

    Change-Id: Ibe145c4929d4944cd8d51c07a64aee6fd5f831f2
    Closes-Bug: #1830967
    Story: 2005797
    (cherry picked from commit 75d527ab8fd13185f8db05ad69c43b3c89e06dc3)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/os-apply-config 9.1.2 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/os-apply-config 8.3.2 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/os-apply-config 10.4.0 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/os-apply-config stein-eol release.