buildah-build.1.md: secret examples

[hdub-tech]

What type of PR is this?

/kind documentation

What this PR does / why we need it:

This PR enhances the buildah build --secret documentation to include examples.

How to verify it

Documentation successfully builds

• make docs with man docs/buildah-build.1 confirmation

  

  

Confirmed examples

Included below is proof that each example works using buildah version 1.38.1. The Containerfile used to confirm was:

FROM alpine
RUN --mount=type=secret,id=mysecret \
    ls -la /run/secrets && \
    cat /run/secrets/mysecret

• buildah build --secret=id=mysecret . - with file named mysecret

  $ echo foobar > mysecret; buildah build --secret=id=mysecret .
  STEP 1/2: FROM alpine
  STEP 2/2: RUN --mount=type=secret,id=mysecret     ls -la /run/secrets &&     cat /run/secrets/mysecret
  total 4
  drwxr-xr-x    1 root     root            16 Feb 22 05:16 .
  drwxr-xr-x    1 root     root            40 Feb 22 05:16 ..
  -r--------    1 root     root             7 Feb 22 05:16 mysecret
  foobar
  COMMIT
  <snipped>

• buildah build --secret=id=mysecret . - with env variable named mysecret

  $ mysecret=foobarenv buildah build --secret=id=mysecret .
  STEP 1/2: FROM alpine
  STEP 2/2: RUN --mount=type=secret,id=mysecret     ls -la /run/secrets &&     cat /run/secrets/mysecret
  total 4
  drwxr-xr-x    1 root     root            16 Feb 22 05:20 .
  drwxr-xr-x    1 root     root            40 Feb 22 05:20 ..
  -r--------    1 root     root             9 Feb 22 05:20 mysecret
  foobarenvCOMMIT
  <snipped>

• buildah build --secret=id=mysecret,env=MYSECRET .

  $ MYSECRET=foobarenv2 buildah build --secret=id=mysecret,env=MYSECRET .
  STEP 1/2: FROM alpine
  STEP 2/2: RUN --mount=type=secret,id=mysecret     ls -la /run/secrets &&     cat /run/secrets/mysecret
  total 4
  drwxr-xr-x    1 root     root            16 Feb 22 05:24 .
  drwxr-xr-x    1 root     root            40 Feb 22 05:24 ..
  -r--------    1 root     root            10 Feb 22 05:24 mysecret
  foobarenv2COMMIT
  <snipped>

• buildah build --secret=id=mysecret,src=MYSECRET,type=env .

  $ MYSECRET=foobarenv3 buildah build --secret=id=mysecret,src=MYSECRET,type=env .
  STEP 1/2: FROM alpine
  STEP 2/2: RUN --mount=type=secret,id=mysecret     ls -la /run/secrets &&     cat /run/secrets/mysecret
  total 4
  drwxr-xr-x    1 root     root            16 Feb 22 05:28 .
  drwxr-xr-x    1 root     root            40 Feb 22 05:28 ..
  -r--------    1 root     root            10 Feb 22 05:28 mysecret
  foobarenv3COMMIT
  <snipped>
  

• buildah build --secret=id=mysecret,src=.mysecret,type=file .

  $ echo foobar2 > .mysecret; buildah build --secret=id=mysecret,src=.mysecret,type=file .
  STEP 1/2: FROM alpine
  STEP 2/2: RUN --mount=type=secret,id=mysecret     ls -la /run/secrets &&     cat /run/secrets/mysecret
  total 4
  drwxr-xr-x    1 root     root            16 Feb 22 05:32 .
  drwxr-xr-x    1 root     root            40 Feb 22 05:32 ..
  -r--------    1 root     root             8 Feb 22 05:32 mysecret
  foobar2
  COMMIT
  <snipped>

• buildah build --secret=id=mysecret,src=.mysecret .

  $ echo foobar3 > .mysecret; buildah build --secret=id=mysecret,src=.mysecret .
  STEP 1/2: FROM alpine
  STEP 2/2: RUN --mount=type=secret,id=mysecret     ls -la /run/secrets &&     cat /run/secrets/mysecret
  total 4
  drwxr-xr-x    1 root     root            16 Feb 22 05:40 .
  drwxr-xr-x    1 root     root            40 Feb 22 05:40 ..
  -r--------    1 root     root             8 Feb 22 05:40 mysecret
  foobar3
  COMMIT
  <snipped>

Which issue(s) this PR fixes:

None

Special notes for your reviewer:

None?

Does this PR introduce a user-facing change?

None

[rhatdan]

LGTM
@flouthoc @nalind PTAL

[flouthoc]

LGTM

[rhatdan]

Thanks @hdub-tech
/approve
/lgtm

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: flouthoc, hdub-tech, rhatdan

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