Add Docker plugin test (#97)

* add docker plugin test

* address comments

config.yaml

@@ -17,3 +17,4 @@ options:
       Comma-separated list of allowed plugin short names. If empty, any plugin can be installed.
       Plugins installed by the user and their dependencies will be removed automatically if not on
       the list. Included plugins are not automatically installed. 
+    default: "bazaar,docker-build-publish,ldap,matrix-combinations-parameter,postbuildscript,ssh-agent,blueocean,thinBackup,rebuild,openid,oic-auth"

tests/integration/test_plugins.py

@@ -365,6 +365,23 @@ async def test_bzr_plugin(unit_web_client: UnitWebClient):
     assert "Bazaar" in config_page, f"Bzr configuration option not found. {config_page}"
 
 
+async def test_docker_build_publish_plugin(unit_web_client: UnitWebClient):
+    """
+    arrange: given a Jenkins charm with docker-build-publish plugin installed.
+    act: when a job configuration page is accessed.
+    assert: docker-build-publish plugin option exists.
+    """
+    await install_plugins(unit_web_client, ("docker-build-publish",))
+    unit_web_client.client.create_job("docker_plugin_test", gen_test_job_xml("k8s"))
+    res = unit_web_client.client.requester.get_url(
+        f"{unit_web_client.web}/job/docker_plugin_test/configure"
+    )
+    config_page = str(res.content, "utf-8")
+    assert (
+        "Docker Build and Publish" in config_page
+    ), f"docker-build-publish configuration option not found. {config_page}"
+
+
 @pytest.mark.usefixtures("k8s_agent_related_app")
 async def test_rebuilder_plugin(unit_web_client: UnitWebClient):
     """