Fixes wizard asking for plugins install on initial setup

Check for setup completed was wrong, added groovy script which
bypasses plugin install but leaves admin password visible in logs.

See
jenkinsci/docker#310
jenkinsci/docker#608

Dockerfile

@@ -8,7 +8,12 @@ COPY executors.groovy /usr/share/jenkins/ref/init.groovy.d/executors.groovy
 #Install default plugins and mark Jenkins as fully configured
 COPY plugins.txt /usr/share/jenkins/ref/plugins.txt
 RUN /usr/local/bin/install-plugins.sh < /usr/share/jenkins/ref/plugins.txt
-RUN echo 2.0 > /usr/share/jenkins/ref/jenkins.install.UpgradeWizard.state
+#RUN echo 2.0 > /usr/share/jenkins/ref/jenkins.install.UpgradeWizard.state
+
+#RUN echo 2.176.1 > /usr/share/jenkins/ref/jenkins.install.InstallUtil.lastExecVersion
+
+# Disable installation of plugins during setup wizard
+COPY disable-plugin-install-wizard.groovy /usr/share/jenkins/ref/init.groovy.d/
 
 # Add the docker group and make jenkins a member so it can run docker inside containers
 USER root

disable-plugin-install-wizard.groovy

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2019-2019 Gryphon Zone
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import jenkins.install.InstallState
+import jenkins.install.InstallStateFilter
+import jenkins.model.Jenkins
+
+import javax.inject.Provider
+import java.util.logging.Logger
+
+final Logger log = Logger.getLogger(getClass().getName())
+
+class SkipPluginInstallStepStateFilter extends InstallStateFilter {
+
+    private final Logger log = Logger.getLogger(getClass().getName())
+
+    private static String name(InstallState state) {
+        return state == null ? null : state.name()
+    }
+
+    @Override
+    InstallState getNextInstallState(InstallState current, Provider<InstallState> proceed) {
+        final InstallState proposedNext = proceed.get()
+
+        InstallState next
+
+        /*
+         * At the time of writing, the state transition during a new installation is:
+         *
+         * 1) INITIAL_SECURITY_SETUP
+         * 2) NEW
+         * 3) INITIAL_PLUGINS_INSTALLING
+         * 4) CREATE_ADMIN_USER
+         *
+         * The InstallStateFilter isn't called for the transition from NEW -> INITIAL_PLUGINS_INSTALLING, and
+         * INITIAL_PLUGINS_INSTALLING is the state immediately following the user going through the plugin installation
+         * wizard, which means that the only way to bypass the plugin installation section is to transition directly
+         * from INITIAL_SECURITY_SETUP -> CREATE_ADMIN_USER.
+         *
+         * Ideally the state transition would look like the following, with the filter being called for each:
+         *
+         * 1) INITIAL_SECURITY_SETUP
+         * 2) NEW
+         * 3) INITIAL_PLUGINS_SELECTION
+         * 4) INITIAL_PLUGINS_INSTALLING
+         * 5) CREATE_ADMIN_USER
+         *
+         * so that the filter could move directly from NEW -> CREATE_ADMIN_USER without interfering with other steps.
+         *
+         * The only thing that _appears_ to happen during the 'NEW' state is installation of plugins via the wizard,
+         * so bypassing it appears to be safe currently, however that could change the future and this hack could
+         * cause the installer to break
+         */
+        if (Objects.equals(name(proposedNext), name(InstallState.NEW))) {
+            next = InstallState.CREATE_ADMIN_USER
+        } else {
+            next = proposedNext
+        }
+
+        if (next != proposedNext) {
+            log.warning("Current state: '${name(current)}', default next state: '${name(proposedNext)}', overridden to: '${name(next)}'")
+        }
+
+        return next
+    }
+}
+
+Jenkins instance = Jenkins.get()
+
+log.info("Installing custom ${InstallStateFilter.class.simpleName} '${SkipPluginInstallStepStateFilter.class.simpleName}'")
+
+//noinspection GrDeprecatedAPIUsage
+instance.getExtensionList(InstallStateFilter.class).add(new SkipPluginInstallStepStateFilter())
+
+instance.save()