Develop Reference

Cannot connect to Wildfly in Dockerfile

I'm creating a custom Dockerfile with extensions for official keycloak docker image. I want to change web-context and add some custom providers.
Here's my Dockerfile:
FROM jboss/keycloak:7.0.0
COPY startup-config.cli /opt/jboss/tools/cli/startup-config.cli
RUN /opt/jboss/keycloak/bin/jboss-cli.sh --connect --controller=localhost:9990 --file="/opt/jboss/tools/cli/startup-config.cli"
ENV KEYCLOAK_USER=admin
ENV KEYCLOAK_PASSWORD=admin
and startup-config.cli file:
/subsystem=keycloak-server/:write-attribute(name=web-context,value="keycloak/auth")
/subsystem=keycloak-server/:add(name=providers,value="module:module:x.y.z.some-custom-provider")
Bu unfortunately I receive such error:
The controller is not available at localhost:9990: java.net.ConnectException: WFLYPRT0053: Could not connect to remote+http://localhost:9990. The connection failed: WFLYPRT0053: Could not connect to remote+http://localhost:9990. The connection failed: Connection refused
The command '/bin/sh -c /opt/jboss/keycloak/bin/jboss-cli.sh --connect --controller=localhost:9990 --file="/opt/jboss/tools/cli/startup-config.cli"' returned a non-zero code: 1
Is it a matter of invalid localhost? How should I refer to the management API?
Edit: I also tried with ENTRYPOINT instead of RUN, but the same error occurred during container initialization.

You are trying to have Wildfly load your custom config file at build-time here. The trouble is, that the Wildfly server is not running while the Dockerfile is building.
Wildfly actually already has you covered regarding automatically loading custom config, there is built in support for what you want to do. You simply need to put your config file in a "magic location" inside the image.
You need to drop your config file here:
/opt/jboss/startup-scripts/
So that your Dockerfile looks like this:
FROM jboss/keycloak:7.0.0
COPY startup-config.cli /opt/jboss/startup-scripts/startup-config.cli
ENV KEYCLOAK_USER=admin
ENV KEYCLOAK_PASSWORD=admin
Excerpt from the keycloak documentation:
Adding custom script using Dockerfile
A custom script can be added by
creating your own Dockerfile:
FROM keycloak
COPY custom-scripts/ /opt/jboss/startup-scripts/
Now you can simply start the image, and the built features in keycloak (Wildfly feature really) will go look for a config in that spedific directory, and then attempt to load it up.
Edit from comment with final solution:
While the original answer solved the issue with being able to pass configuration to the server at all, an issue remained with the content of the script. The following error was received when starting the container:
=========================================================================
Executing cli script: /opt/jboss/startup-scripts/startup-config.cli
No connection to the controller.
=========================================================================
The issue turned out to be in the startup-config.cli script, where the jboss command embed-server was missing, needed to initiate a connection to the jboss instance. Also missing was the closing stop-embedded-server command. More about configuring jboss in this manner in the docs here: CHAPTER 8. EMBEDDING A SERVER FOR OFFLINE CONFIGURATION
The final script:
embed-server --std-out=echo
/subsystem=keycloak-server/theme=defaults/:write-attribute(name=cacheThemes,value=false)
/subsystem=keycloak-server/theme=defaults/:write-attribute(name=cacheTemplates,value=false)
stop-embedded-server

WildFly management interfaces are not available when building the Docker image. Your only option is to start the CLI in embedded mode as discussed here Running CLI commands in WildFly Dockerfile.
A more advanced approach consists in using the S2I installation scripts to trigger CLI commands.

error resolving localhost while running java servlets in eclipse's browser

I am new to java servlets. I have installed apache-tomcat-9.0.0.M21.
When I run the project containing servlet in eclipse browser, sometimes I get the error-
Error resolving 'localhost': Name or service not known.
Other times the error is -
Error resolving 'localhost' : Temporary failure in name resolution.
This project runs fine in my web browser.
Also, after I add <servlet>...</servlet> and <servlet-mapping>...<servlet-mapping> in web.xml, I get the error - Server Tomcat v9.0 Server at localhost failed to start.
One more thing, I use Ubuntu operating system (if it has to do something with the question).
Please help. I googled for the solution but I am not able to resolve the error.

Try adding the below to your /etc/hosts file.
127.0.0.1 localhost

Activiti Explorer - Request resource is not available

I have big problem to run activiti-explorer when i try access: http://localhost:8080/activiti-explorer/ tomcat shows me HTTP Status 404 - The requested resource is not available. I'm really don't have any idea why that dosen't work. Can you help me?
This what have I done on my PC:
I'm using 5.19.0 version of activiti-explorer
7.0.63 tomcat
JDK 1.8.0.77 (i think there is no point to downgrade java to previous versions (<=1.7) becouse my main application using this version)
I'm sure I have correctly configured environment variables (JAVA_HOME,JRE_HOME,PATH,CATALINA_HOME)
I configured data base connection (db.properties, context.xml) in activiti-explorer.war and i moved this file to tomcat/webapps
I don't have any errors about activiti during tomcat start

Check if activiti explorer is deployed to tomcat in manager.
http://{host}:{port}/manager/html
More info in https://tomcat.apache.org/tomcat-7.0-doc/manager-howto.html

Check the catalina.out log. There will be something in there that leads you to the solution.

Check Admin Console (cmd that runs behind) after hitting the link. most recent exception occurred will be displayed there.

Managed VM deploy failed because "env" setting is not supported

Trying to deploy a Java app to Google Appengine Managed VM. I'm using console gcloud and already prepared WAR file. Plus app.yaml.
Using following command:
gcloud preview app deploy ./build/libs/app.yaml
Right now it fails with:
Building and pushing image for module [default]
-------------------------------------------------------------------------------- DOCKER BUILD OUTPUT --------------------------------------------------------------------------------
Step 0 : FROM gcr.io/google_appengine/jetty9
---> 005014071b64
Step 1 : ADD webapp-webapp.war $JETTY_BASE/webapps/root.war
---> 3e9023930cc8
Removing intermediate container 342e8a2f5750
Successfully built 3e9023930cc8
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Beginning teardown of remote build environment (this may take a few seconds).
Updating module [default]...failed.
ERROR: (gcloud.preview.app.deploy) Error Response: [400] "env" setting is not supported for this deployment.
I see similar error (there) for maven-gcloud-plugin that happens when project is not configured as WAR. But notice that:
i'm using plain command line tool gcloud, a latest version
and my project is packaged into WAR already
Also i'm using following app.yaml (which i've got from maven plugin sources):
runtime: java
env: 2
api_version: 1
handlers:
- url: .*
script: dynamic
So the question, where from this error is coming from (docker image is already prepared at this moment, right?). What it means? And how to fix this?
Update
I noticed that it uses FROM gcr.io/google_appengine/jetty9 for VM. But for Appengine it should be FROM gcr.io/google_appengine/jetty9-compat. I've tried to switch to exploded app instead of WAR, and it started using correct Docker base image. But still fails:
Building and pushing image for module [default]
-------------------------------------------------------------------------------- DOCKER BUILD OUTPUT --------------------------------------------------------------------------------
Step 0 : FROM gcr.io/google_appengine/jetty9-compat
---> 2ad8572ef3d8
Step 1 : ADD . /app/
---> b10f4bc6718e
Removing intermediate container 8b149f4baf9c
Successfully built b10f4bc6718e
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Beginning teardown of remote build environment (this may take a few seconds).
Updating module [default]...failed.
ERROR: (gcloud.preview.app.deploy) Error Response: [400] "env" setting is not supported for this deployment.

The reason was this line in app.yaml:
env: 2
it was too simple and too obvious to try to deploy w/o this option. Also, every doc, official and unofficial, mentions that you need to have env: 2 option set to deploy your app as Appengine app. That's really strange.
Removing this line also changed base Docker image to gcr.io/google_appengine/java-compat. I guess it means that jetty images, including jetty9-compat, aren't compatible with Appengine apps

FileNotFoundException while running SolrCloud on Tomcat

I have a Solr 4.2.0 server which is running under the Tomcat 7.0 container. I'm trying to wire it with my external zookeeper (actually, it doesn't work with the embdedded zookeeper too).
I tried this java opts:
-Dbootstrap_confdir=./solr/collection1/conf
-Dcollection.configName=myconf
-DzkRun
-DnumShards=2
for running the embedded zookeeper.
And also this java opts:
-Dbootstrap_confdir=./solr/collection1/conf
-Dcollection.configName=myconf
-DzkHost=localhost:2181
-DnumShards=2
For connecting to external zookeeper
In both cases I continue to get the same exception:
java.io.FileNotFoundException: File '.\solr\collection1\conf \admin-extra.html' does not exist
But the problem is that file admin-extra.html exists and it's right here. And I can't figure out what the problem is.

From your exception it seems your path has a white space after the config directory.
Try to define your bootstrap_configdir between "", like:
-Dbootstrap_confdir="./solr/collection1/conf"