Maven - How to use two mirrors - maven

I have to use two mirrors.
In .m2/settings I have
<mirrors>
<mirror>
<id>nexus_xyz</id>
<mirrorOf>*</mirrorOf>
<url>https://../</url>
</mirror>
<mirror>
<id>nexus_wso2</id>
<mirrorOf>*</mirrorOf>
<url>http://maven.wso2.org/nexus/content/groups/wso2-public/</url>
</mirror>
</mirrors>
Then in the pom.xml of my project I don't know how to say to download something from the first mirror and something from the second mirror. Thanks

The bad news: You cannot determine for different dependencies where they should be downloaded from.
But the good news: You don't need such a thing. Mirroring usually makes only sense if you want to send (nearly) every request to the same repository. You usually do this if you have a company Nexus/Artifactory and use it to proxy all external repositories you need. If you don't have a company Nexus/Artifactory, you should list the repositories you need unter the <repositories> tag in the settings.xml. In this case, you don't define a mirror, or you only mirror all requests that you do not handle otherwise (by setting <mirrorOf> to something like *,!rep1,!rep2). Maven will then go through all the defined repositories until it finds the required artifact.

If the package isn't in the first mirror, it should fallback to the second one.
In Maven, it's not possible to tell it "download this dependency from this mirror, or repository".

Related

How to disable maven blocking external HTTP repositories?

Maven blocks external HTTP repositories by default since version 3.8.1 (see https://maven.apache.org/docs/3.8.1/release-notes.html)
Is there a way to disable that or to exempt a repository from this rule?
I found a solution to do this by inspecting the commit in the Maven git repository that is responsible for the default HTTP blocking: https://github.com/apache/maven/commit/907d53ad3264718f66ff15e1363d76b07dd0c05f
My solution is as follows:
In the Maven settings (located in ${maven.home}/conf/settings.xml or ${user.home}/.m2/settings.xml), the following entry must be removed:
<mirror>
<id>maven-default-http-blocker</id>
<mirrorOf>external:http:*</mirrorOf>
<name>Pseudo repository to mirror external repositories initially using HTTP.</name>
<url>http://0.0.0.0/</url>
</mirror>
If you work in a project and cannot make sure the Maven settings are always like that, e.g. because you share code with other people or want to use CI/CD with automated testing, you may do the following: Add a directory named .mvn in the project. In the .mvn directory, add a file named maven.config with the content --settings ./.mvn/local-settings.xml. In the .mvn directory, add a file named local-settings.xml. This file should look like this:
<settings xmlns="http://maven.apache.org/SETTINGS/1.2.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.2.0 http://maven.apache.org/xsd/settings-1.2.0.xsd">
<mirrors>
<mirror>
<id>my-repository-http-unblocker</id>
<mirrorOf>my-blocked-http-repository</mirrorOf>
<name></name>
<url>http://........</url>
</mirror>
</mirrors>
</settings>
Where inside the <mirrorOf> tag, you need to specify the id of the blocked repository, and in the <url> tag, you specify the original url of the repository again. You need to create this unblocker mirror for every repository you have that is blocked.
Example:
If you have the following HTTP repositories defined in the pom.xml:
<repositories>
<repository>
<snapshots>
<enabled>false</enabled>
</snapshots>
<id>central</id>
<name>libs-release</name>
<url>http://my-url/libs-release</url>
</repository>
<repository>
<id>snapshots</id>
<name>libs-snapshot</name>
<url>http://my-url/libs-snapshot</url>
</repository>
</repositories>
Then you need in the .mvn/local-settings.xml:
<settings>
<mirrors>
<mirror>
<id>release-http-unblocker</id>
<mirrorOf>central</mirrorOf>
<name></name>
<url>http://my-url/libs-release</url>
</mirror>
<mirror>
<id>snapshot-http-unblocker</id>
<mirrorOf>snapshots</mirrorOf>
<name></name>
<url>http://my-url/libs-snapshot</url>
</mirror>
</mirrors>
</settings>
I hope my work can help other people who stumble upon this. However, if you have a more elegant or better solution, please share!
In my case, I just added a dummy mirror with the id maven-default-http-blocker to override the existing one. This disable HTTP blocking for all repositories.
<settings xmlns="http://maven.apache.org/SETTINGS/1.2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.2.0 http://maven.apache.org/xsd/settings-1.2.0.xsd">
<mirrors>
<mirror>
<id>maven-default-http-blocker</id>
<mirrorOf>dummy</mirrorOf>
<name>Dummy mirror to override default blocking mirror that blocks http</name>
<url>http://0.0.0.0/</url>
</mirror>
</mirrors>
</settings>
Another possible solution/workaround is to override the new default http-blocking behavior by commenting out the maven-default-http-blocker mirror in the <mirrors> section of the maven's 'main' settings.xml file (under /opt/maven/conf in my case);
<!--mirror>
<id>maven-default-http-blocker</id>
<mirrorOf>external:http:*</mirrorOf>
<name>Pseudo repository to mirror external repositories initially using HTTP.</name>
<url>http://0.0.0.0/</url>
<blocked>false</blocked>
</mirror-->
P.S. Whether unblocking all the insucure http repositories is a good idea is a whole other story.
You should just add a mirror to your http repository that allows http in your maven settings. You shouldn't eliminate the default maven behavior for all repositories. Then tell your devops team to use https!
in .m2/settings.xml:
<mirrors>
<mirror>
<id>my-repo-mirror</id>
<name>My Repo HTTP Mirror</name>
<url>http://url-to.my/repo</url>
<mirrorOf>my-repo</mirrorOf>
</mirror>
</mirrors>
In macOS Monterey, and using Intellij Ultimate 2021.3 (and up), with maven NOT INSTALLED in the system and using maven as a plugin inside Intellij, i found the "settings.xml" file in the path:
${user.home}/Library/Application Support/JetBrains/Toolbox/apps/IDEA-U/ch-0/213.5744.223/IntelliJ IDEA.app/Contents/plugins/maven/lib/maven3/conf/settings.xml
Note: the above path is when the Intellij is installed using the Jetbrains Toolbox App, and the version number indicated (213.5744.223) can defer if you have another version, verify when travelling the path to the file.
Open the "settings.xml" file with your favourite editor, and comment the next lines:
<!--<mirror>
<id>maven-default-http-blocker</id>
<mirrorOf>external:http:*</mirrorOf>
<name>Pseudo repository to mirror external repositories initially using HTTP.</name>
<url>http://0.0.0.0/</url>
<blocked>true</blocked>
</mirror>-->
Hope it helped.
I solved the issue by simply replacing "http" with "https" in .xml file (in my case pom.xml).
This solved my error.
Unblock a Specific HTTP Repository
To unblock a specific repository, you may define a dummy mirror of it in your settings by adding a <mirror> with the same url, and its <mirrorOf> value matching your repository's id. Nothing else needs to change for this to work.
For example:
If your repo id is team-internal-repo, then a mirror added to your ~/.m2/settings.xml might look like this:
<settings>
...
<!-- Add a mirror. -->
<mirrors>
<mirror>
<id>team-internal-repo-mirror</id>
<mirrorOf>team-internal-repo</mirrorOf> <!-- Must match repository id. -->
<name>Dummy mirror to unblock the team repo server</name>
<url>http://insecure-internal-server/repository/team-repo/</url>
<!-- <blocked>false</blocked> --> <!-- This is not needed, the mirror is unblocked by default. -->
</mirror>
</mirrors>
<!-- Existing profile does not need to change. -->
<profiles>
<profile>
<id>default_profile</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<repositories>
<repository>
<id>team-internal-repo</id>
<name>Dev Team Internal Artifacts</name>
<url>http://insecure-internal-server/repository/team-repo/</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
</repositories>
...
</profile>
</profiles>
</settings>
The <blocked> tag is not needed here. Other users have commented that the tag breaks older versions of maven. I tested an http repo with and without this tag and it worked both ways. (Tested using maven 3.8.2.)
Unblocking one or more explicit repos is better than universally unblocking all http repositories. Doing that may be a bad idea:
It presents a greater security risk. There's a reason apache made this change, and it is discussed in the release notes referenced by OP: https://maven.apache.org/docs/3.8.1/release-notes.html#cve-2021-26291
Modifying the internal configuration of your Maven installation (i.e. the settings file in /opt/apache-maven-3.8.1 instead of your own in ~/.m2) could create a headache when updating or reinstalling future releases of maven. If that file gets overridden, your repo might suddenly be blocked again.
Same problem with macOS Monterey 12.3.1 and IntelliJ 2022.1 using bundled maven (3.8.1). The solution is similar to the one proposed by MrBitwise but the settings file has a different path (it is the one embedded inside the app contents folder):
/Applications/IntelliJ\ IDEA\ CE.app/Contents/plugins/maven/lib/maven3/conf/settings.xml
Then I commented the following code:
<mirror>
<id>maven-default-http-blocker</id>
<mirrorOf>external:http:*</mirrorOf>
<name>Pseudo repository to mirror external repositories initially using HTTP.</name>
<url>http://0.0.0.0/</url>
<blocked>true</blocked>
</mirror>
You could follow the official recommendation from the Maven documentation, it is explained in the same link that you shared: https://maven.apache.org/docs/3.8.1/release-notes.html#how-to-fix-when-i-get-a-http-repository-blocked
Options to fix are:
upgrade the dependency version to a newer version that replaced the
obsolete HTTP repository URL with a HTTPS one,
keep the dependency version but define a mirror in your settings.
It includes a link to Maven - Guide to Mirror Settings
As others mentioned, you should not override the default security settings.
Sometimes, when your local version of settings.xml is low and your maven version is higher than that, then removing this configuration cannot solve the problem:
<mirrors>
<mirror>
<id>my-repository-http-unblocker</id>
<mirrorOf>my-blocked-http-repository</mirrorOf>
<name></name>
<url>http://........</url>
</mirror>
Maybe see if adding <blocked>false</blocked> will solve the problem:
<mirrors>
<mirror>
<id>my-repository-http-unblocker</id>
<mirrorOf>my-blocked-http-repository</mirrorOf>
<name></name>
<url>http://your blocked url</url>
<blocked>false</blocked>
</mirror>
</mirrors>
Use the latest versions of your dependencies and plugins. I had the same issue with libraries from 'com.sun.xml.ws', but changing their versions from 3.8.3 to 4.0.0 fixed it.
If you are using maven version 3.8 or greater HTTP is not supported. Try to use a lower version or upgrade the repo to HTTPS For more information please refer
https://help.mulesoft.com/s/article/Maven-error-when-building-application-Blocked-Mirror-for-repositories#:~:text=Upgrade%20the%20Maven%20repository%20so,of%20the%20obsolete%20HTTP%20one.&text=Define%20a%20mirror%20in%20your%20settings.&text=Define%20an%20exception%20for%20a%20specific%20repository.&text=The%20false%3C%2F,be%20used%20as%20an%20exception.
A bit different solution that has helped me, is more related to our corporate environment and involves the fact that we are slowly moving out of maven to another dep/build tool, but there is still a 'corporate' settings.xml file defined.
So just rename it to a different file (instead of deleting), like mv settings.xml settings-backup.xml, and returning maven again would help you to check if it's the issue.
I encountered this issue when I installed a new version of maven. Fixed this by renaming .m2 directory to whatever or like .m2-old then run maven again. it will recreate the directory, the drawback is it will redownload all jar since the new .m2 is empty. Then just transfer your settings.xml to that new .m2 directory.
I've yet to test if copy the repository directory from the old .m2 to the new one will just work fine.
Update : copying the repository directory from ~/.m2-old to the new ~/.m2 didnt cause any errors when running maven afterwards
For your local environment, the quickest way is to set the blocked value from true to false in your .m2\settings.xml
<id>maven-default-http-blocker</id>
<mirrorOf>external:http:*</mirrorOf>
<name>Pseudo repository to mirror external repositories initially using HTTP.</name>
<url>http://0.0.0.0/</url>
<blocked>false</blocked>
</mirror>
I was able to compile by commenting the code:
/Applications/IntelliJ\ IDEA.app/Contents/plugins/maven/lib/maven3/conf/settings.xml
<!--<mirror>
<id>maven-default-http-blocker</id>
<mirrorOf>external:http:*</mirrorOf>
<name>Pseudo repository to mirror external repositories initially using HTTP.</name>
<url>http://0.0.0.0/</url>
<blocked>false</blocked>
</mirror>-->
Pude compilar comentando el codigo dentro de la ruta
/Applications/IntelliJ\ IDEA.app/Contents/plugins/maven/lib/maven3/conf/settings.xml
Unblock a password protected HTTP repository
I didn't like to modify the global settings.xml of IntelliJ (probably requires fix again after every update), and the method unblocking all http-repos didn't work for me - I guess because our HTTP-repo is password protected.
What worked for me finally was a mirror entry that exactly fits the original repo:
Same ID as the repo.
Same URL as the repo (it's just a fake mirror)
mirrorOf also has that same ID.
blocked set to false of course.
Thus the mirror mirrors exactly the HTTP repo and nothing else - you need a mirror for each HTTP repo. But since the mirror has the same ID as the Repo, the authentication settings in the "server" section that refers to that repo also fits to the mirror and allows access.
<mirror>
<id>repoId</id><!-- Must fit to serverID!!! (can be same as repoID) -->
<name>My Mirror</name>
<!-- URL of the mirror - in our case just the same as the repo itself. -->
<url>http://mvn-host/content/repositories/myrepo/</url>
<mirrorOf>repoId</mirrorOf><!-- Mirrors exactly the repo itself -->
<blocked>false</blocked><!-- Unblock http access - only works in mirrors, and that's why we need a mirror. -->
</mirror>
The key to all this is that the mirror needs a server entry if it is protected.
You can use a Maven wrapper to help you with the problem, the version below 3.8.1 work well with it.
To create a Maven wrapper do
mvn -N io.takari:maven:0.7.7:wrapper -Dmaven=3.6.1
After this settings --> build, Execution, Deployment --> build tools --> Maven
Select the Maven Home Path to *Use Maven Wrapper*
Go back to your project and from the Maven Settings
This solved my issue, hope it will help you too.

Maven cannot pull jars from Mirros

We have a central repository within intranet. I set mirror as follow. The issue is when I try to download a dependency that is not available in my local repository, the dependency cannot be downloaded completely. Only .lastUpdated file is downloaded in directory. I cannot figure out whey this weird thing happened. But it I comment the mirror setting, the dependency could be downloaded correctly. But I need some ourselves developed dependencies that are residing on central repository. That means I cannot bypass the central repository to search on internet. Does anyone come across this creepy issue?
<mirror>
<id>central-proxy</id>
<name>Central Repo</name>
<url>http://*.*.*.*.*/artifactory/repo</url>
<mirrorOf>*</mirrorOf>
</mirror>
</mirrors>

Difference between using a single repository and a single mirror

The maven documentation says:
http://maven.apache.org/guides/mini/guide-mirror-settings.html
Using A Single Repository. You can force Maven to use a single
repository by having it mirror all repository requests. The repository
must contain all of the desired artifacts, or be able to proxy the
requests to other repositories. This setting is most useful when using
an internal company repository with the Maven Repository Manager to
proxy external requests.
To achieve this, set mirrorOf to *.
<settings>
...
<mirrors>
<mirror>
<id>internal-repository</id>
<name>Maven Repository Manager running on repo.mycompany.com</name>
<url>http://repo.mycompany.com/proxy</url>
<mirrorOf>*</mirrorOf>
</mirror>
</mirrors>
...
</settings>
I don't understand this paragraph.
Shouldn't it be something like this?
Using A Single Mirror You can force Maven to use a single
mirror by having it mirror all repository requests. The mirror must contain all of the desired artifacts for all the
repositories, or be able to proxy the requests to other
repositories. This setting is most useful when using an internal
company repository with the Maven Repository Manager to proxy external
requests. To achieve this, set mirrorOf to *.
<settings>
...
<mirrors>
<mirror>
<id>internal-mirror</id>
<name>Maven Mirror Manager running on mirror.mycompany.com</name>
<url>http://mirror.mycompany.com/proxy</url>
<mirrorOf>*</mirrorOf>
</mirror>
</mirrors>
...
</settings>
Where is my miss-understanding?
I mean, <mirror><id>internal-repository</id>... seems just wrong to me.
Mirror means a repository that is used as a passerelle/proxy to an other repository.
When using a repository manager like Nexus, Artiafactory, Archiva... you dispose of one local entreprise repository wich proxifies remotes ones.
So there is no need to declare too many repositories in your pom or setting.xml. Using Just one mirror which redirect all requests to the repository manager you have will be sufficient.
That is the meaning of the documentation.
As maven documentation says:
Repositories can be declared inside a project, which means that if you have your own custom repositories, those sharing your project easily get the right settings out of the box. However, you may want to use an alternative mirror for a particular repository without changing the project files.
For repositories in settings.xml, declaring mirrors for them is redundant because you can just replace the repositories directly. You should use mirrors for repositories in pom.xml.
For example. Project X is a public project that list all the repos it required in its pom.xml.
Most people can just download and build the project directly.
Alex wants to build the project on his working PC at company, and his company has an internal enterprice repo. So he uses the company repo in his settings.xml as a mirror for the project repos.
Bob cannot access some project repos directly due to connection issue. He can use other public mirrors for that repo.
Repos in pom.xml is used as default implements and mirrors should be used for special cases.

Should the mirror id be unique in maven

What will happen if i have two mirrors with same id in the settings.xml file?
Which one will be taken into account?
It won't do anything more than 1 repo.
You can even use it to have different mirrors with the same credentials.
But consider that you could did it by yourself ... This is a trivial question which take 1 minutes + build time to test by yourself.
Nevertheless :
<mirrors>
<mirror>
<id>mirror.repo.myorg.fr</id>
<mirrorOf>!tiers-providers-public-snapshots,*</mirrorOf>
<name>Repository Artifactory for snapshots.</name>
<url>http://mirror.repo.myorg.fr/artifactory/repo-snapsthot</url>
</mirror>
<mirror>
<id>mirror.repo.myorg.fr</id>
<mirrorOf>!tiers-providers-public,*</mirrorOf>
<name>Repository Artifactory for realeases</name>
<url>http://mirror.repo.myorg.fr/artifactory/repo</url>
</mirror>
</mirrors>
This is the same machine, but two mirrors for differents purposes. I'm not sure this case would happen, but it is not so far of my own configuration.
I tried it, and it's obviously working.

How should I point to different repository mirrors in maven settings.xml

We have 2 separate products used by different teams and we would like to point to mirrorA for projectA and mirrorB for projectB. How can I achieve this in settings.xml and should I do this away from settings.xml and somehow reference in my project specific POM file.
<mirrors>
<mirror>
<id>internal</id>
<mirrorOf>*</mirrorOf>
<name>Internal Release Repository</name>
<url>http://192.168.1.4:7777/archiva/repository/internal</url>
</mirror>
</mirrors>
Note: This scenario happens when a developer contributes to both of these projects.
I think you might be confusing "mirrors" with "repositories". You should very probably not have a mirror configuration like that in your settings.xml. If different projects should deploy to or get their dependencies from different repositories, you just specify those repositories in the respective projects' poms. Setting up mirrors solves an entirely different problem than setting up repositories does.

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