LostWorld

Manage multiple versions of Go with GVM

2020-10-27T01:28:00.002-07:00

Keep multiple Go environments, including versions and modules, with Go Version Manager for easy GOPATH management.

Image by : WOCinTech Chat. Modified by Opensource.com. CC BY-SA 4.0

Go Version Manager (GVM) is an open source tool for managing Go environments. It supports installing multiple versions of Go and managing modules per-project using GVM "pkgsets." Developed originally by Josh Bussdieker, GVM (like its Ruby counterpart, RVM) allows you to create a development environment for each project or group of projects, segregating the different Go versions and package dependencies to allow for more flexibility and prevent versioning issues.

There are several options for managing Go packages, including Go 1.11 Modules, built right into Go. I find GVM to be simple and intuitive, and even if I didn't use it to manage packages, I'd still use it to manage Go versions.

Installing GVM

Installing GVM is straightforward. The GVM repository installation documentation instructs you to download the installer script and pipe it to Bash:

-s -S -L https://raw.githubusercontent.com/moovweb/gvm/master/binscripts/gvm-installer)

Despite the growing adoption of this kind of installation method, it's still good practice to take a look at what the installer is doing before you do it. In the case of GVM, the installer script:

1. Checks some dependencies

2. Clones the GVM repo

3. Uses shell scripts to:

o Install Go

o Manage the GOPATH environment

o Add a line to your bashrc, zshrc, or profile

If you want to double-check what it's doing, you can clone the repo and review the shell scripts, then run ./binscripts/gvm-installer to set it up using the local scripts.

Note: Since GVM can be used to download and compile new Go versions, there are some expected dependencies like Make, Git, and Curl. You can find the complete list for your distribution in GVM's README.

Installing and managing Go versions with GVM

Once GVM is installed, you can start using it to install and manage different versions of Go. The gvm listall command shows the available versions of Go that can be downloaded and compiled:

[chris@marvin ]$ gvm listall
$ gvm listall

gvm gos (available)

go1
go1.0.1
go1.0.2
go1.0.3

<output truncated>

Installing a specific Go version is as easy as gvm install <version>, where <version> is one of the ones returned by the gvm listall command.

Say you're working on a project that uses Go version 1.12.8. You can install it with gvm install go1.12.8:

[chris@marvin]$ gvm install go1.12.8
Installing go1.12.8...
* Compiling...
go1.12.8 successfully installed!

Enter gvm list, and you see Go version 1.12.8 is installed along with the system Go version (the version that comes packed using your OS's package manager):

[chris@marvin]$ gvm list

gvm gos (installed)

go1.12.8
=> system

GVM is still using the system version of Go, denoted by the => symbol next to it. You can switch your environment to use the newly installed go1.12.8 with the gvm use command:

[chris@marvin]$ gvm use go1.12.8
Now using version go1.12.8

[chris@marvin]$ go version
go version go1.12.8 linux/amd64

GVM makes it extremely simple to manage installed versions of Go, but it gets even better!

Using GVM pkgset

Out of the box, Go has a brilliant—and frustrating—way of managing packages and modules. By default, if you go get a package, it is downloaded into the src and pkg directories in your $GOPATH; then it can be included in your Go program by using import. This makes it easy to get packages, especially for unprivileged users, without requiring sudo or root privileges (much like pip install --user in Python). The tradeoff, however, is the difficulty in managing different versions of the same packages across different projects.

There are a number of ways to try fixing or mitigating the issue, including the experimental Go Modules (preliminary support added in Go v1.11) and go dep (an "official experiment" and ongoing alternative to Go Modules). Before I discovered GVM, I would build and test Go projects in their own Docker containers to ensure segregation.

GVM elegantly accomplishes management and segregation of packages between projects by using "pkgsets" to append a new directory for projects to the default $GOPATH for the version of Go installed, much like $PATH works on Unix/Linux systems.

It is easiest to visualize how this works in action. First, install a new version of Go, v1.12.9:

[chris@marvin]$ echo $GOPATH
/home/chris/.gvm/pkgsets/go1.12.8/global

[chris@marvin]$ gvm install go1.12.9
Installing go1.12.9...
* Compiling...
go1.12.9 successfully installed

[chris@marvin]$ gvm use go1.12.9
Now using version go1.12.9

When GVM is told to use a new version, it changes to a new $GOPATH, which corresponds to a default gloabl pkgset for that version:

[chris@marvin]$ echo $GOPATH
/home/chris/.gvm/pkgsets/go1.12.9/global

[chris@marvin]$ gvm pkgset list

gvm go package sets (go1.12.9)

=> global

Packages in the global pkgset are available to any project using this specific version of Go, although by default there are no extra packages installed.

Now, suppose you're starting a new project, and it needs a specific package. First, use GVM to create a new pkgset called introToGvm:

[chris@marvin]$ gvm pkgset create introToGvm

[chris@marvin]$ gvm pkgset use introToGvm
Now using version go1.12.9@introToGvm

[chris@marvin]$ gvm pkgset list

gvm go package sets (go1.12.9)

global
=> introToGvm

As mentioned above, a new directory for the pkgset is prepended to the $GOPATH:

[chris@marvin]$ echo $GOPATH
/home/chris/.gvm/pkgsets/go1.12.9/introToGvm:/home/chris/.gvm/pkgsets/go1.12.9/global

Change directories into the introToGvm path that was prepended and examine the directory structure—and take the opportunity to have some fun with awk and bash as you do:

[chris@marvin]$ cd $( awk -F':' '{print $1}' <<< $GOPATH )
[chris@marvin]$ pwd
/home/chris/.gvm/pkgsets/go1.12.9/introToGvm

[chris@marvin]$ ls
overlay pkg src

Notice that the new directory looks a lot like a normal $GOPATH. New Go packages can be downloaded using the same go get command you'd normally use with Go, and they are added to the pkgset.

As an example, use the following to get the gorilla/mux package, then examine the directory structure of the pkgset:

[chris@marvin]$ go get github.com/gorilla/mux
[chris@marvin]$ tree
[chris@marvin introToGvm ]$ tree
.
├── overlay
│ ├── bin
│ └── lib
│ └── pkgconfig
├── pkg
│ └── linux_amd64
│ └── github.com
│ └── gorilla
│ └── mux.a
src/
└── github.com
└── gorilla
└── mux
├── AUTHORS
├── bench_test.go
├── context.go
├── context_test.go
├── doc.go
├── example_authentication_middleware_test.go
├── example_cors_method_middleware_test.go
├── example_route_test.go
├── go.mod
├── LICENSE
├── middleware.go
├── middleware_test.go
├── mux.go
├── mux_test.go
├── old_test.go
├── README.md
├── regexp.go
├── route.go
└── test_helpers.go

As you can see, gorilla/mux was added to the pkgset $GOPATH directory as expected and can now be used with projects that use this pkgset.

GVM makes Go management a breeze

GVM is an intuitive and non-intrusive way to manage Go versions and packages. It can be used on its own or in combination with other Go module management techniques and make use of GVM's Go version management capabilities. Segregating projects by Go version and package dependency makes development easier and leads to fewer complications with managing version conflicts, and GVM makes this a breeze.

For more Please visit: opensource.com

Top 10 Badass Anime You've Never Seen Before!

2020-10-26T22:07:00.001-07:00

10. Anonymous Noise

The manga tells a romance story with the themes of "music x one-sided love." Nino, a girl who loves singing, made a childhood promise with her first crush Momo and song-composing Yuzu to someday find her voice. The three went their separate ways, but Nino kept her promise and continued to sing. Years later, the three are now high school students, and Nino is drawn into the world of band clubs.

Alias: Fukumenkei Noise

Categories: Music, Romance

Status: Finished Airing

Episodes:12

9. Sekai Seifuku: Bouryaku no Zvezda

What does it take to conquer the world?! Every leader of the past has thought of it... but all they have done was to merely dream of its greatness. World domination... nobody has been able to achieve it. Until one little girl by the name of Kate Hoshimiya came along. Kate Hoshimiya will shock the world! How was she able to carry out such a magnificent stunt? So frightful! So glorious! Could this be... the Zvezda Plot?! Let the light of our great Zvezda shine upon this land far and wide!

Alias: World Conquest Zvezda Plot

Categories: Action, Comedy, Fantasy

Status: Finished Airing

Episodes:12

8. Choujigen Game Neptune: The Animation

This is Gamindustri. Beings called the Goddesses rule the countries of this unreal world. The four Goddesses govern four states: Planeptune, Lastation, Lowee, and Leanbox. For many long years, these countries fought each other over the Shares, the source of the Goddess power.However, fearful that the conflict would pointlessly erode their countries' strength, the Goddesses signed a Friendship Treaty forbidding them from taking Shares by force.Under the treaty, the Goddesses and their younger sisters took a step forward to a new stage in their relations. It was the dawn of a new, dynamic era marked occasionally by shared laughter, disputes as well cooperation.What does the future hold in store for Gamindustri?

Alias: Hyperdimension Neptunia: The Animation

Categories: Action, Comedy, Fantasy, Sci-Fi, Supernatural

Status: Finished Airing

Episodes:12 + season 2

7. Rokujouma no Shinryakusha!?

Now that he enters his high school career, Satomi Koutaro begins his life living alone in an apartment that only costs him 5000 yen per month, an extremely cheap deal even for this small apartment. There’s a catch: the apartment is apparently haunted by a cute ghost that has driven its prior occupants away. Next thing he knows, not only is there a ghost trying to drive him out of his new home, but magical girls and other unique female characters turn this small apartment into a battleground of sorts.

Alias: Invaders of the Rokujoma!?

Categories: Comedy, Romance, Supernatural

Status: Finished Airing

Episodes: 12

6. Suki ni Naru Sono Shunkan wo.: Kokuhaku Jikkou Iinkai

Second film starring characters from the HoneyWorks vocaloid group.

Alias: The Moment You Fall in Love

Categories: Comedy, Drama, Romance, Slice of Life

Status: Finished Airing

Episodes:1(movie)

5. Gatchaman Crowds

Hajime Ichinose's ordinary life is in for a change when a transcendent being named J.J Robinson hands her a small book called NOTE—a device which transforms her into one of the Gatchaman, the legendary protectors of Tachikawa City. Stressing that the existence of their group must remain a secret, fellow Gatchaman Sugane Tachibana takes Hajime to their base of operations, where Paiman, the panda-like alien leader of the Gatchaman, reveals their purpose: to eliminate aliens that pose a danger to humanity.These existential threats, called MESS, are becoming increasingly dangerous, destroying everything they touch. Now it's up to the Gatchaman and their new recruit to stop them before the world is engulfed in chaos.

Categories: Adventure, sci-fi

Episodes: 12

4. Uchouten Kazoku

In Kyoto, there are three kinds of residents: humans, raccoon dogs, and tengu. Shimogamo Yasaburou is the third son of the Shimogamo raccoon dog family. His father, Souichirou, had been the head of Kyoto raccoon dog community until he was eaten by the human members of "Friday Club". While taking care of old tengu, fighting with other raccoon dogs, and playing with a psychic human girl, Yasaburou approaches the truth of his father's death.

Alias: The Eccentric Family

Categories: Comedy, Drama, Fantasy, Slice of Life

Status: Finished Airing

Episodes:13 + season 2

3. Princess Principal

In the early 20th century, the discovery of the substance Cavorite allowed the production of advanced military technology and steered the country toward conflict. London is now divided by a wall, and the Kingdom and the Commonwealth of Albion battle a silent war where espionage is the only weapon that can destabilize the enemy. A group of girls from the prestigious Queen's Mayfaire school work as undercover spies for the Commonwealth.

Categories: action, historical, mystery

Episodes: 12

2. Denpa-teki na Kanojo

Delinquent Juu Juuzawa is a lone wolf who does not see much use in befriending people. So when a girl named Ame Ochibana claims they are linked together from their previous lives, he is highly skeptical and doesn't want anything to do with her. Even stranger is that her fondest wish is to be his servant. Thinking that Ame must be delusional, he tries to distance himself from her. But when a classmate is murdered, Juu instead decides to keep her close, believing the strange girl to be the culprit. However, her intelligence and skill begin to prove invaluable as the two begin working together to solve the murder.

Categories: Mystery, thriller, school

Episodes: 2

1. Neppuu Kairiku Bushi Road

The story takes place in a time when the world is in the pits of despair after being ravaged by a poison called "shinobi" that came to earth via an asteroid. The people run away to the place called "Kairiku," a place that used to be the bottom of the ocean. Here, the people try and protect themselves against the effects of the poison. In such a world, there was a single light of hope. The "Holy Weapon Giga Road" and the legendary warrior "Yagyuu" are needed in order to counter the effects of the poison. In order to save the world, Ame, a princess of a fallen nation, stands up in order to save the world.

Top 10 New Romance Anime Of 2019

2020-10-26T21:21:00.001-07:00

10. Meiji Tokyo Renka

In its fifth anniversary event "Meiji Tokyo Renka -Haikara Roman Gekijyou 4-" held at Maihama Amphi Theater in Chiba Prefecture yesterday, it was officially announced that a TV anime series based on Broccoli's romance simulation game for female, Meiji Tokyo Renka, is now in the works.

Alias: Meiji Tokyo Renka

Categories: Fantasy, Romance

Status: Finished Airing

Episodes: 12

9. W'z

The anime centers on Yukiya, who is "probably" 14 years old. He spends his time DJ-ing alone. Due to his father's influence, he's listened to house music since he was young, and he uploads videos online. He wants to convey something to someone. He wants to be recognized, and become important. But getting hurt is scary. One day, while trying to get more views, he does something that can't be undone. And he sees a live broadcast from "that world." Yukiya believes he can't do anything alone, but that he could accomplish something if he were doing it together with someone else.

Categories: Action, Music

Status: Finished Airing

Episodes: 13

8. How Clumsy you are, Miss Ueno

The story centers on Ueno, a genius inventor who is in the third grade at her junior high school. She also serves as the head of the school's science club and secretly falls in love with one of its members, second grade student Tanaka. Using her eccentric inventions, Ueno tries to confess her love to him indirectly. But her attempt always ends in failure.

Alias: Ueno-san wa Bukiyou

Categories: Comedy, Ecchi, Romance

Status: Finished Airing

Episodes: 12

7. Girly Air Force

In the novels' story, mysterious flying creatures known as Zai suddenly appear, and in order to fight the creatures, mankind creates fighter aircraft called "Daughters," as well as the automatic fighting mechanism "Anima," which are shaped like human girls. The story centers on a young man named Kei Narutani, who yearns to fly in the sky, and an Anima considered to be humanity's trump card, a girl name Gripen.

Alias: Girly Air Force

Categories: Action, Sci-Fi

Status: Finished Airing

Episodes: 12

6. 3D Kanojo: Real Girl

Hikari Tsutsui is a high school boy who is satisfied with the virtual girls he encounters in anime and games. He does not have many friends and he lives in his own world. One day, when he is stuck on pool cleaning duty, he is approached by Iroha, a "real girl" who is showy and popular with boys.

Alias: Real Girl

Categories: Romance, Slice of Life, Comedy, Drama

Status: Finished Airing

Episodes: 12 + second season

5. Date A Live III

Itsuka Shidou's life has been a whirlwind as of late. Or more precisely, a spatial quake. Several of them, in fact. Powerful "Spirits" from other dimensions that take the form of girls are unintentionally causing these spatial quakes in his reality. And Shidou is the only one who can stop them with his unique ability: kissing them! By having the girls kiss and fall deeply in love with him, their devastating quake powers are sealed. The alternative to romancing them is to have a more militant and technological organization called the AST (Anti-Spirit Team) destroy the Spirits, something Shidou is vehemently against.So far in the story, six Spirits have fallen for Shidou (as well as a few others). The girls compete with one another and vie for his affection, leaving him no end of headaches and misadventures. But a new challenger approaches.

Categories: Comedy, Mecha, Romance, Sci-Fi, Ecchi

Status: Finished Airing

Episodes: 12

4. The Quintessential Quintuplets

One day, a poor high school second-year named Futaro Uesugi comes across a private tutoring gig with good pay. But his pupils are his classmates!! And they’re quintuplets!! A-and they’re all gorgeous girls, but they’re also troublemakers who hate to study and are on the verge of flunking out! And his first task is simply gaining the sisters’ trust?! Every day is a party! The curtain is rising on the Nakano quintuplets’ quirky romantic comedy with five times the cute!!

Alias: 5-Toubun no Hanayome

Categories: Comedy, Romance, Ecchi

Status: Finished Airing

Episodes:12

3. Kaguya-sama: Love is War

Kaguya Shinomiya and Miyuki Shirogane are the members of the incredibly prestigious Shuichi'in Academy's student council, asserting their positions as geniuses among geniuses. All the time they spend together has caused the two of them to develop feelings for each other, but their pride will not allow them to be the one to confess and become the submissive one in the relationship! Love is war, and their battle to make the other confess begins now!

Alias: Kaguya-sama wa Kokurasetai: Tensai-tachi no Renai Zunousen

Categories: Comedy, Romance

Status: Finished Airing

Episodes: 12

2. Domestic na Kanojo

High schooler Natsuo is hopelessly in love with his cheerful and popular teacher, Hina. However, one day at a mixer, he meets a moody girl by the name of Rui and ends up sleeping with her. Soon after, his father announces that he's getting remarried to a woman with two daughters of her own. And who shows up in tow, other than both Hina and Rui?! Natsuo's outrageous new life starts now!

Alias: Domestic Girlfriend

Categories: Romance, Drama

Status: Finished Airing

Episodes:13

1. The Rising of the Shield Hero

Naofumi Iwatani, an uncharismatic Otaku who spends his days on games and manga, suddenly finds himself summoned to a parallel universe! He discovers he is one of four heroes equipped with legendary weapons and tasked with saving the world from its prophesied destruction. As the Shield Hero, the weakest of the heroes, all is not as it seems. Naofumi is soon alone, penniless, and betrayed. With no one to turn to, and nowhere to run, he is left with only his shield. Now, Naofumi must rise to become the legendary Shield Hero and save the world!The first episode was pre-aired on December 27th, 2018. Regular broadcast begins on January 9th, 2019.

Alias: Tate no Yuusha no Nariagari

Categories: Action, Adventure, Fantasy, Romance

Status: Finished Airing

Episodes: 25