Packer by HashiCorp : First Steps

A few days ago I wrote about some Vagrant Box Drama I was having. Martin Bach replied saying I should build my own Vagrant boxes. I’ve built Vagrant boxes manually before, as shown here.

The manual process is just boring, so I’ve tended to use other people’s Vagrant boxes, like “bento/oracle-8”, but then you are at the mercy of what they decide to include/exclude in their box. Martin replied again saying,

“Actually I thought the same until I finally managed to get around automating the whole lots with Packer and Ansible. Works like a dream now and with minimum effort”

Martin Bach

So that kind-of shamed me into taking a look at Packer. πŸ™‚

I’d seen Packer before, but had not really spent any time playing with it, because I didn’t plan on being in the business of maintaining Vagrant box images. Recent events made me revisit that decision a little.

So over the weekend I spent some time playing with Packer. Packer can build all sorts of images, including Vagrant boxes (VirtualBox, VMware, Hyper-V etc.) and images for Cloud providers such as AWS, Azure and Oracle Cloud. I focused on trying to build a Vagrant box for Oracle Linux 8.2 + UEK, and only for a VirtualBox provider, as that’s what I needed.

The Packer docs are “functional”, but not that useful in my opinion. I got a lot more value from Google and digging around other people’s GitHub builds. As usual, you never find quite what you’re looking for, but there are pieces of interest, and ideas you can play with. I was kind-of hoping I could fork someone else’s repository and go from there, but it didn’t work out that way…

It was surprisingly easy to get something up and running. The biggest issue is time. You are doing a Kickstart installation for each test. Even for minimal installations that takes a while to complete, before you get to the point where you are testing your new “tweak”. If you can muscle your way through the boredom, you quickly get to something kind-of useful.

Eventually I got to something I was happy with and tested a bunch of my Vagrant builds against it, and it all seemed fine, so I then uploaded it to Vagrant Cloud.

I’ve already made some changes and uploaded a new version. πŸ™‚

You will see a couple of older manually built boxes of mine under oraclebase. I’ll probably end up deleting those as they are possibly confusing, and definitely not maintained.

I’ve also altered all my OL8 Vagrant builds to use this box now.

You will also see a new sub-directory called “packer”. I think you can guess what’s in there. If I start to do more with this I may move it to its own repository, but for now this is fine.

I’m not really sure what else I will do with Packer from here. I will probably do an Oracle Linux 7 build, which will be very similar to what I already have. This first image is pretty large, as I’ve not paid much attention to reducing it’s size. I’ve looked at what some other builds do, and I’m not sure I agree with some of the stuff they remove. I’m sure I will alter my opinion on this over time.

I’m making no promises about these boxes. That same way I make no promised about any of my GitHub stuff. It’s stuff I’m playing around with, and I will mostly try to keep it up to date, but I’m not an expert and it’s not my job to maintain this. It’s just something that is useful for me, and if you like it, great. If not, there are lots of other places to look for inspiration. πŸ™‚

Cheers

Tim…

Automating SQL and PL/SQL Deployments using Liquibase

You’ll have heard me barking on about automation, but one subject that’s been conspicuous by its absence is the automation of SQL and PL/SQL deployments…

I had heard of some products that might work for me, like Flyway and Liquibase, but couldn’t really make up my mind or find the time to start learning them. Next thing I knew, SQLcl got Liquibase built in, so I figured that was probably the decision made for me in terms of product. This also coincided with discussions about making a deployment pipeline for APEX applications, which kind-of focused me. It’s sometimes hard to find the time to learn something when there is not a pressing demand for it…

Despite thinking I would probably be using the SQLcl implentation, I started playing with the regular Liquibase client first. Kind of like starting at grass roots. If you are working in a mixed environment, you might prefer to use the regular client, as it will work with multiple engines.

Once I had found my feet with that, I essentially rewrote the article to use the SQLcl implementation of Liquibase. If you are focused on Oracle, I think this is better than using the standard client.

Both these articles were written more than 3 months ago, but I was holding them back on publishing them for a couple of reasons.

  1. I’m pretty new to this, and I realise some of the ways I’m suggesting to use them do not fall in line with the way I guess many Liquibase users would want to use them. I’m not trying to make out I know better, but I do know what will suit me. I don’t like defining all objects as XML and the Formatted SQL Changelogs don’t look like a natural way to work. I want the developer to do their job in their normal way as much as possible. That means using DDL, DML and PL/SQL scripts.
  2. I thought there was a bug in one aspect of the SQLcl implementation, but thanks to Jeff Smith, I found out it was a problem between my keyboard and seat. πŸ™‚

With a little cajoling from Jeff, I finally released them last night, then found a bunch of typos that quickly got corrected. Why are those never visible until you hit the publish button? πŸ™‚

The biggest shock for most people will probably be that it’s not magic! I’m semi-joking there, but I figure a lot of people assume these products solve your problems, but they don’t. Both Flyway and Liquibase provide a tool set to help you, but ultimately you are going to need to modify the way you work. If you are doing random-ass stuff with no discipline, automation is never going to work for you, regardless of products. If you are prepared to work with some discipline, then tools like Liquibase can help you build the type of automated deployment pipelines you see all the time with other languages and tech stacks.

The ultimate goal is to be able to progress code through environments in a sensible way, making sure all environments are left in the same state, and allow someone to do that promotion of code without having to give them loads of passwords etc. You would probably want a commit in a branch of your source control to trigger this.

So looking back to the APEX deployments, we might think of something like this.

  • A developer finishes their work and exports the current application using APEXExport. It doesn’t have to be that tool, but humans have a way of screwing things up, so having a guaranteed export mechanism makes sense.
  • Code gets checked into your source control. This includes any DDL, DML, packages, and of course the APEX application script.
  • A new changelog is created for the work which includes any necessary scripts, including DDL and DML, as well as the APEX script, all included in the correct order. That new changelog for this piece of work is included in the master changelog, and these are committed to source control.
  • That commit of the changelog, or more likely a merge into a branch triggers the deployment automation.
  • A build agent pulls down the latest source, which will probably include stuff from multiple repositories, then applies it with Liquibase, using the changelog to tell it what to do.

That sounds pretty simple, but depending on your company and how you work, that might be kind-of hard.

  • The master changelog effectively serialises the application of changes to the database. That has to be managed carefully. If stuff is done out of order, or clashes with another developer, that has to be managed. It’s not always a simple process.
  • You will need something to react to commits and merges in source control. In my company we use TeamCity, and I’ve also used GitLab Pipelines to do this type of thing, but if you don’t have any background in these automation tools, then that part of the automation is going to be a learning curve.
  • We also have to consider how we handle actions from privileged accounts. Not all changes in the database are done using the same user.

Probably the biggest factor is the level of commitment you need as a team. It’s a culture change and everyone has to be on board with this. One person manually pushing their stuff into an environment can break all your hard work.

I’m toying with the idea of doing a series of posts to demonstrate such a pipeline, but it’s kind-of difficult to know how to pitch it without making it too specific, or too long and boring. πŸ™‚

Cheers

Tim…

APEX 19.2 : Vagrant and Docker Builds

I’m sure anyone who cares knows that APEX 19.2 was officially released on Friday. I did an upgrade of one of our development instances straight away and it worked fine. it’s subsequently gone to a bunch of other development instances. I’ll be pushing to get this out to production as quickly as possible.

Over the weekend I worked through a bunch of my GitHub stuff.

Vagrant : I’ve updated all my Vagrant builds to use APEX 19.2 and the latest versions of Tomcat 9 and OpenJDK 11. I was using newer versions of OpenJDK, but it seemed a bit silly, so I reverted back to the long term support release. I tried updating the base box to ‘bento/oracle-7.7’, but it kept giving me timeouts, so I’ve reverted back to ‘bento/oracle-7.6’ for the moment.

Docker : Same as above, I’ve updated all my Docker builds to use APEX 19.2 and the latest versions of Tomcat 9 and OpenJDK 11. I noticed oraclelinux:8-slim was behaving a little strangely. I thought it was a PATH issue, but I need to spend some time to understand what is happening. It seems you can’t run basic commands like dnf during the build phase. It’s probably something stupid I’m doing, but for now I’ve switched from oraclelinux:8-slim to oraclelinux:8. Just making that switch made everything work as expected.

My Docker builds within the company have gone through a similar process, so as I’m rolling out APEX 19.2 to the databases, I’m also switching the ORDS containers over to the new images. You gotta love containers!

I guess I’ll be working through all this again when the next version of ORDS and SQLcl drop. πŸ™‚

Cheers

Tim…

Video : Docker Compose – Defining Multi-Container Applications

In today’s video we’ll take a look at Docker Compose, which allows you to define multi-container applications. In this example we are using the Oracle REST Data Services and Oracle Database 19c images we built on Oracle Linux 8 (oraclelinux:8-slim) in previous videos.

For those that prefer to read, this is based on the following information.

The star of today’s video is Murali Vallath, who looks incredibly suspicious of my motivation for videoing him. πŸ™‚

Cheers

Tim…

DevOps : Why do you focus on Flow and Automation?

A few weeks ago I did a DevOps “Lunch & Learn” talk inside my company. I’m not trying to claim I’m “Billy DevOps”, but I need our company to move in that direction or we will die. While I was preparing for that talk I did some Googling for the common complaints about DevOps talks and training courses, hoping to avoid them, and what I got back was a bunch of people complaining about the heavy focus on “The Principle of Flow”, specifically the automation piece of that.

Take a look at any conference agenda and the DevOps talks are mostly focused on automation, whether that’s builds (Ansible, Terraform, Vagrant, Cloud) or Continuous Integration/Deployment (CI/CD). Automation is certainly a part of DevOps, but DevOps isn’t just automation. So why do people focus on the automation aspect of DevOps so much?

I started off my talk by saying something like this,

“I Googled the common complaints about DevOps talks and training, and most people complained about too much focus on the Principle of Flow and automation. I’m going to do the same thing!”

So why did I come to this conclusion? Well, there are a few reasons.

The principle of feedback relies on you getting that feedback and doing something with it, like improving applications or processes etc. I realise I’m being simplistic, but how can you do anything with that feedback unless you have flow sorted? If it takes you weeks/months/years to effect basic changes because of bad flow, the feedback becomes almost irrelevant. It only serves to demotivate you, as you identify all the problems, with no way of fixing them.

The principle of continual learning and experimentation relies on flow being sorted. If you can’t quickly and reliably build kit and deploy apps to it, how do you expect to be able to experiment and learn new things? I discussed this point in a post called Why Automation Matters : Reducing the Cost of Failure.

It feels like the majority of people I speak to don’t have basic automation sorted yet. In public they talk a good talk, but behind the scenes the processes in their company suck just as bad as ours. Either that, or they have one aspect of automation sorted, which they talk about all the time, forgetting to mention the other manual processes that persist.

Let’s not forget that most of the people I see talking about DevOps come from a technical background, and I suspect are probably more interested in the automation aspects of DevOps than the process side of things. Also, in their current roles they have the ability to influence automation more than they do process change, so they are going to focus on a fight they have a chance of winning.

I think it’s important to emphasise to people that automation isn’t the be-all and end-all of DevOps, but that doesn’t stop it being the fun bit for me. πŸ™‚

Check out the rest of the series here.

Cheers

Tim…

Vagrant Build of AWX on Oracle Linux 7 Using Docker-Compose Method

I may need to do a bunch of scripting related to our load balancers, and I have the choice of using the API from the servers directly, Ansible Core or the web services exposed by AWX. I wanted to play around with AWX anyway, so that seemed like a good excuse…

First step was to install AWX. It’s pretty easy, but I must admit to spending a few minutes in a state of confusion until I rebooted my brain and started again. Turning things off and on always works. I’m an Oracle Linux person and “I do Docker”, so the obvious choice was to install it using the Docker-Compose method on Oracle Linux 7 (OL7).

The post includes the basic Docker setup, but if you need something a little more, check out the installation article and video.

If you don’t care about the build and just need AWX up quickly, you can use this Vagrant build that does everything for you, including Docker and AWX on Oracle Linux. πŸ™‚

Cheers

Tim…

Video : Install Docker on Oracle Linux 7 (OL7)

Today’s video is a run through installing the Docker engine on Oracle Linux 7 (OL7).

You can get the commands mentioned in this video from the following article.

You can see my other Docker posts and builds here.

The star of today’s video is Robyn Sands, formerly of the Oracle Real World Performance Group, and now something to do with some fruit company… πŸ™‚

Cheers

Tim…

Birmingham Digital & DevOps Meetup : August 2019

Yesterday evening I went along to the Birmingham Digital & DevOps Meetup for the first time. It followed the usual meetup format of quick intro, talk, break, talk then home.

First up was Elton Stoneman from Docker with “Just What Is A β€œService Mesh”, And If I Get One Will It Make Everything OK?” The session started by describing the problems associated with communication between the building blocks of a system, and how a service mesh can alleviate some of them. It then moved on to some service mesh demos using Istio. These included examples of altering the routing of traffic to do canary testing and targeting specific groups etc.

Elton was really honest about the learning curve, issues and overhead associated with this sort of setup. One comment I really liked was when he showed a slide containing the following, saying that often people assume there is a progression from left to right.

Meaning people assume you learn Docker, then you need some form of orchestration so you learn Swarm. From there you naturally progress to Kubernetes and once you understand that, you will inevitably move on to a service mesh using something like Istio. Elton’s point was you don’t *have to* continue on this progression. You can step off at any point once you’ve achieved the functionality you need. I think this is a really important point and I can see it reflected in what I do with Docker. We’ve got some things that stop at just using Docker containers, with no orchestration at all. I work on a project that requires some orchestration, so we use Swarm, which is really easy to use. So far I’ve had no reason to go beyond Swarm, and even considering a service mesh is so far down the line for us. I’m not discounting the relevance of these for everyone, but they don’t make sense for me at this point.

It was a really good session and I learned a lot. You can check out Elton’s blog here.

After the break it was James Relph with “Container Security Fundamentals”. This started of with a basic introduction to containers, using that as an entry point to explain how containers can be problematic from a security perspective, and what you can do to reduce the impact. He covered a lot of stuff, some of which I already do, some I know about and some stuff that was new to me. This is not an exhaustive list.

  • Don’t automatically trust images from Docker hub. Do your due diligence, even when they are from a reputable source.
  • Use your own image repository. He mentioned ECR amongst others. This can be used for your own images, but also base images from Docker Hub, which you have verified.
  • Don’t use “latest”, but use specific tagged versions. Latest gives you all the latest fixes, but all the latest bugs too. You should test and verify before you let images out into your infrastructure.
  • Multi-stage builds to reduce the size of containers and minimise the attack surface. Basically, copy out what you need and leave the crap behind.
  • Using sidecar containers to provide specific services, allowing your application images to remain more focused. The sidecar images can be maintained by feature experts to make sure they are as secure as possible.
  • Scanning images using Clair, amongst other things, to check for dodgy software. One of the audience mentioned Anchore.
  • Using microVMs like Firecracker to provide additional isolation, whilst retaining the ease of use of containers. I’ve not played with this, but I have tried Kata Containers, which seems to do pretty much the same.

There was a lot in there!

I was a bit nervous going into the event thinking it would all go over my head, and some of it probably did, but it was cool. I got to speak to a few people before the event, during the break and at the end. It seemed like there were quite a mix of people there from beginners in these areas upward, so I didn’t feel out of place.

A few times I found myself thinking, that’s great, but what do I do about my 3rd party applications? I’ve written before (here) about how 3rd party apps screw everything up. πŸ™‚

Thanks to Elton Stoneman and James Relph for taking the time to come and speak to us. Thanks to the folks from BrumDigitalDevOps for organising the event, and to Capgemini UK for sponsoring the event.

Cheers

Tim…

Video : Vagrant : Oracle Database Build (19c on OL8)

Today’s video is an example of using Vagrant to perform an Oracle database build.

In this example I was using Oracle 19c on Oracle Linux 8. It also installs APEX 19.1, ORDS 19.2, SQLcl 19.2, with ORDS running on Tomcat 9 and OpenJDK 12.

If you’re new to Vagrant, there is an introduction video here. There’s also an article if you prefer to read that.

If you want to play around with some of my other Vagrant builds, you can find them here.

If you want to read about some of the individual pieces that make up this build, you can find them here.

The star of today’s video is Noel Portugal. It’s been far too long since I’ve seen you dude!

Cheers

Tim…

I’m 2% DevOps, 3% agile and 4% automated because of 3rd party apps…

I was having a discussion with my boss about the impact of 3rd party apps on the way we work, and how difficult things are when you have to deal with 3rd party apps, as opposed to just writing your own software.

It’s easier to do things well when you are in control of all the pieces. Most of the examples you see are people writing their own software, typically on new projects. That’s very different to dealing with old projects and 3rd party apps. I’ll give you some examples, without trashing the companies responsible for this.

Example 1

Our student system is provided by a 3rd party. The company in question has a really antiquated way of delivering applications. In recent years they’ve tried to resolve this by writing their own delivery mechanism, made up of some custom software and Jenkins. The problem is, this is just a wrapper over the old process, so it is not the most reliable tool in the world. Someone like me would describe it as putting lipstick on a pig.

In addition to that, you have to use a GUI to perform the operations. At this point there is no API to allow you to script operations, which makes building them into a bigger process really problematic. We have internal development which is gradually moving to something resembling CI/CD, but it will never truly meet that goal, because we have to include manual management of things because of the limitations of the 3rd party software.

I’m sure long-term customers see the new delivery mechanism as a great improvement, but it’s not something you would deliver for a new product. It’s less painful than it was, but not really good.

Example 2

We have a publishing system that is written in Java and runs on Tomcat. It is so close to being hands-off, but there are a couple of problems.

  • When you deploy a new version, it starts in maintenance mode and you need manual interaction to click an OK button a few times on a web-based maintenance screen. I’ve never “not clicked” the OK button, so I just want a “just do it” option, so I can let it get on with it.
  • When some features are enabled by the power users, the next restart of the application flips you into maintenance mode. We’ve had P1 incidents because a host failure has caused the VM to start on a new host, and because a user has enabled a new feature in the app, the automatic startup stalls, waiting for me to click the OK button a few times.

There are some other annoyances, which impact on availability and possible topology, as well. There is no way to resolve these because of limitations in the application. All we can do is raise enhancement requests with the vendor.

I could go on with more examples, but I think you get the message.

So what do you do?

It can be quite disheartening when you want to do things well, but you have to keep compromising because of factors outside your control. You have to try not to give up, and just keep plugging away.

  • Don’t make unrealistic comparisons between your environment and others. There’s no point comparing your mixed environment to a software house. I’ve worked in both. They are very different. Take what works. Ditch what doesn’t.
  • Semi-automated processes are better than processes that are 100% manual. Maybe you can use Robotic Process Automation (RPA) to automate what is essentially a manual process.
  • Try to make sure these considerations become part of your procurement process, or you will keep buying crap.
  • Try to be creative and find workarounds, don’t just bury your head in the sand. There’s always *something* you can do to improve things.
  • Even if something is terrible, that doesn’t stop you improving the processes around it.

I guess you should focus on the values, rather than trying to exactly match some prescriptive ideal.

Good luck!

Cheers

Tim…

PS. I’m pretty sure my boss is reading this laughing, as I’m following none of this advice myself, but instead stomping round the place like a thirteen year old having a strop because, “Everything is crap!” πŸ™‚